Acetaminophen, Caffeine, Dihydrocodeine Bitartrate

WARNINGS: Hepatotoxicity : Acetaminophen has been associated with cases of acute liver failure, at times resulting in liver transplant and death. Most of the cases of liver injury are associated with the use of acetaminophen at doses that exceed 4000 milligrams per day, and often involve more than one acetaminophen containing product. The excessive intake of acetaminophen may be intentional to cause self-harm or unintentional as patients attempt to obtain more pain relief or unknowingly take other acetaminophen-containing products. The risk of acute liver failure is higher in individuals with underlying liver disease and in individuals who ingest alcohol while taking acetaminophen. Instruct patients to look for acetaminophen or APAP on package labels and not to use more than one product that contains acetaminophen. Instruct patients to seek medical attention immediately upon ingestion of more than 4000 milligrams of acetaminophen per day, even if they feel well. Serious Skin Reactions Rarely, acetaminophen may cause serious skin reactions such as acute generalized exanthematous pustulosis (AGEP), Stevens-Johnson Syndrome (SJS), and toxic epidermal necrolysis (TEN), which can be fatal. Patients should be informed about the signs of serious skin reactions, and use of the drug should be discontinued at the first appearance of skin rash or any other sign of hypersensitivity. Death Related to Ultra-Rapid Metabolism of Codeine to Morphine: Respiratory depression and death have occurred in children who received codeine in the postoperative period following tonsillectomy and/or adenoidectomy and had evidence of being ultra-rapid metabolizers of codeine (i.e., multiple copies of the gene for cytochrome P450 isoenzyme 2D6 or high morphine concentrations). Deaths have also occurred in nursing infants who were exposed to high levels of morphine in breast milk because their mothers were ultra-rapid metabolizers of codeine [see Error! Hyperlink reference not valid. ]. Some individuals may be ultra-rapid metabolizers because of a specific CYP2D6 genotype (gene duplications denoted as *1/*1xN or *1/*2xN). The prevalence of this CYP2D6 phenotype varies widely and has been estimated at 0.5 to 1% in Chinese and Japanese, 0.5 to 1% in Hispanics, 1 to 10% in Caucasians, 3% in African Americans, and 16 to 28% in North Africans, Ethiopians, and Arabs. Data are not available for other ethnic groups. These individuals convert dihydrocodeine into its active metabolite, dihydromorphine, more rapidly and completely than other people. This rapid conversion results in higher than expected serum dihydromorphine levels. Even at labeled dosage regimens, individuals who are ultra-rapid metabolizers may have life-threatening or fatal respiratory depression or experience signs of overdose (such as extreme sleepiness, confusion, or shallow breathing) [see Overdosage ]. Children with obstructive sleep apnea who are treated with codeine for post-tonsillectomy and/or adenoidectomy pain may be particularly sensitive to the respiratory depressant effects of codeine that has been rapidly metabolized to morphine. Dihydrocodeine-containing products are contraindicated for post-operative pain management in all pediatric patients undergoing tonsillectomy and/or adenoidectomy [see Contraindications ]. When prescribing dihydrocodeine-containing products, healthcare providers should choose the lowest effective dose for the shortest period of time and inform patients and caregivers about these risks and the signs of morphine overdose [see Overdosage ]. Hypersensitivity/Anaphylaxis: There have been post-marketing reports of hypersensitivity and anaphylaxis associated with use of acetaminophen. Clinical signs included swelling of the face, mouth, and throat, respiratory distress, urticarial, rash, pruritus, and vomiting. There were infrequent reports of life-threatening anaphylaxis requiring emergency medical attention. Instruct patients to discontinue TREZIX™ immediately and seek medical care if they experience these symptoms. Do not prescribe TREZIX™ for patients with acetaminophen allergy. Usage in Ambulatory Patients: Dihydrocodeine may impair the mental and/or physical abilities required for the performance of potentially hazardous tasks such as driving a car or operating machinery. Respiratory Depression: Respiratory depression is the most dangerous acute reaction produced by opioid agonist preparations, although it is rarely severe with usual doses. Opioids decrease the respiratory rate, tidal volume, minute ventilation, and sensitivity to carbon dioxide. Respiratory depression occurs most frequently in elderly or debilitated patients, usually after large initial doses in nontolerant patients, or when opioids are given in conjunction with other agents that depress respiration. This combination product should be used with caution in patients with significant chronic obstructive pulmonary disease or cor pulmonale and in patients with a substantially decreased respiratory reserve, hypoxia hypercapnia, or respiratory depression. In such patients, alternative non-opioid analgesics should be considered, and opioids should be administered only under careful medical supervision at the lowest effective dose. Head Injury: This combination product should be used cautiously in the presence of head injury or increased intracranial pressure. The effects of opioids on pupillary response and consciousness may obscure neurologic signs of increases in intracranial pressure in patients with head injuries. The respiratory depressant effects including carbon dioxide retention and secondary elevation of cerebrospinal fluid pressure may be markedly exaggerated in the presence of head injury, intracranial lesions, or other causes of increased intracranial pressures. Hypotensive Effect: Dihydrocodeine, like all opioid analgesics, may cause hypotension in patients whose ability to maintain blood pressure has been compromised by a depleted blood volume or who receive concurrent therapy with drugs such as phenothiazines or other agents which compromise vasomotor tone. Acetaminophen, caffeine and dihydrocodeine bitartrate capsules may produce orthostatic hypotension in ambulatory patients. This combination product should be administered with caution to patients in circulatory shock, since vasodilation produced by the drug may further reduce cardiac output and blood pressure. Drug Dependence: Dihydrocodeine can produce drug dependence of the codeine type and has the potential of being abused (See DRUG ABUSE AND DEPENDENCE ).