MEDICINAL CHEMISTRY

Cl
Cl
CH2CH=CH2 N
N
N
H
Alinidine (174)
N
HOH 2C
N
OH
NH 2
O
OH
N
N
Adenosine (175)
Official Drugs:
Quinidine Sulphate, B.P., I.P. Quinidine sulphate is the dihydrate of (8R,9S)-6'-
methoxycinchonan-9-ol sulphate. Quinidine sulphate forms white, needle-like crystals.
It is sparingly soluble in water. Quinidine is rapidly absorbed from the gastrointestinal
tract, peak plasma concentrations being achieved about 1.5 hours after oral administration
of quinidine sulphate. Quinidine and its salts are used to maintain sinus
rhythm after cardioversion of atrial fibrillation, and for the prevention and treatment of
supraventricular and ventricular arrhythmias. However, other drugs are generally
preferred. Quinidine may be used, as an alternative to quinine in the treatment of
malaria when quinine is not immediately available. In the prophylaxis of cardiac
arrhythmias the oral dose is 0.2 g three or four times daily. In the treatment of atrial
fibrillation, 0.2 to 0.4 g dose is given every two to four hours to a total dose of 3 g
daily.
PreparationI: Quinidine Tablets, (Quinidine Sulphate Tablets, B.P.) Proprietary Name:
CIN-QUIN
Procainamide Hydrochloride, B.P., I.P. 4- Am i no-N-(2-d iethy lam inoethy
I)benzamide hydrochloride. Procainamide may be prepared by interaction between pnitrobenzoyl
chloride and NN-diethylethylenediamine, followed by catalytic reduction
of the nitro group of the product. Procainamide hydrochloride occurs as a white to
yellowish-white crystalline powder. It is hygroscopic. It is very soluble in water.
Procainamide hydrochloride is given for the treatment of ventricular arrhythmias
particularly those which are resistant to lignocaine and those following myocardial
infarction. It is also employed to maintain sinus rhythm after cardio version of atrial
fibrillation and has been used for prevention of supraventricular and ventricular
arrhythmias. In case oral route is not suitable procainamide hydrochloride may be given
intramuscularly. The dose is stated to be 0.5 to 1.5 g.
Preparations: p rocainamide Injection, B.P., I.P. Procainamide Tablets, B.P. Proprietary
Names: PROCAINAMIDE DURULES; PRONESTYL
Disopyramide, B.P. 4-Diisopropylamino-2- phenyl-2-(2-pyridyl)butyramide. It is a
white powder, which is slightly soluble in water.
CH