Tapentadol

Is tapentadol safe?

Tapentadol is an effective painkiller for severe pain, and it has a few real advantages over older strong opioids. It is also a Schedule IIControlled substanceA medicine or drug that the law restricts because it can be misused or cause dependence. Countries group them into schedules or classes.More in the glossary opioid with the same boxed warningBoxed warningThe strongest safety warning the US FDA puts on a medicine's label, printed inside a black border at the top.More in the glossary as oxycodone: slowed breathing that can kill, physical dependenceDrug dependenceThe body's adaptation to a drug taken regularly, so that stopping it suddenly causes withdrawal symptoms. It is not the same as addiction.More in the glossary within weeks, and addiction even at prescribed doses. On top of that it can trigger seizures and, with some antidepressants, serotonin syndromeSerotonin syndromeA reaction caused by too much serotonin in the body, usually from combining medicines that raise it. Symptoms range from shivering to high fever.More in the glossary. We score it 32, below tramadol (34) and above oxycodone (26).

It was designed by Grünenthal, the maker of tramadol, and approved in the US in 2008 as Nucynta. Outside the US it is sold as Palexia.

How it differs from tramadol and oxycodone

Tapentadol acts on two targets. It switches on the mu opioid receptor, like morphine, and blocks the reuptake of noradrenaline, which dampens pain signals in the spinal cord. Tramadol does the same, but tapentadol has little effect on serotonin and works by itself rather than through a liver product.

That matters for safety. Tramadol and codeine depend on the CYP2D6CYP450 enzymesA family of liver enzymes that break down many medicines. When another drug or supplement speeds them up or slows them down, drug levels change.More in the glossary enzyme, which some people run so fast that normal doses become dangerous. Tapentadol is cleared mainly by glucuronidation, CYP enzymes play only a minor part, and none of its breakdown products relieve pain. Its effect is more predictable from one person to the next.

The CDC's 2022 guideline counts it at 0.4 times oral morphine, so 100 mg of tapentadol is about 40 morphine milligram equivalents. The guideline adds a caution: that figure is based on opioid activity alone, and nobody knows whether overdose risk follows the same scale.

Side effects: less constipation, more nausea

In the US trials behind the tablets, nausea affected 30% of patients and vomiting 18%, against 13% and 4% on placebo. Constipation, the side effect that troubles most long-term opioid users, was 8% against 3%. With the extended-release form it was 17% against 7%. Headache, dizziness and sleepiness are common, especially at the start. A 2015 Cochrane review of cancer pain trials found pain relief and serious side effects comparable with morphine and oxycodone, but the trials were small.

Seizures and serotonin syndrome

The MHRA strengthened its warnings in January 2019 after a European review. About half of the reported seizures happened in people also taking a drug that lowers the seizure threshold, such as an SSRI like sertraline, an SNRI such as duloxetine, a tricyclic or an antipsychotic. Serotonin syndromeSerotonin syndromeA reaction caused by too much serotonin in the body, usually from combining medicines that raise it. Symptoms range from shivering to high fever.More in the glossary has been reported with the same antidepressants. The MHRA lists the signs as muscle jerks (clonus), sweating, agitation, shaking, stiff muscles and a temperature above 38°C; it needs urgent care. MAOIs must not be taken with tapentadol or within 14 days of stopping one.

Overdose, misuse and alcohol

Deaths are rare but rising where use has grown. The Office for National Statistics found tapentadol mentioned on 18 death certificates in England and Wales in 2024 and 20 in 2023, up from none in 2015, against 213 for tramadol in 2024. In New South Wales, Australia, tapentadol poison centre calls rose 4.5-fold from 2016 to 2020, and three in four overdoses involved other drugs, most often benzodiazepines or other opioids. Australia recorded 35 tapentadol-related deaths from January 2015 to October 2021.

US surveillance in the first two years after launch found abuse and diversion rates similar to tramadol and lower than oxycodone or hydrocodone, and a 2016 study found the extended-release form rarely sold on the street. Those rates partly reflect how few people take it. The label still says addiction can occur at recommended doses.

Alcohol is a specific problem with Nucynta ER. In a label study, 240 mL of 40% spirit taken with a 100 mg tablet raised peak tapentadol levels by 48% on average and up to 4.4 times in some volunteers. Do not drink at all while taking it.

Who should be careful

Talk to your doctor before starting tapentadol, or about extra safeguards, if you:

• have epilepsy or have had a seizure
• take an antidepressant, an antipsychotic, a triptan or any MAOI
• take a benzodiazepine, sleeping pill, gabapentin or pregabalin, or drink alcohol
• have severe kidney or moderate to severe liver disease, sleep apnoea or COPD
• have had problems with alcohol or drugs, or are pregnant

Swallow extended-release tablets whole, keep all tablets locked away and take leftovers to a pharmacy. In an overdose, call emergency services and give naloxone if you have it; US Poison Help is 1-800-222-1222. After regular use, do not stop suddenly or change the dose without your prescriber.

How we scored it

Track record (75) is the only middling factor, held back by a shorter history than older opioids. Regulatory warnings (12), dependence (20), interactions (25) and overdose marginOverdose marginHow far a normal dose is from a harmful one. A wide margin means an accidental extra dose is unlikely to cause serious harm.More in the glossary (30) are in the lowest band, as for every Schedule IIControlled substanceA medicine or drug that the law restricts because it can be misused or cause dependence. Countries group them into schedules or classes.More in the glossary opioid. Serious side effects (35) score a little better than oxycodone's because of fewer bowel problems and no genetic surprises, offset by the seizure and serotonin risks. Confidence is medium because independent long-term data are thinner than for older opioids.