Nurses Compass
Drug Guide
Metaproterenol Sulfate
Classification
Therapeutic: Bronchodilator
Pharmacological: Beta-adrenergic agonist
FDA Approved Indications
- Asthma
- Bronchospasm associated with COPD
Mechanism of Action
Metaproterenol is a non-selective beta-adrenergic receptor agonist that stimulates beta-2 receptors in bronchial smooth muscle, leading to relaxation and bronchodilation.
Dosage and Administration
Adult: Typically, inhalation of 0.2-0.3 mL of a 0.2% solution 3-4 times daily as needed.
Pediatric: Dosing varies by age and weight; usually 0.2 mL of 0.2% solution 2-4 times daily. Specific pediatric dosing should follow physician guidance.
Geriatric: Use with caution; start at the lower end of dosing range due to potential increased sensitivity.
Renal Impairment: Use with caution; no specific adjustment established.
Hepatic Impairment: Use with caution; monitor for exaggerated response.
Pharmacokinetics
Absorption: Rapid via inhalation
Distribution: Widely distributed in tissues, with limited studies on plasma protein binding.
Metabolism: Primarily hepatic metabolism; undergoes conjugation.
Excretion: Renal elimination of metabolites.
Half Life: Approximately 3-6 hours.
Contraindications
- Hypersensitivity to metaproterenol or related compounds.
- Tachyarrhythmias including tachycardia, or severe cardiac disease.
Precautions
- Use cautiously in patients with hypertension, diabetes, hyperthyroidism, or tremors; monitor for paradoxical bronchospasm. Not recommended for use in acute heart attack.
Adverse Reactions - Common
- Tremor (frequent)
- Nervousness or anxiety (common)
- Palpitations (common)
- Headache (common)
Adverse Reactions - Serious
- Tachycardia (rare)
- Cardiac arrhythmias (rare)
- Paradoxical bronchospasm (rare)
Drug-Drug Interactions
- Might have additive effects with other sympathomimetics or stimulants.
- Beta-blockers may diminish the effectiveness.
Drug-Food Interactions
N/ADrug-Herb Interactions
N/ANursing Implications
Assessment: Monitor respiratory status, lung sounds, and patient response.
Diagnoses:
- Ineffective airway clearance
- Risk for decreased cardiac output
Implementation: Administer via inhalation as prescribed, observe for tolerance or adverse effects.
Evaluation: Assess improvement in airflow, reduction in wheezing, and patient comfort.
Patient/Family Teaching
- Use inhaler correctly; teach proper inhalation technique.
- Report increased or unusual shortness of breath, chest pain, or adverse reactions.
- Avoid extraneous stimuli and triggers.
Special Considerations
Black Box Warnings:
- Potential for paradoxical bronchospasm; discontinue if occurs.
Genetic Factors: No specific genetic considerations documented.
Lab Test Interference: None known.
Overdose Management
Signs/Symptoms: Severe tachycardia, hypertension, hypokalemia, tremors.
Treatment: Discontinue medication, support airway and respiration, manage cardiac symptoms with beta-blockers if appropriate, and provide symptomatic treatment.
Storage and Handling
Storage: Store at room temperature, away from heat and moisture.
Stability: Stable under recommended storage conditions.