Comparison of the effect of diuretics on carotid blood flow in stroke patients

Objectives: Indapamide (IND) and bendroflumethiazide (BDZ) are both widely used in the management of blood pressure after stroke. There are theoretical reasons why these agents may differ with regard to their cardiovascular effects. We compared the effect of these agents on blood pressure and cerebral blood flow in a group of stroke patients. Methods: In a prospective, randomized, double-blinded study we investigated the effect of 28 days' treatment with BDZ 2.5 mg od or IND 2.5 mg od on blood pressure and cerebral blood flow in a group patients with recent first-ever ischemic stroke. Using extracranial carotid and transcranial ultrasound we assessed carotid blood flow and intracranial hemodynamics. Results: All data are expressed as mean (SD). Twenty-five patients completed the protocol (age 68.8 ± 10.6 y). Groups I (IND) and B (BDZ) comprised 13 and 12 patients, respectively. Groups were well matched for demography and baseline characteristics. Percent change in mean arterial pressure reduction from baseline was (I = - 14.7 ± 12.5, P < 0.001 vs. B = -7.7 ± 9.16 mm Hg, P = 0.02). There was a trend toward increased carotid blood flow in both groups (I = + 10% ± 47, P = 0.4 vs. B = +33% ± 47, P = 0.12). No significant change in middle cerebral artery mean flow velocity or pulsatility index was observed. There was no significant difference between the 2 drugs with regard to change in blood pressure (95% confidence interval for difference -2.5 to 16.3 mm Hg, P = 0.14) or carotid blood flow (95% confidence interval for difference -58 to 27 mL/s, P = 0.45). Conclusions: Both diuretics reduced blood pressure to a similar and significant degree. There was no evidence of an adverse effect on cerebral blood flow or intracranial hemodynamics induced by either agent. No significant difference between the effect of IND and BDZ was observed.