Drug Interactions between mefloquine and nitazoxanide

ADJUST DOSING INTERVAL: Food enhances the oral absorption and bioavailability of mefloquine. The proposed mechanism is increased drug solubility in the presence of food. In 20 healthy volunteers, administration of a single 750 mg oral dose of mefloquine 30 minutes following a high-fat meal increased the mean peak plasma concentration (Cmax) and area under the concentration-time curve (AUC) of mefloquine by 73% and 40%, respectively, compared to administration in the fasting state. The Cmax and AUC of the carboxylic acid metabolite were also increased by 35% and 33%, respectively, compared to fasting. In addition, the time to reach peak plasma concentration (Tmax) of mefloquine was significantly shorter after food intake (17 hours) than in the fasting state (36 hours). There was no difference in the elimination half-life of mefloquine and metabolite, or the Tmax for the metabolite.

MANAGEMENT: To ensure maximal oral absorption, mefloquine should be administered immediately after a meal with at least 8 ounces of water.

ADJUST DOSING INTERVAL: Food enhances the bioavailability of the pharmacologically active metabolite tizoxanide (desacetyl-nitazoxamide) from nitazoxanide administration. According to the product labeling, administration of nitazoxanide tablets with food increases the area under the plasma concentration-time curve (AUC) of tizoxanide and tizoxanide glucuronide in plasma by almost 2-fold and the peak plasma concentration (Cmax) by almost 50%. Administration of nitazoxanide oral suspension with food increases the AUC of tizoxanide and tizoxandie glucuronide by about 45% to 50% and the Cmax by less than 10%.

MANAGEMENT: Nitazoxanide tablets and oral suspension were administered with food in clinical trials and are recommended to be administered with food to ensure maximal drug levels in plasma.