Drug Interaction Report

ADJUST DOSING INTERVAL: Coadministration of oral probiotic preparations with oral antibiotics may reduce the efficacy of the probiotic. It has been theorized that concomitant antibiotics may kill the live organisms found in lactobacillus-, bacillus coagulans-, and bifidobacteria-containing oral probiotic preparations. However, the clinical significance of the interaction has not been established.

MANAGEMENT: Although data are limited, it may be prudent to advise patients to take oral probiotics at least 1 to 2 hours before or after an oral antibiotic.

CONTRAINDICATED: Use of alcohol or products containing alcohol during therapy with nitrofurans may result in a disulfiram-like reaction in some patients. The presumed mechanism is inhibition of aldehyde dehydrogenase (ALDH) by nitrofurans in a manner similar to disulfiram. Following ingestion of alcohol, inhibition of ALDH results in increased concentrations of acetaldehyde, the accumulation of which can produce 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, arrhythmia, myocardial infarction, acute congestive heart failure, unconsciousness, convulsions, and death.

ADJUST DOSING INTERVAL: Food enhances the oral bioavailability of nifurtimox. When a single 120 mg oral dose of nifurtimox was administered with a high-fat meal (800 to 1000 calories; approximately 60% fat) in adult Chagas patients, nifurtimox peak plasma concentration (Cmax) and systemic exposure (AUC) increased by 68% and 71%, respectively, compared to administration under fasted conditions. Nifurtimox was administered with food in clinical trials.

MANAGEMENT: Consumption of alcohol is considered contraindicated during nifurtimox therapy. To ensure maximal oral absorption, nifurtimox should be administered with food.