ALBUTEROL
Clinical safety rating: caution
Comprehensive clinical and safety monograph for ALBUTEROL (ALBUTEROL).
Beta-2 adrenergic receptor agonist; relaxes bronchial smooth muscle by increasing intracellular cyclic AMP, leading to bronchodilation.
| Metabolism | Primarily metabolized via sulfotransferase (SULT1A3) to inactive sulfate conjugate; minor hepatic metabolism by CYP450 enzymes. |
| Excretion | Primarily renal: approximately 60-70% of the dose is excreted in urine as unchanged drug and metabolites (sulfate conjugate) within 24 hours. Fecal excretion accounts for less than 10%. |
| Half-life | Terminal elimination half-life is 3.8-6.0 hours. In patients with asthma, the half-life is similar, but clinical effect duration is shorter due to rapid redistribution from the receptor site. |
| Protein binding | Approximately 52-65% bound to human serum albumin and alpha-1-acid glycoprotein. |
| Volume of Distribution | Approximately 1.4-2.0 L/kg. This relatively large Vd indicates extensive distribution into tissues, including lung parenchyma. |
| Bioavailability | Inhaled: 10-20% of the dose reaches the lungs systemically; Oral: approximately 28-40% (due to first-pass metabolism to sulfate conjugate); Subcutaneous: nearly 100%. |
| Onset of Action | Inhaled (MDI or nebulized): 5-15 minutes; Oral: 15-30 minutes; Subcutaneous: 5-15 minutes. Onset is rapid for inhalation and injection. |
| Duration of Action | Inhaled: 4-6 hours (bronchodilation); Oral: 4-6 hours; Subcutaneous: 2-4 hours. Tolerance may develop with regular use, shortening duration. |
2.5 mg (0.5 mL of 0.5% solution) via nebulization every 4-6 hours as needed; or 1-2 inhalations (90 mcg/inhalation) from a metered-dose inhaler every 4-6 hours as needed.
| Dosage form | AEROSOL, METERED |
| Renal impairment | No dosage adjustment required for renal impairment. |
| Liver impairment | No specific guidelines; use with caution in severe hepatic impairment due to potential for increased systemic exposure. |
| Pediatric use | Nebulized: 0.05-0.15 mg/kg/dose (minimum 1.25 mg) every 4-6 hours as needed. MDI: 1-2 inhalations (90 mcg/inhalation) every 4-6 hours as needed. Maximum: 12 inhalations/day. |
| Geriatric use | Initiate at lower end of dosing range; monitor for tremors, tachycardia, and hypertension. No specific dose adjustment required. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Comprehensive clinical and safety monograph for ALBUTEROL (ALBUTEROL).
| Breastfeeding | Excreted into breast milk in low concentrations; M/P ratio not established. Limited data suggest no adverse effects in infants. American Academy of Pediatrics considers compatible with breastfeeding. Use with caution in preterm infants or those with tachycardia. |
| Teratogenic Risk | FDA Pregnancy Category C. In first trimester, no increased risk of major congenital anomalies based on human data. Second and third trimesters: risk of maternal tachycardia, hyperglycemia; fetal tachycardia, hypoglycemia at birth if used near term. Possible association with gastroschisis in first trimester from some studies, but not confirmed. |
■ FDA Black Box Warning
None.
| Serious Effects |
["Hypersensitivity to albuterol or any component of the formulation"]
| Precautions | ["Paradoxical bronchospasm may occur with excessive use","Cardiovascular effects: increased heart rate, hypertension, arrhythmias","Hypokalemia may occur with high doses","Immediate hypersensitivity reactions possible","Use caution in patients with cardiovascular disorders, hyperthyroidism, diabetes, or seizure disorders"] |
| Food/Dietary | No clinically significant food interactions. Caffeine may potentiate stimulant effects; avoid excessive caffeine intake. |
| Clinical Pearls |
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| Fetal Monitoring | Monitor maternal heart rate, blood pressure, serum glucose, and potassium levels. Assess fetal heart rate during prolonged use. Monitor for signs of tocolysis (uterine relaxation) if used for asthma. |
| Fertility Effects | No known adverse effects on fertility in humans. Animal studies show no impairment of fertility at doses up to 50 times the human dose. |
| Monitor for paradoxical bronchospasm; use with caution in patients with cardiovascular disorders due to beta-adrenergic stimulation; may cause hypokalemia with high doses; combine with ipratropium for acute exacerbations; not recommended for long-term control without anti-inflammatory therapy. |
| Patient Advice | Use only as prescribed; do not exceed recommended dose. · Rinse mouth after use to prevent oral candidiasis (if using with corticosteroid), but albuterol alone does not require rinsing. · Seek emergency care if symptoms worsen or inhaler provides less relief. · Shake inhaler well before each use; use spacer if available for better delivery. · Monitor for palpitations, tremors, or nervousness; report if severe. |