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Equivalents and Conversions

Opioid, steroid and benzodiazepine equivalence; units that trip people up

Reviewed by Alex G, BSN, RN, CEN, CCRN, CMC, NREMT-P · From the Reference tab of the app

Opioid equianalgesic doses

Equal to morphine 10 mg IV

Morphine	10 mg IV = 30 mg PO
Hydromorphone	1.5 mg IV = 7.5 mg PO
Fentanyl	100 mcg IV (patch: 25 mcg/h ≈ morphine 60–90 mg PO/day)
Oxycodone	20 mg PO
Hydrocodone	30 mg PO
Methadone	Non-linear; specialist conversion
Tramadol	About 100–120 mg PO (weak; ceiling 400 mg/day)

When switching drugs, reduce the calculated dose by 25–50% for incomplete cross-tolerance, then titrate.

Corticosteroid equivalence

Glucocorticoid doses with the same anti-inflammatory effect

Hydrocortisone	20 mg (short-acting; strong mineralocorticoid effect)
Cortisone	25 mg
Prednisone / prednisolone	5 mg
Methylprednisolone	4 mg (little mineralocorticoid effect)
Dexamethasone	0.75 mg (long-acting; no mineralocorticoid effect)

Stress dosing for a patient on long-term steroids: hydrocortisone 50–100 mg IV, then 50 mg every 6–8 h, tapering as the illness settles.

Benzodiazepine equivalence

Approximate equal doses

Lorazepam	1 mg (IV onset 5–10 min; no active metabolites)
Midazolam	2 mg IV (fast, short; accumulates in infusion)
Diazepam	5 mg (fast IV onset; long active metabolites)
Alprazolam	0.5 mg PO
Clonazepam	0.5 mg PO
Chlordiazepoxide	25 mg PO

Equivalence tables vary; use them to start, then dose to the RASS or CIWA target.

Unit conversions

Pressures, glucose, electrolytes, mass

Pressure

1 mmHg	1.36 cm H₂O = 0.133 kPa
1 cm H₂O	0.74 mmHg
1 kPa	7.5 mmHg
1 atm	760 mmHg = 1,033 cm H₂O = 14.7 psi

Labs

Glucose	mg/dL ÷ 18 = mmol/L (180 mg/dL = 10 mmol/L)
Creatinine	mg/dL × 88.4 = µmol/L
Calcium (total)	mg/dL ÷ 4 = mmol/L; ionized 1.1–1.3 mmol/L = 4.4–5.2 mg/dL
Magnesium	1 mEq/L = 0.5 mmol/L = 1.2 mg/dL
Bilirubin	mg/dL × 17.1 = µmol/L
Lactate	mmol/L × 9 = mg/dL

Mass and volume

1 g	1,000 mg = 1,000,000 mcg
1 mg	1,000 mcg = 1,000,000 ng
1 kg	2.2 lb; 1 lb = 454 g
1 grain	65 mg (nitroglycerin 1/150 gr = 0.4 mg)
1 oz	30 mL; 1 tsp = 5 mL; 1 tbsp = 15 mL
°F to °C	(°F − 32) × 5/9; 100.4 °F = 38 °C

Electrolyte salts

KCl	1 mEq = 75 mg; 20 mEq in 100 mL over 1 h is a typical IV limit
NaCl 0.9%	154 mEq/L sodium; 3%: 513 mEq/L
Sodium bicarbonate 8.4%	1 mEq/mL
Calcium gluconate 10%	1 g = 4.65 mEq (93 mg) elemental calcium
Calcium chloride 10%	1 g = 13.6 mEq (272 mg) elemental calcium
Magnesium sulfate	1 g = 8.1 mEq

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For education and exam preparation only. Follow your institution’s protocols. Typical adult values for study. Follow the order, the label and your institution's protocols.