Theophylline timed administration

Administration of zafirlukast and aspirin increases plasma levels of zafirlukast, When zafirlukast is administered with warfarin, there is an increased effect of the anti coagulant. Administration of zafirlukast and theophylline or erythromycin may result in a decreased level of zafirlukast. Administration of montelukast with other drugs has not revealed any adverse responses. Administration of montelukast with aspirin and NSAIDs is avoided in patients with known aspirin sensitivity. Administration of zileuton with propranolol increases the activity or the propranolol with theophylline increases serum theophylline levels and with warfarin may increase prothrombin time (PT). A prothrombin blood test should be done regularly in the event dosages of warfarin need to be decreased. 

Patients currently receiving theophylline products - Determine, where possible, the time, amount, dosage form, and route of administration of the last dose the patient received. 

Drug Interactions Increased prothrombin time after warfarin administration Phenytoin Cyclosporine Tolbutamide Tacrolimus Glyburide Glipizide Rifampin Cisapride Terfenadine Astemizole Theophylline ... 

The selection of a salt form directly influences the physicochemical and biopharmaceutical properties of a compound. The impact of salt selection has been reviewed. Nelson examined the dissolution of theophylline salts and commented on their impact on oral administration. The dissolution rates of the theophylline salts proceeded independently of the pH of the medium but was governed by the diffusion layer pH. The choline and isopropanolamine salts dissolved three to four times faster than the ethylenediamine salt and produced higher and prolonged blood levels. 

Although chronic theophylline administration has been used extensively in the past, this therapy is being employed with decreasing frequency in favor of aerosolized /32-receptor agonists. Albuterol is used most commonly, one to two puffs of the metered-dose inhaler three to four times daily. The role of aerosolized surfactant also has been assessed in patients with stable chronic bronchitis and has demonstrated encouraging results with respect to improvement in pulmonary function and sputum transport by cilia (i.e., clearance). The role of surfactant as a carrier vehicle for other aerosol medications also appears promising and most likely will continue to be evaluated. 

Theophylline administered in liquids or uncoated tablets is absorbed rapidly and completely. In the absence of food, solutions or uncoated tablets of theophylline produce maximal concentrations in plasma within 2 hours and maximal plasma concentrations are achieved within I hour. Numerous sustained-release preparations of theophylline are available, designed for dosing intervals of 8, 12, or 24 hours. There is marked interpatient variability in the rate and extent of absorption, and especially in the effect of food and time of administration on these parameters. Thus, it is necessary to avoid substituting one apparently similar product for another. 

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