L-type calcium channel regulation of dopamine activity in the ventral tegmental area to nucleus accumbens pathway: Implications for substance use, mood disorders and co-morbidities

L-type calcium channels (LTCCs), including the Cav1.2 and Cav1.3 LTCC subtypes, are important regulators of calcium entry into neurons, which mediates neurotransmitter release and synaptic plasticity. Cav1.2 and Cav1.3 are encoded by the CACNA1C and CACNA1D genes, respectively. These genes are implicated in substance use disorders and depression in humans, as demonstrated by genetic-wide association studies (GWAS). Pre-clinical models have also revealed a critical role of LTCCs on drug and mood related behavior, including the co-morbidity of substance use and mood disorders. Moreover, LTCCs have been shown to regulate the neuronal firing of dopamine (DA) neurons as well as drug and stress-induced plasticity within the ventral tegmental area (VTA) to nucleus accumbens (NAc) pathway. Thus, LTCCs are interesting targets for the treatment of neuropsychiatric diseases. In this review, we provide a brief introduction to voltage-gated calcium channels, specifically focusing on the LTCCs. We place particular emphasis on the ability of LTCCs to regulate DA neuronal activity and downstream signaling in the VTA to NAc pathway, and how such processes mediate substance use and mood disorder-related behavioral responses. We also discuss the bi-directional control of VTA LTCCs on drug and mood-related behaviors in pre-clinical models, with implications for co-morbid psychiatric diagnosis. We conclude with a section on the clinical implications of LTCC blockers, many which are already FDA approved as cardiac medications. Thus, pre-clinical and clinical work should examine the potential of LTCC blockers to be repurposed for neuropsychiatric illness. This article is part of the Special Issue on 'L-type calcium channel mechanisms in neuropsychiatric disorders'.

Comparative efficacy of generic nifedipine versus brand-name amlodipine for hypertension management in Taiwan

The control rate of hypertension remains concerning, indicating the requirement for better management strategies. The calcium channel blockers brand‐name amlodipine and nifedipine with extended‐release formulations demonstrate similar clinical efficacy. However, the efficacy of generic nifedipine remains obscure. We compared the efficacy of generic nifedipine and brand‐name amlodipine in terms of cardiovascular (CV) outcomes. Patients prescribed generic nifedipine (SRFC CYH) or brand‐name amlodipine besylate (Norvasc, Pfizer) between August 1, 2017, and July 31, 2018, were enrolled; patients with CV events within 3 months were excluded. CV outcomes included CV death, nonfatal myocardial infarction (MI), nonfatal ischemic stroke, hospitalization for heart failure, and composite endpoints of 3P‐ and 4P‐major adverse cardiac events (MACE). A total of 1625 patients treated with nifedipine (SRFC CYH) and 16 587 patients treated with Norvasc were included. After propensity score matching, there were 995 and 4975 patients in the nifedipine CYH and Norvasc groups, respectively. At a mean follow‐up period of 30.3 ± 6.4 months, nifedipine CYH was comparable to Norvasc in terms of CV death (P = .107), nonfatal MI (P = .121), nonfatal ischemic stroke (P = .453), hospitalization for heart failure (P = .330), 3P‐MACE (P = .584), and 4P‐MACE (P = .274). Cox regression analysis revealed that nifedipine CYH and Norvasc had similar efficacy in terms of 3P‐MACE (hazard ratio, 0.970; 95% confidence interval, 0.601–1.565, P = .900) and 4P‐MACE (hazard ratio, 0.880; 95% confidence interval, 0.628–1.233, P = .459). In conclusion, Nifedipine SRFC CYH and Norvasc have comparable clinical efficacy for hypertension management.

Effectiveness and Tolerability of Nifedipine GITS in Patients with Chronic Kidney Disease and Uncontrolled Hypertension: A Prospective, Multicenter, Observational Study (ADRENAL)

INTRODUCTION

Achieving target blood pressure (BP) goals in patients with chronic kidney disease (CKD) and uncontrolled hypertension is a challenge. Various studies have shown the efficacy of nifedipine gastrointestinal therapeutic system (GITS) 60 mg in patients with hypertension. However, there is a paucity of clinical studies in patients with CKD. Hence, we conducted this study to evaluate the effectiveness and tolerability of nifedipine GITS 60 mg in Chinese patients with CKD and uncontrolled hypertension in real-world clinical settings.

METHODS

In a prospective, multicenter, observational study, Chinese patients with CKD and uncontrolled hypertension were given nifedipine GITS 60 mg with a primary endpoint of change in office systolic BP (SBP) at 12 weeks. The secondary endpoints included changes at 12 weeks in office diastolic BP (DBP), office SBP and DBP in SBP subgroups (140-160 mmHg and ≥ 160 mmHg) and CKD stages subgroups, SBP and DBP control rate, and the adverse events (AEs). Statistical analysis was performed using SAS^® version 9.4.

RESULTS

In total, 871 and 622 patients were included in the safety analysis set and efficacy analysis set respectively. The mean office SBP and DBP at baseline were 162.9 and 97.3 mmHg, respectively. At week 12, the mean change in SBP was - 24.0 mmHg (95% confidence interval [CI] - 25.32, - 22.65 mmHg); after missing data were accounted for, it was - 23.9 mmHg (95% CI - 25.25, - 22.60 mmHg). Marked decreases in DBP, and office SBP and DBP in baseline SBP subgroups as well as CKD stages were observed at week 12. The BP control rate at week 12 was 50.0%. Twenty-three (2.6%) patients reported at least one drug-related AEs. No event of hypotension or death occurred during the study.

CONCLUSION

Nifedipine GITS 60 mg showed effectiveness and tolerability in reducing office SBP and DBP in Chinese patients with CKD and uncontrolled hypertension.

TRIAL REGISTRATION

ClinicalTrials.gov identifier NCT03194633.

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.

Long-acting nifedipine for hypertensive patients in the Middle East and Morocco: observations on efficacy and tolerability of monotherapy or combination therapy

Background

The Middle Eastern and North African region of developing countries is associated with poor rates of blood pressure (BP) control and antihypertensive prescribing patterns. This post hoc analysis of data from an international observational study aimed to investigate the efficacy and tolerability of long-acting nifedipine (30 mg or 60 mg; monotherapy or in combination) in the Middle Eastern and Moroccan populations defined as having high cardiovascular risk.

Methods

This was a prospective, noninterventional, multicenter observational study. Observations from patients (aged ≥ 18 years) with treated or untreated hypertension from the Middle East (Jordan, Saudi Arabia, Kuwait, Lebanon, Qatar, United Arab Emirates, and Yemen) and Morocco are presented. Hypertension grade and cardiovascular risk were defined at baseline, and systolic/diastolic BP change was defined at post-baseline visits (≤3). Adverse events and ratings of therapy efficacy and patient/physician satisfaction were recorded.

Results

The study included 1466 patients from the Middle East and 524 from Morocco. Characteristics of the populations differed, with a more severe hypertension profile in Moroccan patients. Despite these differences, nifedipine reduced BP to a similar extent in each group, with efficacy dependent on cardiovascular risk factors such as hypertension grade and age. Few adverse drug reactions occurred and nifedipine was well-tolerated in both populations. Efficacy and satisfaction with therapy were rated highly.

Conclusion

Good rates of BP control were observed with nifedipine in patients with moderate-to-severe hypertension and high added risk. Published data in these countries suggest poor antihypertensive prescribing patterns and BP control; these data confirm this trend and suggest that suboptimal dosing may be prevalent.