Theophylline: A Bronchodilator for Asthma and COPD
Theophylline is a methyl-xanthine derivative and a non selective PDE inhibitor, used for the management of reversible airflow obstruction. It is a bronchodilator commonly used to treat asthma and chronic obstructive pulmonary disease (COPD). It works by relaxing the muscles around the airways, helping patients breathe easier during an asthma attack or exacerbation of COPD.
Mechanism of Action
Theophylline inhibits the enzyme phosphodiesterase (PDE), which increases the levels of cAMP (cyclic adenosine monophosphate) in the smooth muscle cells, leading to bronchodilation (relaxation of airway muscles). It also improves diaphragmatic contractility, helping with breathing.
Indications
● Asthma: To prevent asthma attacks and control chronic symptoms.
● COPD: To improve lung function in patients with chronic obstructive pulmonary disease.
Dosage and Administration
● Adults: 250–500 mg twice daily, typically in divided doses. Dose adjustments are made based on blood concentration levels of Theophylline. For acute severe bronchospasm the loading dose is 4.6 mg/kg to achieve a peak effect following which a maintenance dose of 0.4 mg/kg/hour is started.
● Pediatric Dosage: 9 mg/kg twice a day, adjusted based on response. For acute severe bronchospasm the loading dose is 4.6 mg/kg via infusion over 30 minutes is administered. The maintenance dose is generally 0.7-0.8 mg/kg/hour adjusted based on response.
Side Effects
● Common: Nausea, headache, insomnia, irritability, and increased heart rate.
● Serious: Seizures, cardiac arrhythmias, and toxicity, especially at high blood levels.
Pregnancy Category: Category C – Use with caution during pregnancy.
Common Brands
● Theo-24
● Theobid
● Unicontin E