What is the recommended dosing and monitoring for a patient with asthma or chronic obstructive pulmonary disease (COPD) using a terbutaline patch?

Terbutaline Patch Does Not Exist

There is no FDA-approved terbutaline transdermal patch formulation available for clinical use. Terbutaline is only available as subcutaneous injection, oral tablets, and nebulized solution 1.

Available Terbutaline Formulations and Dosing

Subcutaneous Administration

• Standard dose: 0.25 mg injected into the lateral deltoid area 1
• If no significant improvement occurs within 15-30 minutes, a second 0.25 mg dose may be given 1
• Maximum total dose: 0.5 mg within 4 hours 1
• Onset of action occurs within 5 minutes with subcutaneous administration 2

Nebulized Administration

• Acute asthma/COPD exacerbations: 5-10 mg nebulized every 4-6 hours 3
• For severe exacerbations, may repeat every 20 minutes initially 3
• Continue until peak expiratory flow >75% predicted and diurnal variability <25% 3

Oral Administration

• Maintenance therapy: 2.5 mg every 6-8 hours, adjusted based on clinical response 2
• The 5 mg oral dose produces nearly equivalent bronchodilation to 10 mg but with half the cardiac side effects 4

Clinical Monitoring Requirements

Cardiovascular Monitoring

• Check heart rate and blood pressure before and after each dose 4
• ECG monitoring is recommended for first dose in elderly patients with ischemic heart disease 5
• Watch for T-wave depression or inversion on ECG 4
• Beta-agonists may precipitate angina in elderly patients; first treatment should be supervised 3

Respiratory Monitoring

• Measure peak expiratory flow (PEF) before treatment and 30 minutes after each dose 3
• Record best of three PEF readings twice daily (morning and evening) for at least 5 days on each treatment regimen 3
• A response is defined as >15% increase in PEF over baseline 3

Safety Considerations in COPD

• In patients with CO2 retention and acidosis, nebulizers must be driven by compressed air, NOT oxygen 3, 5
• Measure arterial blood gases in patients requiring hospital admission 3
• Monitor for worsening hypercapnia within 60 minutes of starting treatment 6

Common Pitfalls to Avoid

• Do not use vials for intravenous infusion—they are only for subcutaneous administration 1
• Do not exceed 0.5 mg total subcutaneous dose in 4 hours to avoid excessive cardiac stimulation 1
• Do not continue nebulized therapy indefinitely—switch to metered-dose inhalers within 24-48 hours once stable 3, 6
• Do not use oxygen to drive nebulizers in COPD patients with hypercapnia 3, 5