Methoxylated Flavones - Letairis (Ambrisentan) Interaction

Interaction Details

Ambrisentan is classified as belonging to the following category: P-Glycoprotein Substrates

In vitro evidence shows that some methoxylated flavones including tangeretin, nobiletin, and heptamethoxyflavone, inhibit P-glycoprotein. Theoretically, these methoxylated flavones might increase absorption and blood levels of drugs that are transported by P-glycoprotein.
Some of these drugs include some chemotherapeutic agents (daunorubicin, docetaxel, etoposide, paclitaxel, vinblastine, vincristine, vindesine), antifungals (ketoconazole, itraconazole), protease inhibitors (amprenavir, indinavir, nelfinavir, saquinavir), H2 antagonists (cimetidine, ranitidine), some calcium channel blockers (diltiazem, verapamil), corticosteroids, erythromycin, cisapride (Propulsid), fexofenadine (Allegra), cyclosporine, loperamide (Imodium), quinidine, and others.

Interaction Rating

Likelihood of Occurrence

Interaction has been documented in animal or in lab research, or the interaction has been documented in humans but is limited to case reports or conflicting clinical research exists

References

• Takanaga H, Ohnishi A, Yamada S, et al. Polymethoxylated flavones in orange juice are inhibitors of P-glycoprotein but not cytochrome P450 3A4. J Pharmacol Exp Ther 2000;293:230-6.
• Feng SL, Yuan ZW, Yao XJ, et al. Tangeretin, a citrus pentamethoxyflavone, antagonizes ABCB1-mediated multidrug resistance by inhibiting its transport function. Pharmacol Res 2016;110:193-204.

Interaction Details

Ambrisentan is classified as belonging to the following category: Cytochrome P450 3A4 (Cyp3A4) Substrates

In vitro evidence suggests that methoxylated flavones might inhibit cytochrome P450 3A4 (CYP3A4). This effect seems to be structure-dependent, and does not occur with all methoxylated flavones. So far this interaction has not been reported in humans. Theoretically, concurrent use of certain methoxylated flavones with drugs metabolized by CYP3A4 might result in increased drug levels and an increased risk for adverse effects.
Some drugs metabolized by CYP1A2 include clozapine (Clozaril), cyclobenzaprine (Flexeril), fluvoxamine (Luvox), haloperidol (Haldol), imipramine (Tofranil), mexiletine (Mexitil), olanzapine (Zyprexa), Pentazocine (Talwin), propranolol (Inderal), tacrine (Cognex), theophylline (Slo-bid, Theo-Dur, others), zileuton (Zyflo), Zolmitriptan (Zomig), and others.

Interaction Rating

Likelihood of Occurrence

Interaction has been documented in animal or in lab research, or the interaction has been documented in humans but is limited to case reports or conflicting clinical research exists

References

• Li Y, Ning J, Wang Y, et al. Drug interaction study of flavonoids toward CYP3A4 and their quantitative structure activity relationship (QSAR) analysis for predicting potential effects. Toxicol Lett. 2018 Sep 15;294:27-36.

Ambrisentan Overview

• Ambrisentan is used alone or in combination with tadalafil (Adcirca, Cialis) to treat pulmonary arterial hypertension (PAH, high blood pressure in the vessels that carry blood to the lungs). Ambrisentan may improve the ability to exercise and slow the worsening of symptoms in people with PAH. Ambrisentan is in a class of medications called endothelin receptor antagonists. It works by stopping the action of endothelin, a natural substance that causes blood vessels to narrow and prevents normal blood flow in people who have PAH.

Methoxylated Flavones - More Interactions

Methoxylated Flavones interacts with 845 drugs

Interaction Rating Key

These severity listings are for informational use only. Never start, stop or otherwise change your therapy before speaking with your provider.