Neuron blocking agents, adrenergic

The treatment of hypertension by compounds which affect adrenergic neuron transmission has been the main form of therapy for many years. Consequently there are a large number of available drugs in the physician s armamentarium, but only one compound causes hypersensitivity problems - methyldopa. The Swedish Advisory Drug Reactions Committee analyzed 308 patients on methyldopa therapy between 1966 and 1975 and listed the adverse effects associated with methyldopa as shown in Table 1 (Notice from the Swedish Adverse Drug Reaction 1977). 

Other hematological effects including positive Coombs test 11 

It can be seen that 23 patients were reported as experiencing some type of allergic reaction, but it is likely that fever, hemolysis, and certain of the hepatic effects may also have an immunological basis. 

Fever is known to occur in about 3% of all cases treated (Robinson 1978) but it is not a typical hypersensitivity fever. It usually runs a relapsing course with night sweats and often subsides despite continued treatment it is also evident only during the first week of treatment. 

Hemolytic anemia is a rare complication occurring in about 0.5%-3% of cases. A number of such cases have been reported (Mehrotra and Gupta 1971 Kessey et al. 1973 Inzoli and Almici 1973). 

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The answers are 321-cT 322-e, 323-i. (Hardman, pp 238-239, 791.) Reserpine is an adrenergic neuronal blocking agent that causes depletion of central and peripheral stores of NE and dopamine Reserpine acts by irreversibly inhibiting the magnesium-dependent ATP transport process that functions as a carrier for biogenic amines from the cytoplasm... 

An excellent review of the pharmacological actions of adrenergic neurone blocking agents has been given by Boura and Green [10]. The biochemistry of guanethidine itself has been reviewed by Furst [11], with particular emphasis on tissue distribution and metabolism consequently these two topics are not discussed in detail. 

Quaternary ammonium analogues of the 5-chloro and 5- and 6-methyl substituted guanidines were inactive as adrenergic neurone blocking agents... 

The bicyclic amidoximes (LXIV) and (LXV) cause a reduction in blood pressure in various animal species, but apparently they are not adrenergic neurone blocking agents [270]. The activity of (LXIV)i thought to be mainly due to catecholamine release and subsequent depletion, whilst the action of (LXV) involves blockade at a-receptors [270]. 

The dimethylguanidine (LXVII, R = R = Me) causes vasodilatation but lowers blood pressure as a consequence of adrenergic neurone blockade [278]. Apparently, the related imidazoline (LXVIII) is not an adrenergic neurone blocking agent but a hypotensive, which acts by vasodilatation and blockade of a-receptors [279]. 

The tetrahydrobenzazepine (LXIX) related to debrisoquine (LXVII) is reported to be a potent adrenergic neurone blocking agent (three-fifths as potent as guanethidine in anaesthetized cats) [280]. Marked sympathomimetic activity is not associated with (LXIX) and in this respect it is similar to the hexahydrobenzazo-... 

Tricyclic antidepressants potentiate the pressor effects of directly acting sympathomimetic amines, such as adrenaline (epinephrine) or noradrenaline (norepinephrine), to cause hypertension. Small amounts of these, such as may be present in local anaesthetic solutions, can be dangerous. Tricyclic antidepressants will inhibit the antihypertensive effects of the older anti hypertensive drugs, such as adrenergic neurone-blocking agents, e.g. guanethidine, a-methyl-DOPA, and clonidine. 

The exact mechanism of this peripheral adrenergic neuron blocking agent is not well defined. Reserpine administration results in depleted stores of norepinephrine, dopamine, and serotonin in multiple organs. The decreased peripheral resistance and cardiac output that results is manifested as a decrease in blood pressure. A central nervous system (CNS) effect may also play a role in decreasing blood... 

Bretylate > bretylium tosylate. bretylium tosylate [ban, inn, usan] (BretyloP Bretylate ) is a quaternary ammonium ANTISYMPATHETIC and ADRENERGIC NEURON BLOCKING AGENT used as an ANTIHYPERTENSIVE and (class III) ANTI ARRHYTHMIC. Bretylol bretylium tosylate. 

Activities and sites of antinociceptive action of morphine-like analgesics. 6, 79 Adrenergic neurone blocking agents, 1, 161 Advances in penicillin research, 7, 1... 

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