Respiratory/Acute asthma / COPD exacerbation drugs

Acute asthma & COPD exacerbation

also: acute asthma · magnesium sulfate · prednisolone · oxygen · exacerbation

Overview

The bundle for an acute attack — oxygen, bronchodilators, steroids and (in severe asthma) magnesium, with the COPD-specific target sats and antibiotics.

Mechanism

Controlled oxygen + nebulised bronchodilators (salbutamol ± ipratropium) reverse bronchospasm; systemic corticosteroid reduces airway inflammation; IV magnesium sulfate is a smooth-muscle relaxant/bronchodilator in severe asthma; antibiotics if infective COPD exacerbation.

Indications

Acute asthma exacerbation
Acute COPD exacerbation

The agents

Oxygenacute

target sats

Asthma 94–98%; COPD 88–92% (CO₂ retainers) via Venturi.

Salbutamol ± ipratropium (nebulised)bronchodilators

back-to-back if severe

Driven by oxygen in asthma, air in COPD if CO₂ retention.

Prednisolone (or IV hydrocortisone)steroid

5 days

All acute asthma + COPD exacerbations.

Magnesium sulfate IVsevere asthma

single dose

Acute severe / life-threatening asthma (senior decision).

Antibiotic (COPD)if infective

amoxicillin/doxycycline/clarithromycin

Increased sputum purulence/volume.

Adverse effects

Hypokalaemia (β₂-agonist + steroid + aminophylline)serious

Monitor K⁺.

CO₂ narcosis from uncontrolled O₂ in COPD retainersserious

Cautions & contraindications

High-flow uncontrolled O₂ in COPD CO₂ retainersall

Worsens hypercapnia — target 88–92%, Venturi.

Interactions

Additive hypokalaemia

Monitoring & kinetics

ABG (esp. COPD — T2RF → consider NIV/BiPAP), peak flow, K⁺, sats

Nebulised + oral/IV. Escalate: O₂ → nebs → steroid → IV magnesium → senior/ICU.

Source: NICE NG245/NG115 — Acute asthma / COPD · BTS — Acute asthma