Quinidine is an antimalarial schizonticide and an antiarrhythmic agent with Class la activity; it is the d-isomer of quinine, and its molecular weight is 324.43. Quinidine sulfate (quinidine sulfate (quinidine sulfate (quinidine sulfate tablet, film coated, extended release) tablet, film coated, extended release) tablet, film coated, extended release) is the sulfate salt of quinidine; its chemical name is cinchonan-9-ol, 6'-methoxy-, (9S)-, sulfate (2:1) (salt) dihydrate; its molecular weight is 782.94, of which 82.9% is quinidine base; and it has the following structural formula:

(C₂₀H₂₄N₂0₂)₂•H₂S0₄•2H₂0        M.W. 782.94

Each Quinidine Sulfate Extended-release Tablet contains 300 mg of quinidine sulfate (quinidine sulfate (quinidine sulfate (quinidine sulfate tablet, film coated, extended release) tablet, film coated, extended release) tablet, film coated, extended release) (249 mg of quinidine base) in a formulation to provide extended release; the inactive ingredients are: fumaric acid, hypromellose, lactose monohydrate, magnesium stearate, polydextrose, polyethylene glycol, povidone, triacetin and titanium dioxide.

These tablets comply with USP Drug Release Test 1.

Last reviewed on RxList: 12/29/2008
This monograph has been modified to include the generic and brand name in many instances.