Karl Beyer Creates Cholorothiazide (Diuril) to Lower Blood Pressure

The most important breakthrough in the history of the drug treatment of hypertension came with the discovery of the orally effective diuretic, chlorothiazide.

The thiazide diuretics were discovered by Beyer and Sprague. In hypertensive patients chlorothiazide was effective in reducing BP and produced the same volume changes as the strict low-salt diet. Furthermore, the drug was much more acceptable to the patients than a strict diet.

The other drug, a thiazide diuretic marketed as Diuril, helped millions of people, and was the first in a new class of drugs that is well established in the treatment of cardiovascular and other diseases. Previous treatments for hypertension were inefficient and had serious side effects -- in effect, poisoning the kidneys. Dr. Beyer's discovery reduced blood pressure more safely and eliminated the hypertension.

Karl Beyer, a research chemist, tried several variations of the sulfonamide formula and developed Diuril (chlorothiazide). It proved to be safer and more effective in reducing edema and it also lowered blood pressure in hypertensive patients without evidence of significant fluid retention. Diuril and other thiazide diuretics like Hydrodiuril and Hygroton quickly became the treatment of choice for hypertension. Support for their use came from animal studies showing a correlation between increased sodium content of arterial vessels and elevated blood pressure.