Tramadol: general

Tramadol is an opioid pain reliever, but an atypical one: alongside its opioid activity it also inhibits the reuptake of noradrenaline and serotonin, which is why it's classed separately from the classic opioids [1]. It's described as a weak, phenylpiperidine-type opioid analgesic [2], first reported in a 1965 British patent and marketed from 1977 under the trade name Tramal [3]. In the US it's approved specifically for moderate-to-severe pain [4], and since 2014 it has been a controlled substance there because of its potential for misuse and addiction [4].

Two things matter most before anything else. First, tramadol's metabolism and pharmacology are described as unpredictable and complex, and that unpredictability is linked to unique, serious adverse effects — the same dose can behave very differently from one person to the next [5]. Second, compared with options like acetaminophen, NSAIDs, or other opioids, tramadol is reported to offer no therapeutic advantage while carrying some disadvantages of its own [5]. In some countries — reports point particularly to parts of Africa and Western Asia — tramadol misuse, dependence, and overdose have become a significant public health concern [2].

As with opioids generally, opioids bind to receptors in the brain and interrupt the signals that tell the body to keep breathing, causing respiratory failure [6]. That's the risk to plan around before taking any: know the signs of overdose, keep naloxone accessible if you can, and don't use alone.

References

1. Discovery and development of tramadol for the treatment of pain - PubMed — PubMed
2. Tramadol - Expert Committee on Drug Dependence (ECDD) — WHO ECDD
3. Tramadol - American Chemical Society — American Chemical Society
4. Tramadol - StatPearls - NCBI Bookshelf — NCBI (Treasure Island: StatPearls)
5. Tramadol - Therapeutics Letter - NCBI Bookshelf — NCBI (Therapeutics Initiative)
6. Opioid Overdose: Signs, Symptoms & Treatment — Cleveland Clinic