What to spot & stop

Triple-check dose, units and the decimal against the BNF medicinal forms. Learn the mcg list. Borderline mg↔g: metformin, some antibiotics, some antiepileptics. Always grams: paracetamol, lithium, calcium carbonate, NAC.

Match frequency/timing to the drug. Morning: diuretics, steroids. Night: statins, sedation. With meals: insulin, Creon. Weekly: methotrexate (+ folic acid on a different day), alendronic acid 70 mg.

Check the route fits the formulation. PR: laxatives, diazepam, diclofenac. IM: depots. SC: LMWH, insulin, EOLC meds. SL: GTN.

For a young child, prescribe the liquid / oral suspension. Confirm the dose on the BNFC, not the adult BNF.

Check the BNF for a separate elderly maximum. Reduce SSRIs and opioids; apixaban has explicit age/weight/creatinine reduction criteria.

Avoid, or monitor the INR closely and adjust the dose.

Avoid the combination; methotrexate is weekly and folate-sensitive.

Avoid or monitor U&E and potassium closely.

Avoid combining a rate-limiting CCB with a β-blocker.

Suspend the statin with a macrolide; cap the dose with amlodipine/diltiazem.

Add a PPI with an NSAID; avoid serotonergic combinations.

Reduce digoxin dose / monitor levels and potassium.

Avoid or monitor lithium levels closely.

Avoid or monitor levels; watch for tachycardia, vomiting, seizures.

Avoid, or reduce azathioprine to ~25% of the dose with specialist input.

Absolute contraindication — never co-prescribe.

Avoid alcohol during and for 48 h after the course.

Use pantoprazole or lansoprazole for gastroprotection instead.

Use a rate-limiting CCB; cardioselective β-blocker only with specialist caution.

Avoid nephrotoxins; dose-adjust renally-cleared drugs.

Avoid; use heart-failure-appropriate agents (ACEi, β-blocker, MRA).

Avoid NSAIDs; co-prescribe a PPI if antiplatelet/anticoagulant is essential.

Use domperidone for nausea; quetiapine/clozapine if antipsychotic needed.

Avoid combining QT-prolonging drugs; correct K⁺/Mg²⁺.

Avoid; pick alternatives that don't block the neuromuscular junction.

Avoid the trigger; manage the flare.

Avoid; pioglitazone is contraindicated in heart failure.

Switch to an ARB for an intolerable cough.

Dose-reduce or switch class; oedema is not heart failure.

Monitor U&E; review if symptomatic hyponatraemia or gout.

Monitor U&E and fluid status.

Gastroprotection, bone protection; never stop abruptly.

Monitor TFTs and LFTs 6-monthly.

Check level and potassium; Digifab for severe toxicity.

Co-prescribe a laxative; naloxone for toxicity.

Review the indication; use the lowest effective dose.

Review in asthma, PVD, and brittle diabetes.

Co-prescribe a laxative with opioids; review iron / anticholinergics.

Send stool for C. diff if antibiotic-associated; review metformin / colchicine.

Stop the culprit; catheterise if acute.

Review the offending drug.

Deprescribe; look for other delirium causes.

Switch to a prolactin-sparing alternative; check serum prolactin.

Rationalise sedatives and antihypertensives; check lying/standing BP.

Review the diuretic; don't stop urate-lowering therapy during an acute attack.

Bone protection (calcium / vit D + bisphosphonate) with long-term steroids.

Monitor capillary glucose; adjust diabetic therapy.

Review the dose; long-acting sulfonylureas are a STOPP target in the elderly.

Rinse the mouth after an inhaled steroid; treat with nystatin 100,000 units QDS (7 days, continued 48 h after lesions clear).

Avoid stacking QT-prolongers; correct K⁺/Mg²⁺ (BNF Appendix 1 Table 8).

Monitor U&E; replace potassium; consider a K-sparing combination.

Stop the culprit; ECG and emergency hyperkalaemia treatment if high.

Check paired serum/urine osmolality; review the drug.

Monitor sodium and fluid balance.

Stop the COC 4 weeks before major/leg surgery; restart 2 weeks after mobilising.

Stop 24 h before major surgery; continue for minor surgery with monitoring.

Consider stopping 24 h before surgery.

Withhold on the morning of surgery.

Stop and bridge per individualised plan; aspirin often continued if high thrombotic risk.

Review the indication; stop or switch to a safer agent.

Double the steroids; hold metformin, the gliflozins and the "DAMN" drugs while unwell.

Hold the DAMN drugs; treat the cause (pre-renal → fluids; post-renal → relieve obstruction).

Stop long-term preventatives; continue / convert symptomatic drugs (often subcutaneous).

Switch to a pregnancy-safe alternative (e.g. labetalol/nifedipine for BP; LMWH for anticoagulation).

Avoid in women of child-bearing potential unless conditions of the PPP are met.

Use a condom + a long-acting method, or a non-affected method (e.g. copper IUD / injectable).

No extra precautions needed for ordinary antibiotics, except enzyme inducers like rifampicin.