A fixed-dose combination of two methylxanthine derivatives, Etofylline and Theophylline, used primarily as a bronchodilator and respiratory stimulant. Etofylline is a theophylline derivative with improved solubility and a more favorable side effect profile. The combination provides synergistic bronchodilation, reduces bronchial hyperreactivity, and improves diaphragmatic contractility. It is a mainstay in the management of obstructive airway diseases in the Indian clinical setting.
Adult: One tablet (Etofylline 115mg + Theophylline 35mg) two to three times daily, preferably after meals. Maximum: 3 tablets per day. Dosage must be individualized based on clinical response and serum levels.
Note: Take with a full glass of water, preferably after meals to reduce gastric irritation. Do not crush or chew unless advised. Maintain consistent timing of doses. Avoid taking with high-fat meals as it can increase absorption and peak levels.
The exact mechanism is multifactorial. Primary actions include non-selective inhibition of phosphodiesterase (PDE) enzymes (especially PDE3 and PDE4), leading to increased intracellular cyclic AMP (cAMP) and cyclic GMP (cGMP). This causes relaxation of bronchial smooth muscle, inhibition of inflammatory cell activation, and stabilization of mast cells. Antagonism of adenosine A1 and A2B receptors contributes to bronchodilation and may reduce airway hyperresponsiveness. Additional effects include increased diaphragmatic contractility and mild central respiratory stimulation.
Pregnancy: Category C: Animal studies show risk, human data limited. Use only if potential benefit justifies potential fetal risk. Theophylline crosses the placenta. Clearance may increase in the 3rd trimester, requiring dose adjustment.
Driving: May cause dizziness, nervousness, or visual disturbances. Patients should not drive or operate machinery until they know how the medicine affects them.
| Ciprofloxacin, Levofloxacin, Enoxacin | Markedly decreases theophylline clearance, leading to toxicity. | Major |
| Erythromycin, Clarithromycin | Decreases theophylline clearance. Monitor levels. | Major |
| Cimetidine, Fluvoxamine | Potent inhibitors of CYP1A2; significantly increase theophylline levels. | Major |
| Phenytoin, Phenobarbital, Carbamazepine | Increase theophylline metabolism, reducing efficacy. | Moderate |
| Rifampicin | Dramatically increases clearance, leading to subtherapeutic levels. | Major |
| Beta-blockers (e.g., Propranolol) | Antagonize bronchodilator effect; may cause bronchospasm. | Moderate |
| Lithium | Theophylline increases renal lithium excretion, reducing lithium levels. | Moderate |
| Warfarin | Theophylline may slightly potentiate anticoagulant effect. | Moderate |
Same composition (Etofylline (115mg) + Theophylline (35mg)), different brands: