The Effects of Passiflora Syrup on The Blood and Tissue Concentrations of Fluoxetine in Rats

Objective: Interactions between medications and herbal supplements can lead to clinically unpredictable adverse effects. Fluoxetine, a commonly prescribed antidepressant, is highly susceptible to herbal-drug interactions due to its extensive metabolism via cytochrome P450 enzymes. This study aimed to investigate possible interactions between fluoxetine and passiflora, which are frequently used to treat anxiety and insomnia. Materials and Methods: Twelve male Wistar Albino rats, ages three to four months, were split into two experimental groups of six each: fluoxetine and passiflora (40 mg/kg and 1 mL/kg, respectively) and fluoxetine alone (40 mg/kg). Gavage was used to provide treatments orally. Results: Fluoxetine concentrations in kidney and brain tissues were significantly greater in the passiflora group, but there was no significant rise in blood or liver levels, according to high-performance liquid chromatography (HPLC) examination of blood and tissue samples taken at the conclusion of the experiment. Furthermore, concentrations of norfluoxetine, the active metabolite, were significantly increased in liver, kidney, and brain tissues in the passiflora group. These findings demonstrate that administration of passiflora significantly alters the tissue distribution profiles of fluoxetine and its active metabolite. Conclusion: Potential pharmacokinetic interactions and toxicity risks should be considered when using herbal supplements in combination with antidepressant medications.