Karl H. Beyer Jr. (1914–1996), Edward D. Freis (1912–2005)
The introduction of Diuril in 1958 was not only a major advance in the evolution of diuretics (drugs that promote the flow of urine), but also, and far more significantly, it revolutionized the treatment of hypertension. Before Diuril, organic mercury-containing diuretics were the most effective drugs for the elimination of excessive body fluids, but their use required injections and was associated with severe toxicity. In addition, the treatment of hypertension was limited to severe cases, and all the available drugs produced a high incidence of undesirable side effects at their usual doses.
Karl Beyer at Merck, Sharp & Dohme (MSD), sought to develop a safe, orally effective diuretic that could reduce fluids in heart failure and edema, and he initially envisioned Diuril (chlorothiazide) to be that drug. Rather unexpectedly, clinical studies revealed that it not only reduced edema but also decreased blood pressure. Older drugs decreased blood pressure in all patients, but Diuril only did so in hypertensive patients. It was a specific antihypertensive drug.
Not surprisingly, the thrust of MSD’s marketing campaign expanded beyond diuresis and focused on Diuril’s antihypertensive effects, a far more lucrative market. Many articles proclaimed Diuril to be the biggest medical breakthrough in recent years.
QUIETING THE SILENT KILLER. Until the 1950s, only “severe” hypertension was treated, as medical experts were divided as to whether “mild” hypertension—present but without discernable symptoms—should be. Unlike older antihypertensives, Diuril could be used safely, with little risk to the patient, which shifted the tide toward routine drug treatment of mild hypertension. By 1970, hypertension researcher Edward Freis, conducting nationwide studies in Veterans Administration hospitals, demonstrated that treatment of even mild-to-moderate hypertension significantly reduced the risk of heart attack, heart failure, stroke, and other complications of hypertension.
Today, Diuril-like thiazides and related diuretics, used alone or in combination with other antihypertensives, are the most commonly used drugs for the treatment of elevated blood pressure.
SEE ALSO Merbaphen (1920), Sulfanilamide (1936), Diamox (1952), Propranolol (1964), Lasix (1966), Captopril (1981).
Diuril promotes the elimination of excessive water and salt. The first step in this process is the filtration of blood by the kidney, involving the passage of blood through the glomerulus. The human glomerulus, magnified here 100x, resembles tiny tubules.