Equianalgesic Dosing Guidelines

OPIOID ANALGESICS STARTING ORAL DOSE COMMONLY USED FOR SEVERE PAIN

EQUIANALGESIC DOSESTARTING ORAL DOSE
NAMEORAL*PARENTERAL†ADULTSCHILDRENCOMMENTSPRECAUTIONS AND CONTRAINDICATIONS
Morphine-like agonists (mu agonists)
morphine30 mg10 mg15–30 mg0.3 mg/kgStandard 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.
hydromorphone (Dilaudid)7.5 mg1.5 mgOpioid naïve: 4–8 mg0.06 mg/kgSlightly shorter duration than morphine. Sustained release preparations release over 24 hr.
fentanyl–0.1 mg––
oxycodone20 mg–10–20 mg0.2 mg/kg
methadone10 mg5 mg5–10 mg0.2 mg/kgGood 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.
levorphanol2 mg (acute), 1 mg (chronic)–2–4 mg0.04 mg/kgLong 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.
oxymorphone (Opana)10 mg––––
meperidine (Demerol)300 mg100 mgNot 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.‡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.‡
Centrally acting mu agonists
tramadol (Ultram), ConZip120 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.
tapentadol (Nucynta) 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 mg10 mg every 3–6 hr0.1–0.2 mg/kg every 3–4 hrNot 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 mg1–4 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
buprenorphine (Buprenex)–0.4 mg0.3 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.
*Starting dose should be lower for older adults.
†These 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.
‡Irritating to tissues with repeated IM injections.

Kishner, S. (2022). Opioid equivalents and conversions. Medscape. https://emedicine.medscape.com/article/2138678-overview?form;eqfpf

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