Category: 02. Drugs Acting On Autonomic Nervous System

The b – adrenergic receptor blocking drugs in use may be classified by their selectivity for receptors in different tissues. Drugs blocking all the b receptor effects of adrenaline (non-selective beta blockers) e.g. propanalol, pinadolol, timolol etc Drugs blocking mainly the b1 effects (those on the heart) with less effect on the bronchi and blood…

Adrenergic receptor blockers may be considered in two groups: Drugs blocking the ą adrenergic receptor Drugs blocking the b Adrenergic receptor These drugs prevent the response of effectors organs to adrenaline, noradrenaline and other sympathomimetic amines whether released in the body or injected. Circulating catecholamines are antagonized more readily than are the effects of sympathetic…

Most of the non- catecholamines function by releasing the physiologic catecholamines from the postganglionic nerve endings EPHEDRINE Pharmacokinetics Ephedrine in absorbed from the gastrointestinal tract and from all parenteral sites. It has a good distribution through out the body and is resistant to hydrolysis by the liver enzymes. Major proportion of the drug is excreted…

Nor adrenaline is the neurochemical mediator released by nerve impulses and various drugs from the postganglionic adrenergic nerves. It also constitutes 20% of the adrenal medulla catecholamine out put. Pharmacokinetics Like adrenaline, noradrenaline is ineffective orally so it has to be given intravenously with caution. It is not given subcutaneous or intramuscularly because of its…

This is the prototype of adrenergic drugs and is produced in the body by the cells of the Adrenal medulla and by chromaffin tissues. Pharmacokinetics Adrenaline is rapidly destroyed in the gastrointestinal tract, conjugated, and oxidized in the liver. It is therefore ineffective when given orally and should be given intramuscularly or subcutaneous. Intravenous injection…

As their name suggests, these drugs resemble sympathetic nerve stimulation in their effects; they may be divided into two groups on the basics of their chemical structure. 1. Catecholamines: -these are compounds which have the catechol nucleus. Catecholamines have a direct action on sympathetic effectors cells through interactions with receptor sites on the cell membrane.…

There are a number of synthetic atropine derivatives, which are used in the treatment of various conditions, their actions are similar to that of atropine but have fewer side effects. These groups of drugs include Mydriatic atropine substitutes, this group of drugs have shorter duration of action than atropine and are used locally in the…

This drug has the same effect as atropine except for some differences which includes:- It has shorter duration of action It is more depressant to the CNS. All other properties are similar to atropine. It has certain advantage over atropine. These include: Better for preanesthetic medication because of strong antisecretory and antiemetic action and also…

Atropine is found in the plant Atropa belladonna and it is the prototype of muscarinic antagonists. Pharmacokinetics Atropine is absorbed completely from all sites of administration except from the skin wall, where absorption is for limited extent; it has good distribution. About 60% of the drug is excreted unchanged in urine. Pharmacodynamics Atropine antagonizes the…

Anticholinergics block the effects of acetylcholine and other cholinergic drugs at cholinergic receptors of effector cells. Anticholinergics fall into two major families: Antinicotinics which include ganglion blockers such as hexamethonium, trimethaphan, etc., and neuromuscular blockers such as gallamine, tubocurarine, pancuronium, etc. Antimuscarinics include tertiary amines such as atropine, scopolamine, tropicamide, etc, andquaternary amines such as…