Reduces the effectiveness of indirect anticoagulants (fenprokumona, warfarin), imatinib and other cytostatics, midazolam, digoxin, amitriptyline, fexofenadine, benzodiazepines, nortriptyline, theophylline, methadone, verapamil, simvastatin, finasteride.
When taken concomitantly with certain antidepressants, such as nefazodone, paroxetine, sertraline, buspirone, tryptans may enhance their action (with such symptoms as nausea, vomiting, fear, anxiety, confusion).
The drug is able to enhance the photosensitizing effect of several other drugs: tetracyclines, sulfonamides, thiazide diuretics, quinolones, piroxicam.
Lengthens sleep caused by drugs for general anesthesia and narcotic analgesics, but shortens sleep caused by barbiturates.
Reduces the hypotensive effect of reserpine.
Reduces the concentration of cyclosporine in the blood.
St. John's wort cuts down the concentration in the blood and the effectiveness of indinavir therapy.
With simultaneous use with ethinyl estradiol and desogestrel, the risk of bleeding "breakthrough" increases.
Increases the metabolic rate of theophylline.
Reducing the concentration in the blood of digoxin, reduces its effectiveness.
For women taking oral contraceptives, additional contraceptive methods should be used during treatment with the drug.