Ivermectin bioavailability

Following the oral administration of ivermectin, peak plasma concentration is achieved in four hours. Ivermectin is absorbed well on an empty stomach. The bioavailability is 50 to 60%. It is mainly metabolized in the liver and the tissue concentration is maximum in liver and fat. Ivermectin and its metabolites are excreted mainly in faeces. 

Edwards G, Dingsdale A, Helsby N, Orme MLE, Breckenridge AM. The relative stemic bioavailability of ivermectin after administration as capsule, tablet, and oral solution. EurJ Clin Pharmacol( 9ZZ) 35,681. ... 

The manufacturer notes that the bioavailability of ivermectin 30 mg was increased by about 2.5-fold when it was taken after a high-fat meal (48.6 g of fat) when compared with the fasted state. They recommend that ivermectin is taken on a empty stomach with water. ... 

Levamisole may markedly increase the bioavailability of ivermectin. Ivermectin does not alter the pharmacokinetics of levamisole. 

Orange juice modestly reduces the bioavailability of ivermectin. 

A study in 16 healthy subjects found that the AUC and peak plasma levels of a single 150-micrograms/kg dose of ivermectin were reduced by 36% and 39%, respectively, when the ivermectin was given with orange juice (750 mL over 4 hours) rather than with water. The mechanism for the reduced bioavailability is not known but it does not seem related to P-glyc-oprotein activity. The clinical relevance of these changes is uncertain. 

Vanapalli SR, Chen Y, Ellingrod VL, Kitzman D, Lee Y, Hohl RJ, Fleckenstein L. Orai e juice decreases the oral bioavailability of ivermectin in healthy volunteers. Clin Pharmacol... 

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