ATC Group: C04A Peripheral vasodilators

Naftidrofuryl oxalate is a powerful vasodilator agent with an antagonist effect on 5-HT₂ receptors of the smooth muscle cells. The vasodilator effect, which occurs in both the cerebral and peripheral circulation, is probably the main action. It is claimed that this action protects cells against the metabolic effects of ischaemia.

Pentoxifylline has been shown to increase leukocyte deformability and to inhibit neutrophil adhesion and activation.

Phenoxybenzamine is a non competitive long acting α-adrenergic receptor antagonist.

Phentolamine is a competitive non-selective α₁- and α₂-adrenergic receptor blocker of relatively short duration of action. It causes vasodilatation and a fall in blood pressure resulting from the blockade of both post-junctional vascular α₁- and α₂-adrenoceptors. It also antagonises the vasoconstrictor response to noradrenaline and adrenaline infusions.

Niacin (nicotinic acid) is an essential B complex Vitamin (B₃), whose deficiency results in the clinical syndrome known as pellagra. Nicotinamide (niacinamide), the active ingredient, is the physiologically active form of niacin and is the chemical form of Vitamin B₃ found in virtually all multivitamin products. Though nicotinic acid and nicotinamide are so closely related chemically, they differ somewhat in pharmacological properties.