Adverse Effects of Excessive Bronchodilator Use
Excessive use of bronchodilators can cause serious cardiovascular effects including tachycardia, arrhythmias, hypertension, myocardial ischemia, and in rare cases takotsubo cardiomyopathy, as well as metabolic effects such as hypokalemia, tremor, and paradoxical bronchospasm. 1
Cardiovascular Effects
- Tachycardia is a common side effect, with heart rate increases averaging 13 beats per minute with some agents like metaproterenol 1
- Palpitations occur frequently with salbutamol (albuterol) use 1
- Premature ventricular contractions have been documented with fenoterol and albuterol 1
- Risk of myocardial ischemia increases in patients with underlying cardiac disease 1
- Rare but serious cardiac complications include takotsubo cardiomyopathy associated with repetitive albuterol use 1
- Delivery method impacts cardiovascular effects - metered dose inhalers (MDIs) cause less tachycardia than nebulizers (6.47 beats/min less) 1
- Intravenous administration causes more rapid heart rate increases than inhaled routes 1
Metabolic Effects
- Hypokalemia is consistently documented with short-acting β-agonists 1, 2
- Mean decreases in serum potassium typically range from 0.52-0.54 mmol/L 1
- Hyperglycemia can occur with excessive use 1
- Lactic acidosis has been reported 1
Neurological and Musculoskeletal Effects
- Skeletal muscle tremor is one of the most frequent dose-limiting side effects 3
- Headache is commonly reported 1
- Dizziness can occur with excessive use 1
- Nervousness and weakness may be experienced 1
Respiratory Effects
- Paradoxical bronchospasm can occur and may be life-threatening 2
- Severe bronchospasm has been reported after exposure to albuterol inhaler and nebulizer treatment 1
Other Adverse Effects
- Unilateral mydriasis has been reported with ipratropium when it comes in contact with the eye 1
- Urticaria, angioedema, rash, and oropharyngeal edema may occur as hypersensitivity reactions 2
- Altered sleep and behavior patterns can develop, particularly with methylxanthines like theophylline 1
- Gastroesophageal reflux may worsen with methylxanthines 1
Overdose Considerations
- Seizures may occur in severe overdose 2
- Anginal pain can develop 2
- In children, tachycardia with rates exceeding 200 beats/min has been observed 2
- Exaggeration of all pharmacological effects occurs in overdose 2
Risk Factors and Special Considerations
- Patients with underlying cardiac disease are at higher risk for serious cardiovascular complications 1, 4
- The risk of cardiovascular death is higher with oral or nebulized β-agonists (RR = 2.4) compared to metered-dose inhalers (RR = 1.2) 4
- Theophylline use is associated with increased risk of cardiovascular death (RR = 2.7) 4
- Monitoring heart rate, PaO2, plasma potassium, and ECG is recommended when administering high doses, especially intravenously 3
Prevention of Adverse Effects
- Use the lowest effective dose to minimize side effects 1, 3
- Metered dose inhalers cause fewer systemic effects than nebulizers or oral administration 1, 4
- Starting with a low dose and gradually increasing can reduce tremor 3
- Selective tolerance develops to many side effects with regular use 3
- Regular cleaning of HFA actuators prevents drug plugging and improper dosing 1