Dosing and uses of Primatene (ephedrine (pulmonary))
Adult dosage forms and strengths
injectable solution
- 50mg/mL
capsule
- 25mg
Bronchospasm
25-50 mg SC/IM, Or
5-25 mg slow IV
12.5-25 mg PO q4hr PRN (not to exceed 150 mg/day)
Pediatric dosage forms and strengths
injectable solution
- 50mg/mL
capsule
- 25mg
Bronchospasm
>12 years old: 12.5-25 mg PO q4hr PRN (no more than 150 mg/day)
0.5 mg/kg SC/IM Or
16.7 mg/m² SC/IM q4-6hr
Potential toxic dose <6 years: 2 mg/kg
Primatene (ephedrine (pulmonary)) adverse (side) effects
Frequency not defined
Anxiety
Insomnia
Nervousness
Palpitations
Tachycardia
Vertigo
Difficult and painful urination (vesical sphincter spasm)
Precordial pain and cardiac arrhythmias may occur from ephedrine sulfate injection
Warnings
Contraindications
Hypersensitivity to ephedrine or other sympathomimetic agents
Angle-closure glaucoma
Concurrent use of other sympathomimetic agents
Pregnancy and lactation
Pregnancy category: C
Lactation: Likely excreted in breast milk
Pregnancy categories
A: Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.
B: May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk.
C: Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done.
D: Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk.
X: Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist.
NA: Information not available.
Pharmacology of Primatene (ephedrine (pulmonary))
Mechanism of action
Alpha, beta-1, & beta-2 receptor agonist
Pharmacokinetics
Onset: 10-20 min (SC/IM);15-60 min (PO)
Half-Life: 4.85-6.47
Duration: <1 hr (SC/IM); 3-5hr (PO)
Peak Plasma: PO: 20-80 ng/mL
Vd: 220-240 L
Metabolism: liver
Metabolites: p-hydroxyephedrine, p-hydroxynorephedrine, norephedrine, and their conjugates
Clearance: 25.5-34.1 L/hr
Excretion: urine
