Efficacy and safety of doxazosin GITS in hypertensive renal transplant patients: comparison of 8 and 4 mg

Abstract

Background Hypertension (HT), a prevalent complication in renal transplant patient (RT), must be accurately treated because cardiovascular disease is the leading cause of death and of chronic graft dysfunction. Sympathetic activity may contribute to HT in RT, yielding the rationale to suspect that doxazosin, an α 1-adrenergic receptor inhibitor, may lower blood pressure (BP). The aim of this study was to evaluate the efficacy and safety of doxazosin GITS (4 and 8 mg) in RT. Methods Twenty-three hypertensive RT received doxazosin 4 mg once daily for 4 weeks (W 4) followed by a 4-week washout (W 0) and 17/23 treated with doxazosin 8 mg for 4 more weeks (W 8) due to persistent HT. All patients underwent 24-hour ambulatory blood pressure monitoring (ABPM) after W 0, W 4, and W 8. Laboratory tests were performed, adverse events recorded, and prostatic symptomatology examined. Statistical analysis included Saphiro-Wilks, Student t, ANOVA, Wilcoxon, or Friedman tests. Results The systolic, diastolic, and mean BP were significantly lowered at W 4 in awake ( P < .001) and 24 hour period ( P < .005) but not sleep recordings. Doxazosin 8 mg had no significant additional effect to lower BP at any period. Normotension was reached in 13% and 21.7% of patients at W 4 and W 8, respectively. Palpitations were the only reported adverse event after treatment (incidence similar to placebo). There was no significant change in the laboratory values. Conclusions Doxazosin (−4 mg) effectively decreased BP in awake and 24-hour periods without a significant improvement during sleep. A double dose of the drug added little benefit. Optimal BP was reached by an insufficient number of patients. Doxazosin proved to have a good tolerance and safe profile. This results suggest that doxazosin should be considered a good add-on treatment to other antihypertensive drugs in RT.