Benzodiazepines Fexofenadine and St Johns Wort

Benzodiazepines alprazolam and midazolam are metabolized by CYP3A4. Although short-term ingestion of St. John's wort (900 mg/day for 1-3 days) does not alter the pharmacokinetics of alprazolam and midazolam in healthy volunteers, long-term ingestion (900 mg/day for 2 weeks) significantly increased oral clearance of midazolam and decreased oral bioavailability by 39.3% (44). Fexofenadine is a non-sedating antihistamine. A single dose of St. John's wort (900mg) significantly increased the maximum plasma concentration of fexofenadine by 45% and significantly decreased the oral clearance by 20% without any significant change in half-life or renal clearance. However, long-term use of St. John's wort (2 weeks) caused a significant decrease of 35% in maximum plasma concentration and a significant increase (47%) in oral clearance. This is probably due to inhibition of intestinal P-glycoprotein when a single dose of St. John's wort was given, but a long-term use reversed the changes in fexofenadine disposition (45).

Anxiety and Depression 101

Anxiety and Depression 101

Everything you ever wanted to know about. We have been discussing depression and anxiety and how different information that is out on the market only seems to target one particular cure for these two common conditions that seem to walk hand in hand.

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