Tapentadol, is it the new menace in the "drug-world" ?

Codeine, dextropropoxyphene, and tramadol were assigned "scheduled" category due to their abuse potential in 2011, 2017, and 2018, respectively, which has restricted their availability in India. Hence, there is a chance of emergence of abuse of a new pharmaceutical opioid. A recent study published by Basu et al in current issue of Indian Journal of Psychiatry shows rising abuse potential of a new drug- Tapentadol in India.

The 2019 Magnitude of Substance Use in India survey showed pharmaceutical opioids to be the second most commonly abused opioids (0.96%), after heroin (1.14%). Tapentadol is a synthetic opioid with both μ-opioid receptor agonist and selective serotonin reuptake inhibitor actions. The μ-receptor agonism of tapentadol lies in between that of morphine and tramadol. Although tapentadol has not yet been scheduled under the Narcotic Drugs and Psychotropic Substances Act, there is emerging clinical experience and initial evidence showing its abuse liability in India.

Basu et al aimed to study the prevalence and profile of tapentadol users in a treatment seeking population. The study had prospective and retrospective arms. They collected 8-month prospective data by face-to-face interviews (n = 70) and 8-year retrospective data from case notes (n = 26) with either tapentadol misuse/abuse or dependence in patients attending a de-addiction center. They included all the patients with reported or recorded history of tapentadol use.

There were a total of 3084 new cases, including 1860 cases with opioid dependence. In brief, the results of the study were:

1. There were 279 cases with pharmaceutical and/or mixed opioid use and 70 cases of tapentadol use.

2. The prevalence of tapentadol use was 2.3% among all new cases, 3.8% among opioid users, and 25.1% among pharmaceutical/ mixed opioid users.

3. Concurrent use of other opioids was seen in >80% of participants of both the arms.

4. Major sources of tapentadol were chemists (without a prescription) (53%) and doctors (prescriptions) (40%). Patients in the tapentadol dependence group had a significantly higher dose, duration, and pharmaceutical opioid use.

Discussing the findings, Dr. Basu pointed out, "We believe that this is the first prospective study from India on tapentadol abuse or dependence with a reasonably large sample. The prospective arm of the study shows the prevalence of tapentadol abuse and dependence in the clinic, whereas the retrospective arm reflects an apparently increasing trend of use in the treatment seekers."

Nearly 3/4th of the total 96 patients with tapentadol use were identified during the prospective study. It highlights the importance of proactive case finding and gathering additional relevant information (reason of initiation, subjective psychoactive effect, etc.) for better case profiling in patients with an emerging substance of abuse.

Around 40% of cases were prescribed tapentadol by a doctor, possibly to treat withdrawal symptoms. This practice raises concern for diversion and use of nonevidence-based treatment for opioid dependence. Volkow and McLellan asserted that in the USA, the major source of diverted pharmaceutical opioids was physicians' prescription.

Also Read:Volkow ND, McLellan AT. Opioid abuse in chronic pain‑‑Misconceptions and mitigation strategies. N Engl J Med 2016;374:1253‑63.

A reason for nonevidence-based prescriptions could be the overt legal restriction on the availability of opioid agonist treatment in India. Therefore, we should ensure physicians' education and awareness, prescription monitoring, and improved access and availability of evidence-based treatment to address the problem.

The authors concluded, "With its unrestricted availability, tapentadol is causing concern among medical professionals in India as it is emerging as a substitute for illicit pharmaceutical opioids. Both from the policy and the clinical perspectives, India needs awareness promotion, training, availability restriction, and provision of treatment for tapentadol abuse or dependence."

Source: Indian Journal of Psychiatry: Basu D, Mahintamini T, Ghosh A, Roub F, Subodh BN, Mattoo SK, et al. Tapentadol, the new kid on the block in India: Is it time to worry? Indian J Psychiatry 2020;62: 697-702