Dose and Administration

Indications

1. Bronchospasm in infants with bronchopulmonary dysplasia.

Contraindications and Precautions

1. Known hypersensitivity to atropine and/or the propellant mixture.
2. Caution in newborn infants with glaucoma

Clinical Pharmacology

Ipratropium bromide is a quaternary derivative of atropine. Has low lipid solubility. The drug is a parasympathetic inhibitor (anticholinergic antimuscarinic agent) that blocks the vagal reflexes which mediate bronchoconstriction. Exerts a local effect on the airways. Has a high therapeutic ratio, producing bronchodilation without significant effect on other organ systems.

Systemic absorption after inhalation is very low (bioavailability <5%). Distribution is limited. Does not cross the blood brain barrier. Low binding (<20%) to human plasma protein. Some hepatic biotransformation, excretion via the kidneys. Elimination half-life in the adult is 3-4 hours.

Onset of action 5-30 minutes after inhalation. Peak effect occurs at approximately 60-120 minutes. Duration of action 3-8 hours. Incidence of systemic side effects is extremely low following inhalation. There is no evidence that in the therapeutic dose range ipratropium has any adverse effect on sputum viscosity or volume.

Possible Adverse Effects

1. Dryness of the mouth
2. Irritation and cough
3. Mild reversible accommodation disorder (if the eye is exposed to the drug).

Special Considerations

1. There is very little data about the pharmacokinetics and pharmacodynamics of this drug in the newborn and young infant. Dosage recommendations are largely empirical.
2. The efficacy of anticholinergic drugs in asthma is inferior to that of b adrenergic agonists. The use of inhaled anticholinergic drugs should generally be limited to those patients who do not adequately respond to maximal b adrenergic therapy.
3. The role of ipratropium in the management of bronchodilator responsive bronchospasm occurring in infants with BPD has not been clearly established.