Drugs antagonism

A consideration of the more striking examples of specific drug antagonisms shows that these in many cases follow recognizable laws, both in the case of enzymes and cells. 

Bradley, P. B., and Briggs, 1.(1974) Further studies on the mode of action of psychotomimetic drugs Antagonism of the excitatory action of 5-hydroxytryptamine by methylated derivatives of tryptamine. Br. J. Pharmacol., 50 345-354. 

Leach, G.D.H. (1956). Estimation of drug antagonisms in the isolated guinea pig vas deferens. J. Pharm. Pharmacol. 8 501. 

The coadministration of methenamine with certain sulfonamides (sulfamethizole or sulfathiazole) can form a urine precipitate resulting in drug antagonism. 

On receptor basis, drug antagonism will be of two types competitive and noncompetitive antagonism. 

Atropine like drugs antagonize the rigidity and akinesia and cause reduction in the intensity of tremors. They act by reducing the unbalanced cholinergic activity in parkinsonism. Benzhexol is most commonly used and effective drug among the atropine substitutes used in parkinsonism. 

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