indication

For use as a temporary measure in hospitalized patients with acute respiratory insufficiency superimposed on chronic obstructive pulmonary disease.

pharmacology

Doxapram is an analeptic agent (a stimulant of the central nervous system). The respiratory stimulant action is manifested by an increase in tidal volume associated with a slight increase in respiratory rate. A pressor response may result following doxapram administration. Provided there is no impairment of cardiac function, the pressor effect is more marked in hypovolemic than in normovolemic states. The pressor response is due to the improved cardiac output rather than peripheral vasoconstriction. Following doxapram administration, an increased release of catecholamines has been noted.

mechanism of action

Doxapram produces respiratory stimulation mediated through the peripheral carotid chemoreceptors. It is thought to stimulate the carotid body by inhibiting certain potassium channels.

toxicity

Intravenous LD₅₀ values in the mouse and rat were approximately 75 mg/kg and in the cat and dog were 40 to 80 mg/kg. Symptoms of overdosage are extensions of the pharmacologic effects of the drug. Excessive pressor effect, tachycardia, skeletal muscle hyperactivity, and enhanced deep tendon reflexes may be early signs of overdosage.