Opioid Analgesics Commonly Used for Severe Pain
| Name | Equianalgesic Dose (mg) | Starting Oral Dose | Comments | Precautions and Contraindications | ||
|---|---|---|---|---|---|---|
| Morphine-like agonists | Oral | Parenteral | Adults (mg) | Children (mg/kg) | ||
| Morphine | 30 | 10 | 15–30 | 0.30 | Standard of comparison for opioid analgesia. Sustained-release preparation (MS Contin, Oramorph SR) release drug over 8–12 hours. | For all opioids, caution in patients with impaired ventilation, bronchial asthma, increased intracranial pressure, liver failure |
| Hydromorphone (Dilaudid) | 7.5 | 1.5 | 4–8 | 0.06 | Slightly shorter duration than morphine | |
| Oxycodone | 20 | – | 10–20 | 0.30 | ||
| Methadone (Dolophine) | 10 | 5 | 5–10 | 0.20 | Good oral potency, long plasma half-life (24–36 hours) | Accumulates with repeated dosing, requiring decreases in dose size and frequency, especially on days 2–5 |
| Levorphanol (Levo-Dromoman) | 4 acute 1 chronic | 2 acute 1 chronic | 2–4 | 0.04 | Long plasma half-life (12–16 hours) | Accumulates on days 2–3 |
| Fentanyl | 0.1 | Transdermal fentanyl (Duragesic) 25 mcg/hour, roughly equivalent to sustained release morphine, 50 mg/day. Oral transmucosal fentanyl citrate available for treatment of breakthrough pain in chronic cancer pain patients already taking around-the-clock opioids. Buccal form of fentanyl (Fentora) now available. | Because of skin reservoir of drug, 12-hour delay in onset and offset of transdermal patch; fever increases dose rate. Transdermal patch must be applied to area of body with subcutaneous fat to ensure absorption. | |||
| Oxymorphone (Numorphan) | — | 1 | — | — | 5 mg rectal suppository = 5 mg morphine parenteral | Like parenteral morphine |
| Meperidine (Demerol) | 300 | 75 | Not recommended | Not recommended | Slightly shorter acting than morphine | Normeperidine (toxic metabolite) accumulates with repetitive dosing, causing CNS excitation; avoid in children with impaired renal function or who are receiving monoamine oxidase inhibitors Side effects profile makes this drug unacceptable to use for most pain |
| Mixed agonist-antagonist | ||||||
| Nalbuphine (Nubain) | — | 10 | — | — | Not available orally, not scheduled under Controlled Substances Act | Incidence of psychotomimetic effects lower than with pentazocine; may precipitate withdrawal in narcotic dependent patients |
| Butorphanol (Stadol) | — | 2 | — | — | Like nalbuphine | Like nalbuphine |
Source: Adapted from American Pain Society (2003). Principles of analgesic use in treatment of acute pain and cancer pain (5th ed). Skokie, IL: American Pain Society.