OPIOID ANALGESICS STARTING ORAL DOSE COMMONLY USED FOR SEVERE PAIN
| EQUIANALGESIC DOSE | STARTING ORAL DOSE | |||||
|---|---|---|---|---|---|---|
| NAME | ORAL1 | PARENTERAL2 | ADULTS | CHILDREN | COMMENTS | PRECAUTIONS AND CONTRAINDICATIONS |
| Morphine-like agonists (mu agonists) | ||||||
| morphine | 30 mg | 10 mg | 15–30 mg | 0.3 mg/kg | Standard of comparison for opioid analgesics. Sustained release preparations (MS Contin) release over 8–12 hr. Other formulations (MS Contin) last 12–24 hr. Generic sustained release morphine preparations are now available. | For all opioids, caution in patients with impaired ventilation, bronchial asthma, ↑ intracranial pressure, liver failure. |
| hydromorphoneDilaudid | 7.5 mg | 1.5 mg | Opioid naïve: 4–8 mg | 0.06 mg/kg | Slightly shorter duration than morphine. Sustained release preparations release over 24 hr. | |
| fentanyl | — | 0.1 mg | — | — | ||
| oxycodone | 20 mg | — | 10–20 mg | 0.2 mg/kg | ||
| methadone | 10 mg | 5 mg | 5–10 mg | 0.2 mg/kg | Good oral potency, long plasma half-life (24–36 hr). | Accumulates with repeated dosing, requiring decreases in dose size and frequency, especially on days 2–5. Use with caution in older adults. |
| levorphanol | 2 mg (acute), 1 mg (chronic) | — | 2–4 mg | 0.04 mg/kg | Long plasma half-life (12–16 hr, but may be as long as 90–120 hr after one wk of dosing). | Accumulates on days 2 and 3. Use with caution in older adults. |
| oxymorphoneOpana | 10 mg | — | — | — | — | |
| meperidineDemerol | 300 mg | 100 mg | Not Recommended | — | Slightly shorter acting than morphine; accumulates with repetitive dosing causing CNS excitation; avoid in children with impaired renal function or who are receiving monoamine oxidase inhibitors.3 | Use with caution. Normeperidine (toxic metabolite) accumulates with repetitive dosing causing CNS excitation and a high risk of seizure. Avoid in children, renal impairment, and patients on monoamine oxidase inhibitors.3 |
| Centrally acting mu agonists | ||||||
| tramadol UltramConZip | 120 mg | — | 50–100 mg every 4–6 hr | — | Prodrug; significant serotonin reuptake inhibition. Maximum dose: IR 400 mg/day; ER 300 mg/day. | Caution with pre-existing seizure disorder, concurrent use of medications that ↓ seizure threshold, or medications that ↑ risk of serotonin syndrome. |
| tapentadolNucynta | 100 mg | — | 50–100 mg every 4–6 hr | — | Sustained release preparation (Nucynta ER) releases over 12 hr. Blocks reuptake of norepinephrine > serotonin. | Caution with pre-existing seizure disorder or concurrent use of medications that ↓ seizure threshold. |
| Mixed agonists–antagonists (kappa agonists) | ||||||
| nalbuphine | — | 10 mg | 10 mg every 3–6 hr | 0.1–0.2 mg/kg every 3–4 hr | Not available orally; not scheduled under Controlled Substances Act. Kappa agonist, partial mu antagonist. | Incidence of psychotomimetic effects lower than with pentazocine; may precipitate withdrawal in opioid-dependent patients. |
| butorphanol | — | 2 mg | 1–4 mg every 3–4 hr (IM); 0.5–2 mg every 3–4 hr (IV) | — | Kappa agonist, partial mu antagonist. Also available in nasal spray. | Likenalbuphine. |
| Partial agonist | ||||||
| buprenorphineBuprenex | — | 0.4 mg | 0.3 mg every 6–8 hr (IM/IV) | 2–12 yr: 0.2–0.6 mg every 4–6 hr (IM/IV) | Sublingual tablets now available both plain and with naloxone for opioid-dependent patient management for specially certified physicians. These tablets are not approved as analgesics. Also available as a long-acting transdermal patch (Butrans), and buccal film (Belbuca). | May precipitate withdrawal in opioid-dependent patients; not readily reversed by naloxone; avoid in labor. |
1Starting dose should be lower for older adults.
2These are standard parenteral doses for acute pain in adults and can also be used to convert doses for IV infusions and repeated small IV boluses. For single IV boluses, use half the IM dose. IV doses for children >6 mo. = parenteral equianalgesic dose times weight (kg)/100.
3Irritating to tissues with repeated IM injections.
Kishner, S. (2022). Opioid equivalents and conversions. Medscape. https://emedicine.medscape.com/article/2138678-overview?form;eqfpfGUIDELINES FOR PATIENT-CONTROLLED INTRAVENOUS OPIOID ADMINISTRATION FOR ADULTS WITH ACUTE PAIN
| DRUG4 | USUAL STARTING DOSE AFTER LOADING | USUAL DOSE RANGE | USUAL LOCKOUT (MIN) | USUAL LOCKOUT RANGE (MIN) |
|---|---|---|---|---|
| Morphine (1 mg/mL) | 1 mg | 0.5–2.5 mg | 8 | 5–10 |
| Hydromorphone (0.2 mg/mL) | 0.2 mg | 0.05–0.4 mg | 8 | 5–10 |
| Fentanyl (50 mcg/mL) | 20 mcg | 10–50 mcg | 6 | 5–8 |
4Standard concentrations for most PCA machines are listed in parentheses.
Modified from American Pain Society, Principles of Analgesic Use in the Treatment of Acute Pain and Cancer Pain, ed.7. American Pain Society, 2016.
FENTANYL TRANSDERMAL DOSE BASED ON DAILY MORPHINE DOSE5| ORAL 24-HR MORPHINE (mg/day) | TRANSDERMAL FENTANYL (mg/day) | FENTANYL TRANSDERMAL (mcg/hr) |
|---|---|---|
| 30–90 | 0.6 | 25 |
| 91–150 | 1.2 | 50 |
| 151–210 | 1.8 | 75 |
| 211–270 | 2.4 | 100 |
| 271–330 | 3.0 | 125 |
| 331–390 | 3.6 | 150 |
| 391–450 | 4.2 | 175 |
| 451–510 | 4.8 | 200 |
| 511–570 | 5.4 | 225 |
| 571–630 | 6.0 | 250 |
| 631–690 | 6.6 | 275 |
| 691–750 | 7.2 | 300 |
| For each additional 60 mg/day | +0.6 | +25 |
5A 10-mg IM or 60-mg oral dose of morphine every 4 hr for 24 hr (total of 60 mg/day IM or 360 mg/day oral) was considered approximately equivalent to fentanyl transdermal 100 mcg/hr.