Theophylline should not be used concurrently with other preparations containing xanthine derivatives. The clearance of theophylline is increased by barbiturates, carbamazepine, lithium, phenytoin, rifampicin and sulphinpyrazone and it may therefore be necessary to increase dosage. On the other hand, the clearance of the drug is reduced by allopurinol, cimetidine, ciprofloxacin, corticosteroids, erythromycin, frusemide, isoprenaline, oral contraceptive and thiabendazole and a reduced dosage may therefore be needed to avoid side effects. Theophylline can potentiate hypokalemia resulting from beta-2-agonist therapy, steroids, diuretics and hypoxia, so serum potassium levels should be monitored in such instances.
Generally side effects are rare at normal dosage. It may include gastrointestinal discomfort, headache, nausea, insomnia and hypotension. CNS stimulation and diuresis may also occur, especially in children.
It is not known whether Theophylline can cause foetal harm when administered to pregnant woman. Xanthines should be given to a pregnant woman only if clearly needed. Theophylline is excreted into breast milk and may cause irritability or other signs of mild toxicity in nursing human infants. Serious adverse effects in the infant are unlikely unless the mother has toxic serum Theophylline concentrations.
Careful consideration is needed for various interacting drugs and physiologic conditions that can alter Theophylline clearance. Dosage adjustment is required prior to initiation of Theophylline therapy, prior to increases in Theophylline dose, and during follow up. The dose of Theophylline selected for initiation of therapy should be low and, if tolerated, increased slowly over a period of time.
Pediatrics use: The clearance of Theophylline is very low in neonates. Careful attention to dosage selection and monitoring of serum Theophylline concentrations are required in pediatric patients.
Bronchodilator, Theophylline & related drugs
Keep all medicines out of reach of children. Store in a cool and dry place, protected from light.