Abacavir Sulfate, Dolutegravir Sodium, Lamivudine

1 INDICATIONS AND USAGE TRIUMEQ and TRIUMEQ PD are indicated for the treatment of HIV-1 infection in adults and in pediatric patients aged at least 3 months and weighing at least 6 kg. Limitations of Use: TRIUMEQ and TRIUMEQ PD alone are not recommended in patients with resistance‑associated integrase substitutions or clinically suspected integrase strand transfer inhibitor (INSTI) resistance because the dose of dolutegravir in TRIUMEQ and TRIUMEQ PD is insufficient in these subpopulations. See full prescribing information for TIVICAY (dolutegravir). TRIUMEQ and TRIUMEQ PD are a combination of dolutegravir (integrase strand transfer inhibitor [INSTI]), abacavir, and lamivudine (both nucleoside analogue reverse transcriptase inhibitors) indicated for the treatment of HIV-1 infection in adults and in pediatric patients aged at least 3 months and weighing at least 6 kg. ( 1 ) Limitations of Use: TRIUMEQ and TRIUMEQ PD alone are not recommended in patients with resistance-associated integrase substitutions or clinically suspected INSTI resistance because the dose of dolutegravir in TRIUMEQ and TRIUMEQ PD is insufficient in these subpopulations. See the dolutegravir prescribing information. ( 1 )

2 DOSAGE AND ADMINISTRATION • Before initiating TRIUMEQ or TRIUMEQ PD, screen for the HLA‑B*5701 allele because TRIUMEQ and TRIUMEQ PD contain abacavir. ( 2.1 ). • Prior to or when initiating TRIUMEQ or TRIUMEQ PD, test patients for HBV infection. ( 2.2 ) • TRIUMEQ and TRIUMEQ PD may be taken with or without food. ( 2.4 , 2.5 ) • Adults: One tablet of TRIUMEQ daily. ( 2.4 ) ABC = abacavir, DTG = dolutegravir, 3TC = lamivudine. Pediatric Population Body Weight Number of Tablets (once daily) Recommended Daily Dose TRIUMEQ PD Tablets (6 kg to <25 kg) 6 kg to <10 kg 3 180 mg ABC, 15 mg DTG, and 90 mg 3TC 10 kg to <14 kg 4 240 mg ABC, 20 mg DTG, and 120 mg 3TC 14 kg to <20 kg 5 300 mg ABC, 25 mg DTG, and 150 mg 3TC 20 kg to <25 kg 6 360 mg ABC, 30 mg DTG, and 180 mg 3TC TRIUMEQ Tablets (≥25 kg) ≥25 kg 1 600 mg ABC, 50 mg DTG, and 300 mg 3TC • Do not substitute TRIUMEQ and TRIUMEQ PD on a milligram-per-milligram basis. ( 2.3 ) • If dosing with certain UGT1A or CYP3A inducers, then the recommended dolutegravir dosage regimen should be adjusted. See Table 2 for complete dosing recommendations. ( 2.6 ) • Because TRIUMEQ and TRIUMEQ PD are fixed-dose tablets and cannot be dose adjusted, TRIUMEQ and TRIUMEQ PD are not recommended in patients with creatinine clearance <30 mL/min and pediatric patients with a similar degree of renal impairment based on age-appropriate assessment of renal function, or patients with hepatic impairment. ( 2.7 , 4 ) 2.1 Screening for HLA−B*5701 Allele prior to Initiating TRIUMEQ Screen for the HLA‑B*5701 allele prior to initiating therapy with TRIUMEQ or TRIUMEQ PD [see Boxed Warning , Warnings and Precautions ( 5.1 )]. 2.2 Testing prior to or When Initiating Treatment with TRIUMEQ Prior to or when initiating TRIUMEQ or TRIUMEQ PD, test patients for HBV infection [see Warnings and Precautions ( 5.2 )] . 2.3 Overview of TRIUMEQ Dosage Forms TRIUMEQ is available in two dosage forms. Do not substitute TRIUMEQ tablets and TRIUMEQ PD tablets for oral suspension on a milligram-per-milligram basis due to differing pharmacokinetic profiles for the dolutegravir component [see Warnings and Precautions ( 5.7 ) , Clinical Pharmacology ( 12.3 )] . • TRIUMEQ tablets: 600 mg of abacavir, 50 mg of dolutegravir, and 300 mg of lamivudine. TRIUMEQ is recommended in adults and pediatric patients weighing at least 25 kg [see Dosage and Administration ( 2.4 , 2.5 )] . • TRIUMEQ PD tablets for oral suspension: 60 mg of abacavir, 5 mg of dolutegravir, and 30 mg of lamivudine. TRIUMEQ PD is recommended in pediatric patients weighing 6 kg to less than 25 kg [see Dosage and Administration ( 2.5 )] . • Because TRIUMEQ PD is a fixed-dose tablet and the dosage of individual components cannot be adjusted, it may lead to a suboptimal dosing for patients weighing ≥25 kg. TRIUMEQ PD is not recommended in patients weighing 25 kg or more [see Dosage and Administration ( 2.4 , 2.5 )] . 2.4 Recommended Dosage in Adults TRIUMEQ is a fixed-dose combination product containing 600 mg of abacavir, 50 mg of dolutegravir, and 300 mg of lamivudine. The recommended dosage regimen of TRIUMEQ in adults is one tablet once daily orally with or without food. Do not use TRIUMEQ PD in adults. 2.5 Recommended Dosage and Administration Instructions for Pediatric Patients Weighing at Least 6 kg The dosage and dosage form recommended for pediatric patients varies by weight as shown in Table 1 below. Table 1. Recommended Dosage of TRIUMEQ Tablets and TRIUMEQ PD Tablets for Oral Suspension in Pediatric Patients a TRIUMEQ is a fixed-dose combination product containing 600 mg of abacavir, 50 mg of dolutegravir, and 300 mg of lamivudine. b TRIUMEQ PD is a fixed-dose combination product containing 60 mg of abacavir, 5 mg of dolutegravir, and 30 mg of lamivudine. Body Weight TRIUMEQ Tablets a TRIUMEQ PD b Number of Tablets Total Daily Dose 6 kg to <10 kg Not recommended 3 tablets once daily 180 mg abacavir, 15 mg dolutegravir, and 90 mg lamivudine once daily 10 kg to <14 kg Not recommended 4 tablets once daily 240 mg abacavir, 20 mg dolutegravir, and 120 mg lamivudine once daily 14 kg to <20 kg Not recommended 5 tablets once daily 300 mg abacavir, 25 mg dolutegravir, and 150 mg lamivudine once daily 20 kg to <25 kg Not recommended 6 tablets once daily 360 mg abacavir, 30 mg dolutegravir, and 180 mg lamivudine once daily ≥25 kg 1 tablet once daily Not recommended 600 mg of abacavir, 50 mg of dolutegravir, and 300 mg of lamivudine Administer TRIUMEQ PD tablets for oral suspension with or without food. Instruct patients (or instruct caregivers) to fully disperse the tablets for oral suspension in 20 mL of drinking water (if using 4, 5, or 6 tablets for oral suspension) or 15 mL (if using 3 tablets for oral suspension) in the supplied cup; swirl the suspension so that no lumps remain. After full dispersion, administer the oral suspension within 30 minutes of mixing [see Instructions for Use] . Do not swallow the tablets for oral suspension whole, and do not chew, cut, or crush the tablets. For children unable to use the supplied cup, an appropriate-sized syringe may be used to administer the oral suspension. Administer TRIUMEQ tablet with or without food. Do not chew, cut, or crush the tablet. 2.6 Dosage Recommendation with Certain Concomitant Medications The dolutegravir dose in TRIUMEQ (50 mg) and TRIUMEQ PD (5 mg) is insufficient when coadministered with medications listed in Table 2 that may decrease dolutegravir concentrations; the following dolutegravir dosage regimen is recommended. Table 2. Dosing Recommendations for TRIUMEQ and TRIUMEQ PD with Coadministered Medications Coadministered Drug Dosing Recommendation Efavirenz, fosamprenavir/ritonavir, tipranavir/ritonavir, carbamazepine, or rifampin In adults and in pediatric patients weighing at least 25 kg , the recommended dolutegravir dosage regimen is 50 mg twice daily. Thus, an additional TIVICAY 50-mg tablet, separated by 12 hours from TRIUMEQ, should be taken. In pediatric patients weighing 6 kg to <25 kg , an additional weight-based dose of dolutegravir should be given separated by 12 hours from TRIUMEQ PD. • 6 to <10 kg: administer an additional 15-mg dose of dolutegravir (3 TIVICAY PD tablets for oral suspension), 12 hours after TRIUMEQ PD. • 10 to <14 kg: administer an additional 20-mg dose of dolutegravir (4 TIVICAY PD tablets for oral suspension), 12 hours after TRIUMEQ PD. • 14 to <20 kg: administer an additional 25-mg dose of dolutegravir (5 TIVICAY PD tablets for oral suspension), 12 hours after TRIUMEQ PD. • 20 to <25 kg: administer an additional 30-mg dose of dolutegravir (6 TIVICAY PD tablets for oral suspension), 12 hours after TRIUMEQ PD. 2.7 Not Recommended Due to Lack of Dosage Adjustment Because TRIUMEQ and TRIUMEQ PD are fixed-dose tablets and cannot be dose adjusted, TRIUMEQ and TRIUMEQ PD are not recommended in: • patients with creatinine clearance <30 mL/min and pediatric patients with a similar degree of renal impairment based on age-appropriate renal function assessment. There are no data available on the use of lamivudine, a component of TRIUMEQ and TRIUMEQ PD, in pediatric patients with renal impairment [see Use in Specific Populations ( 8.4 , 8.6 )] . • patients with mild hepatic impairment. TRIUMEQ and TRIUMEQ PD are contraindicated in patients with moderate or severe hepatic impairment [see Contraindications ( 4 ), Use in Specific Populations ( 8.7 )] .

6 ADVERSE REACTIONS The following adverse reactions are discussed in other sections of the labeling: • Serious and sometimes fatal hypersensitivity reaction [see Boxed Warning , Warnings and Precautions ( 5.1 )] . • Exacerbations of hepatitis B [see Boxed Warning , Warnings and Precautions ( 5.3 )] . • Hepatotoxicity [see Warnings and Precautions ( 5.3 )] . • Lactic acidosis and severe hepatomegaly with steatosis [see Warnings and Precautions ( 5.4 )] . • Immune reconstitution syndrome [see Warnings and Precautions ( 5.6 )] . • Myocardial infarction [see Warnings and Precautions ( 5.8 )] . The most commonly reported adverse reactions of at least moderate intensity and incidence at least 2% (in those receiving TRIUMEQ) were insomnia, headache, and fatigue. ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact ViiV Healthcare at 1-877-844-8872 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch . 6.1 Clinical Trials Experience Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared with rates in the clinical trials of another drug and may not reflect the rates observed in clinical practice. Clinical Trials in Adults Serious and Fatal Abacavir-Associated Hypersensitivity Reactions: In clinical trials, serious and sometimes fatal hypersensitivity reactions have occurred with abacavir, a component of TRIUMEQ and TRIUMEQ PD [see Boxed Warning , Warnings and Precautions ( 5.1 )]. These reactions have been characterized by 2 or more of the following signs or symptoms: (1) fever; (2) rash; (3) gastrointestinal symptoms (including nausea, vomiting, diarrhea, or abdominal pain); (4) constitutional symptoms (including generalized malaise, fatigue, or achiness); (5) respiratory symptoms (including dyspnea, cough, or pharyngitis). Almost all abacavir hypersensitivity reactions include fever and/or rash as part of the syndrome. Other signs and symptoms have included lethargy, headache, myalgia, edema, arthralgia, and paresthesia. Anaphylaxis, liver failure, renal failure, hypotension, adult respiratory distress syndrome, respiratory failure, myolysis, and death have occurred in association with these hypersensitivity reactions. Physical findings have included lymphadenopathy, mucous membrane lesions (conjunctivitis and mouth ulcerations), and maculopapular or urticarial rash (although some patients had other types of rashes and others did not have a rash). There were reports of erythema multiforme. Laboratory abnormalities included elevated liver chemistries, elevated creatine phosphokinase, elevated creatinine, and lymphopenia and abnormal chest x‑ray findings (predominantly infiltrates, which were localized). Serious Dolutegravir Hypersensitivity Reactions: In clinical trials, hypersensitivity reactions have occurred with dolutegravir, a component of TRIUMEQ and TRIUMEQ PD [see Warnings and Precautions ( 5.1 )]. These hypersensitivity reactions have been characterized by rash, constitutional findings, and sometimes organ dysfunction, including liver injury. Additional Treatment-Emergent Adverse Drug Reactions (ADRs) with Use of TRIUMEQ: The safety assessment of TRIUMEQ is primarily based on the analyses of data from a randomized, international, multicenter, double-blind, active-controlled trial, SINGLE (ING114467) and supported by data in treatment-experienced, INSTI-naive subjects from SAILING (ING111762) and by data from other treatment-naive trials. See full prescribing information for TIVICAY. Treatment-Naive Subjects: In SINGLE, 833 adult subjects were randomized and received at least one dose of either dolutegravir (TIVICAY) 50 mg with fixed-dose abacavir and lamivudine (EPZICOM) once daily (n = 414) or fixed-dose efavirenz/emtricitabine/tenofovir (ATRIPLA) once daily (n = 419) (study treatment was blinded through Week 96 and open-label from Week 96 through Week 144). Through 144 weeks, the rate of adverse events leading to discontinuation was 4% in subjects receiving TIVICAY + EPZICOM and 14% in subjects receiving ATRIPLA once daily. Treatment‑emergent ADRs of moderate to severe intensity observed in at least 2% of subjects in either treatment arm of SINGLE are provided in Table 3 . Table 3. Treatment-Emergent Adverse Drug Reactions of at Least Moderate Intensity (Grades 2 to 4) and at Least 2% Frequency in Treatment-Naive Subjects in SINGLE (Week 144 Analysis) a Includes pooled terms: rash, rash generalized, rash macular, rash maculo-papular, rash pruritic, and drug eruption. Adverse Reaction TIVICAY + EPZICOM Once Daily (n = 414) ATRIPLA Once Daily (n = 419) Psychiatric Insomnia 3% 3% Depression 1% 2% Abnormal dreams <1% 2% Nervous System Dizziness <1% 5% Headache 2% 2% Gastrointestinal Nausea <1% 3% Diarrhea <1% 2% General Disorders Fatigue 2% 2% Skin and Subcutaneous Tissue Rash a <1% 6% Ear and Labyrinth Vertigo 0 2% Treatment-Experienced Subjects: SAILING is an international, double-blind trial in INSTI-naive, antiretroviral treatment-experienced adult subjects. Subjects were randomized and received either TIVICAY 50 mg once daily or raltegravir 400 mg twice daily with investigator-selected background regimen consisting of up to 2 agents, including at least one fully active agent. At 48 weeks, the rate of adverse events leading to discontinuation was consistent with that seen in the overall treatment-naive patient population. See full prescribing information for TIVICAY. The ADRs observed in the subset of subjects who received TIVICAY + EPZICOM were generally consistent with those seen in the overall treatment-naive patient population. Less Common Adverse Reactions Observed in Clinical Trials: The following adverse reactions occurred in <2% of treatment-naive or treatment-experienced subjects in any one trial. These events have been included because of their seriousness and/or assessment of potential causal relationship. Gastrointestinal Disorders: Abdominal pain, abdominal distention, abdominal discomfort, dyspepsia, flatulence, gastroesophageal reflux disease, upper abdominal pain, vomiting. General Disorders: Fever, lethargy. Hepatobiliary Disorders: Hepatitis. Metabolism and Nutrition Disorders: Anorexia, hypertriglyceridemia. Musculoskeletal Disorders: Arthralgia, myositis. Nervous System Disorders: Somnolence. Psychiatric Disorders: Suicidal ideation, attempt, behavior, or completion. These events were observed primarily in subjects with a pre-existing history of depression or other psychiatric illness. Nightmare and sleep disorder. Renal and Urinary Disorders: Renal impairment. Skin and Subcutaneous Tissue Disorders: Pruritus. Laboratory Abnormalities: Treatment-Naive Subjects: Selected laboratory abnormalities (Grades 2 to 4) with a worsening grade from baseline and representing the worst-grade toxicity in at least 2% of subjects in SINGLE are presented in Table 4 . The mean change from baseline observed for selected lipid values is presented in Table 5 . Table 4. Selected Laboratory Abnormalities (Grades 2 to 4) in Treatment-Naive Subjects in SINGLE (Week 144 Analysis) ALT = Alanine aminotransferase, AST = Aspartate aminotransferase, ULN = upper limit of normal. Laboratory Abnormality TIVICAY + EPZICOM Once Daily (n = 414) ATRIPLA Once Daily (n = 419) ALT Grade 2 (>2.5-5.0 x ULN) 3% 5% Grade 3 to 4 (>5.0 x ULN) 1% <1% AST Grade 2 (>2.5-5.0 x ULN) 3% 4% Grade 3 to 4 (>5.0 x ULN) 1% 3% Creatine kinase Grade 2 (6.0-9.9 x ULN) 5% 3% Grade 3 to 4 (≥10.0 x ULN) 7% 8% Hyperglycemia Grade 2 (126-250 mg/dL) 9% 6% Grade 3 (>250 mg/dL) 2% <1% Lipase Grade 2 (>1.5-3.0 x ULN) 11% 11% Grade 3 to 4 (>3.0 ULN) 5% 4% Total neutrophils Grade 2 (0.75-0.99 x 10 9 ) 4% 5% Grade 3 to 4 (<0.75 x 10 9 ) 3% 3% Table 5. Mean Change from Baseline in Fasted Lipid Values in Treatment-Naive Subjects in SINGLE (Week 144 Analysis a ) HDL = High-density lipoprotein, LDL = Low-density lipoprotein. a Subjects on lipid-lowering agents at baseline were excluded from these analyses (TIVICAY + EPZICOM: n = 30 and ATRIPLA: n = 27). Seventy-two subjects initiated a lipid-lowering agent post-baseline; their last fasted on-treatment values (prior to starting the agent) were used regardless of whether they discontinued the agent (TIVICAY + EPZICOM: n = 36 and ATRIPLA: n = 36). Lipid TIVICAY + EPZICOM Once Daily (n = 414) ATRIPLA Once Daily (n = 419) Cholesterol (mg/dL) 24.0 26.7 HDL cholesterol (mg/dL) 5.4 7.2 LDL cholesterol (mg/dL) 16.0 14.6 Triglycerides (mg/dL) 13.6 31.9 Treatment-Experienced Subjects: Laboratory abnormalities observed in SAILING were generally similar compared with observations seen in the treatment-naive trials. Hepatitis C Virus Co-infection: In SINGLE, the pivotal Phase 3 trial, subjects with hepatitis C virus co-infection were permitted to enroll provided that baseline liver chemistry tests did not exceed 5 times the upper limit of normal; subjects with hepatitis B co-infection were excluded. Overall, the safety profile in subjects with hepatitis C virus co-infection was similar to that observed in subjects without hepatitis C co-infection, although the rates of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) abnormalities were higher in the subgroup with hepatitis C virus co-infection for both treatment groups. Grades 2 to 4 ALT abnormalities in hepatitis C co-infected compared with HIV mono-infected subjects receiving TRIUMEQ were observed in 15% and 2% (vs. 24% and 4% of subjects treated with ATRIPLA) (Week 96 analysis), respectively [see Warnings and Precautions ( 5.2 )] . See also full prescribing information for TIVICAY. Changes in Serum Creatinine: Dolutegravir has been shown to increase serum creatinine due to inhibition of tubular secretion of creatinine without affecting renal glomerular function [see Clinical Pharmacology ( 12.2 )] . Increases in serum creatinine occurred within the first 4 weeks of treatment and remained stable through 144 weeks. In SINGLE, a mean change from baseline of 0.14 mg/dL (range: -0.25 mg/dL to 0.81 mg/dL) was observed after 144 weeks of treatment. Creatinine increases were similar in treatment-experienced subjects. Abacavir and Lamivudine: Laboratory abnormalities observed in clinical trials of ZIAGEN (in combination with other antiretroviral treatment) were anemia, neutropenia, liver function test abnormalities, and elevations of creatine phosphokinase (CPK), blood glucose, and triglycerides. Additional laboratory abnormalities observed in clinical trials of EPIVIR (in combination with other antiretroviral treatment) were thrombocytopenia and elevated levels of bilirubin, amylase, and lipase. Clinical Trials Experience in Pediatric Subjects Abacavir, Dolutegravir and Lamivudine: The safety of TRIUMEQ PD and TRIUMEQ in pediatric subjects with HIV-1 infection weighing at least 6 kg was evaluated in the IMPAACT 2019 trial. This was a multicenter, open-label, non-comparative trial of pediatric subjects with HIV-1 infection, younger than 12 years of age. Fifty-seven subjects weighing at least 6 kg to less than 40 kg were enrolled in this trial [ see Use in Specific Populations ( 8.4 ), Clinical Pharmacology ( 12.3 ), Clinical Studies ( 14.2 )] . Overall, the safety data in this pediatric study was similar to that seen in adults. The safety analysis through Week 48 included 57 subjects weighing at least 6 kg at enrollment who received the recommended dose (determined by weight) and formulation. This analysis showed that 26% of subjects experienced clinical adverse reactions. The most common adverse reactions were classified as laboratory abnormalities and included decreased glomerular filtration rate (n = 13, 23%), increased blood creatinine (n = 10, 18%), and increased ALT (n = 3, 5%). All other adverse reactions occurred at a rate of <2% of participants. Two subjects reported Grade 3 or 4 adverse reactions. One subject, an 8-year-old female who weighed 22 kg at baseline, experienced Grade 3 increased blood creatinine and Grade 3 decreased glomerular filtration rate. By Week 48, the glomerular filtration rate was improving, and the events did not lead to drug discontinuation. Another subject, a 7-year-old male who weighed 20 kg at baseline, experienced drug-induced liver injury with Grade 4 increased ALT and AST following 36 weeks of treatment with TRIUMEQ PD. Clinical signs or symptoms of hepatitis were not reported, and ALT and AST values normalized after TRIUMEQ PD was discontinued. Abacavir and Lamivudine: The safety of once-daily compared with twice-daily dosing of abacavir and lamivudine, administered as either single products or as EPZICOM, was assessed in the ARROW trial (n = 336). Primary safety assessment in the ARROW (COL105677) trial was based on Grade 3 and Grade 4 adverse events. One event of Grade 4 hepatitis in the once-daily cohort was considered as uncertain causality by the investigator and all other Grade 3 or 4 adverse events were considered not related by the investigator. No additional safety issues were identified in pediatric subjects compared with historical data in adults. Dolutegravir: The safety of dolutegravir in pediatric subjects with HIV-1 infection weighing at least 6 kg was evaluated in the IMPAACT P1093 trial [see Use in Specific Populations ( 8.4 ), Clinical Pharmacology ( 12.3 )] . Overall, the safety data in this pediatric study was similar to that seen in adults. IMPAACT P1093 is an ongoing multicenter, open-label, non-comparative trial of pediatric subjects with HIV-1 infection, aged <18 years. One hundred and forty-two subjects weighing at least 6 kg were enrolled in this trial [see Use in Specific Populations ( 8.4 ), Clinical Pharmacology ( 12.3 ), Clinical Studies ( 14.2 )] . The safety analysis through Week 24 included 60 subjects weighing at least 6 kg at enrollment who received the recommended dose (determined by weight and age) and formulation. This analysis showed that 13% of subjects experienced adverse reactions. Grade 1 to 2 adverse reactions reported by more than one subject was immune reconstitution inflammatory syndrome (n = 2). There were no Grade 3 or 4 adverse reactions reported. No adverse reactions led to discontinuation. The Grade 3 or 4 laboratory abnormalities reported in more than one subject weighing at least 6 kg at enrollment were decreased neutrophil count (n = 5), decreased blood bicarbonate (n = 3), increased lipase (n = 2), and increased blood potassium (n = 2). These laboratory events were not considered to be drug related. Changes in median serum creatinine were similar to those observed in adults. 6.2 Postmarketing Experience In addition to adverse reactions reported from clinical trials, the following adverse reactions have been identified during postmarketing use with one or more of the components of TRIUMEQ and TRIUMEQ PD. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure. Blood and Lymphatic Systems Aplastic anemia, anemia (including pure red cell aplasia, sideroblastic anemia and severe anemias progressing on therapy), lymphadenopathy, splenomegaly. Digestive Stomatitis. Gastrointestinal Pancreatitis. General Weakness. Hepatobiliary Disorders Acute liver failure, liver transplant [see Warnings and Precautions ( 5.3 )] . Hypersensitivity Sensitization reactions (including anaphylaxis), urticaria [see Warnings and Precautions ( 5.1 ), Adverse Reactions ( 6.1 )] . Investigations Weight increased. Metabolism and Nutrition Disorders Hyperlactemia. Musculoskeletal CPK elevation, muscle weakness, myalgia, rhabdomyolysis. Nervous Paresthesia, peripheral neuropathy, seizures. Psychiatric Anxiety. Respiratory Abnormal breath sounds/wheezing. Skin Alopecia, erythema multiforme. Suspected Stevens‑Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) have been reported in patients receiving abacavir primarily in combination with medications known to be associated with SJS and TEN, respectively. Because of the overlap of clinical signs and symptoms between hypersensitivity to abacavir and SJS and TEN, and the possibility of multiple drug sensitivities in some patients, abacavir should be discontinued and not restarted in such cases [see Adverse Reactions ( 6.1 )] .

12.3 Pharmacokinetics Pharmacokinetics in Adults One TRIUMEQ tablet was bioequivalent to one dolutegravir (TIVICAY) tablet (50 mg) plus one abacavir and lamivudine fixed-dose combination tablet (EPZICOM) under fasted conditions in healthy subjects (n = 62). TRIUMEQ tablets and TRIUMEQ PD tablets for oral suspension are bioequivalent for the abacavir and lamivudine components, but not for the dolutegravir component. The relative dolutegravir bioavailability of TRIUMEQ PD is approximately 1.7-fold higher than TRIUMEQ; therefore, the 2 dosage forms are not substitutable on a milligram-per-milligram basis [see Dosage and Administration ( 2.3 ), Warnings and Precautions ( 5.7 )] . The relative dolutegravir bioavailability is expected to be similar between TRIUMEQ PD and TIVICAY PD. Abacavir: Following oral administration, abacavir is rapidly absorbed and extensively distributed. After oral administration of a single dose of 600 mg of abacavir in 20 subjects, C max was 4.26 ± 1.19 mcg/mL (mean ± SD) and AUC ∞ was 11.95 ± 2.51 mcg•hour/mL. Binding of abacavir to human plasma proteins is approximately 50% and was independent of concentration. Total blood and plasma drug‑related radioactivity concentrations are identical, demonstrating that abacavir readily distributes into erythrocytes. The primary routes of elimination of abacavir are metabolism by alcohol dehydrogenase to form the 5′‑carboxylic acid and glucuronyl transferase to form the 5′‑glucuronide. In single-dose trials, the observed elimination half-life (t ½ ) was 1.54 ± 0.63 hours. After intravenous administration, total clearance was 0.80 ± 0.24 L/h/kg (mean ± SD). Dolutegravir: Following oral administration of dolutegravir, peak plasma concentrations were observed 2 to 3 hours postdose. With once-daily dosing, pharmacokinetic steady state is achieved within approximately 5 days with average accumulation ratios for AUC, C max , and C 24 h ranging from 1.2 to 1.5. Dolutegravir is a P-gp substrate in vitro. The absolute bioavailability of dolutegravir has not been established. Dolutegravir is highly bound (≥98.9%) to human plasma proteins based on in vivo data and binding is independent of plasma concentration of dolutegravir. The apparent volume of distribution (Vd/F) following 50-mg once-daily administration is estimated at 17.4 L based on a population pharmacokinetic analysis. Dolutegravir is primarily metabolized via UGT1A1 with some contribution from CYP3A. After a single oral dose of [ 14 C] dolutegravir, 53% of the total oral dose is excreted unchanged in the feces. Thirty-one percent of the total oral dose is excreted in the urine, represented by an ether glucuronide of dolutegravir (18.9% of total dose), a metabolite formed by oxidation at the benzylic carbon (3.0% of total dose), and its hydrolytic N-dealkylation product (3.6% of total dose). Renal elimination of unchanged drug was <1% of the dose. Dolutegravir has a terminal half-life of approximately 14 hours and an apparent clearance (CL/F) of 1.0 L/h based on population pharmacokinetic analyses. The pharmacokinetic properties of dolutegravir have been evaluated in healthy adult subjects and HIV‑1–infected adult subjects. Exposure to dolutegravir was generally similar between healthy subjects and HIV‑1–infected subjects. Table 7. Dolutegravir Steady-State Pharmacokinetic Parameter Estimates in HIV-1–Infected Adults Parameter 50 mg Once Daily Geometric Mean (%CV) AUC (0-24) (mcg•h/mL) 53.6 (27) C max (mcg/mL) 3.67 (20) C min (mcg/mL) 1.11 (46) Cerebrospinal Fluid (CSF): In 11 treatment-naive subjects on dolutegravir 50 mg daily plus abacavir/lamivudine, the median dolutegravir concentration in CSF was 18 ng/mL (range: 4 ng/mL to 23.2 ng/mL) 2 to 6 hours postdose after 2 weeks of treatment. The clinical relevance of this finding has not been established. Lamivudine: Following oral administration, lamivudine is rapidly absorbed and extensively distributed. After multiple‑dose oral administration of lamivudine 300 mg once daily for 7 days to 60 healthy subjects, steady-state C max (C max,ss ) was 2.04 ± 0.54 mcg/mL (mean ± SD) and the 24‑hour steady‑state AUC (AUC 24,ss ) was 8.87 ± 1.83 mcg•hour/mL. Binding to plasma protein is low. Approximately 70% of an intravenous dose of lamivudine is recovered as unchanged drug in the urine. Metabolism of lamivudine is a minor route of elimination. In humans, the only known metabolite is the trans‑sulfoxide metabolite (approximately 5% of an oral dose after 12 hours). In most single-dose trials with plasma sampling up to 48 or 72 hours after dosing, the observed mean elimination half-life (t ½ ) ranged from 13 to 19 hours. In HIV-1–infected subjects, total clearance was 398.5 ± 69.1 mL/min (mean ± SD). Effect of Food on Oral Absorption TRIUMEQ or TRIUMEQ PD may be taken with or without food. Overall, when compared with fasted conditions, administration of TRIUMEQ to healthy adult subjects with a high-fat meal (53% fat, 869 calories) resulted in decreased C max for abacavir and increased C max and AUC for dolutegravir. Lamivudine exposures were not affected by food. With a high-fat meal, the C max of abacavir decreased 23% and the C max and AUC of dolutegravir increased 37% and 48%, respectively. When compared with fasted conditions, administration of TRIUMEQ PD to healthy adult subjects with a high-fat meal (50% fat, 917 calories) resulted in decreased C max for abacavir (55%), dolutegravir (29%) and lamivudine (36%). AUCs for all 3 components were not affected by food. Specific Populations Patients with Renal Impairment: The pharmacokinetics for the individual components of TRIUMEQ and TRIUMEQ PD have been evaluated in patients with renal impairment (see the U.S. prescribing information for the individual abacavir, dolutegravir, and lamivudine components). Patients with Hepatic Impairment: The pharmacokinetics for the individual components of TRIUMEQ and TRIUMEQ PD have been evaluated in patients with varying degrees of hepatic impairment (see the U.S. prescribing information for the individual abacavir, dolutegravir, and lamivudine components). Pregnant women: Abacavir: Abacavir pharmacokinetics were studied in 25 pregnant women during the last trimester of pregnancy receiving abacavir 300 mg twice daily. Abacavir exposure (AUC) during pregnancy was similar to those in postpartum and in HIV-infected non-pregnant historical controls. Consistent with passive diffusion of abacavir across the placenta, abacavir concentrations in neonatal plasma cord samples at birth were essentially equal to those in maternal plasma at delivery. Lamivudine: Lamivudine pharmacokinetics were studied in 36 pregnant women during 2 clinical trials conducted in South Africa. Lamivudine pharmacokinetics in pregnant women were similar to those seen in non-pregnant adults and in postpartum women. Lamivudine concentrations were generally similar in maternal, neonatal, and umbilical cord serum samples. Pediatric Patients: The pharmacokinetics of TRIUMEQ, TRIUMEQ PD (abacavir, dolutegravir, and lamivudine) and their individual components have been evaluated in pediatric subjects. Abacavir, Dolutegravir and Lamivudine: The pharmacokinetics of TRIUMEQ and TRIUMEQ PD were evaluated in the IMPAACT 2019 trial. Steady-state plasma exposure at doses by weight band are summarized in Table 8 [see Use in Specific Populations ( 8.4 ), Clinical Studies ( 14.2 )] . Overall, exposures of abacavir, dolutegravir and lamivudine at the recommended doses for TRIUMEQ PD and TRIUMEQ are within the observed exposure ranges at the recommended doses of individual products in adults and pediatrics. Refer to the prescribing information for EPIVIR, TIVICAY, and ZIAGEN for pharmacokinetic information on lamivudine, dolutegravir, and abacavir, respectively, in pediatric patients. Table 8. Summary of Pharmacokinetic Parameters in Pediatric HIV-1–Infected Subjects (IMPAACT 2019 Trial) %CV, coefficient of variation expressed as a percentage. a The relative dolutegravir bioavailability of TRIUMEQ PD tablets for oral suspension is ~1.7-fold that of TRIUMEQ tablets. Drug Weight Band Dose a of single entities in TRIUMEQ or TRIUMEQ PD n Pharmacokinetic Parameter Geometric Mean (%CV) C max (mcg/mL) AUC 0-24h (mcg∙h/mL) C 24h (ng/mL) Abacavir 6 to <10 kg 180 mg once daily TRIUMEQ PD 7 7.30 (20) 17.7 (34) 3 (128) 10 to <14 kg 240 mg once daily TRIUMEQ PD 7 8.36 (44) 19.8 (51) 5 (127) 14 to <20 kg 300 mg once daily TRIUMEQ PD 7 6.26 (31) 15.1 (40) 3 (108) 20 to <25 kg 360 mg once daily TRIUMEQ PD 7 6.65 (28) 17.4 (19) 4 (85) 25 to <40 kg 600 mg once daily TRIUMEQ 7 9.04 (22) 25.7 (15) 11 (229) Dolutegravir 6 to <10 kg 15 mg once daily TRIUMEQ PD 7 7.40 (28) 75.9 (34) 910 (68) 10 to <14 kg 20 mg once daily TRIUMEQ PD 7 8.85 (21) 91.0 (36) 1220 (77) 14 to <20 kg 25 mg once daily TRIUMEQ PD 7 7.04 (17) 71.4 (23) 790 (44) 20 to <25 kg 30 mg once daily TRIUMEQ PD 7 7.29 (17) 84.4 (26) 1350 (95) 25 to <40 kg 50 mg once daily TRIUMEQ 7 6.25 (21) 71.8 (14) 980 (28) Lamivudine 6 to <10 kg 90 mg once daily TRIUMEQ PD 7 2.29 (40) 10.7 (46) 55 (39) 10 to <14 kg 120 mg once daily TRIUMEQ PD 7 3.55 (19) 14.2 (24) 46 (48) 14 to <20 kg 150 mg once daily TRIUMEQ PD 7 2.92 (23) 13.0 (16) 58 (37) 20 to <25 kg 180 mg once daily TRIUMEQ PD 7 2.99 (32) 14.5 (17) 60 (18) 25 to <40 kg 300 mg once daily TRIUMEQ 7 4.15 (29) 21.7 (26) 84 (35) Geriatric Patients: Population analyses using pooled pharmacokinetic data from adult trials indicated age had no clinically relevant effect on the pharmacokinetics of dolutegravir. The pharmacokinetics of abacavir or lamivudine have not been studied in subjects older than 65 years. Male and Female Patients: There are no significant or clinically relevant gender differences in the pharmacokinetics of the individual components (dolutegravir, abacavir, or lamivudine) based on the available information that was analyzed for each of the individual components. Racial Groups: There are no significant or clinically relevant racial differences in pharmacokinetics of the individual components (dolutegravir, abacavir, or lamivudine) based on the available information that was analyzed for each of the individual components. Drug Interaction Studies The drug interaction trials described were conducted with dolutegravir, abacavir, and/or lamivudine as single entities; no drug interaction trials have been conducted using the combination of abacavir, dolutegravir, and lamivudine. No clinically significant drug interactions are expected between dolutegravir, abacavir, and lamivudine. Dosing recommendations as a result of established and other potentially significant drug-drug interactions with the individual components of TRIUMEQ and TRIUMEQ PD are provided in Section 7.3 [see Drug Interactions ( 7 )] . Table 9. Summary of Effect of Dolutegravir on the Pharmacokinetics of Coadministered Drugs a The number of subjects represents the maximum number of subjects that were evaluated. Coadministered Drug(s) and Dose(s) Dose of Dolutegravir n Geometric Mean Ratio (90% CI) of Pharmacokinetic Parameters of Coadministered Drug with/without Dolutegravir No Effect = 1.00 C max AUC C τ or C 24 Ethinyl estradiol 0.035 mg 50 mg twice daily 15 0.99 (0.91 to 1.08) 1.03 (0.96 to 1.11) 1.02 (0.93 to 1.11) Metformin 500 mg twice daily 50 mg once daily 15 a 1.66 (1.53 to 1.81) 1.79 (1.65 to 1.93) _ Metformin 500 mg twice daily 50 mg twice daily 15 a 2.11 (1.91 to 2.33) 2.45 (2.25 to 2.66) _ Methadone 16 to 150 mg 50 mg twice daily 11 1.00 (0.94 to 1.06) 0.98 (0.91 to 1.06) 0.99 (0.91 to 1.07) Midazolam 3 mg 25 mg once daily 10 _ 0.95 (0.79 to 1.15) _ Norelgestromin 0.25 mg 50 mg twice daily 15 0.89 (0.82 to 0.97) 0.98 (0.91 to 1.04) 0.93 (0.85 to 1.03) Rilpivirine 25 mg once daily 50 mg once daily 16 1.10 (0.99 to 1.22) 1.06 (0.98 to 1.16) 1.21 (1.07 to 1.38) Tenofovir disoproxil fumarate 300 mg once daily 50 mg once daily 15 1.09 (0.97 to 1.23) 1.12 (1.01 to 1.24) 1.19 (1.04 to 1.35) Table 10. Summary of Effect of Coadministered Drugs on the Pharmacokinetics of Dolutegravir a Comparison is rifampin taken with dolutegravir 50 mg twice daily compared with dolutegravir 50 mg twice daily. b Comparison is rifampin taken with dolutegravir 50 mg twice daily compared with dolutegravir 50 mg once daily. c The number of subjects represents the maximum number of subjects that were evaluated. Coadministered Drug(s) and Dose(s) Dose of Dolutegravir n Geometric Mean Ratio (90% CI) of Dolutegravir Pharmacokinetic Parameters with/without Coadministered Drugs No Effect = 1.00 C max AUC C τ or C 24 Atazanavir 400 mg once daily 30 mg once daily 12 1.50 (1.40 to 1.59) 1.91 (1.80 to 2.03) 2.80 (2.52 to 3.11) Atazanavir/ritonavir 300/100 mg once daily 30 mg once daily 12 1.34 (1.25 to 1.42) 1.62 (1.50 to 1.74) 2.21 (1.97 to 2.47) Darunavir/ritonavir 600/100 mg twice daily 30 mg once daily 15 0.89 (0.83 to 0.97) 0.78 (0.72 to 0.85) 0.62 (0.56 to 0.69) Efavirenz 600 mg once daily 50 mg once daily 12 0.61 (0.51 to 0.73) 0.43 (0.35 to 0.54) 0.25 (0.18 to 0.34) Etravirine 200 mg twice daily 50 mg once daily 16 0.48 (0.43 to 0.54) 0.29 (0.26 to 0.34) 0.12 (0.09 to 0.16) Etravirine + darunavir/ritonavir 200 mg + 600/100 mg twice daily 50 mg once daily 9 0.88 (0.78 to 1.00) 0.75 (0.69 to 0.81) 0.63 (0.52 to 0.76) Etravirine + lopinavir/ritonavir 200 mg + 400/100 mg twice daily 50 mg once daily 8 1.07 (1.02 to 1.13) 1.11 (1.02 to 1.20) 1.28 (1.13 to 1.45) Fosamprenavir/ritonavir 700 mg/100 mg twice daily 50 mg once daily 12 0.76 (0.63 to 0.92) 0.65 (0.54 to 0.78) 0.51 (0.41 to 0.63) Lopinavir/ritonavir 400/100 mg twice daily 30 mg once daily 15 1.00 (0.94 to 1.07) 0.97 (0.91 to 1.04) 0.94 (0.85 to 1.05) Rilpivirine 25 mg once daily 50 mg once daily 16 1.13 (1.06 to 1.21) 1.12 (1.05 to 1.19) 1.22 (1.15 to 1.30) Tenofovir 300 mg once daily 50 mg once daily 15 0.97 (0.87 to 1.08) 1.01 (0.91 to 1.11) 0.92 (0.82 to 1.04) Tipranavir/ritonavir 500/200 mg twice daily 50 mg once daily 14 0.54 (0.50 to 0.57) 0.41 (0.38 to 0.44) 0.24 (0.21 to 0.27) Antacid (MAALOX) simultaneous administration 50 mg single dose 16 0.28 (0.23 to 0.33) 0.26 (0.22 to 0.32) 0.26 (0.21 to 0.31) Antacid (MAALOX) 2 h after dolutegravir 50 mg single dose 16 0.82 (0.69 to 0.98) 0.74 (0.62 to 0.90) 0.70 (0.58 to 0.85) Boceprevir 800 mg every 8 h 50 mg once daily 13 1.05 (0.96 to 1.15) 1.07 (0.95 to 1.20) 1.08 (0.91 to 1.28) Calcium carbonate 1,200 mg simultaneous administration (fasted) 50 mg single dose 12 0.63 (0.50 to 0.81) 0.61 (0.47 to 0.80) 0.61 (0.47 to 0.80) Calcium carbonate 1,200 mg simultaneous administration (fed) 50 mg single dose 11 1.07 (0.83 to 1.38) 1.09 (0.84 to 1.43) 1.08 (0.81 to 1.42) Calcium carbonate 1,200 mg 2 h after dolutegravir 50 mg single dose 11 1.00 (0.78 to 1.29) 0.94 (0.72 to 1.23) 0.90 (0.68 to 1.19) Carbamazepine 300 mg twice daily 50 mg once daily 16 c 0.67 (0.61 to 0.73) 0.51 (0.48 to 0.55) 0.27 (0.24 to 0.31) Ferrous fumarate 324 mg simultaneous administration (fasted) 50 mg single dose 11 0.43 (0.35 to 0.52) 0.46 (0.38 to 0.56) 0.44 (0.36 to 0.54) Ferrous fumarate 324 mg simultaneous administration (fed) 50 mg single dose 11 1.03 (0.84 to 1.26) 0.98 (0.81 to 1.20) 1.00 (0.81 to 1.23) Ferrous fumarate 324 mg 2 h after dolutegravir 50 mg single dose 10 0.99 (0.81 to 1.21) 0.95 (0.77 to 1.15) 0.92 (0.74 to 1.13) Multivitamin (One-A-Day) simultaneous administration 50 mg single dose 16 0.65 (0.54 to 0.77) 0.67 (0.55 to 0.81) 0.68 (0.56 to 0.82) Omeprazole 40 mg once daily 50 mg single dose 12 0.92 (0.75 to 1.11) 0.97 (0.78 to 1.20) 0.95 (0.75 to 1.21) Prednisone 60 mg once daily with taper 50 mg once daily 12 1.06 (0.99 to 1.14) 1.11 (1.03 to 1.20) 1.17 (1.06 to 1.28) Rifampin a 600 mg once daily 50 mg twice daily 11 0.57 (0.49 to 0.65) 0.46 (0.38 to 0.55) 0.28 (0.23 to 0.34) Rifampin b 600 mg once daily 50 mg twice daily 11 1.18 (1.03 to 1.37) 1.33 (1.15 to 1.53) 1.22 (1.01 to 1.48) Rifabutin 300 mg once daily 50 mg once daily 9 1.16 (0.98 to 1.37) 0.95 (0.82 to 1.10) 0.70 (0.57 to 0.87) Abacavir or Lamivudine: The drug interactions described are based on trials conducted with abacavir or lamivudine as single entities. Effect of Abacavir and Lamivudine on the Pharmacokinetics of Other Agents: In vitro studies have shown that abacavir has potential to inhibit CYP1A1 and limited potential to inhibit metabolism mediated by CYP3A4. Lamivudine does not inhibit or induce CYP3A4. Abacavir and lamivudine do not inhibit or induce other CYP enzymes (such as CYP2C9 or CYP2D6). Based on in vitro study results, abacavir and lamivudine at therapeutic drug exposures are not expected to affect the pharmacokinetics of drugs that are substrates of the following transporters: OATP1B1/3, BCRP or P-gp, OCT1, OCT2, OCT3 (lamivudine only), or MATE1 and MATE2‑K. Abacavir, Dolutegravir, and Lamivudine: Coadministration of a single dose of riociguat (0.5 mg) to HIV-1–infected subjects receiving TRIUMEQ is reported to increase riociguat AUC (∞) compared with riociguat AUC (∞) reported in healthy subjects due to CYP1A1 inhibition by abacavir. The exact magnitude of increase in riociguat exposure has not been fully characterized based on findings from two studies [see Drug Interactions ( 7.3 )] . Effect of Other Agents on the Pharmacokinetics of Abacavir or Lamivudine: In vitro, abacavir is not a substrate of OATP1B1, OATP1B3, OCT1, OCT2, OAT1, MATE1, MATE2-K, MRP2 or MRP4; therefore, drugs that modulate these transporters are not expected to affect abacavir plasma concentrations. Abacavir is a substrate of BCRP and P-gp in vitro; however, considering its absolute bioavailability (83%), modulators of these transporters are unlikely to result in a clinically relevant impact on abacavir concentrations. Lamivudine is a substrate of MATE1, MATE2-K, and OCT2 in vitro. Trimethoprim (an inhibitor of these drug transporters) has been shown to increase lamivudine plasma concentrations. This interaction is not considered clinically significant as no dose adjustment of lamivudine is needed. Lamivudine is a substrate of P-gp and BCRP; however, considering its absolute bioavailability (87%), it is unlikely that these transporters play a significant role in the absorption of lamivudine. Therefore, coadministration of drugs that are inhibitors of these efflux transporters is unlikely to affect the disposition and elimination of lamivudine. Ethanol: Abacavir has no effect on the pharmacokinetic properties of ethanol. Ethanol decreases the elimination of abacavir causing an increase in overall exposure. Interferon Alfa: There was no significant pharmacokinetic interaction between lamivudine and interferon alfa in a trial of 19 healthy male subjects. Methadone: In a trial of 11 HIV‑1–infected subjects receiving methadone‑maintenance therapy (40 mg and 90 mg daily), with 600 mg of abacavir twice daily (twice the currently recommended dose), oral methadone clearance increased 22% (90% CI: 6% to 42%) [see Drug Interactions ( 7.3 )]. The addition of methadone has no clinically significant effect on the pharmacokinetic properties of abacavir . Ribavirin: In vitro data indicate ribavirin reduces phosphorylation of lamivudine, stavudine, and zidovudine. However, no pharmacokinetic (e.g., plasma concentrations or intracellular triphosphorylated active metabolite concentrations) or pharmacodynamic (e.g., loss of HIV‑1/HCV [hepatitis C virus] virologic suppression) interaction was observed when ribavirin and lamivudine (n = 18), stavudine (n = 10), or zidovudine (n = 6) were coadministered as part of a multi‑drug regimen to HIV‑1/HCV co‑infected subjects. Sorbitol (Excipient): Lamivudine and sorbitol solutions were coadministered to 16 healthy adult subjects in an open-label, randomized-sequence, 4-period, crossover trial. Each subject received a single 300-mg dose of lamivudine oral solution alone or coadministered with a single dose of 3.2 g, 10.2 g, or 13.4 g of sorbitol in solution. Coadministration of lamivudine with sorbitol resulted in dose-dependent decreases of 20%, 39%, and 44% in the AUC (0-24) ; 14%, 32%, and 36% in the AUC (∞) ; and 28%, 52%, and 55% in the C max ; of lamivudine, respectively. Abacavir, Lamivudine, Zidovudine: Fifteen HIV‑1–infected subjects were enrolled in a crossover-designed drug interaction trial evaluating single doses of abacavir (600 mg), lamivudine (150 mg), and zidovudine (300 mg) alone or in combination. Analysis showed no clinically relevant changes in the pharmacokinetics of abacavir with the addition of lamivudine or zidovudine or the combination of lamivudine and zidovudine. Lamivudine exposure (AUC decreased 15%) and zidovudine exposure (AUC increased 10%) did not show clinically relevant changes with concurrent abacavir. Lamivudine and Zidovudine: No clinically significant alterations in lamivudine or zidovudine pharmacokinetics were observed in 12 asymptomatic HIV‑1–infected adult patients given a single dose of zidovudine (200 mg) in combination with multiple doses of lamivudine (300 mg every 12 hours). The effects of other coadministered drugs on abacavir or lamivudine are provided in Table 11 . Table 11. Effect of Coadministered Drugs on Abacavir or Lamivudine ↑ = Increase; ↔ = No significant change. a The drug-drug interaction was only evaluated in males. Coadministered Drug and Dose Drug and Dose n Concentrations of Abacavir or Lamivudine Concentration of Coadministered Drug AUC Variability Ethanol 0.7 g/kg Abacavir Single 600 mg 24 ↑41% 90% CI: 35% to 48% ↔ a Nelfinavir 750 mg every 8 h x 7 to 10 days Lamivudine Single 150 mg 11 ↑10% 95% CI: 1% to 20% ↔ Trimethoprim 160 mg/ Sulfamethoxazole 800 mg daily x 5 days Lamivudine Single 300 mg 14 ↑43% 90% CI: 32% to 55% ↔