Theo-Dur

What is it?

A bronchodilator and xanthine, available as mottled white, elliptical, sustained-release, scored tablets in 2 strengths containing 200mg and 300mg of theophylline, all marked with name and strength.

Medical Uses

Bronchospasm in asthma andacute bronchitis, asthma at night.

Dosage

Adults, lof 300mg strength every 12 hours at first, then adjust dose up or down by 1/z a tablet, as needed. Children, weighing less than 35kg, 100mg; weighing over 35kg, 200mg, all taken every 12 hours. In nocturnal asthma, dose should be taken at 8p. m.

Special Care

Elderly, pregnancy, breastfeeeding, viral infections, heart or liver disease.

Possible Drug and Food Interactions

The following reduce clearance of xanthines: influenza vaccine, oxpentifylline, viloxazine, interferon, allopurinol, clarithromycin, methotrexate, propanol, disulfram, cimetidine, ofloxacin, thiabendazole, erythromycin, carbimazole, isoprenaline, verapamil, ciprofloxacin, isoniazid, propafenone, diltiazem, mexiletine, fluconazole, norfloxacin, fluvoxamine, nizatidine. The following increase clearance of xanthines: alcohol, smoking, aminoglutethimide, ritonavir, moracizine, sulphinpyrazone, rifampicin, carbamazepine, primidone, barbiturates, phenytoin, St John's Wort. Plasma levels may need to be checked and dose adjustments made, if necessary. Xanthines Also, may interact with: ketamine, doxapram, 1blockers.