DocPasser

MRCPI Part 1 → Clinical pharmacology and therapeutics

Clinical pharmacology and therapeutics for MRCPI Part 1

Clinical pharmacology and therapeutics accounts for roughly 8% of the MRCPI Part 1 blueprint. This bank has 1 item tagged to it.

How much of MRCPI Part 1 is clinical pharmacology and therapeutics?

Around 8% of the paper, per RCPI examination regulations and training curricula. That weighting is why the DocPasser mock builder samples sections in proportion rather than shuffling everything into one pile — practising a flat distribution trains you for a paper that does not exist.

Verification status. All 3 published figures on this page have been read in the source document and dated above. Source of truth: RCPI examination regulations and training curricula, Royal College of Physicians of Ireland. How we verify.

Sample clinical pharmacology and therapeutics questions

A 71-year-old woman on lithium for bipolar disorder is admitted with vomiting, coarse tremor and confusion. She recently started a new medication. Lithium level is 2.4 mmol/L, creatinine 168 micromol/L. Which newly started drug is the most likely precipitant?

  1. Amoxicillin No significant interaction with lithium and no effect on renal lithium handling.
  2. Lisinopril correct Correct. ACE inhibitors reduce renal lithium clearance and are a well-recognised cause of lithium toxicity, particularly in older patients where they also reduce glomerular filtration. Thiazides and NSAIDs act the same way.
  3. Omeprazole No clinically important effect on lithium clearance.
  4. Levothyroxine Lithium can cause hypothyroidism so thyroxine may well be co-prescribed, but it does not raise lithium levels.
  5. Salbutamol No effect on lithium levels, beta-2 agonists actually shift potassium, not lithium.

The point: Lithium toxicity is precipitated by anything that reduces renal clearance: ACE inhibitors and ARBs, thiazides, NSAIDs, dehydration and acute kidney injury. Toxicity gives coarse tremor, ataxia, confusion and seizures, as opposed to the fine tremor of therapeutic use. Severe toxicity is treated with haemodialysis.

Source: BNF — Lithium carbonate: interactions and monitoring British National Formulary · tier 3, national formulary

The other sections of MRCPI Part 1

Cardiology · Respiratory medicine · Gastroenterology and hepatology · Neurology · Endocrinology and metabolic medicine · Nephrology · Rheumatology · Haematology · Infectious diseases and tropical medicine · Oncology and palliative care · Dermatology · Clinical sciences and statistics · Acute and critical care medicine

Back to MRCPI Part 1

DocPasser is exam preparation material, not clinical guidance. Nothing here should be used to make a decision about a real patient. Always work from your own local guidelines and seniors.