doxapram hydrochloride: clinical use

Prescribing considerations

• Ensure a patent airway and consider airway protection because vomiting may occur.
• Respiratory stimulation may wear off before depressant medicines; continue observation until recovery is established.
• Use oxygen in severe irreversible airway obstruction or markedly reduced lung compliance, and an appropriate bronchodilator when bronchoconstriction is present.
• Use cautiously with hepatic dysfunction, hypertension, impaired cardiac reserve or phaeochromocytoma.
• Do not use with mechanical ventilation.

Contraindications and cautions

• Hypersensitivity to doxapram hydrochloride or an excipient.
• Severe hypertension, coronary artery disease or hyperthyroidism/thyrotoxicosis.
• Status asthmaticus, physical airway obstruction, restricted chest-wall or respiratory-muscle movement, or impaired alveolar expansion.
• Epilepsy or another convulsive disorder, cerebral oedema, previous cerebrovascular accident or head injury.
• Proven or suspected pulmonary embolism.

Monitoring

• Continuously assess ventilation, airway patency, consciousness and response to other peri-operative medicines.
• Monitor blood pressure and deep-tendon reflexes for excessive stimulation.
• Use arterial blood-gas analysis where clinically indicated; doxapram does not replace respiratory monitoring.
• Stop administration if sudden hypertension or dyspnoea develops.
• Observe for arrhythmias, muscle hyperactivity and seizures.

Clinical pharmacology

Doxapram is a ventilatory stimulant acting mainly at peripheral carotid chemoreceptors. It principally increases tidal volume, with a smaller effect on respiratory rate. It is extensively metabolised, primarily by the liver, and only a small proportion is excreted unchanged in urine.

Formulation and product differences

• The selected product is a clear, colourless, sterile solution for intravenous injection in glass ampoules.
• Water for injections is the only listed excipient.
• It is for single use and should be used immediately after opening; unused contents must be discarded.
• It is incompatible with alkaline solutions such as aminophylline, furosemide and thiopental sodium.

Injection

Route: Parenteral

Strengths: 20 mg/mL