Salbutamol
Mechanism :
Salbutamol is a beta2-adrenergic agonist. The pharmacologic effects of beta2-adrenoceptor agonist drugs are at least in part attributable to stimulation of intracellular adenyl cyclase, the enzyme that catalyzes the conversion of adenosine triphosphate (ATP) to cyclic-3,5 -adenosine monophosphate (cyclic AMP). Increased cyclic AMP levels cause relaxation of bronchial smooth muscle and inhibition of release of mediators of immediate hypersensitivity from cells, especially from mast cells.
Indication :
- Relief of severe bronchospasm
- Hyperkalemia (Use as nebuliser)
Contraindications :
Patients with a history of hypersensitivity to any of its components.
Dosing :
Oral:
Use in children >2 years.
0.3-0.4 mg/kg/day PO in 3 divided doses; Maximum: 4 mg/dose.
Aerosol inhaler:
Upto 100-200 mcg single dose on demand.
Nebuliser:
4 to 11 years: 2.5 mg to 5 mg up to four times a day.
<4 years: 1.25-2.5 mg 6 hourly.
>12 years: 2.5 mg as a single dose. This may be increased to 5 mg. Treatment may be repeated up to four times a day.
Injectable:
Use in children >12 years of age.
Subcutaneous route: 500 mcg (8 mcg/kg) and repeated every four hours as required.
Intramuscular route: 500 mcg (8 mcg/kg) and repeated every four hours as required.
IV:
250 mcg (4 mcg/kg) injected slowly. If necessary the dose may be repeated.
Adverse Effect :
Dose related: hypokalemia, tremor, nervousness, mild tachycardia (most frequently seen with systemic therapy).
Interaction :
Corticosteroids: Increase the risk of hypokalemia, if high dose corticosteroids are given with high doses of salbutamol.
Diuretics: Increase the risk of hypokalemia if acetazolamide, loop diuretics, and thiazides are given with high doses of salbutamol.
Theophylline: Increases the risk of hypokalemia if given with high doses of salbutamol.
Beta-blockers: May partially or totally inhibit the effects of salbutamol.
Renal Dose :
Dose in Renal Impairment GFR (mL/min)
| 20-50 | Dose as in normal renal function |
| 10-20 | Dose as in normal renal function |
| <10 | Dose as in normal renal function |
Dose in Patients undergoing Renal Replacement Therapies
| CAPD | Unknown dialysability. Dose as in normal renal function |
| HD | Unknown dialysability. Dose as in normal renal function |
| HDF/High flux | Unknown dialysability. Dose as in normal renal function |
| CAV/VVHD | Unknown dialysability. Dose as in normal renal function |
Hepatic Dose :
No dosage adjustments are recommended.