What are the first-line antihypertensives in patients with various comorbidities, considering accessibility and affordability in the Philippines?

First-Line Antihypertensives for Various Comorbidities in the Philippines

For patients with hypertension and various comorbidities in the Philippines, the selection of first-line antihypertensive medications should be based on both clinical efficacy and cost-accessibility, with RAS blockers (ACEIs/ARBs), calcium channel blockers (CCBs), and diuretics being the cornerstone of therapy for most conditions. 1

General Principles for Antihypertensive Selection

• Blood pressure should be lowered if ≥140/90 mmHg and treated to a target of <130/80 mmHg in most patients (<140/80 mmHg in elderly patients) 1
• Initial drug therapy should consider both the patient's comorbidities and medication accessibility/affordability in the Philippines 2
• Combination therapy may be necessary for many patients to achieve blood pressure goals, especially when BP is >20/10 mmHg above target 3

First-Line Antihypertensives by Comorbidity

Cardiovascular Conditions

• Coronary Artery Disease/Stable Ischemic Heart Disease:

  • First-line: Beta-blockers, ACE inhibitors, or ARBs 1
  • For angina: Add dihydropyridine calcium channel blockers for additional BP control 1
  • Post-MI: Guideline-directed beta-blocker therapy (carvedilol, metoprolol succinate, bisoprolol) 1

• Heart Failure:

  • Heart Failure with reduced EF (HFrEF): Beta-blockers (avoid non-dihydropyridine calcium antagonists) 1
  • Heart Failure with preserved EF (HFpEF): Diuretics for volume overload; add ACEIs or ARBs and beta-blockers for additional BP control 1
  • Consider angiotensin receptor-neprilysin inhibitor (ARNI) as an alternative to ACEIs or ARBs in HFrEF 1

• Atrial Fibrillation:

  • First-line: ARBs (may reduce AF recurrence) 1
  • For permanent AF: Beta-blockers or non-dihydropyridine calcium channel blockers 1

• Aortic Disease:

  • First-line: Beta-blockers (especially for thoracic aortic disease) 1

• Post-Stroke:

  • First-line: Thiazide diuretics, ACEIs, ARBs, or thiazide + ACEI combination 1
  • Start treatment a few days post-event if BP ≥140/90 mmHg 1
  • Target LDL-cholesterol <1.8 mmol/L (70 mg/dL) is mandatory for ischemic stroke 1

Renal Conditions

• Chronic Kidney Disease (CKD):

  • First-line: ACEIs or ARBs (ARB if ACEI not tolerated) 1
  • Add CCBs and diuretics (loop diuretics if eGFR <30 ml/min/1.73m²) 1
  • Monitor eGFR, microalbuminuria, and blood electrolytes regularly 1, 4

• Post-Kidney Transplant:

  • First-line: Calcium channel antagonists (can improve kidney graft survival and GFR) 1
  • Use ACEIs with caution, especially in first month post-transplant 1

Metabolic Conditions

• Diabetes Mellitus:

  • First-line: ACEIs or ARBs (especially if albuminuria is present) 1
  • Consider usual first-line drugs if no albuminuria 1
  • Target HbA1c <7% (53 mmol/mol) 1

• Metabolic Syndrome:

  • First-line: ACEIs, ARBs, or CCBs 1
  • Avoid thiazide diuretics if possible (may worsen metabolic parameters) 1

Respiratory Conditions

• Chronic Obstructive Pulmonary Disease (COPD):
  • First-line: ARBs, CCBs, and/or diuretics 1
  • Beta-blockers may be used if selective for β1-receptors (e.g., bisoprolol) 1
  • Avoid non-selective beta-blockers 1

Special Populations

• Elderly Patients:

  • First-line for Isolated Systolic Hypertension: Diuretics or CCBs 1
  • Consider higher BP target (<140/80 mmHg) 1
  • Start with lower doses to prevent hypotension 5

• Pregnant Women:

  • First-line: Calcium channel blockers, methyldopa, or selective beta-blockers 1
  • Avoid ACEIs and ARBs (contraindicated in pregnancy) 1

• Black Patients:

  • First-line: Diuretics or CCBs (generally more effective) 1, 6

Cost and Accessibility Considerations in the Philippines

• Most Accessible and Affordable Options:

  • Generic ACEIs (e.g., enalapril) and thiazide diuretics are typically the most affordable options 2
  • Generic beta-blockers (e.g., atenolol, metoprolol) are moderately priced 2
  • Generic CCBs (e.g., amlodipine) are widely available but may be more expensive than diuretics 2
  • ARBs (e.g., losartan) are generally more expensive but becoming more accessible with generic versions 7, 2

• Common Prescribing Patterns in the Philippines:

  • Monotherapy has been the mode of treatment in more than 80% of Filipino patients, which may explain low BP control rates (only 27% of hypertensive patients have controlled BP) 2
  • Consider initiating with combination therapy for more effective BP control, especially in patients with BP >20/10 mmHg above target 2, 3

Practical Approach to Selection

1. Identify comorbidities and select the most appropriate first-line agent based on the condition-specific recommendations above 1

2. Consider cost and accessibility - prioritize medications available in the Philippine National Formulary and those covered by PhilHealth or other insurance programs 2

3. Start with lower doses and titrate up as needed, especially in elderly patients 1, 5

4. Consider fixed-dose combinations to improve adherence and reduce costs when multiple medications are needed 1, 3

5. Monitor regularly for efficacy and adverse effects, with follow-up approximately monthly for drug titration until BP is controlled 1

Common Pitfalls to Avoid

• Undertreatment - monotherapy is often insufficient; don't hesitate to use combination therapy when needed 2, 3

• Inappropriate drug selection - avoid non-dihydropyridine CCBs in heart failure with reduced EF, and avoid beta-blockers in patients with reactive airway disease 1

• Inadequate monitoring - regularly check renal function, electrolytes, and metabolic parameters, especially with ACEIs, ARBs, and diuretics 1

• Poor adherence - consider once-daily dosing regimens and fixed-dose combinations to improve compliance 1

• Ignoring cost factors - high medication costs can lead to non-adherence; always consider affordable alternatives when available 2