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NSAID (Non-Steroidal Anti-Inflammatory Drug) Pregnancy: Avoid in third trimester (premature closure of ductus arteriosus); use with caution in first and second trimesters

Diclofenac

Brand names: Voltarol, Diclomax

Adult dose

Dose: 75-150 mg/day in divided doses
Route: Oral / Topical
Frequency: Two to three times daily with food
Max: 150 mg/day (oral)
Topical diclofenac (Voltarol gel 1%) has significantly lower systemic exposure and is preferred in elderly for localised musculoskeletal pain

Paediatric dose

Dose: Seek specialist opinion N/A/kg
Route: Oral
Frequency: Seek specialist opinion
Max: Seek specialist opinion
Seek specialist opinion

Dose adjustments

Renal

Avoid in eGFR under 30; use with caution in mild-moderate renal impairment — NSAIDs reduce renal prostaglandins causing AKI

Hepatic

Avoid in severe hepatic impairment

Paediatric weight-based calculator

Seek specialist opinion

Clinical pearls

  • Beers Criteria 2023 and STOPP v3: Oral NSAIDs are potentially inappropriate in elderly — GI bleeding risk 3-5x higher; cardiovascular risk increased particularly with diclofenac
  • MHRA 2013: Diclofenac has similar cardiovascular risk to COX-2 inhibitors — contraindicated in established cardiovascular disease
  • Topical diclofenac (Voltarol gel) is preferred for localised osteoarthritis pain in elderly — equivalent efficacy for knee/hand OA with minimal systemic absorption
  • Triple whammy: ACEi or ARB + diuretic + NSAID = high risk of acute kidney injury — avoid combination in elderly
  • If oral NSAID unavoidable: use lowest dose for shortest time; co-prescribe PPI (e.g. lansoprazole 15 mg); avoid in patients on anticoagulants

Contraindications

  • Established ischaemic heart disease, peripheral arterial disease, or cerebrovascular disease
  • Active peptic ulcer or GI bleeding
  • Severe renal or hepatic impairment
  • Heart failure
  • Third trimester of pregnancy

Side effects

  • GI ulceration and bleeding
  • Renal impairment (AKI)
  • Fluid retention and hypertension
  • Cardiovascular events (MI, stroke)
  • Hepatotoxicity
  • Hypersensitivity (aspirin-sensitive asthma)

Interactions

  • Warfarin / DOACs (increased bleeding risk)
  • ACE inhibitors / ARBs (triple whammy — AKI risk with diuretics)
  • Aspirin (reduces cardioprotective effect of low-dose aspirin)
  • Lithium (increases lithium levels)
  • Methotrexate (reduces excretion — toxicity)

Monitoring

  • Renal function (U&E) before and 2 weeks after starting
  • Blood pressure
  • GI symptoms
  • Signs of fluid retention

Reference: BNFc; BNF 90; MHRA Drug Safety Update 2013 (diclofenac cardiovascular risk); AGS Beers Criteria 2023; STOPP/START v3; NICE CG177. Verify against your local formulary and the latest BNF before prescribing.

Related

Curated clinical cross-links plus same-class fallbacks.

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