In hypertension the usual dose is 50 mg once daily. The maximum effect is achieved in about 3 to 6 weeks after initiating treatment. The dose may be increased, if necessary to 100 mg daily in one or two divided doses. An initial dose of 25 mg once daily is suggested for the elderly over 75 years-of-age, and for patients with moderate to severe renal impairment (creatinine clearance less than 20 mL per minute), or intravascular fluid depletion. A reduced dose should also be considered for patients with hepatic impairment.