Drug Interaction Report

GENERALLY AVOID: Risperidone oral solution is not compatible with either tea or cola. In addition, alcohol may potentiate some of the pharmacologic effects of risperidone. Use in combination may result in additive central nervous system depression and/or impairment of judgment, thinking, and psychomotor skills.

MANAGEMENT: Risperidone oral solution should not be mixed with tea or cola. It may be taken with water, coffee, orange juice, or lowfat milk. Patients should also be advised to avoid consumption of alcohol.

GENERALLY AVOID: Some cephalosporins may occasionally induce a disulfiram-like reaction when coadministered with alcohol. The interaction has been reported for cefamandole, cefoperazone, cefotetan, and moxalactam. These agents contain an N-methylthiotetrazole (NMTT) side chain that may inhibit aldehyde dehydrogenase (ALDH) similar to disulfiram. Following ingestion of alcohol, inhibition of ALDH results in increased concentration of acetaldehyde, the accumulation of which produces an unpleasant physiologic response referred to as the 'disulfiram reaction'. Symptoms include flushing, throbbing in head and neck, throbbing headache, respiratory difficulty, nausea, vomiting, sweating, thirst, chest pain, palpitation, dyspnea, hyperventilation, tachycardia, hypotension, syncope, weakness, vertigo, blurred vision, and confusion. Severe reactions may result in respiratory depression, cardiovascular collapse, arrhythmias, myocardial infarction, acute congestive heart failure, unconsciousness, convulsions, and death. Cefonicid contains a structurally similar side chain but did not produce elevations in blood acetaldehyde or a disulfiram reaction to ethanol in 15 healthy volunteers given single and multiple one gram doses of the drug.

MANAGEMENT: Patients receiving cephalosporins with the NMTT side chain should avoid the concomitant use of alcohol and alcohol-containing products.