When switching medications, voluntarily or not, you need to make sure that you do not inadvertently take more than is needed, resulting in overdose. Below you will find a number of opioid conversion calculators.

DISCLAIMER

The opiate/narcotic dosage converters and charts listed on this page were not created by us; before changing medications, double check the calculations, start safely, and consult a doctor.

External Links

Conversion Chart

Drug Duration Half-life Route Equianalgesic
Dosage
Codeine 4–6 h 3 h IM/IV/SC 120 mg
PO 200 mg
Fentanyl 1–2 h 1.5–6 h IM/IV 0.1 – 0.2 mg
Hydrocodone 4–8 h 3.3–4.5 h PO 20-30 mg
Hydromorphone 4–5 h 2–3 h IM/IV/SC 1.3–1.5 mg
PO 7.5 mg
Levorphanol 6–8 h 12–16 h IM/IV/SC 2 mg
PO 4 mg
Meperidineæ 2–4 h 3–4 h IM/IV/SC 75 mg
PO 300 mg
Methadone 4–6 h 15–30 h IM/IV/SC 1-10 mg§ Medline
Short term: 5-10mg
Chronic use: 1-4 mg
(2 mg)
PO 2 – 20 mg§ Medline
Short term use: 20 mg
Chronic dosing: 2-4 mg
(3mg)
Morphine 3–6 h 1.5–3 h IM/IV/SC 10 mg
PO 30–60 mg#
Oxycodone 4–6 h NA PO 15-30 mg (20 mg)
Oxymorphone 3–6 h NA IM/IV/SC 1 mg
Important Update: Opana™ and Opana ER™ oxymorphone immediate release and oxymorphone extended release tablets) have been approved by the FDA.
PO 10 mg
Propoxyphene 4–6 h 6–12 h PO 130-200 mg *

*

 Propoxyphene HCL: 130mg;  Napsylate: 200mg. Not recommended for chronic pain management and therefore not available in program above.
# Acute dosing (opiate naive): 60mg.   Chronic dosing: 30 mg.
§: Many equianalgesic tables underestimate methadone potency – more studies are needed..
æ Meperidine should be used for acute dosing only and not used for chronic pain management (meperidine has a short half-life and a toxic metabolite: normeperidine). Its use should also be avoided in patients with renal insufficiency, CHF, hepatic insufficiency, and the elderly because of the potential for toxicity due to accumulation of the metabolite normeperidine.  Seizures, confusion, tremors,  or mood alterations may be seen.