Hydrocodone conversion and pharmacology
A semi-synthetic opioid commonly prescribed for moderate to severe pain, often in combination with acetaminophen.
Equianalgesic estimate
30mg Oral ≈ 30mg Oral Morphine
Published equianalgesic ratios vary between references and with clinical context. Read how to interpret conversion results before applying an estimate.
Mechanism of action
Selective full agonist of the mu-opioid receptor. Also acts centrally as an antitussive.
Brand names: Vicodin (w/ APAP), Norco (w/ APAP), Lortab (w/ APAP), Zohydro ER
Pharmacokinetics
- Protein binding
- Variable
- Volume of distribution
- 3.3-4.7 L/kg
- Half-life
- 3.8-6 hours
| Route | Form | Bioavailability | Onset | Peak | Duration |
|---|---|---|---|---|---|
| Oral | IR | — | 10-30 min | 30-60 min | 4-6 hours |
Metabolism
- CYP2D6 (O-demethylation)
- CYP3A4 (N-demethylation)
Metabolites
- Hydromorphone Potent analgesic (formed via CYP2D6); significantly contributes to analgesic effect.
- Norhydrocodone Weak activity (formed via CYP3A4).
Acts functionally as a prodrug for hydromorphone. Efficacy is highly dependent on CYP2D6 phenotype. CYP2D6 inhibitors (e.g., paroxetine, bupropion) reduce efficacy.
Renal and hepatic impairment
Renal
Use with caution; metabolites may accumulate.
Hepatic
Metabolism impaired; use with caution.
Clinical cautions
- CYP2D6 Poor Metabolizers may experience inadequate analgesia.
- Often combined with acetaminophen; monitor total daily APAP dose (max 4g/day).
For qualified healthcare professionals. This page is an educational reference, not prescribing advice. Check medicine information and conversion factors against a current clinical source and local guidance.
Other opioids in this reference
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Last updated 30 August 2026. Read how to interpret conversion results and the Terms of Service.