A-Sympatholytics

C. Trimethaphan is a ganglionic blocking agent that will lower blood pressure very rapidly. Hydralazine is a vasodilator hydrochlorothiazide and spironolactone are diuretics and methyldopa is a sympatholytic acting in the central nervous system. All of these drugs are used clinically as antihypertensive agents. None work as rapidly as trimethaphan. Clinically, however, either nitroprusside or clonidine is used much more commonly than trimethaphan in this situation. 

The antiarrythmic drug amiodarone inhibits reserpine binding in a concentration-dependent manner and has a sympatholytic, anti-adrenergic effect in the heart, inhibiting the uptake of norepinephrine (Haikerwal et al., 1999). Blockers of VMAT and L-type calcium channels have also been reported to exert reciprocal inhibitory actions (Mahata et al., 1996). 

A variety of thiochromans possess biological activity. For example, 7-sulfamoylthiochroman 1,1-dioxides are effective diuretics ° thiochroman-6-acetic acids possess antiinflammatory, antipyretic, and analgesic activity phenethylamines from the Mannich reaction on thiochroman-4-ones are a-sympatholytic and antidepressant 4-substituted aminothiochromans are active as antihypertensives, as antidepressants, and as agents against angina pains " 3,3-dibromo-6-halothiochroman-4-one S-oxides exhibit antitumor characteristics substituted 4-phenylthiochroman-4-ols have been prepared... 

THERAPEUTIC USES Minoxidil is reserved for the treatment of severe hypertension that responds poorly to other antihypertensive medications, especially in male patients with renal insufficiency. Minoxidil must be given concurrently with a diuretic to avoid fluid retention and with a sympatholytic drug (usually a fi receptor antagonist) to control reflex cardiovascular effects. The drug usually is administered either once or twice a day, but some patients may require more frequent dosing for adequate control of blood pressure. The initial daily dose of minoxidil may be as little as 1.25 mg, which can be increased gradually to 40 mg in one or two daily doses. 

Stepped care in hypertension Progressive addition of drugs to a regimen, starting with one (usually a diuretic) and adding in stepwise fashion a sympatholytic, a vasodilator, and (sometimes) an ACE inhibitor... 

Paris RR, Moyse-Mignon H 1953 A sympatholytic Apocynaceae, Vinca rosea. C R Acad Sci 240 1993-1995... 

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