Because no information is available on the use of lisinopril during breastfeeding, an alternate drug may be preferred, especially while nursing a newborn or preterm infant.

Hydrochlorothiazide doses of 50 mg daily or less are acceptable during lactation. Intense diuresis with large doses may decrease breastmilk production.

The main objective of this multicenter study was to compare the efficacy of an increase in dose and of a synergic combination in the 68 patients out of 126 (54%) with hypertension (DBP between 95 and 120 mm Hg after 2 weeks of placebo) who did not respond (DBP > or = 95 mmHg) to a 4-week treatment of 20 mg per day of lisinopril. Patients were randomized to receive a 4-week double-blind treatment of either 40 mg per day of lisinopril or the combination of 20 mg of lisinopril and 12.5 mg of hydrochlorothiazide per day. Mean reductions of systolic (inter-group comparison: p = 0.08) and diastolic BP (p = 0.006) as well as the proportion of responders (82% versus 45%, p < or = 0.01) were greater with the lisinopril-hydrochlorothiazide combination than with 40 mg of lisinopril. Tolerance was good in the 3 groups. The administration of a synergic combination is justified when hypertension is not controlled by a monotherapy.