Doxair

Elderly : 200 mg tablet two or three times daily. Adults : 400 mg tablet two or three times daily or as prescribed by the physician. Children: >12 years of age : 10 ml syrup or 200 mg tablet two or three times daily. 6-12 years of age : 6-9 mg/kg body weight two times daily, i.e. if body weight is 10 kg, 3 ml (60 mg) two times daily or as prescribed by the physician. If required daily dose of Doxophylline is 400 mg then Doxophylline SR tablet to be taken once daily or as prescribed by the physician

Doxophylline is a novel bronchodilator. It structurally differs from Theophylline due to the presence of a dioxolane group in position 7. Doxophylline selectively inhibits phosphodiesterase 4 thereby relaxes bronchial smooth muscle. However, differently from Theophylline, Doxophylline appears to have decreased affinities toward adenosine A1 and A2 receptors, which may account for the better safety profile of the drug. Doxophylline is reported to inhibit platelet activating factor (PAF) and generation of leukotriene production.

Doxophylline rarely causes serious side effects, however possible side effects are similar for taking excess amount of caffeine. These include: nausea, vomiting, headache, upset stomach and heartburn.

Doxophylline is contraindicated in acute myocardial infarction. It is also contraindicated in patients with hypotension, in lactating women & patients who have shown hypersensitivity to its components.

The half-life of xanthine derivatives is influenced by a number of known variables. It may be prolonged in patients with liver disease, in patients with congestive heart failure and in those patients taking certain other drugs like erythromycin, troleandomycin, lincomycin, allopurinol, cimetidine, propanolol and anti-flu vaccine. In these cases, a lower dose of Doxophylline may be needed. Phenytoin, other anticonvulsants and smoking may cause an increase in clearance with a shorter mean half-life. In these cases higher doses of Doxophylline may be needed.

Doxophylline should not be administered together with other xanthine derivatives. Toxic synergism with ephedrine has been documented for xanthines. Like other xanthines, concomitant therapy with troleandomycin, lincomycin, clindamycin, allopurinol, cimetidine, ranitidine, propranolol and anti-flu vaccine may decrease the hepatic clearance of xanthines causing an increase in blood levels. No evidence of a relationship between Doxophylline serum concentrations and toxic events have been reported.