Efficacy of initiating therapy with amlodipine and hydrochlorothiazide or their combination in hypertensive Nigerians

Amlodipine in the current management of hypertension

Hypertension is the leading cause of death worldwide, affecting 1.4 billion people. Treatment options include the widely used calcium channel blockers, among which amlodipine, a dihydropyridine, has unique characteristics that distinguish it from other drugs within this class. This review aims to provide an updated overview of the evidence supporting the use of amlodipine over the past 30 years and highlights its cardiovascular benefits in current hypertension management. Amlodipine has low renal clearance (7 mL/min/mg) and long half-life (35-50 h) and duration of action, which allows it to sustain its anti-hypertensive effect for more than 24 h following a single dose. Additionally, blood pressure (BP) control is maintained even when a dose has been missed, providing continuous protection in case of incidental noncompliance. It has proven to reduce BP variability and successfully lower BP. Amlodipine also controls BP in patients with a systolic/diastolic BP of 130/80 mm Hg or higher, diabetes, or chronic kidney disease without worsening glycemic or kidney function. Additionally, amlodipine is a wise choice for older adults due to its ability to control BP and protect against stroke and myocardial infarction. Side effects of amlodipine include edema, palpitations, dizziness, and flushing, which are more common with the higher dose of 10 mg. Amlodipine is cost effective and predicted to be cost saving when compared with usual care.

Real-World Effectiveness and Safety of Two-Drug Single Pill Combinations of Antihypertensive Medications for Blood Pressure Management: A Follow-Up on Daily Cardiology Practice in Douala, Cameroon

INTRODUCTION

Hypertension is the leading cause of morbidity and mortality in sub-Saharan Africa (SSA). Current guidelines recommend using two or more antihypertensive agents in single pill combinations (SPCs) to treat hypertension, but data from African patients that support these recommendations are lacking. We assessed the effectiveness and tolerance of three SPCs in lowering blood pressure (BP) amongst hypertensive patients in Douala.

METHOD

All patients included in the hypertension registry of the Douala General Hospital and the Douala Cardiovascular Center between January 2010 and May 2020, and receiving a two-drug SPCs (renin-angiotensin system inhibitors (RAASi) + diuretics (DIU), calcium channel blockers (CCB) + RAASi, or DIU + CCB) were tracked from baseline through 16 weeks. Our primary outcome was a decrease in systolic BP (SBP) from baseline up to 16 weeks after initiation of treatment. A mixed linear repeated model was used to evaluate the change of SBP from baseline to week 16, while controlling for age, gender, and baseline SBP. Statistical significance was set at p < 0.05.

RESULTS

Of 377 participants on two-drug SPCs, 123 were on CCB + DIU, 96 on RAASi + CCB, and 158 on RAASi + DIU. The mean age was 54.6 (± 11.2) years. At baseline, participants on RAASi + CCB presented with slightly higher SBP compared to the other two groups. Overall, the SBP decreased by 34.3 (± 14.2) mmHg from baseline values and this was comparable across the three groups of SPCs (p = 0.118). The control rate after 16 weeks of follow-up was 62.3% with no significant difference between groups. The occurrence of adverse events was 3.4% and was comparable among the three groups.

CONCLUSION

The three two-drug SPCs were highly effective in reducing and controlling BP with low and similar rates of adverse effects. Long-term data documenting safety and whether these agents exert a differential cardiovascular effect in addition to and independent of their BP-lowering effect are needed for SSA populations.

Pathophysiologically based antihypertensive pharmacotherapeutics rationality, efficacy and safety in Sub Saharan African Nations – A review

Background

Hypertension (HT) prevalence, Uncontrolled Blood Pressure (UBP), morbidity and mortality are highest in Sub-Saharan Africa (SSA). Correlating pathophysiology of HT to pharmaco-therapy with antihypertensive drugs (AHD) may bring amelioration. Aims:To review peculiarities of HT in SSA, UBP causes, diagnostic modalities, AHD use, rationality and efficacy.

Methods and results

14 published therapeutic audits in 4 SSA nations on Google Scholar or PUBMED, (total n = 6496 patients) were evaluated. Calcium Channel blockers (CCB) amlodipine, and thiazide diuretics (TD), hydrochlorothiazide (HCTZ) were the commonest AHD. Thiazide Like Diuretics (TLD) were underutilized. The % of patients on AHD were: 1 drug 5.4–55%; 2 drugs 37–82%; >/ = 3 drugs 6–50.3%. 2-drug combinations were: ACEI/ARB + TD (42%); CCB + TD (36.8%); ACEI + CCB (15.8%) of studies. Triple/quadruple therapy included Methyldopa (MTD) with ACEI + CCB or TD. The (%) attaining BP < 140/< 90 mmHg, ranged from 29 to 53.6%, median, 44%. The co-morbidities, range and median were: Diabetes Mellitus (DM): 9.8–64%, 19.2%; Chronic Kidney Disease (CKD): 5.7–7.5%, 6.9%, and Coronary artery Disease (CAD): 0.9–2.6%, 2.3%. ACEI + CCB ± TD were the preferred AHD for comorbidities.

Conclusions

Therapeutic inertia; Non-compliance; co-morbidities; refractory HT; ignorance; substandard AHD; contribute to UBP. Studies relating 24 hour ABPM to complications and mortality in SSA hypertensives; and impact of different AHD classes on ABPM, are needed. Study of ACEI + alpha-₁ blockers + TLD on 24 hour ABPM and personalized care, are required.

The coArtHA trial-identifying the most effective treatment strategies to control arterial hypertension in sub-Saharan Africa: study protocol for a randomized controlled trial

BACKGROUND

Arterial hypertension is the most prevalent risk factor for cardiovascular disease in sub-Saharan Africa. Only a few and mostly small randomized trials have studied antihypertensive treatments in people of African descent living in sub-Saharan Africa.

METHODS

In this open-label, three-arm, parallel randomized controlled trial conducted at two rural hospitals in Lesotho and Tanzania, we compare the efficacy and cost-effectiveness of three antihypertensive treatment strategies among participants aged ≥ 18 years. The study includes patients with untreated uncomplicated arterial hypertension diagnosed by a standardized office blood pressure ≥ 140/90 mmHg. The trial encompasses a superiority comparison between a triple low-dose antihypertensive drug combination versus the current standard of care (monotherapy followed by dual treatment), as well as a non-inferiority comparison for a dual drug combination versus standard of care with optional dose titration after 4 and 8 weeks for participants not reaching the target blood pressure. The sample size is 1268 participants with parallel allocation and a randomization ratio of 2:1:2 for the dual, triple and control arms, respectively. The primary endpoint is the proportion of participants reaching a target blood pressure at 12 weeks of ≤ 130/80 mmHg and ≤ 140/90 mmHg among those aged < 65 years and ≥ 65 years, respectively. Clinical manifestations of end-organ damage and cost-effectiveness at 6 months are secondary endpoints.

DISCUSSION

This trial will help to identify the most effective and cost-effective treatment strategies for uncomplicated arterial hypertension among people of African descent living in rural sub-Saharan Africa and inform future clinical guidelines on antihypertensive management in the region.

TRIAL REGISTRATION

Clinicaltrials.gov NCT04129840 . Registered on 17 October 2019 ( https://www.clinicaltrials.gov/ ).

Pharmacotherapy for hypertension in Sub-Saharan Africa: a systematic review and network meta-analysis

BACKGROUND

The highest burden of hypertension is found in Sub-Saharan Africa (SSA) with a threefold greater mortality from stroke and other associated diseases. Ethnicity is known to influence the response to antihypertensives, especially in black populations living in North America and Europe. We sought to outline the impact of all commonly used pharmacological agents on both blood pressure reduction and cardiovascular morbidity and mortality in SSA.

METHODS

We used similar criteria to previous large meta-analyses of blood pressure agents but restricted results to populations in SSA. Quality of evidence was assessed using a risk of bias tool. Network meta-analysis with random effects was used to compare the effects across interventions and meta-regression to explore participant heterogeneity.

RESULTS

Thirty-two studies of 2860 participants were identified. Most were small studies from single, urban centres. Compared with placebo, any pharmacotherapy lowered SBP/DBP by 8.51/8.04 mmHg, and calcium channel blockers (CCBs) were the most efficacious first-line agent with 18.46/11.6 mmHg reduction. Fewer studies assessing combination therapy were available, but there was a trend towards superiority for CCBs plus ACE inhibitors or diuretics compared to other combinations. No studies examined the effect of antihypertensive therapy on morbidity or mortality outcomes.

CONCLUSION

Evidence broadly supports current guidelines and provides a clear rationale for promoting CCBs as first-line agents and early initiation of combination therapy. However, there is a clear requirement for more evidence to provide a nuanced understanding of stroke and other cardiovascular disease prevention amongst diverse populations on the continent.

TRIAL REGISTRATION

PROSPERO, CRD42019122490. This review was registered in January 2019.

Monotherapy with amlodipine or hydrochlorothiazide in patients with mild to moderate hypertension: Comparison of their efficacy and effects on electrolytes

Background

Amlodipine and hydrochlorothiazide (HCTZ) are commonly prescribed in Nigeria either as a monotherapy or in combination with other drugs. The present study was designed to investigate the antihypertensive efficacy of monotherapy with amlodipine or HCTZ and their effects on electrolyte profile in patients with mild to moderate hypertension.

Methods

A single-blind randomized clinical study was used; fifty patients newly diagnosed with mild to moderate hypertension (aged 33 to 60 years) were recruited and divided into two groups: amlodipine or hydrochlorothiazide each comprising of 25 subjects. The subjects received 5mg of amlodipine or 25mg of hydrochlorothiazide in their respective group once daily for 4 weeks. Blood pressure, serum and urine electrolytes were measured at baseline and weekly throughout the experiment.

Results

At the end of follow up, amlodipine reduced systolic and diastolic blood pressure significantly more (p<0.001) than HCTZ. At the end of follow up, blood pressure was reduced to normal in 80% of the subjects in amlodipine group compared to 50% in HCTZ. Amlodipine had no significant effect on electrolyte profile of subjects unlike HCTZ which significantly changed both their serum and urine electrolytes.

Conclusions

Monotherapy with amlodipine was more effective than HCTZ in black patients with mild to moderate hypertension and in addition maintained electrolyte balance.