Tapentadol

Tapentadol, sold under the brand names Nucynta and Palexia among others, is a synthetic opioid analgesic with a dual mode of action as a highly selective full agonist of the μ-opioid receptor and as a norepinephrine reuptake inhibitor (NRI). Tapentadol is used medically for the treatment of moderate to severe pain. It is highly addictive and is a commonly abused drug. Frequently reported adverse effects include euphoria, constipation, nausea, vomiting, headaches, loss of appetite, drowsiness, dizziness, itching, dry mouth, and sweating. More severe adverse reactions can occur, including addiction and dependence, substance abuse, respiratory depression, and an elevated risk of serotonin syndrome. Concurrent use of tapendatol with serotonergic drugs can heighten the risk of excessive serotonin accumulation while concurrent use with CNS depressants — alcohol, benzodiazepines, other opioids — can heighten the risk of profound sedation, dangerously slowed breathing, and death. Analgesia occurs within 32 minutes of oral administration, and lasts for 4–6 hours. Tapentadol is taken by mouth, and is available in immediate-release and controlled-release formulations. Tapentadol's combined mechanism of action is often compared to that of tramadol. Unlike tramadol, tapentadol is not metabolised by cytochrome P450 enzymes, but rather through glucuronidation. Due to this, tapentadol has fewer interactions with other medications and fewer side effects when compared with tramadol. Like tramadol, tapentadol affects both the opioid system and the norepinephrine system to relieve pain. Unlike tramadol, it has only weak effects on the reuptake of serotonin and is a significantly more potent opioid with no known active metabolites. The potency of tapentadol is somewhere between that of tramadol and morphine, with an analgesic efficacy comparable to that of oxycodone despite a lower incidence of side effects. The CDC Opioid Guidelines Calculator estimates a conversion rate of 50mg of tapentadol equaling 10 mg of oral oxycodone in terms of...