Efficacy and Safety of Nifedipine GITS in Asians with Hypertension

Comparative Bioequivalence and Food Effect of Two Formulations of 30-mg Nifedipine Controlled-Release Tablets in Healthy Chinese Adults

Nifedipine is a potent antihypertensive medication classified as a dihydropyridine calcium channel blocker. The objective of this trial was to assess the bioequivalence of a 30-mg nifedipine controlled-release tablet and a reference drug in a cohort of healthy Chinese individuals. Two independent open-label, randomized, single-dose, crossover studies were conducted, 1 under fasting conditions (N = 44, with 1 participant dropping out midway) and the other under fed conditions (N = 44, with 4 participants dropping out midway). Plasma concentrations of nifedipine were determined using liquid chromatography-mass spectrometry, and pharmacokinetic (PK) parameters were calculated using noncompartmental analysis with Phoenix WinNonlin 8.0 software. In both fasting and fed studies, reasonable bioequivalence was observed for the PK parameters of both the test product and the reference drug. A good safety profile was demonstrated for both the test product and reference drug, with no serious adverse events reported, and both were similarly well tolerated. An important observation with food coadministration was that systemic exposure to nifedipine (based on area under the curve, AUC0-∞) was reduced by approximately 12%. The bioequivalence of the test product and reference drug under fasting/fed conditions in healthy subjects in China was demonstrated by the study results.

Impact of baseline blood pressure on the magnitude of blood pressure lowering by nifedipine gastrointestinal therapeutic system: refreshing the Wilder's principle

Background

The objective of the study was to investigate the relationship between baseline blood pressure (BP) and the magnitude of BP reduction in patients with essential hypertension treated with nifedipine gastrointestinal therapeutic system (NGTS).

Methods and patients

One hundred and thirty-eight patients with essential hypertension were enrolled in this prospective, single-arm, open-label study. NGTS was administered for 24 weeks to achieve target BP of 140/90 mmHg. The dose could be uptitrated to 60 mg/d in case of unsatisfactory BP reduction after 4-week treatment. Home blood pressure measurement was recorded through the initial 1–14 days, and office BP and heart rate were evaluated at 2, 4, 8, 12, and 24 weeks.

Results

One hundred and seventeen patients (84.8%) completed the study, and their average BP decreased by 19.0/11.3 mmHg after 24 weeks. The reduction of either systolic or diastolic BP was positively correlated with baseline BP at weeks 2, 4, or 24 after treatment (r=0.603–0.762, all p<0.05). The maximal BP reduction was observed in 83% of patients at 4 weeks of treatment even though the dose of nifedipine remained unchanged (30 mg/day).

Conclusion

These findings show that BP reduction is greatly influenced by the baseline level. Patients with high baseline BP had maximum reduction after treatment with NGTS, and the maximal antihypertensive efficacy of NGTS could appear even at 4 weeks after treatment initiation.

Combination therapy with nifedipine GITS 60 mg: subanalysis of a prospective, 12-week observational study (AdADOSE)

Background: AdADOSE was a 12-week, international, observational study conducted in the Middle East and Russia where patients received nifedipine gastrointestinal therapeutic system (GITS) at a daily dose of 30, 60, or 90 mg as part of an antihypertensive combination therapy. This subgroup analysis of the AdADOSE study assesses the efficacy and tolerability of nifedipine GITS combination therapy when used specifically at the 60-mg strength. Methods: Patients with hypertension who received a daily nifedipine GITS dose of 60 mg, either at constant dose (n = 686) or up-titrated from 30 mg (n = 392), were analyzed. Target blood pressure (BP) was <140/90 mmHg (or <130/80 mmHg for those at high/very high cardiovascular risk). Results: Following nifedipine GITS combination therapy, target BP was achieved by 33.7% patients in the 60 mg group (previously untreated, 42.5%; previously treated, 32.0%) and 32.4% patients in the 30–60 mg group (previously untreated, 45.2%; previously treated, 30.7%). Mean systolic BP/diastolic BP changes were −40.3/−20.7 mmHg and −35.6/−18.5 mmHg, respectively, and were similar regardless of previous antihypertensive treatment or the number of concomitant diseases. Incidences of drug-related adverse events (AEs) were low (3.2%, 60 mg; 2.0%, 30–60 mg group), few patients discontinued because of AEs (0.6% and 1.0%, respectively), and there were no serious AEs. Conclusion: Combination therapy with nifedipine GITS 60 mg in a real-life observational setting was effective and well tolerated in hypertensive patients, with low rates of treatment-related AEs.

Effectiveness of combination therapy with nifedipine GITS: a prospective, 12-week observational study (AdADOSE)

Background

Observational studies can provide important information on the efficacy and safety of antihypertensive agents in the real-life clinical setting. AdADOSE was a large observational study to assess the effectiveness of nifedipine GITS in combination with other antihypertensive agent(s). The study was also the first to examine the role of combination therapy with nifedipine GITS in the Middle East, Pakistan and Russia, regions that are associated with particularly high cardiovascular risk.

Methods

AdADOSE was a 12-week, international, multicenter, prospective, observational study. Patients with hypertension (ie, blood pressure [BP] >140/90 mm Hg, or >130/80 mm Hg in patients at high or very high cardiovascular risk) received once-daily nifedipine GITS (30, 60 or 90 mg) in combination with another antihypertensive or as add-on to existing therapy. The primary study endpoint was the proportion of patients who achieved the target BP of <140/90 mm Hg (or <130/80 mm Hg for those at high or very high cardiovascular risk). Study outcomes are reported by descriptive statistics.

Results

The study enrolled 4497 patients (n = 4477, safety population; n = 3430, efficacy population). Baseline mean systolic/diastolic BP (SBP/DBP) was 166.4/99.7 mm Hg; 85.2 % of patients had received prior antihypertensive treatment, and 90.6 % had ≥1 concomitant diseases. Following combination treatment with nifedipine GITS, target BP was achieved by 64.8 % of patients without concomitant diseases, and by 56.5 %, 32.3 % and 22.6 % with 1, 2–3 and >3 concomitant diseases, respectively. The proportion of patients achieving target BP was 51.5 % in previously untreated and 33.7 % in previously treated patients. Nifedipine GITS combination treatment provided mean SBP/DBP changes of −36.1/−18.8 mm Hg in all patients, −40.2/−21.5 mm Hg in previously untreated patients, and −35.6/−18.4 mm Hg in previously treated patients, with similar BP reductions irrespective of the number of concomitant diseases. Drug-related adverse events (AEs) were reported in 2.6 % patients. There were no serious AEs and only 0.8 % of patients discontinued due to drug-related AEs.

Conclusions

Combination therapy with nifedipine GITS in a real-life observational setting was highly effective in reducing SBP/DBP in a range of hypertensive patients, with low rates of treatment-related AEs.

Trial registration

Trial registration: at ClinicalTrials.gov registration number NCT01118286.