Oxycodone: general

Oxycodone is a semisynthetic opioid made from thebaine [1]. It was first synthesized from thebaine in 1916 [2], and brought into clinical use in Germany in 1917 [3]. It's prescribed for moderate to severe pain, both as an immediate-release product and as an extended-release product for chronic pain [4][5][6]. It's in a class of medications called opiate (narcotic) analgesics [7], which work by changing the way the brain and nervous system respond to pain [7]. It has agonist activity at mu, kappa, and delta opioid receptors [5], and shares the abuse liability of other mu-opioid agonists [3].

The thing to know before anything else: as with opioids generally, breathing that slows and stops is how overdose kills [8]. As with opioids generally, co-ingestion with alcohol, benzodiazepines, or other GABA-ergic drugs like pregabalin is common and can make respiratory depression worse [9]. Stimulants such as crack cocaine, or synthetic cannabinoids, can mask the usual signs of opioid overdose or add their own effects on top, so the overdose may look different than expected [9].

Naloxone reverses opioid overdose if given in time [10][11], and death from opioid overdose is preventable with naloxone and basic life support [10]. It has essentially no effect on someone who hasn't taken opioids [10]. When in doubt, giving it is the safer call. If there's an inadequate response to naloxone, standard supportive care should continue until the drugs involved are metabolized and eliminated [12].

Pills given to you or bought from a friend may look like a safer drug, but might contain lethal doses of nonmedical opioids, including fentanyl [8].

References

1. oxycodone | Ligand page | IUPHAR/BPS Guide to PHARMACOLOGY — IUPHAR/BPS Guide to Pharmacology
2. Oxycodone — Wikipedia
3. Oxycodone: A Current Perspective on Its Pharmacology, Abuse, and Pharmacotherapeutic Developments — Pharmacological Reviews (via PMC)
4. Oxycodone | C18H21NO4 | CID 5284603 - PubChem — National Center for Biotechnology Information (NCBI)
5. Oxycodone - StatPearls - NCBI Bookshelf — StatPearls Publishing (via NCBI)
6. Oxycodone - LiverTox® - NCBI Bookshelf — National Institute of Diabetes and Digestive and Kidney Diseases (via NCBI)
7. Oxycodone: MedlinePlus Drug Information — U.S. National Library of Medicine (MedlinePlus)
8. Opioid Overdose: Signs, Symptoms & Treatment — Cleveland Clinic
9. Best Practice Guideline: Acute Opioid Toxicity — Royal College of Emergency Medicine (RCEM)
10. Opioid overdose — World Health Organization
11. Opioid medicines - side effects, withdrawal symptoms, dependency — Australian Government Department of Health and Aged Care
12. Opioid Overdose Management — Ontario Poison Centre