PSA ADRs, Interactions & “Safe Prescribing” Thinking: medical study guide (2026)

Key points

The PSA rewards risk recognition: identify what could harm the patient and what you must monitor.
Use a repeatable scan: indication → contraindications → interactions → renal/hepatic → pregnancy → monitoring.
Most high-stakes mistakes cluster around: anticoagulants, NSAIDs, QT-prolongers, opioids/benzos, and polypharmacy.

A large portion of “safe prescribing” is not knowing obscure facts—it is behaving like a clinician who systematically checks for predictable harm. The PSA blueprint explicitly tests reasoning around adverse drug reactions, interactions, and safety behaviours.

The PSA safety scan (do this every time)

1) Why this drug? (indication) 2) Who is this patient? (age, pregnancy, renal/hepatic, frailty) 3) What else are they taking? (interactions) 4) What could go wrong? (ADR pattern) 5) What will you monitor? (explicit monitoring + advice) 6) What will you tell the patient? (warnings + safety net)

Step 1 — Spot the ‘risk multipliers’ in 5 seconds

Before choosing an answer, scan for: CKD, liver disease, pregnancy/breastfeeding, older age/falls risk, anticoagulation, history of GI bleed, QT risk, allergy, and polypharmacy. These drive most of the safe prescribing logic.

Step 2 — Use pattern-based ADR recognition

Instead of memorising lists, learn patterns: • Bleeding (anticoagulants, antiplatelets, NSAIDs combos) • Renal injury (dehydration + nephrotoxins) • Electrolytes (K+, Na+ disruptions) • QT prolongation (multiple QT agents + risk factors) • Serotonin toxicity (stacking serotonergic meds) Then map the scenario to the pattern.

Step 3 — Make monitoring explicit (PSA loves this)

If the safest answer includes monitoring, write/choose the option that states: what you will check, when, and what action you will take if abnormal. “Monitor” alone is vague and often not the best answer.

Step 4 — Patient advice is part of safety

Many PSA questions reward the option that includes clear advice: red flags, what to avoid, and when to seek help. Safety netting is not fluff—it’s prescribing competence.

The ‘Never Skip’ Checks (fast, universal)

Allergy status and nature of reaction.
Current medicines list (including OTC/herbals).
Renal function and whether the drug is renally cleared.
Pregnancy/breastfeeding status where relevant.
Baseline monitoring required (e.g., BP, electrolytes, INR, LFTs—depending on drug).

Avoid the high-risk exam mistake

Do not choose an option because it sounds ‘clinically sensible’ if it fails basic safety checks (renal, pregnancy, interactions). The PSA is designed to punish exactly that type of confidence.

SourcePSA: Blueprint (14.07.2025) — ADRs & interactions are explicit competencies (official PDF)

Open Link

SourcePrescribing Safety Assessment — official site

Open Link

Your learning path

Save your place and choose what comes next

Work through this guide (9 steps)

Use the actions from this article to track what you have worked through.

Step 1 — Spot the ‘risk multipliers’ in 5 seconds
Before choosing an answer, scan for: CKD, liver disease, pregnancy/breastfeeding, older age/falls risk, anticoagulation, history of GI bleed, QT risk, allergy, and polypharmacy. These drive most of the safe prescribing logic.
Return to this section
Step 2 — Use pattern-based ADR recognition
Instead of memorising lists, learn patterns: • Bleeding (anticoagulants, antiplatelets, NSAIDs combos) • Renal injury (dehydration + nephrotoxins) • Electrolytes (K+, Na+ disruptions) • QT prolongation (multiple QT agents + risk factors) • Serotonin toxicity (stacking serotonergic meds) Then map the scenario to the pattern.
Return to this section
Step 3 — Make monitoring explicit (PSA loves this)
If the safest answer includes monitoring, write/choose the option that states: what you will check, when, and what action you will take if abnormal. “Monitor” alone is vague and often not the best answer.
Return to this section
Step 4 — Patient advice is part of safety
Many PSA questions reward the option that includes clear advice: red flags, what to avoid, and when to seek help. Safety netting is not fluff—it’s prescribing competence.
Return to this section
Allergy status and nature of reaction.Return to this section
Current medicines list (including OTC/herbals).Return to this section
Renal function and whether the drug is renally cleared.Return to this section
Pregnancy/breastfeeding status where relevant.Return to this section
Baseline monitoring required (e.g., BP, electrolytes, INR, LFTs—depending on drug).Return to this section

Study methods · Article 25 of 48