Theophylline, Oral
Bronchodilator & Anti-asthma Preps: Orals/Parenterals · Xanthine
Indications
Reversible bronchospasm in asthma and COPD.
Dosage
Adults: 175 mg-350 mg twice daily. Children: Under 2 yr, not recommended. 2-6 yr, 60-120 mg; 6-12 yr, 125-250 mg. Both twice daily.
Adverse Effects
Tachycardia, arrhythmias, palpitations, convulsions, GI upset, headache, insomnia, CNS stimulation, hypotension, urinary retention.
Risk Factor (Pregnancy/Lactation)
Pregnancy: Risk cannot be ruled out. Lactation: Caution advised or effect undetermined. Contraindications: Epilepsy, porphyria, concomitant use of ephedrine in children, recent MI, acute tachycardia. Precautions: Cardiac arrhythmia, other cardiovascular disease, CHF, severe asthma, severe renal impairment, peptic ulcer, hyperthyroidism, hypertension, history of seizures, hepatic dysfunction, ECT, viral infections, cystic fibrosis, urinary tract obstruction, acute febrile illness, chronic alcoholism. Elderly.
Interactions
Plasma levels increased by allopurinol, cimetidine, ciprofloxacin, clarithromycin, diltiazem, disulfiram, erythromycin, fluconazole, ketoconazole, fluvoxamine, influenza vaccine, interferon, acyclovir, oral contraceptives, methotrexate, mexiletine, nizatidine, quinolones, pentoxyfylline, propafenone, propranolol, verapamil, ticlodipine, rofecoxib, BCG vaccine. Plasma levels decreased by carbamazepine, primidone, phenytoin, rifampicin, ritonavir, sulfinpyrazone, barbiturates, smoking, St. John's Wort. Other interactions: beta-agonists, adenosine, benzodiazepines, diuretics, ketamine, halothane, lithium, corticosteroids, B blockers, caffeine, doxapram, imipenem, isoniazid, ranitidine, zafirlukast, lomustine, glucagon, ephedrine.
Advice to Patient
Take with or without meals. To reduce GI discomfort, take with meals. Swallow with a full glass of water. Do not chew or crush sustained release forms, swallow whole. If there is difficulty in swallowing capsules, open and sprinkle contents on soft food. Do not chew beads. Contact prescriber if there is fever, fast heartbeat, chest pain, restlessness, lack of sleep, emotional instability, agitation, acute headache, stomach pain, muscle cramps/tremors, dark or black coloured stool or if there is worsening of condition. Avoid smoking during therapy. Inform prescriber if you start or stop smoking, make dietary changes and take any new medication. Avoid tea, chocolate, colas, caffeine during therapy. Take sufficient amount of fluids (2-3 litres per day) to maintain hydration, unless restricted by the prescriber.
Pharmacokinetics
Absorption: Oral (soln and immediate release): Rapid and complete. Metabolism: Hepatic. Half-life elimination: Highly variable and dependent upon age, hepatic function, cardiac function, lung disease, and smoking history. Premature infants, postnatal age 3-15 days: 30 hrs; Premature infants, postnatal age 25-57 days: 20 hrs; Term infants, postnatal age 1-2 days: 25.7 hrs; Term infants, postnatal age 3-30 wks: 11 hrs; Children 1-4 yrs: 3.4 hrs; Children and Adolescents 6-17 yrs: 3.7 hrs; Adults =18 yrs-=60 yrs (nonsmoking, asthmatic, otherwise healthy): 8.7 hrs; Elderly >60 yrs (nonsmoking, healthy): 9.8 hrs. Time to peak, serum: Oral (solution and immediate release): 1-2 hrs; IV: Within 30 mins. Excretion: Urine (approx. 50% as unchanged drug [Neonates]; approx. 10% as unchanged drug [Infants >3 mths, Adolescents, and Adults]).
Brands with this active ingredient
Compiled by Healify Pharmacy from published drug references. How we compile it →
Always consult a pharmacist or doctor.