Analysis of the available evidence indicates that
diuretics do not increase
coronary heart disease morbidity and mortality. The multiclinic trials supporting the
cardiotoxicity hypothesis are few in number and flawed in design. The majority of the trials, including the well designed trials, indicate no excess of
coronary heart disease (CHD) events in
diuretic-treated patients compared with those given other drugs or placebo. Recent studies indicate no increase in
cardiac arrhythmias after
diuretic treatment. Also, although depletion of intracellular
potassium and
magnesium occurs in patients with
congestive heart failure even without
diuretics, intracellular concentration of these
ions is not significantly reduced by
diuretics in patients with uncomplicated
hypertension. Modest elevations of serum
cholesterol may occur during the first 6 to 12 months of treatment with
thiazide diuretics. However, after this time these elevations fall to or below the pretreatment level. The fall may be greater in patients receiving other drugs but the differences are small and their clinical significance is questionable. The incidences of hyperglycaemia and diabetes were only minimally increased in long term clinical trials while the importance of
hyperinsulinism and
insulin resistance in causing CHD remains unproven in patients.
Thiazides remain, therefore, a safe and effective treatment for patients with
hypertension.