Adult: 400 mg bid-tid. Max: 1,200 mg daily. Child: <12 years 6-9 mg/kg bid; >12 years Same as adult dose. Elderly: 200 mg bid-tid.
Acute MI, hypotension. Lactation.
Patients with cardiac disease (e.g. cardiac arrhythmias, angina pectoris, CHF, acute myocardial injury, hypertension), peptic ulcer, hyperthyroidism, hypoxemia, chronic cor pulmonale, convulsive disorder. Hepatic and renal impairment. Children and elderly. Pregnancy.
Cardiac disorders: Tachycardia, palpitation, extrasystole. Metabolism and nutrition disorders: Hyperglycaemia. Gastrointestinal disorders: Nausea, vomiting, abdominal pain, epigastric pain. General disorders and administration site disorders: Irritability. Nervous system disorders: Headache, nervousness, dizziness. Psychiatric disorders: Insomnia, nervousness. Renal and urinary disorders: Albuminuria.
Symptoms: Nausea, vomiting, gastroinstestinal bleeding, metabolic acidosis, hypokalaemia, hypotension, cardiac arrythmias, and seizures. Management: Symptomatic and supportive treatment. May induce emesis or perform gastric lavage followed by administration of activated charcoal and cathartic. Establish adequate airway. IV diazepam and/or phenobarbital may be given in cases of seizure.
Decreased xanthine clearance with cimetidine, allopurinol, propranolol, antibiotics (e.g. erythromycin, lincomycin, ciprofloxacin) and anti-flu vaccine. Increased xanthine clearance with anticonvulsants (e.g. phenytoin). May potentiate hypokalaemia with β2- agonist.
Description: Doxophylline is a methylxanthine derivative that possesses potent bronchodilator activity by inhibiting phosphodiesterase enzymes followed by an increase in cyclic-3’, 5’ adenosine monophosphate (cAMP) resulting in smooth muscle relaxation. Pharmacokinetics: Absorption: Absolute bioavailability: Approx 62.6%. Time to peak plasma concentration: 30-60 minutes. Distribution: Volume of distribution: Approx 1 L/kg. Plasma protein binding: Approx 48%. Excretion: Via urine (< 4% as unchanged drug). Elimination half-lie: >6 hours.