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Weak Opioid / Serotonin-Noradrenaline Reuptake Inhibitor (Analgesic) Pregnancy: Caution — neonatal withdrawal if used near term; avoid prolonged use

Tramadol (Post-Operative Pain)

Brand names: Tramacet (tramadol/paracetamol combination), Zydol, Tramadol hydrochloride

Adult dose

Dose: 50–100 mg oral or IV/IM every 4–6 hours
Route: Oral, IV slow injection, or IM
Frequency: Every 4–6 hours
Max: 400 mg/day (oral or IV)
IV: dilute in 100 mL NaCl 0.9% and infuse over 15–20 min (slow IV reduces nausea/seizure risk). Suitable for moderate-severe post-operative pain as part of multimodal analgesia regimen.

Paediatric dose

Dose: 1 mg/kg
Route: Oral or IV
Frequency: Every 4–6 hours
Max: 400 mg/day
Concentration: 50 mg/mL (injectable) mg/ml
Children ≥12 years: adult doses. Avoid in children <12 years (MHRA warning — respiratory depression risk, especially post-tonsillectomy). Ultra-rapid CYP2D6 metabolisers at higher risk.

Dose adjustments

Renal

Reduce dose and frequency in renal impairment (eGFR 10–30: 50 mg every 12h max; avoid if eGFR <10)

Hepatic

Reduce dose and frequency in hepatic impairment

Paediatric weight-based calculator

Children ≥12 years: adult doses. Avoid in children <12 years (MHRA warning — respiratory depression risk, especially post-tonsillectomy). Ultra-rapid CYP2D6 metabolisers at higher risk.

Clinical pearls

  • MHRA 2013: avoid tramadol in children <12 years — risk of respiratory depression, especially ultra-rapid CYP2D6 metabolisers after tonsillectomy
  • Serotonin syndrome risk: significant with SSRIs/SNRIs — common combination in surgical patients on antidepressants; monitor for agitation, hyperthermia, clonus
  • Not interchangeable 1:1 with codeine — tramadol has serotonergic mechanism in addition to weak opioid activity
  • Epilepsy: tramadol lowers seizure threshold — avoid or use with extreme caution
  • Antiemetic prophylaxis: nausea is very common with tramadol — always co-prescribe antiemetic

Contraindications

  • MAOI use (within 14 days — serotonin syndrome)
  • Acute intoxication with alcohol, opioids, or psychotropics
  • Severe renal or hepatic impairment
  • Uncontrolled epilepsy
  • Children <12 years (MHRA)

Side effects

  • Nausea and vomiting (common — co-prescribe antiemetic)
  • Dizziness and sedation
  • Seizures (lowers seizure threshold)
  • Constipation
  • Serotonin syndrome (with SSRIs/SNRIs/MAOIs)
  • Respiratory depression (lower risk than strong opioids)

Interactions

  • MAOIs — serotonin syndrome (contraindicated; 14-day washout)
  • SSRIs/SNRIs/TCAs — serotonin syndrome risk (monitor closely)
  • Ondansetron — serotonin syndrome risk (also reduces tramadol analgesia via 5-HT3 antagonism)
  • CNS depressants — additive sedation

Monitoring

  • Pain score
  • Nausea/vomiting
  • Neurological status (seizure risk, serotonin syndrome)
  • Respiratory rate

Reference: BNFc; BNF; MHRA Drug Safety Update 2013 (tramadol children); RCoA Acute Pain Handbook. Verify against your local formulary and the latest BNF before prescribing.

Related

Curated clinical cross-links plus same-class fallbacks.

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