Senna Quinidine

Albumin, aminophylline, aspirin, heparin, insulin, metoclopramide, NSAIDs, muromonab-CD3 (OKT3), opiates, penicillins, propafenone, quinidine, senna, sulfonamide antimicrobials, and vancomycin... 

Clinically important, potentially hazardous interactions with alprazolam, amiodarone, amphotericin B, arbutamine, bendroflumethiazide, benzthiazide, bisacodyl, bumetanide, carbimazole, chlorothiazide, chlorthalidone, cholestyramine, clarithromycin, conivaptan, cyclosporine, cyclothiazide, dan-shen, demeclocycline, devil s claw, dexmedetomidine, doxycycline, erythromycin, esomeprazole, ethacrynic acid, flunisolide, furosemide, ginseng, glycopyrrolate, glycopyrronium, hawthorn (fruit, leaf, flower extract), horsetail, hydrochlorothiazide, hydroflumethiazide, indapamide, licorice, lopinavir, mepenzolate, methyclothiazide, metolazone, minocycline, mistletoe, oxprenolol, oxytetracycline, paroxetine, phenylbutazone, polythiazide, propafenone, propantheline, quinethazone, quinidine, rabeprazole, rifampin, roxithromycin, sarsaparilla, senna, Siberian ginseng, squill, St John s wort, telithromycin, teriparatide, tetracycline, thiazide diuretics, tolvaptan, trichlormethiazide, verapamil... 

Quinidine plasma levels can be reduced by the anthraquinone laxative senna. 

A study in 7 patients with cardiac arrhythmias taking quinidine bisulfate 500 mg every 12 hours found that the anthraquinone laxative senna (Liquedepur) redueed plasma quinidine levels, measured 12 hours after the last dose of quinidine, by about 25%. This might be of clinical importance in patients whose plasma levels are barely adequate to control their arrhythmia. 

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