Salbutamol

# Salbutamol ## Overview - **Classification**: Short-acting beta-2 adrenergic agonist (SABA) - **Mechanism**: Selectively stimulates beta-2 receptors in bronchial smooth muscle, leading to relaxation and bronchodilation. ## Primary Indications 1. **Acute Bronchospasm** - Symptomatic relief and treatment of acute asthma exacerbations. 2. **Exercise-Induced Bronchospasm (EIB) Prevention** - Prophylaxis before strenuous activity. 3. **COPD** - Symptomatic relief of bronchospasm in patients with chronic obstructive pulmonary disease. ## Adult Dosing ### Standard Dosing **Acute Bronchospasm/Asthma Exacerbation** - **Dose**: **2 puffs (180 mcg)** via MDI OR **2.5 mg** via nebulizer solution (0.5 mL of 0.5% solution). - **Frequency**: Every **4-6 hours** as needed. For acute exacerbations, can be given every **20 minutes** for up to **4 hours**, then every **1-4 hours** PRN. - **Route**: Inhalation (Metered Dose Inhaler - MDI or Nebulizer) - **Maximum**: MDI: **12 puffs/day** for regular use. Higher short-term doses may be used in acute settings under medical supervision. **Exercise-Induced Bronchospasm (EIB) Prevention** - **Dose**: **2 puffs (180 mcg)** via MDI - **Frequency**: **15-30 minutes** before exercise. - **Route**: Inhalation (MDI) ### Dose Adjustments - **Renal Impairment**: No specific dose adjustments required for inhaled salbutamol due to low systemic absorption. - **Hepatic Impairment**: No specific dose adjustments required. - **Elderly Patients**: Start at the lower end of the dosing range. Monitor closely for cardiac adverse effects due to increased sensitivity. ## Pediatric Dosing ### Neonates (0-28 days) - **Dose**: Generally **avoided** due to limited safety data. If essential, **0.05-0.15 mg/kg/dose** (max **2.5 mg**). - **Frequency**: Every **4-6 hours**. - **Maximum**: **2.5 mg/dose**. - **Special Notes**: Use under strict medical supervision and cardiac monitoring. Nebulized formulation only. ### Infants (1-12 months) - **Dose**: **1.25-2.5 mg** via nebulizer solution. - **Frequency**: Every **4-6 hours** as needed. For acute exacerbations, can be given every **20 minutes** for up to 3 doses. - **Maximum**: **2.5 mg/dose**. - **Special Notes**: Nebulized preferred. If MDI used, ensure proper technique with a spacer and mask. ### Children (1-12 years) - **Dose**: MDI: **2 puffs (180 mcg)**. Nebulizer: **2.5 mg**. - **Frequency**: Every **4-6 hours** as needed. For acute exacerbations, MDI: **4-8 puffs** every **20 minutes** for up to **4 hours**, then every **1-4 hours** PRN. Nebulizer: **2.5-5 mg** every **20 minutes** for 3 doses, then every **1-4 hours** PRN. - **Maximum**: MDI: **12 puffs/day** for regular use. Nebulizer: **5 mg/dose**. - **EIB Prevention**: **2 puffs (180 mcg)** **15-30 minutes** before exercise. ### Adolescents (13-18 years) - **Dose**: Follow **adult dosing** guidelines. - **Maximum**: Adhere to adult maximum doses. ## Safety Information ### Contraindications - **Absolute**: Hypersensitivity to salbutamol or any component. - **Relative**: Severe milk protein allergy (some MDI products contain lactose). ### Common Adverse Effects - **Very Common (>10%)**: Tremor, headache, tachycardia, palpitations. - **Common (1-10%)**: Muscle cramps, dry mouth, throat irritation, cough. - **Serious but Rare**: Paradoxical bronchospasm, severe hypokalemia, cardiac arrhythmias, angioedema. ### Key Drug Interactions - **Non-selective Beta-blockers**: Can block bronchodilatory effect and induce severe bronchospasm. **AVOID** concomitant use. - **Diuretics (loop or thiazide)**: May potentiate hypokalemia. Monitor **serum potassium** levels. - **MAOIs/TCAs**: Increased risk of cardiovascular adverse effects. Use with **caution**; may potentiate salbutamol's vascular effects. - **Digoxin**: May decrease digoxin levels. Monitor **digoxin** levels if co-administered. ## Monitoring & Follow-up - **Before Treatment**: Assess baseline lung function (FEV1/PEF), heart rate, blood pressure. - **During Treatment**: Monitor respiratory rate, oxygen saturation, heart rate, and peak flow measurements. For frequent use/severe exacerbations, monitor **serum potassium** levels. - **Clinical Signs**: Watch for worsening shortness of breath, increased reliance on rescue inhaler, chest pain, tremors. ## Clinical Pearls - 💡 **Proper Inhaler Technique**: Essential for drug delivery. Educate patients on correct MDI/nebulizer use. - 💡 **Rescue Medication**: Salbutamol is for acute symptom relief, not daily maintenance. Frequent use indicates poor asthma control. - 💡 **Spacer Use**: Recommended with MDI for all ages, especially children, to improve drug delivery and reduce oral side effects. - 💡 **Hypokalemia**: High doses or frequent nebulization can cause temporary, clinically significant hypokalemia. Monitor in at-risk patients. > **⚠️ Important**: This information is for educational purposes only. Always consult current prescribing information, local guidelines, and clinical judgment before prescribing.