inophen in therapeutic doses rarely causes adverse reactions. The most serious adverse reaction is hepatotoxicity from overdosage (see OVERDOSAGE). Thrombocytopenia, leukopenia, pancytopenia, neutropenia, thrombocytopenic purpura, and agranulocytosis have been reported in patients receiving acetaminophen or ρ-aminophenol derivatives. Hypersensitivity reactions including urticarial or erythematous skin reactions, laryngeal edema, angioedema, or anaphylactoid reactions are rare.
Caffeine
Adverse reactions associated with caffeine use include anxiety, anxiety neurosis, excitement, headaches, insomnia, irritability, lightheadedness, restlessness, tenseness, tremor, extrasystoles, palpitations, tachycardia, diarrhea, nausea, stomach pain, vomiting, diuresis, urticaria, scintillating scotoma, and tinnitus.
DRUG ABUSE AND DEPENDENCE
This combination product is subject to the provisions of the Controlled Substance Act, and has been placed in Schedule III.
Dihydrocodeine can produce drug dependence of the codeine type and therefore has the potential of being abused. Like other opioid analgesics, dihydrocodeine may produce subjective effects other than analgesia (e.g., euphoria, relaxation), which may contribute to abuse by some patients. Psychological dependence, physical dependence, and tolerance may develop upon repeated administration of dihydrocodeine, and it should be prescribed and administered with the same degree of caution appropriate to the use of other oral opioid analgesic medications. Symptoms of dihydrocodeine withdrawal consist of irritability, restlessness, insomnia, diaphoresis, anxiety and palpitations.
Prolonged, high intake of caffeine may produce tolerance and habituation. Physical signs of withdrawal, such as headaches, irritation, nervousness, anxiety, and dizziness may occur upon abrupt discontinuation.
OVERDOSAGE
Following an acute overdosage with Acetaminophen, Caffeine and Dihydrocodeine Bitartrate Tablets, toxicity may result from the dihydrocodeine, acetaminophen, or, less likely, caffeine component. An overdose is a potentially lethal polydrug overdose situation, and consultation with a regional poison control center is recommended. A listing of the poison control centers can be found in standard references such as the Physician’s Desk Reference®.
Signs and Symptoms and Laboratory Findings
Toxicity from dihydrocodeine is typical of opioids and includes pinpoint pupils, respiratory depression, and loss of consciousness. Convulsions, cardiovascular collapse, and death may occur. A single case of acute rhabdomyolysis associated with an overdose of dihydrocodeine has been reported. With acetaminophen, dose-dependent potentially fatal hepatic necrosis is the most serious adverse effect. Renal tubular necrosis, hypoglycemic coma, and thrombocytopenia may occur. Early symptoms of hepatotoxicity include nausea, vomiting, diaphoresis, and general malaise. Clinical and laboratory evidence of hepatic toxicity may not be apparent until 48 to 72 hours after ingestion. Acute caffeine poisoning may cause insomnia, restlessness, tremor, delirium, tachycardia, extrasystoles, and seizures.
Because overdose information on this combination product is limited, it is unclear which of the signs and symptoms of toxicity would manifest in any particular overdose situation.
Treatment
Immediate treatme
