Nutritional Status Differentially Alters Cytochrome P450 3A4 (CYP3A4) and Uridine 5-Diphospho-Glucuronosyltransferase (UGT) Mediated Drug Metabolism: Effect of Short-Term Fasting and High Fat Diet on Midazolam Metabolism

Background and ObjectivesPrevious studies have shown that nutritional status can alter drug metabolism which may result in treatment failure or untoward side effects. This study assesses the effect of two nutritional conditions, short-term fasting, and a short-term high fat diet (HFD) on cytochrome P450 3A4 (CYP3A4) and uridine 5-diphospho-glucuronosyltransferase (UGT) mediated drug metabolism by studying the pharmacokinetics of midazolam and its main metabolites.MethodsIn a randomized-controlled cross-over trial, nine healthy subjects received a single intravenous administration of 0.015mg/kg midazolam after: (1) an overnight fast (control); (2) 36h of fasting; and (3) an overnight fast after 3days of a HFD consisting of 500ml of cream supplemented to their regular diet. Pharmacokinetic parameters were analyzed simultaneously using non-linear mixed-effects modeling.ResultsShort-term fasting increased CYP3A4-mediated midazolam clearance by 12% (p<0.01) and decreased UGT-mediated metabolism apparent 1-OH-midazolam clearance by 13% (p<0.01) by decreasing the ratio of clearance and the fraction metabolite formed (CL1-OH-MDZ/f(1-OH-MDZ)). Furthermore, short-term fasting decreased apparent clearance of 1-OH-midazolam-O-glucuronide (CL1-OH-MDZ-glucuronide/(f(1-OH-MDZ-glucuronide)xf(1-OH-MDZ))) by 20% (p<0.01). The HFD did not affect systemic clearance of midazolam or metabolites.ConclusionsShort-term fasting differentially alters midazolam metabolism by increasing CYP3A4-mediated metabolism but by decreasing UGT-mediated metabolism. In contrast, a short-term HFD did not affect systemic clearance of midazolam.