Hypertension Management: Drug Initiation & Follow-Up Protocols

Classification & Initial Drug Choice

• Mild, uncomplicated hypertension is defined here as elevated blood pressure without:
  1. Additional cardiovascular (CV) risk factors
  2. Target-organ damage (TOD).
• First-line drug in this subgroup: a thiazide diuretic.
  • Acceptable molecules: hydrochlorothiazide (HCTZ) or a thiazide-like diuretic (indapamide).
  • Practical supply note: indapamide is not stocked in the state formulary of the Western Cape, though it can be sourced in some other South-African provinces.

When to Initiate Combination Therapy Immediately

• Blood pressure at presentation >180/110 \text{\ mmHg} and no evidence of acute TOD ⇒ not a hypertensive emergency, but too high for monotherapy.
• Management at the first visit:
  1. Comprehensive lifestyle modification (dietary sodium restriction, weight control, exercise, alcohol moderation, smoking cessation).
  2. Start two antihypertensive agents simultaneously.

Acceptable Two-Drug Combinations

1. Traditional mix:
   • A thiazide diuretic plus either an ACE inhibitor or a dihydropyridine calcium-channel blocker (CCB).
2. Evidence-driven alternative:
   • ACE inhibitor + CCB.
   – Recent trials demonstrate superior long-term CV endpoints with this pairing (compared to thiazide-containing combos) in selected patients.

Drug Selection: Specific Clinical Clues

• Look actively for reasons to choose or avoid a class. Examples cited:
  • Thiazide diuretics
  – Useful in patients with osteoporosis (positive effect on calcium balance).
  – Logical choice when peripheral oedema is present.
  • ACE inhibitors
  – Preferred if persistent proteinuria, especially in diabetes (renal protective).
  – Added benefit on left-ventricular remodeling/contractility.

Agents Not Routine First-Line

• Several drug classes mentioned (beta-blockers, centrally acting agents, direct vasodilators, etc.) have narrow indications in hypertension and should only be first-line when those specific indications exist.

ARBs vs. ACE Inhibitors: Switching Rules

• Angiotensin-receptor blockers (ARBs) may be considered first-line only after an ACE inhibitor has caused side-effects.
  • If the ACE-induced problem is a dry cough → ARB is an acceptable substitute.
  • If the ACE-induced problem is angio-oedema → ARB is contra-indicated (cross-reactivity risk).

Follow-Up & “Treatment Inertia”

• At every management step (lifestyle change, dose titration, adding drugs) you must schedule a re-assessment:
  • Recommended interval: $\approx 1 \text{ month}$.
  • Six-month gaps create unacceptable periods of uncontrolled BP.
• Once target blood pressure is reached and stable, visit spacing can be safely extended (e.g.
  $\le 6 \text{ months}$).

Special Follow-Up for Markedly Elevated BP

• For patients who started at >180/110 \text{\ mmHg} and were given two drugs at the index visit:
  • Bring back within 1–2 weeks to verify response and fine-tune therapy.

Key Take-Home Points

1. Mild uncomplicated HTN → thiazide monotherapy is enough.
2. BP >$180/110$ (no TOD) → lifestyle + immediate dual therapy.
3. ACE + CCB combo now has good evidence for superior CV outcomes.
4. Match drugs to comorbidities: diuretic in osteoporosis/oedema, ACE in proteinuria/diabetes.
5. ARB can replace ACE only if cough, never after angio-oedema.
6. Re-evaluate in about 4 weeks; high-risk presentations need 1–2-week check-up.
7. Avoid long follow-up gaps to prevent persistent uncontrolled hypertension.