MEDICINAL CHEMISTRY

Preparatio: Disopyramide Capsules, B.P.Proprietary Name: REGUBEAT FORTE
Disopyramide Phosphate, B.P. 4-Diisopropy lam ino-2-phenyl-2-(2-pyridyl)
butyramide dihydrogen orthophosphate. It is a white powder which is soluble in
water. Disopyramide is readily and almost completely absorbed from the
gastrointestinal tract. The major metabolite is mono-N-dealkylated disopyramide which
retains some antiarrhythmic and antimuscarinic activity. Disopyramide is mainly used for
the prevention and treatment of ventricular arrhythmias. It is also used for the treatment
of supraventricular arrhythmias. It may be given by mouth as either the base or the
phosphate, the dose being generally expressed in terms of the base. A dose of 100 to
150 mg is given every 6 hours adjusted according to the patient's response.
Preparation: Disopyramide Phosphate Capsules, B.P.Proprietary Names: NAPAMIDE;
NORPACE; RYTHMODAN
7. Anti-hyperlipidemic Agents
Introduction
The pharmacological agents which reduce the concentration of plasma lipids are called
hypocholesterolemic agents or antihyperlipidemic agents or lipid Lowering Agents.
An increase in plasmalipids, particularly cholesterol, is a common feature of
atherosclerosis, a condition involving arterial damage, which may lead to ischaemic heart
diseases myocardial infarction and cerebral vascular accidents. These conditions are
responsible for one third of all deaths from disease in industrial nations. Lipids are
insoluble in water, and they are transported in the plasma as lipoproteins. An increase in
the plasma concentration of these substances is termed hyperlipidemia (or
hyperlipoproteinaeinia).
Lipoproteins consist of a central core of hydrophobic lipid (triglycerides or cholesteryl
esters) encased in a more hydrophilic coat of polar substances-phospholipids, free
cholesterol and associated proteins (apoproteins). There are four main classes of
lipoprotein, differing in the relative proportion of the core lipids and in the type of
apoprotein.
(i) High Density Lipoproteins (HDL): This is a group of heterogeneous
lipoproteins having low lipid content. A further subclassification in HDL is based upon
density value of these particles. HDL apparently enhances the removal of cholesterol
from the arterial wall. Hence chances of development of atherosclerotic lesions are more
when HDL value falls below normal. While the elevated levels of VLDL, IDL and LDL
are always correlated with increased risk of atherosclerosis.
(ii) Very low density lipoproteins (VLDL): These are globular particles synthesized
in the liver having diameter of 30-80 nm. They contain apoproteins B, C and E. They are
involved in the transport of endogenous lipid from liver to the plasma.