| Albuterol Pharmacology |
| Albuterol |
| About Albuterol |
| Adrenergic beta2 agonist, Bronchodilator. |
| Mechanism of Action of Albuterol |
| Albuterol is a short acting ?2 receptor agonist. It selectively stimulates ?2 receptors present in airway, Uterus, and Vascular Smooth muscles. It directly relaxes the airway smooth muscles and produces bronchodilation. Stimulation of ?2 receptors activates Gs adenylyl-cyclase -cyclic AMP path way and produces reduction in smooth muscle tone. ?2 receptor agonists also increases the conductance of large Ca2+sensitive K+ channels in airway smooth muscles and leads to membrane hyperpolarisation and relaxation of smooth muscles. ?2 receptor agonists also suppress the release of Leukotrienes and histamine from the mast cells in the lung tissue and enhance mucociliary function and decrease micro vascular permeability and also inhibits Phospholipase A2 which produces inhibition of prostaglandins production. Thus Albuterol can inhibit the broncho-constriction produced by inflammatory mediators. |
| Pharmacokinets of Albuterol |
| Absorption: It is well absorbed after oral administration.Distribution: It does not cross the blood brain barrier.Metabolism: It is metabolised to inactive metabolites in the liver.Excretion: It is excreted primarily in the urine and small amount in the faeces. |
| Onset of Action for Albuterol |
| 15 – 30 minutes |
| Duration of Action for Albuterol |
| 6 – 12 hours |
| Half Life of Albuterol |
| 4 hours |
| Side Effects of Albuterol |
| 1. Drowsiness 2. Headache 3. Dizziness 4. Nervousness 5. Tremor 6. Weakness 7. Palpitations 8. Tachycardia 9. Arrhythmia 10. Vomiting 11. Nausea 12. Heartburn 13. Diaphoresis 14. Hypokalaemia (high dose) |
| Contra-indications of Albuterol |
| 1.Hypersensitivity to Albuterol and other sympathomimetic amines. |
| Special Precautions while taking Albuterol |
| 1. Myocardial insufficiency 2. Arrhythmia 3. Hypertension 4. Hyperthyroidism 5. Epilepsy 6. Diabetes |
| Pregnancy Related Information |
| Use with caution. |
| Old Age Related Information |
| Use with caution. |
| Breast Feeding Related Information |
| Use with caution. |
| Children Related Information |
| Use with caution Below 6 years: contraindicated |
| Indications for Albuterol |
| 1. Obstructive airway diseases 2. Acute Bronchospasm 3. Status asthmaticus 4. Premature labour |
| Interactions for Albuterol |
| Beclomethasone, Theophylline: Enhances respiratory function. Beta-blockers: Inhibit bronchodilator effect. Diuretics and Xanthines: Increased risk of hypokalemia. Digitalis: Increased risk of digitalis toxicity when salbutamol is given in hilgh doses due to hypokalaemia. |
| Typical Dosage for Albuterol |
| Adult: Oral: Immediate release tablet: 2 – 4 mg every 6 – 8 hours daily, maximum dose 32mg / day Sustained release tablets: 8 mg / day in 2 divided doses and if sufficient response does not obtained then dose can be gradually increased to 16mg / day in 2 divided doses Children: 6 – 14 years Syrup: 6 – 8mg / day in 3 – 4 divided doses and if needed dose can be increased maximum up to 24mg / day Uterine Relaxant: (I.V) 4 to 32 mcg/minutes |
| Schedule of Albuterol |
| H |
| Storage Requirements for Albuterol |
| Store at 15 – 30 degree C. Protect from heat and light. Keep out of the reach of children |
| Effects of Missed Dosage of Albuterol |
| Take the missed dose as soon as noticed and if it is the time for next dose then skip the missed dose. Continue the regular schedule. Do not double the dose. |
| Effects of Overdose of Albuterol |
| Give supportive measures and symptomatic treatment. Drug can be removed from the body by gastric lavage or by inducing emesis. Absorption of drug can be reduced by administration of activated charcoal. |