MEDICINAL CHEMISTRY

NH
ClCH 2CN
NCH 2CN
Perhydroazocine (71) an intermediate (72)
Guanethidine (72)
Catalytic
Reduction
CH 3S-C
NH
NH 2
S-methylisothiourea
N CH 2CH 2NH 2
1-(2-Aminoethyl)perhydroazocine
(73)
Official Drugs
Reserpine B.P., I.P. Methyl 11,17a-dimethoxy- I 8β-(3, 4, 5- trimethoxybenzoyloxy)
-3β, 20α- yohimbane- 16β-carboxylate. Reserpine forms white or pale buff to slightly
yellowish, crystalline powder. It is practically insoluble in water. Reserpine is absorbed
from the gastrointestinal tract. Reserpine is metabolized by the liver and intestine to
methyl reserpate and 3, 4, 5-trimethoxybenzoic acid.
Reserpine is used in mild to moderate hypertension. It has been used in chronic
psychoses. In psychiatric states 1 to 5 mg daily, in divided doses, are given orally, and
in the treatment of hypertension the dose is 0.5 mg daily. Reserpine has also been
given by intravenous and intramuscular injection.
Preparations: Reserpine Injection, I.P. Reserpine Tablets, I.P. Proprietary Name:
SERPASIL
Guanethidine Sulphate, I. P. Guanethidine Monosulphate, B.P. 1-[2-
(Perhydroazocin-1-yl)-ethyl guanidine sulphate. It may be prepared by interaction of 1-(2aminoethyl)
perhydroazocine with S-methyl isothiourea and conversion of the product to
the sulphate. Guanethidine sulphate is a white or almost white, crystalline powder. It is
freely soluble in water. Guanethidine is variably and incompletely absorbed from the
gastrointestinal tract with less than 50% of the dose reaching the systemic circulation. It
is excreted in the urine as metabolites and unchanged drug. It has a terminal half-life
of about 5 days.
Guanethidine sulphate is used in the treatment of hypertension when other drugs have
proved inadequate. Initial dose is 10 to 20 mg daily with the subsequent doses,
increasing at week intervals to a maximum of 300 mg daily, is accordance with the
need of the patient.
Preparation: Guanethidine Tablets, B.P, I..P. Proprietary Name: ISMELIN
A(6). Gaglionic Blocking Agents