Ipratropium

Bronchial asthma: Ipratropium decreases ACh-mediated bronchospasm and mucus secretion within the respiratory airways. Ipratropium can provide short-term relief in chronic asthma, but short-acting beta2 agonists act more quickly and are much more commonly used. Ipratropium by nebulisation may be added to other standard treatment in life-threatening asthma or where acute asthma fails to improve with standard therapy.

COPD: Ipratropium decreases ACh-mediated bronchospasm and mucus secretion within the respiratory airways. Antimuscarinic bronchodilators are effective in chronic obstructive pulmonary disease. The aerosol inhalation of ipratropium has a maximum effect 30–60 minutes after use; its duration of action is 3 to 6 hours and bronchodilation can usually be maintained with treatment 3 times a day.

Bronchial asthma: The side-effects of antimuscarinic bronchodilators such as ipratropium include dry mouth, nausea, constipation, and headache. Tachycardia and atrial fibrillation have also been reported. Acute angle-closure glaucoma reported with nebulised ipratropium, particularly when given with nebulised salbutamol (and possibly other beta2 agonists). Ipratropium doesn't readily cross the blood-brain barrier, so consequence of blocking central muscarinic ACh receptors (confusion, memory loss) is greatly reduced.

COPD: The side-effects of antimuscarinic bronchodilators such as ipratropium include dry mouth, nausea, constipation, and headache. Tachycardia and atrial fibrillation have also been reported. Acute angle-closure glaucoma reported with nebulised ipratropium, particularly when given with nebulised salbutamol (and possibly other beta2 agonists).

Bronchial asthma: Ipratropium is most commonly given by aerosol inhalation (20–40 micrograms) in early treatment 3–4 times daily. It can also be delivered by inhalation of powder. Ipratropium may also be given by inhalation of nebulised solution (100–500 micrograms) up to 4 times daily in severe exacerbations. Because paradoxical bronchospasm may occur, first dose should be inhaled under medical supervision.

COPD: Ipratropium is most commonly given by aerosol inhalation (20–40 micrograms) in early treatment 3–4 times daily. It can also be delivered by inhalation of powder. Ipratropium may also be given by inhalation of nebulised solution (100–500 micrograms) up to 4 times daily in severe exacerbations. Because paradoxical bronchospasm may occur, first dose should be inhaled under medical supervision.

Bronchial asthma: See eBNF.

COPD: See eBNF.

Bronchial asthma: Ipratropium is less frequently used in asthma than COPD.

COPD: Tiotropium is a long-acting antimuscarinic bronchodilator that is licensed for maintenance treatment of chronic obstructive pulmonary disease; it is not suitable for the relief of acute bronchospasm.Tiotropium, a quaternary ammonium derived from ipratropium, is a long-acting nonselective antagonist of the muscarinic receptors M1 to M5. Inhibition of the muscarinic receptors block cholinergic neurotransmission causing bronchodilation. Tiotropium's affinity at muscarinic receptors is 6- to 20-fold greater than ipratropium.Unlike the other muscarinic receptors, blockade of the specific M2 receptor causes an increase in the release of acetylcholine, which is an unwanted effect. Two pharmacological benefits of tiotropium in comparison to ipratropium are that it dissociates much more rapidly from the M2 receptor, and it shows prolonged binding to the M1 and M3 receptors. The resultant pharmacokinetic effects are a slower onset and longer duration of action than ipratropium. This is demonstrated as the half-life of the tiotropium-muscarinic receptor complex in human lung tissue is 212 minutes, while the half-life of the ipratropium-muscarinic receptor complex is only 11 minutes.