In hypertension, peripheral vasodilators should be used first, but diuretics may be added if blood pressure control is not adequate in the presence of excessive edema. This also applies to toxemia. Studies of diuretics for preventing toxemia and improving fetal survival in hypertension, excessive edema or proteinuria have been conflicting, as is the evidence for improved fetal survival. Where a woman has been well established on a thiazide diuretic for hypertension prior to pregnancy, its withdrawal may not be necessary. As thiazides increase blood uric acid concentration, levels should be taken before and during pregnancy but their value in assessing the onset of toxemia may still be lost.
Chlorthalidone appears in breast milk.
If use of the drug is deemed essential, the patient should stop nursing. The hypokalemic effects of diuretics may be increased by corticosteroids, ACTH and amphotericin. Thiazides may increase the responsiveness to curare derivatives and ganglionic blocking agents. In those rare instances when these drugs must be given together, patients should be observed closely for signs and symptoms of lithium toxicity. Close monitoring of serum electrolytes and lithium concentrations and maintenance of adequate fluid, potassium and sodium intake are also necessary.