A- 3 years old child brought to ED after unknown amount ingestion of the below medication .She is drowsy, RR 10 , Spo2 90% in room air, HR 100 ,BP:90/50 , afebrile, blood sugar 6 mmol/l .pupils pinpoint .Rest of exam unremarkable.
Q1What are the expected toxicity?
Q2What is the management of this child including antidote?
Drowsy kid Cont'
Toxic Mechanism:
Tramadol is a weak partial agonist at mu opioid receptors. It also inhibits serotonin and noradrenaline reuptake in the CNS, hence the serotonin toxicity, tachycardia and risk of seizures.
Toxicokinetics:
Rapid absorption
Peak levels at 1-3 hours but can range from 2-12 hours for modified release (even longer in overdose)
Volume of distribution 2-3L/kg
Hepatic metabolism and renal excretion.
Risk Assessment
Seizures: If > 1.5 grams of tramadol is ingested then seizures should be anticipated. (> 10 mg/kg for children).This maybe delayed up to >6 hours after ingestion for modified release.
Opioid effects: Sedation and respiratory depression (and miosis) are usually mild and rarely require intervention.
Serotonin toxicity: Rare with only one serotinergic agent but common if co-ingestants are used (tramadol plus an SSRI or SNRI).
Supportive Care Is the key
Signs of serotonin toxicity (agitation, tachycardia, tremor and myoclonic jerks) can be managed with titrated doses of benzodiazepine.
Antidote
Naloxone has been used to reverse the CNS effects in a pure tramadol overdose but if co-ingestants have been used its effect maybe limited.
Disposition
Children who have ingested >10 mg/kg or adults > 1.5 grams should be observed with an IV in situ for 12 hours. Discharge should not occur at night.
Patients who are symptomatic, need admission for continued observation and supportive care until symptom free.
References
https://litfl.com/tramadol-toxicity/