Loperamide Didanosine

Drugs that may affect tipranavir include aluminum- and magnesium-based antacids, azole antifungals, clarithromycin, efavirenz, loperamide, NRTIs (ie, didanosine, zidovudine), rifamycins (rifampin), St. John s wort, tenofovir. 

Loperamide and metoclopramide do not appear to aiter didanosine pharmacokinetics. 

In 6 men and 6 women who were HIV-positive, the pharmacokinetics of oral buffered didanosine 300 mg were not altered to a clinically relevant extent by 4 mg of loperamide, given 19,13,7 and 1 hour before the didanosine. The rate of didanosine absorption was slightly decreased but the extent of absorption was unchanged. Similarly, the pharmacokinetics of oral buffered didanosine 300 mg were found to be unaffected by 10 mg of intravenous metoclopramide. It appears that neither delaying nor accelerating gastrointestinal transit time appreciably alters the pharmacokinetics of didanosine, which is acid labile. On the basis of this study the authors conclude that neither the dose nor the frequency of didanosine administration need be altered if either loperamide or metoclopramide is given concurrently. ... 

Knupp CA, Milbrath RL, Barbhaiya RH. Effect of metoclopramide and loperamide on the pharmacokinetics of didanosine in HIV seropositive asymptomatic male and female patients. Eur J Clin Pharmacol (1993) 45, 409-13. 

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