This study analysed the effect of low doses ofverapamil added to chronic treatment withangiotensin-converting enzyme (ACE) inhibitors onblood pressure and serum creatinine levels in eightelderly hypertensive patients who had a steadyincrease of serum creatinine while on ACE inhibitors.The study was performed in eight elderly hypertensivesubjects, five men and three women (mean age 70 ±2 years; systolic blood pressure 173 ± 4 mmHg; diastolic blood pressure 99 ± 1 mm Hg) andserum creatinine of 1.60 ± 0.27 mg/dl beforetreatment. During an average of 25 weeks, ACEinhibitors significantly reduced both systolic anddiastolic blood pressures, but serum creatinine levelswere increased over basal levels (0,68 ± 0,20 mg/dl, p < 0.05). During an average of 10 weeks,the addition of verapamil did not decrease bloodpressure further, but serum creatinine levels werereduced to baseline. Our study suggests that theaddition of verapamil to ACE inhibitors can reverseACE-induced increase in creatinine levels in elderlyhypertensive patients in whom this side effect isobserved.