Oxycodone: Opioid Analgesic for Moderate to Severe Pain
Oxycodone is a semi-synthetic opioid derived from thebaine with oral bioavailability of 60–87% — substantially higher than morphine. Available in immediate-release (IR) and extended-release (ER) formulations, it provides reliable analgesia for moderate-to-severe pain.
As a Schedule II controlled substance (BtMG in Germany), oxycodone carries risk of dependence and respiratory depression. ER tablets must not be crushed or chewed.
Mechanism of Action
Oxycodone acts primarily at µ-opioid receptors (MOR), inhibiting adenylate cyclase, closing voltage-gated calcium channels, and opening inward-rectifying potassium channels — suppressing nociceptive transmission in the CNS and spinal dorsal horn.
Indications & Use
Moderate-to-severe cancer pain, post-operative pain, and chronic non-cancer pain where opioid therapy is appropriate. ER formulations are for patients requiring continuous around-the-clock analgesia.
Dosage
Opioid-naive adults: 5–15 mg IR every 4–6 hours. ER: start 10 mg every 12 hours, titrate every 1–2 days. Reduce by 25–50% in elderly, renal, or hepatic impairment.
Side Effects
Very common: constipation (start prophylactic laxative), nausea. Common: somnolence, dizziness. Serious: respiratory depression, physical dependence, opioid-induced hyperalgesia.
Drug Interactions
CNS depressants and alcohol potentiate respiratory depression. CYP3A4 inhibitors (ketoconazole, ritonavir) raise plasma levels; inducers (rifampicin) reduce efficacy. MAO inhibitors: contraindicated within 14 days.
Contraindications
Severe respiratory depression, acute severe asthma, paralytic ileus, hypersensitivity. Caution in raised ICP, severe hepatic/renal impairment, substance use disorder.
Frequently Asked Questions
Is oxycodone stronger than morphine?
Oxycodone is ~1.5× more potent orally than morphine due to higher bioavailability. Both are strong opioids — clinical context determines preference.
How long is oxycodone detectable?
Half-life 3–5 h (IR), 4–6 h (ER). Standard urine immunoassay detects it for 3–4 days.
Can I stop oxycodone suddenly?
No. Abrupt cessation causes withdrawal (sweating, cramps, diarrhoea). Always taper gradually under medical supervision.
References
- EMA EPAR for oxycodone products
- AWMF S3-Leitlinie Palliativmedizin
- WHO Guidelines for Persisting Pain
Medical Disclaimer: This information is for educational purposes only and does not replace professional medical advice.