Efficacy, safety, and palatability of RACTAB(®) formulation amlodipine orally disintegrating tablets

Abstract

Objective: The aim of this study was to confirm the efficacy, safety, and expected palatability of amlodipine orally disintegrating tablets (ODT) [RACTAB(®) formulation (Towa, Osaka, Japan)]. We report the re-analyzed results of 1687 cases in clinical settings obtained through postmarketing surveillance in Japan.

Method: Study subjects were patients receiving treatment for the first time with amlodipine ODT for hypertension under routine care. A multicenter central registration system was used for this prospective survey. The survey was conducted from October 2008 to October 2010. The observational period was 12 weeks, during which time surveys on outpatient blood pressure, adverse events, palatability, etc. were conducted.

Results: Blood pressure stabilized following treatment, and both systolic and diastolic blood pressures were favorably controlled. Adverse events observed were not significantly different from those observed during drug use trials of amlodipine formulations reported in 2003. Moreover, palatability of amlodipine ODT showed a 99.6% (227 of 228 cases) favorable patient acceptance, which is consistent with the initial design concept of RACTAB(®) formulation.

Conclusions: The results of this postmarketing surveillance study indicated that the efficacy, safety, and palatability of amlodipine ODT met our expectations (dissolves quickly in the mouth, tastes good, and is not rough on the tongue). Accordingly, amlodipine ODT are believed to be an easy-to-use formulation for prescribing doctors, dispensing pharmacists, and patients receiving treatment.

Fig. 1

Case configuration.

Fig. 2

Cases where systolic blood pressure (SBP) has been lowered by the antihypertensive from treatment initiation (treatment-naïve cases: single drug [5 mg] dose [non-substituted antihyperintensive]). Paired t-test (time of final observation vs time of treatment initiation). NS = no significant difference; *** p < 0.001.

Fig. 3

Changes in blood pressure and heart rate (substituted cases). Average value and 95% confidence interval. Paired t-test (time of final observation vs time of treatment initiation). DBP = diastolic blood pressure; NS = no significant difference; SBP = systolic blood pressure; * p < 0.05, ** p < 0.01, *** p < 0.001.

Table I

Types of adverse drug reactions (ADRs)^{a b}

Fig. 4

Onset of adverse drug reactions (ADRs) at different periods (excluding substituted cases).

Fig. 5

Amlodipine ODT palatability (228 patients took the tablets mostly without water). Reproduced from Towa Pharmaceutical Co., Ltd.,[11] with permission.