Therapeutics

Hypertension for OPRA: Diagnosis, Treatment, Counselling and MCQs

Q: Are beta blockers first-line for hypertension in Australia?

Generally no — current Australian guidance does not favour beta blockers as a default first-line choice for uncomplicated hypertension, though they remain appropriate where there's a separate compelling indication such as ischaemic heart disease.

Q: Why are ACE inhibitors avoided in pregnancy?

ACE inhibitors and ARBs are associated with fetal renal impairment, oligohydramnios and other adverse outcomes, particularly with second- and third-trimester exposure, so they are avoided throughout pregnancy.

Hypertension is one of the highest-yield Therapeutics topics on OPRA. This guide covers Australian diagnostic thresholds, first-line drug choice, monitoring and counselling — framed the way OPRA actually tests it, not as a general disease overview.

12 min readDifficulty: OPRA LevelTherapeutics and patient care, Pharmacology and toxicologyLast reviewed 2026-07-12

Why this topic matters

Hypertension sits at the intersection of two exam domains — Therapeutics and Pharmacology — and touches nearly every major cardiovascular drug class, so it shows up repeatedly across an OPRA paper in different guises (a counselling scenario, a dose-adjustment scenario, an interaction scenario).

Learning objectives

State Australian diagnostic thresholds for hypertension
Select an appropriate first-line agent for a given patient scenario
Identify key monitoring parameters for common antihypertensive classes
Recognise common counselling points and interaction risks
Avoid the most common OPRA-style distractor traps on this topic

Core concepts

Diagnosis

Hypertension is diagnosed from an average of repeated clinic readings, ideally confirmed with out-of-office measurement (home or 24-hour ambulatory monitoring) before starting long-term therapy — a single elevated clinic reading is not diagnostic on its own. The clinic-BP categories are in the table below (isolated systolic hypertension — systolic ≥140 with diastolic <90 — is common in older patients and is treated the same as combined systolic-diastolic hypertension). These boundaries are periodically revised — confirm the current figures against the latest Heart Foundation / Therapeutic Guidelines publication before treating them as fixed.

First-line drug classes and typical starting doses

ACE inhibitors (e.g. perindopril 2.5–5 mg daily, ramipril 2.5–5 mg daily) or ARBs (e.g. irbesartan 150 mg daily, candesartan 8 mg daily) — preferred first-line with diabetes, chronic kidney disease with proteinuria, or heart failure
Calcium channel blockers (e.g. amlodipine 2.5–5 mg daily) — an equally suitable first-line option; Australian guidance does not single out any one first-line class specifically for older patients — any of them can be used
Thiazide-like diuretics (e.g. indapamide 1.5 mg modified-release daily) — a well-established first-line option
Beta blockers (e.g. metoprolol, atenolol) are not first-line for uncomplicated hypertension in current Australian guidance, but remain the appropriate choice where there is a compelling comorbid indication (e.g. ischaemic heart disease, some arrhythmias)

Clinical application

Matching the drug to the patient

The comorbidity-to-class steer in the table above is the pattern OPRA scenarios test most; the reasoning behind two of those entries is worth knowing specifically. Pregnancy's ACE inhibitor/ARB avoidance is due to teratogenicity — labetalol, methyldopa and nifedipine are the alternatives commonly used instead. The gout caution with thiazides exists because they can raise urate and precipitate a flare. One steer not in the table: asthma/COPD makes non-selective beta blockers a poor choice specifically — a cardioselective agent is generally better tolerated when a beta blocker is otherwise indicated.

Titration and monitoring schedule

Blood pressure recheck: ~4–6 weeks after starting or up-titrating — most agents take several weeks to show their full effect.
Renal function and electrolytes (ACE inhibitors, ARBs, diuretics only): baseline, then again ~1–2 weeks after initiation or a dose increase, since these classes can affect creatinine and potassium.
Routine review once BP is controlled and doses are stable: every 3–6 months.

Common mistakes

Choosing a beta blocker as first-line for uncomplicated hypertension out of habit, when current Australian guidance doesn't support that as a default.
Missing that ACE inhibitors and ARBs are contraindicated in pregnancy — a very common exam trap.
Not checking renal function before starting or up-titrating an ACE inhibitor/ARB.
Confusing the expected creatinine rise after starting an ACE inhibitor (a small, expected rise is normal) with a sign to stop therapy.

Exam tips

• When a scenario gives you a comorbidity, treat it as the question's real subject — the "correct" antihypertensive is almost always the one that also suits the comorbidity.
• Watch for pregnancy or "planning pregnancy" in the stem — it should immediately exclude ACE inhibitors and ARBs from your answer options.

Memory tricks

• "ACE inhibitors protect the kidney, except in pregnancy" — a short line that captures both the primary benefit (renal protection in diabetes/CKD) and the primary absolute contraindication.

Clinical pearls

💡 A rise in creatinine of up to around 30% after starting an ACE inhibitor or ARB is an expected, monitorable finding, not automatically a reason to stop — a distinction OPRA scenarios sometimes test directly.

Tables

Clinic-BP diagnostic categories

Category	Systolic (mmHg)	Diastolic (mmHg)
Optimal	<120	<80
Normal	120–129	80–84
High-normal	130–139	85–89
Grade 1 hypertension	140–159	90–99
Grade 2 hypertension	160–179	100–109
Grade 3 hypertension	≥180	≥110

First-line class vs. common comorbidity steer

Comorbidity in the stem	Class typically favoured
Diabetes or CKD with proteinuria	ACE inhibitor or ARB
Pregnancy	Avoid ACE inhibitor/ARB — see current guidance for preferred agents
Ischaemic heart disease	Beta blocker often has a compelling additional indication
Gout history	Caution with thiazides

From My OPRA Journey

Hypertension was one of the topics where drilling scenario-based MCQs, then reviewing every wrong answer in detail, made the difference — the drug classes themselves are straightforward, but matching class to comorbidity under time pressure takes practice, not just reading.

Practice MCQs (100% original)

1. A 52-year-old woman with type 2 diabetes and microalbuminuria is newly diagnosed with hypertension. Her renal function is normal. Which class of antihypertensive is most appropriate as first-line therapy?

2. A patient starts ramipril for hypertension. Two weeks later, routine bloods show serum creatinine has risen by 20% from baseline, with potassium within normal range. What is the most appropriate action?

3. Which of the following patients should NOT be started on an ARB for hypertension?

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Frequently asked questions

Are beta blockers first-line for hypertension in Australia?