Theophylline is indicated for the treatment of the symptoms and reversible airflow obstruction associated with chronic asthma and other chronic lung diseases, e.g., emphysema and chronic bronchitis.
Xanthine Derivative; Antiasthmatic
Theophylline is a bronchodilator, structurally classified as a Methylxanthine. Theophylline has two distinct actions in the airways of patients with reversible obstruction; smooth muscle relaxation and suppression of the response of the airways to stimuli. Theophylline also increases the force of contraction of diaphragmatic muscles. The half-life of Theophylline is influenced by a number of known variables. In adult nonsmokers with uncomplicated asthma the half-life ranges from 3 to 9 hours
ORAL Acute bronchospasm: Adult: As conventional tablet: 5 mg/kg every 6-8 hr. Child: As conventional tablet: 5 mg/kg every 4-6 hr. Chronic bronchospasm: Adult: As conventional dosage form: 300-1000 mg in divided doses, every 6-8 hr daily. As modifiedrelease preparations: 175-500 mg every 12 hr. Rate of absorption of modified released prep varies for different brands. Child: <2 yr: Not recommended; 2-6 yr:1/4 the adult dose; 20-35 kg (about 6-12 yr old):1/2 the adult dose. Rate of absorption of modified released prep varies for different brands. Apnoea In Infants: Child: Initial dose in neonates: 24 days: 1 mg/kg every 12 hr; >24 days: 1.5 mg/kg every 12 hr. Full-term infants: initial daily dosage calculated based on formula, given in 3-4 divIded doses: daily dose (mg/kg)=(0.2 x age in wk) + 5.0. If loading dose is needed, 5 mg/ kg (or in those already on theophylilne. 1 mg/kg for each 2 mcg/ml increase in serum-theophylline concentration). INTRA VENOUS Severe bronchospasm: Adult: Patients who are not taking theophylline or other xanthine medication: 4-5 mg/kg as loading dose by IV infusion over 20-30 mins followed by maintenance: 0.4 mg/kg/hr. Child: Patients who are not taking theophylline or other xanthine medication: 4-5 mg/kg as loading dose by IV infusion over 20-30 minutes, followed by maintenance dose: 1-9 yr: 0.8 mg/kg/hr; >9 yr: 0.6-0.7 mg/kg/hr.
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.
Hypersensitivity to xanthine derivatives, porphyria. Admin IV inj very slowly to avoid direct stimulation of the CNS & CVS. Cardiac failure, hypertension, epilepsy, hyperthyroidisrn, history of peptic ulcer disease, renal or hepatic dysfunction, glaucoma, DM, severe hypoxaemia, chronic alcoholism, acute febrile illness. On flu immunization or active flu infection, COPD & cor pulmonale. Smokers may need higher dose. Pregnancy, lactation, child & elderly.
Nausea, vomiting, abdominal pain, diarrhoea, headache, insomnia, dizziness, anxiety, restlessness, tremor, palpitations. Convulsions, cardiac arrhythmias, hypotension & sudden death after too rapid IV inj.
Theophylline has been assigned to pregnancy category C by the FDA. Animal studies have revealed evidence of embryolethality and teratogenicity. There are no controlled data in human pregnancy. Theophylline is only recommended for use during pregnancy when there are no alternatives and benefit outweighs risk. heophylline is excreted into human milk and may cause irritability or other signs of mild toxicity. The concentration of theophylline in breast milk is approximately equivalent to the maternal serum concentration. The manufacturer states that serious adverse effects in the infant are unlikely unless the mother has toxic serum theophylline concentrations. The American Academy of Pediatrics considers theophylline to be compatible with breast-feeding.
Keep all medicines out of reach of children. Store in a cool and dry place, protected from light.
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