Salbutamol + Theophylline
Indications
Salbutamol + Theophylline is used for:
Chronic bronchitis, Emphysema, Asthma
Adult Dose
Oral
Chronic bronchitis; Emphysema; Asthma
Adult: Per tab contains salbutamol 2 mg and theophylline 100 mg: 1 or 2 tab 3-4 times daily.
Child Dose
Oral
Chronic bronchitis; Emphysema; Asthma
Child: Child (under 6 yrs) salbutamol (0.5-1mg) + theophylline (25-50mg) t.i.d/q.i.d.
SR (S 4mg+T 300mg) 1 tab b.i.d.
Renal Dose
Administration
Contra Indications
Hypersensitivity, thyrotoxicosis.
Precautions
History of peptic ulcer and convulsive disorders, hepatic impairment, cardiac failure, hypertension, arrhythmias, diabetes mellitus,patients on MAOIs or tricyclic antidepressants, pulmonary oedema, hyperthyroidism, high fever, neonates and infants, pregnancy, lactation.
Pregnancy-Lactation
Pregnancy category: C
Lactation: Unknown whether drug is excreted in breast milk
Interactions
Increased theophylline toxicity with propranolol, cimetidine, erythromycin (7-5 days), quinolone antibiotics. Reduced efficacy with rifampicin, phenobarbitone, phenytoin, carbamazepine, sulfinpyrazone and smoking. Increased risk of hypokalaemia with diuretics.
Potentially Fatal: With anaesthetics, pancuronium bromide and sympathomimetics (increased risk of arrhythmias).
Adverse Effects
Side effects of Salbutamol + Theophylline :
Seizures, tremor, muscle cramps, palpitation, hypokalaemia, headache, anorexia, nausea, anxiety, irritability, insomnia, rarely rash and angioedema.
Potentially Fatal: Arrhythmias including premature ventricular contractions.
Mechanism of Action
Salbutamol is a selective beta2-agonist. It causes bronchial smooth muscle relaxation via the cyclic adenyl cyclase (cAMP) system.
Theophylline is a phosphodiesterase inhibitor. It enhances intracellular cAMP conc thereby contributing to bronchial smooth muscle relaxation. It also suppresses airway hyper-response to stimuli. Advantage of this combination is the additive effect allowing reduction of individual doses.