Doxapram

General information

Generalized stimulation of the central nervous system has been observed with doxapram, particularly in large doses. Adverse reactions have included hyperactivity, tachycardia, increased deep tendon reflexes and muscle twitching, and laryngospasm. Raised blood pressure can also occur.

Doxapram is contraindicated in epilepsy and other convulsive disorders and in hypertension. Doxapram has been used to treat post-anesthetic shivering; in one study it was effective [ ].

Adverse reactions to doxapram are not long-lasting, because of its short half-life of 2–4 hours.

In seven patients treated with doxapram after anesthesia, the adverse effects were not serious and comprised excessive coughing, weeping, muscle tremor, nausea, and hysterical reactions to dreams. However, sweating, excessive salivation, and vomiting were noted in the control patients, and the authors concluded that recovery was smoother with doxapram.

There was a very high incidence of adverse reactions, such as hot flushes, sweating, hyperventilation, tremor, nausea, and vertigo, in postoperative analgesia combined with doxapram 1 mg/kg [ ].

In a controlled study of the use of doxapram infusion for late postoperative hypoxemia [ ] three of nine patients who received doxapram had an adverse event, compared with none of the placebo patients. In 18 patients there was a significant trend toward higher mean oxygen saturation in the doxapram group and a significantly higher minimum oxygen saturation and reduced number of hypoxemic events on the first postoperative night. The authors concluded that although the results were promising, continuous nocturnal postoperative doxapram infusion should be postponed until there is more information about its pharmacokinetics in this condition.

The effects of doxapram given enterally or intravenously have been studied in a prospective randomized trial in 15 infants with apnea of prematurity who had not responded to caffeine [ ]. Of the nine infants randomized to receive enteral treatment, five had to be changed to intravenous treatment, largely owing to doxapram-induced upper gastrointestinal symptoms (vomiting and large gastric residuals). Doxapram significantly reduced the frequency of attacks of apnea and associated bradycardia and hypoxia in 82% of the infants. The major adverse event was feeding intolerance in one-third of infants given enteral treatment. This resolved when doxapram was given intravenously. Importantly, some infants responded to and could tolerate enteral treatment, thus avoiding the need for an intravenous line.

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