Teofillina

Teofillina, known in English as theophylline, is a methylxanthine drug used as a bronchodilator to treat symptoms of reversible airway obstruction in diseases such as asthma and chronic obstructive pulmonary disease (COPD). It is also been used in the past for neonatal apnea of prematurity. Theophylline is the 1,3-dimethylxanthine molecule, related to caffeine and theobromine, and acts through multiple mechanisms to relieve airway constriction.

The primary actions of theophylline include inhibition of phosphodiesterase enzymes, which increases intracellular cyclic adenosine monophosphate (cAMP) leading to smooth muscle relaxation and bronchodilation. It also acts as a nonselective antagonist of adenosine receptors, which may contribute to its anti-inflammatory and stimulant effects. Together these actions can improve airflow and reduce symptoms, but the drug has a relatively modest effect compared with modern inhaled therapies.

Pharmacokinetics and administration vary widely among individuals. Theophylline is well absorbed orally and can be given by intravenous infusion in acute settings. It has a narrow therapeutic index, with target plasma concentrations typically in the range of 5 to 15 micrograms per milliliter. The half-life is influenced by age, liver function, and smoking status, with smokers often clearing the drug more rapidly. Metabolism occurs mainly in the liver via cytochrome P450 enzymes (notably CYP1A2), leading to potential drug interactions.

Safety and monitoring are important due with theophylline. Adverse effects can include nausea, vomiting, tachycardia, tremor, and, at higher levels, seizures or arrhythmias. Because of many drug interactions (for example with antibiotics, other cardiovascular drugs, and caffeine), dosing must be individualized and serum levels monitored regularly.