TAPENTADOL HYDROCHLORIDE
Clinical safety rating: safe
CNS depressants including alcohol and benzodiazepines increase sedation risk MAOIs can cause serotonin syndrome.
Tapentadol is a centrally-acting synthetic analgesic with a dual mechanism of action: mu-opioid receptor agonism and norepinephrine reuptake inhibition. It has no significant activity at other opioid receptors and minimal serotonergic effects.
| Metabolism | Tapentadol is primarily metabolized via glucuronidation by UDP-glucuronosyltransferase (UGT) enzymes, predominantly UGT1A9 and UGT2B7, and to a lesser extent via oxidation by CYP2C9 and CYP2C19 to inactive metabolites. The major metabolite is tapentadol-O-glucuronide. |
| Excretion | Primarily renal (95% excreted in urine; 30% as unchanged tapentadol, 55% as tapentadol-O-glucuronide, and 10% as minor metabolites). Fecal elimination accounts for <3%. |
| Half-life | 4 hours (terminal elimination half-life, clinically relevant for dosing interval every 4-6 hours; prolonged in moderate-severe hepatic impairment [up to 6.4 hours] and moderate-severe renal impairment [up to 7.5 hours]). |
| Protein binding | Approximately 20% bound to plasma proteins (primarily albumin). |
| Volume of Distribution | 540 L (approximately 7.7 L/kg for a 70 kg individual). High Vd indicates extensive tissue distribution. |
| Bioavailability | Oral bioavailability is approximately 32% due to extensive first-pass metabolism. |
| Onset of Action | Immediate-release oral: 30-60 minutes. Extended-release oral: 60-120 minutes. |
| Duration of Action | Immediate-release: 4-6 hours. Extended-release: 12-24 hours (dosed twice daily). Duration may be shorter in opioid-tolerant patients. |
Adults: Immediate-release tablets: 50-100 mg orally every 4-6 hours as needed for pain, not to exceed 600 mg per day. Extended-release tablets: 50 mg orally twice daily, titrated to a maximum of 500 mg per day.
| Dosage form | SOLUTION |
| Renal impairment | GFR 30-80 mL/min: No dose adjustment. GFR <30 mL/min: Not recommended. Hemodialysis: Not recommended. |
| Liver impairment | Child-Pugh Class A: No adjustment. Child-Pugh Class B: Immediate-release: 50 mg every 8 hours. Extended-release: Not recommended. Child-Pugh Class C: Contraindicated. |
| Pediatric use | Not approved for use in pediatric patients. No established dosing guidelines. |
| Geriatric use | Start at the lower end of the dosing range (50 mg immediate-release every 6 hours) and titrate slowly. Monitor for CNS depression and constipation. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
CNS depressants including alcohol and benzodiazepines increase sedation risk MAOIs can cause serotonin syndrome.
| FDA category | Animal |
| Breastfeeding | Tapentadol is excreted into human breast milk; the milk-to-plasma ratio (M/P) is approximately 0.86. Limited data; breastfed infants may experience drowsiness, respiratory depression, and withdrawal. Consider risk-benefit; if used, monitor infant for sedation and poor feeding. |
| Teratogenic Risk | Tapentadol hydrochloride is classified as FDA Pregnancy Category C. First trimester: Limited human data; animal studies show increased risk of skeletal anomalies and reduced fetal weight at high doses. Second and third trimesters: Chronic use may cause neonatal opioid withdrawal syndrome (NOWS) and respiratory depression at birth. Avoid use during labor due to risk of respiratory depression in neonate. |
■ FDA Black Box Warning
Risk of addiction, abuse, and misuse, which can lead to overdose and death. Serious, life-threatening, or fatal respiratory depression may occur, especially during initiation or following dose increases. Concomitant use with benzodiazepines or other CNS depressants may result in profound sedation, respiratory depression, coma, and death. Neonatal opioid withdrawal syndrome (NOWS) can occur with prolonged use during pregnancy.
| Common Effects | Constipation |
| Serious Effects |
["Significant respiratory depression","Acute or severe bronchial asthma in an unmonitored setting or without resuscitative equipment","Known or suspected gastrointestinal obstruction (including paralytic ileus)","Hypersensitivity to tapentadol or any component of the formulation","Concurrent use or within 14 days of MAO inhibitors (MAOIs)","Severe hepatic impairment (Child-Pugh class C)"]
| Precautions | ["Addiction, abuse, and misuse","Respiratory depression","Neonatal opioid withdrawal syndrome","CNS depression with concomitant use of benzodiazepines or other CNS depressants","Adrenal insufficiency","Severe hypotension","Seizures in patients with seizure disorders","Serotonin syndrome with concomitant serotonergic drugs","Increased intracranial pressure","Hepatic impairment (dose adjustment required)","Avoid use in patients with severe hepatic impairment","Withdrawal upon abrupt discontinuation","Avoid in patients with paralytic ileus or gastrointestinal obstruction"] |
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| Fetal Monitoring | Maternal: Monitor vital signs, respiratory rate, sedation level, and bowel function. Fetal: Monitor fetal heart rate and growth with prolonged use; assess for signs of withdrawal in neonate after delivery. Consider umbilical cord blood gas analysis if opioid exposure near delivery. |
| Fertility Effects | No human studies on fertility; animal studies show no significant impairment of fertility at doses up to 10 mg/kg/day. Potential for hormonal alterations with chronic opioid use, possibly affecting menstrual cycle and sperm parameters. |