Description and Composition of Trapidol
Trapidol, a synthetic and atypical opioid pain killer for moderate to severe pain is one of the most highly prescribed drugs in Orthopaedic Hospitals and other health management centres. It contains Tramadol as its active pharmaceutical ingredient. It also contains inactive ingredients called excipients in sufficient quantities. It is a drug of abuse and illicit use in Nigeria and most parts of the world. It is available in different dosage forms including tablets, capsules and injections. It also comes in different dosage strengths.
Indication and Uses of Trapidol
Trapidol is used to relief moderate to moderately severe pain.
Trapidol and Pregnancy
Trapidol crosses the placenta. Post-marketing reports following Tramadol use in pregnancy include neonatal seizures, withdrawal symptoms, fetal death, and stillbirth. It is not recommended for us during labour and delivery.
Pregnancy Risk Factor: Category C
Lactation: It enters breast milk/ contraindicated.
Contraindication of Trapidol
Hypersensitivity to Tramadol, opioids or any component of the formulation; opioid dependent patients, acute intoxication with alcohol; hypnotics; centrally-acting analgesics, opioids or psychotropic drugs.
Not recommended during pregnancy or in nursing mothers. Tolerance or drug dependence may result from extended use (withdrawal symptoms have been reported); abrupt discontinuation should be avoided. Tapering of dose at the time of discontinuation limits the risk of withdrawal symptoms. Safety and efficacy in paediatric patients have not been established.
Adverse Effects of Trapidol
Dizziness, nausea, constipation, headache, somnolence, vomiting, pruritus, xerostomia, flushing, anorexia, diaphoresis, dyspepsia, asthenia. Serious reactions include: seizures, serotonin syndrome, suicidal ideation, Steven Johnson Syndrome.
Overdosage and Toxicology symptoms of Trapidol
This include CNS and respiratory depression, lethargy, coma, seizure, cardiac arrest and death.
Treatment of Toxicity
This consists of Naloxone 2mg IV (0.01mg/kg children) with repeat administration as needed up to 18mg. NOTE: Naloxone may increase the risk of seizures in Tramadol overdose.
Contraindications of Trapidol
Alcohol (if acute alcohol intoxication; otherwise caution advised and consider lower Tramadol dose);
Monoamine oxidase inhibitors e.g. Selegiline. Tramadol use is contraindicated within 14days of MAOI use.
Avoid or use alternative
Carbamazepine – decreases levels of Tramadol and thus efficacy; may alter seizure control, increased risk of CNS depression and psychomotor impairment.
Linezolid – increased risk of serotonin syndrome.
Monitor or modify therapy
Amitriptyline – increased risk of CNS depression, seizures, psychomotor impairment, serotonin syndrome (ADDITIVE EFFECTS)
Codeine – may increase risk of CNS and respiratory depression, seizures, psychomotor impairment (ADDITIVE EFFECT). Consider opioid dose reduction.
Ketamine – may increase risk of CNS and respiratory depression (ADDITIVE EFFECT). Lower Tramadol dose.
Propofol – increased risk of CNS and respiratory depression, psychomotor impairment (ADDITIVE EFFECT).
Use with caution
Aminophylline there may be increased risk of seizures when Tramadol is combined with either of these drugs: Ampicillin, Amoxicillin, Aminophylline
Artemether/Lumefantrine–Artemether induces while Lumefantrine inhibits metabolism of Tramadol, thus the effect may be decreased or increased Tramadol levels with resultant decreased analgesic efficacy or increased risk of adverse effects respectively.
Ethanol, Nutrition/ Herb Interactions –
Ethanol: Avoid alcohol (may increase CNS depression)
Effect of Food on Trapidol
Food does not affect the rate or extent of absorption.
Herb/Nutraceutical: Avoid Valerian, st John’s Wort, Kava kava, gotu kola (may increase risk of CNS depression)
Store at controlled room temperature of 25°C
Mechanism of action
Trapidol binds to µ-opiate receptors in the CNS causing inhibition of ascending pain pathways altering the perception of and response to pain. It also inhibits the reuptake of norepinephrine and serotonin; which also modifies the ascending pain pathway.
Pharmacodynamics and Pharmacokinetics of Trapidol
Onset of action:~1 hour
Duration of action: 9hours
Absorption: Rapid and complete
Distribution: Vd: 2.5 – 3L/Kg
Protein Binding: plasma 20%
Metabolism: extensively hepatic; has primarily active metabolite formed by CYP2D6.
Half-life elimination: Tramadol – ~6hours; active metabolite 7hours.Prolonged in elderly and in hepatic or renal impairment.
Time to peak: 2 hours
Excretion: urine (as metabolites).
Dosage of Trapidol
Adults: moderate to severe chronic pain: 50 – 100mg every 4 to 6 hours; not to exceed 400mg/day.
Elderly:> 75years 50 – 100mg every 4 to 6 hours; not to exceed 300mg/day.
Dosing adjustment in renal impairment:
Creatinine Clearance; Clcr <30mL/minute: administer 50 – 100mg dose every 12 hours (maximum 200mg/day).
Dosing adjustment in hepatic impairment:
Cirrhosis: Recommended dose 50mg every 12 hours
Monitoring Parameters of Trapidol
Pain relief, Respiratory rate, Blood pressure and pulse; signs of tolerance or abuse, Creatinine (at baseline).