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Monthly Archives: January 2011

Local Anesthetics

Local anesthetics(LA) are drugs which have following features: 1. Used for topical application or local injection. 2. Cause reversible loss of sensory perception in a restricted area of the body. 3. Prevent generation and propagation of nerve action potential at all parts of the neuron where they come in contact, …

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Ganglionic Blockers

Acetyicholine is the neurotransmitter in both sympathetic and parasympathetic ganglia. Transmission through autonomic Ganglionic is complex. Both types of cholinergic receptors are present at postganglionic neurone cell bodies. Acetylcholine, released from preganglionic fibres, produces a series of changes as follows: The primary event is that acetyicholine acts on postsynaptic nicotinic …

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Adrenoceptor

Adrenoceptor blocking agents or adrenoceptor antagonists are drugs that inhibit responses mediated by Adrenoceptor activation caused by epinephrine and related drugs. They also block (less completely) effects of adrenergic nerve stimulation. On the other hand, adrenergic neurone blocking drugs act on adrenergic neuronal membrane or contents and block (more completely) …

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Adrenergic Agonists

Drugs which produce effects similar to those of adrenergic nerve stimulation or injection of epinephrine are known as sympathomimetics or Adrenergic Agonists. Before considering Adrenergic Agonists drugs, an account of the physiology of adrenergic nerves would be helpful. Biosynthesis of Adrenergic Agonists: The varicosities (terminal swollen areas) of the adrenergic …

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Anticholinergic Drugs

Anticholinergic Drugs selectively reduce or abolish the muscarinic receptor mediated effects of acetyicholine and parasympathetic stimulation. So Anticholinergic Drugs are also called antimuscarinic or parasympatholytic agents. Anticholinergic Drugs drugs inhibit the actions of endogenous acetylcholine and muscarinic agonists at muscarinic receptor sites in peripheral tissues and in the central nervous …

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Cholinergic Agonists

Acetyicholine is a physiological neurotransmitter which acts on both muscarinic and nicotinic receptors. It is not useful as a drug being non-specific and having short duration of action. So such compounds have been developed which are more selective and have longer duration of action than acetylcholine. Drugs, which combine with …

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Autonomous nervous system

Autonomous nervous system (ANS) is divided into sympathetic (adrenergic) and parasympathetic (cholinergic) divisions. Autonomous nervous system maintains homeostasis by integrating with sensory, somatomotor, endocrinal, metabolic, immunological and emotional activities. The limbic system and hypothalamus coordinate autonomic reactions with emotions. Anteromedial and posterolateral nuclei of hypothalamus are associated with cholinergic and …

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Parkinsonism

Parkinsonismis characterized by rigidity, bradykinesia, tremors and postural instability. It is usually idiopathic but can also occur by a wide variety of reasons. It may have genetic background. Idiopathic disorder may be due to exposure to some unrecognized or neurotoxin or to the occurrence of oxidation reactions with the generation …

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Psychostimulants

Psychostimulants: This group includes amphetamine, congeners of amphetamine and cocaine. They have no clinical utility. They are only drugs of abuse. Psychostimulants cause: (1) elevation of mood (euphoria); (2) a sense of increased self- esteem; (3) physical and mental well-being; (4) decreased appetite, and (5) sleep. Chronic use of Psychostimulants …

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Tricyclic antidepressant

Tricyclic Antidepressant effect of these drugs depends on their effect on biogenic amine neurotransmitters: 1. Imipramine, clomipramine, amitriptyline and doxepin are Tricyclic Antidepressant. They block the amines norepinephrine (NE) or serotonin reuptake pumps and permit a longer sojourn of neurotransmitter at the receptor site. They also bind to c— adrenergic, …

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