In vitro and in vivo postmarketing surveillance of valsartan, alone or in combination with amlodipine or hydrochlorothiazide, among Palestinian hypertensive patients

The objectives of this study were to evaluate the general quality of the most prescribed products of valsartan (VL; alone or in combination) and to evaluate their efficacy and safety among Palestinian population through in vivo postmarketing surveillance. The first part was pharmacopeial quality control assay, including dissolution, disintegration, friability, and weight uniformity for VL. The second part was a 3-month cardiology clinics, observational, postmarketing surveillance pilot study that included 103 hypertensive patients who were prescribed 80 mg or 160 mg of VL as monotherapy or combination therapy. The end points were reduction in blood pressure (BP) and the rate of incidence of adverse effects (AEs) at weeks 4 and 8. According to our quality control tests, all VL products showed high-quality standards according to the international guidelines. A reduction in BP was observed at weeks 4 and 8, and no significant difference was observed between the strengths of 80 mg and 160 mg. Higher BP reduction was observed after the use of combination therapy. Moreover, VL was well tolerated; most of the AEs were of mild-to-moderate intensity. In general, the most frequently reported AEs included headache (17.5%), dizziness (11.75%), and weakness (11.7%). No serious AEs or death cases were reported during the study period. High quality of VL tablet products was used; hence, the observed efficacy and safety results should be related to patient's factors and not due to any product defects or substandard quality. Moreover, VL is an effective treatment for essential hypertension.