Doxapram
Mechanism :
Doxapram hydrochloride produces respiratory stimulation mediated through the peripheral carotid chemoreceptors. As the dosage is increased, the central respiratory centres in the medulla are stimulated with progressive stimulation of other parts of the brain and spinal cord. Increases minute volume and respiratory rate.
Indication :
- It is a central respiratory stimulant.
- Post anesthesia respiratory depression
- Drug induced CNS depression
Contraindications :
Doxapram is contraindicated in neonates due to its benzyl alcohol content. Doxapram should not be used in patients with epilepsy or other convulsive disorders and in patients with mechanical disorders of ventilation such as mechanical obstruction, muscle paresis, flail chest, pneumothorax, acute bronchial asthma, pulmonary fibrosis or other conditions resulting in restriction of chest wall, muscles of respiration or alveolar expansion. Doxapram is contraindicated in patients with evidence of head injury or cerebral vascular accident and in those with significant cardiovascular impairment, severe hypertension, or known hypersensitivity to the drug or any of the injection components.
Dosing :
<12 years: Safety and efficacy not established.
>12 years:
Post anesthesia respiratory depression:
IV infusion: 1-2 mg/min IV infusion for not more than 2 hours. Maximum dose: 3 mg/min. Watch for acidosis/CO2 retention.
IV intermittent dose: 0.5-1 mg/kg IV. Can be repeated at 5-min intervals. Maximum dose: 2 mg/kg.
Drug induced CNS depression:
1-2 mg/kg IV. Repeat in 1-2 hours. Maximum: 3 gm/day.
Adverse Effect :
Fever, sweating, itching, disorientation, dilated pupils, hallucinations, muscle spasticity, cough, bronchospasm, hypo-hyperventilation, arrhythmias, urinary retention, hemolysis, hypertension, anemia, leukopenia.
Interaction :
Sympathomimetic or Monoamine Oxidase Inhibiting drugs: May result in an additive pressor effect.
Muscle Relaxant Drugs: Doxapram may temporarily mask the residual effects of muscle relaxant drugs.
Volatile General Anaesthetics: Administration of doxapram should be delayed until the volatile agent has been excreted.
Renal Dose :
Dose in Renal Impairment GFR (mL/min)
| 20-50 | Dose as in normal renal function |
| 10-20 | Dose as in normal renal function |
| <10 | Dose as in normal renal function |
Dose in Patients undergoing Renal Replacement Therapies
| CAPD | Unlikely to be dialysed. Dose as in normal renal function |
| HD | Unlikely to be dialysed. Dose as in normal renal function |
| HDF/High flux | Unlikely to be dialysed. Dose as in normal renal function |
| CAV/VVHD | Unlikely to be dialysed. Dose as in normal renal function |
Hepatic Dose :
There are no dosage adjustments provided in manufacturer's labeling (has not been studied); however, use caution in severe impairment due to the potential for altered pharmacokinetics.