Theophylline is used in asthma due to (LQ)
|A||Simulates muco-ciliary movements|
|D||All of the following|
a. Theophylline is known as dimethyl xanthine. As a member of xanthine family, it bears structural resemblance with caffeine. The drug is well absorbed orally and is distributed mostly to extracellular fluids.
b. Since, it is distributed to ECF; therefore, Vd of drug is less in obese and more in patients with cirrhosis and malnutrition. The drug undergoes quick metabolism that is mediated by CYP enzymes.
c. The drug relaxes bronchial smooth muscles, increases mucociliary movements that helps to clear the respiratory secretions. It also boosts diaphragmatic contractility.
d. It does so by inhibiting degradation of phosphodiesterase enzyme. Monitoring of blood levels may be needed when treating patients with theophylline (CMDT’2010, pp-228).
Most common side effect of theophylline is gastrointestinal upset. The drug also causes tremors, hypotension on IV injection and cardiovascular stimulation. Hyperreflexia and seizures might occur in overdose. Poisoning is treated by beta-blockers.