EPHEDRINE SULFATE
Clinical safety rating
cautionComprehensive clinical and safety monograph for EPHEDRINE SULFATE (EPHEDRINE SULFATE).
Ephedrine sulfate is a sympathomimetic amine that directly stimulates alpha- and beta-adrenergic receptors and indirectly stimulates norepinephrine release from sympathetic neurons, leading to vasoconstriction, bronchodilation, and increased heart rate and contractility.
| Metabolism | Ephedrine is metabolized primarily by oxidative deamination via monoamine oxidase (MAO) and also by N-demethylation via CYP450 isoenzymes, though specific CYP enzymes are not well characterized. It has a half-life of 3–6 hours. |
| Excretion | Renal excretion of unchanged drug (60-70%) and minor metabolites; small amount biliary; pH-dependent; acidic urine enhances elimination. |
| Half-life | Terminal elimination half-life 3-6 hours in adults with normal renal function; prolonged in renal impairment or alkaline urine. |
| Protein binding | ~20-30% bound, primarily to albumin. |
| Volume of Distribution | ~2-3 L/kg; indicates extensive tissue distribution; crosses blood-brain barrier. |
| Bioavailability | Oral: ~85% (first-pass metabolism minimal); IM/SC: nearly 100%. |
| Onset of Action | IV: <1 minute; IM: 1-2 minutes; SC: 2-5 minutes; Oral: 15-30 minutes. |
| Duration of Action | IV: ~1 hour; IM: 1-2 hours; SC: 1-2 hours; Oral: 3-6 hours; tachyphylaxis may occur with repeated dosing. |
| Molecular Weight | 214.29 |
50 mg orally every 3-4 hours as needed; 25-50 mg intramuscularly or subcutaneously every 3-4 hours; 5-25 mg intravenously slowly every 5-10 minutes as needed, not to exceed 150 mg in 24 hours.
| Dosage form | SOLUTION |
| Renal impairment | GFR 10-50 mL/min: administer 75% of normal dose every 6 hours. GFR <10 mL/min: administer 50% of normal dose every 6 hours. |
| Liver impairment | Child-Pugh Class A: no adjustment; Child-Pugh Class B: reduce dose by 50%; Child-Pugh Class C: avoid use or use with extreme caution, reduce dose by 75%. |
| Pediatric use | Oral: 3 mg/kg/day divided every 4-6 hours. Parenteral: 0.2-0.3 mg/kg/dose intramuscularly or subcutaneously every 4-6 hours; intravenous: 0.05-0.2 mg/kg/dose every 5-10 minutes as needed. |
| Geriatric use | Initiate at lower doses (e.g., 25 mg orally every 4-6 hours) due to increased sensitivity and risk of CNS stimulation and cardiovascular effects; monitor blood pressure and heart rate closely. |
| 1st trimester | Limited data; associated with gastroschisis in some studies. Use only if benefit outweighs risk. |
| 2nd trimester | May cause fetal tachycardia; use with caution. |
| 3rd trimester | May cause neonatal tachycardia, irritability, and withdrawal. Avoid near term due to risk of uterine artery vasoconstriction. |
Clinical note
Comprehensive clinical and safety monograph for EPHEDRINE SULFATE (EPHEDRINE SULFATE).
| Placental transfer | Crosses placenta; peak fetal concentrations similar to maternal. |
| Breastfeeding | Enters breast milk in small amounts; may cause irritability and poor feeding in infants. Use with caution, monitor infant for adverse effects. |
| Lactation Rating | L3 (Moderately Safe) |
| Teratogenic Risk | Ephedrine sulfate crosses the placenta. Use in the first trimester is associated with a small increased risk of gastroschisis. In the second and third trimesters, it may cause fetal tachycardia and uterine artery vasoconstriction, potentially leading to reduced uteroplacental blood flow. Animal studies have shown embryotoxicity at high doses. |
| Fetal Monitoring | Monitor maternal blood pressure, heart rate, and fetal heart rate continuously during intravenous use. Assess for signs of uterine hyperstimulation or fetal distress. In chronic use, monitor fetal growth and amniotic fluid volume. |
| Fertility Effects | Ephedrine may impair fertility in women by altering tubal motility and uterine contractility. In males, high doses have been associated with reduced sperm count and motility in animal studies. Clinical significance in humans is unclear. |
■ FDA Black Box Warning
None.
| Serious Effects |
Hypersensitivity to ephedrine or any componentSevere hypertensionSevere coronary artery diseaseNarrow-angle glaucomaConcurrent use of monoamine oxidase inhibitors (MAOIs) or within 14 days of MAOI usePheochromocytomaAcute porphyria
| Precautions | Cardiovascular effects: hypertension, tachycardia, arrhythmias, Central nervous system stimulation: anxiety, insomnia, tremor, Tachyphylaxis with repeated use, Exacerbation of narrow-angle glaucoma, Use in patients with cardiovascular disease, hyperthyroidism, diabetes, or prostatic hypertrophy requires caution |
| Food/Dietary | Avoid excessive caffeine intake (coffee, tea, colas) as it may increase stimulant effects and risk of cardiovascular side effects. Limit or avoid tyramine-rich foods (aged cheeses, cured meats, fermented products) due to risk of hypertensive crisis. No other significant food interactions. |
| Clinical Pearls | Ephedrine sulfate is a direct and indirect sympathomimetic used primarily for hypotension during spinal/epidural anesthesia. It crosses the placenta and may cause fetal tachycardia. Avoid in patients with narrow-angle glaucoma, hyperthyroidism, or pheochromocytoma. Tachyphylaxis can develop with repeated doses. Use with caution in patients with cardiovascular disease, hypertension, or diabetes. Monitor blood pressure and heart rate closely. |
| Patient Advice | Do not take this medication without your doctor's approval if you have high blood pressure, heart disease, or thyroid problems. · Avoid using other stimulants or decongestants while on this medication. · Report any chest pain, irregular heartbeat, or shortness of breath to your healthcare provider immediately. · This medication may cause dizziness or nervousness; avoid driving or operating heavy machinery until you know how it affects you. · If you are pregnant, planning to become pregnant, or breastfeeding, consult your doctor before using ephedrine. |
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