DOXAPRAM HYDROCHLORIDE
| DOXAPRAM HYDROCHLORIDE (dox'a-pram) Dopram Classifications: cerebral stimulant; respiratory stimulant; Therapeutic: cerebral stimulant; repiratory stimulant Prototype: Caffeine Pregnancy Category: B |
Availability
20 mg/mL injection
Action
Short-acting analeptic capable of stimulating all levels of the cerebrospinal axis. Respiratory stimulation by direct medullary action or possibly by indirect activation of peripheral chemoreceptors increases tidal volume and slightly increases respiratory rate.
Therapeutic Effect
Decreases Pco2 and increases Po2 by increasing alveolar ventilation; may elevate BP and pulse rate by stimulation of brainstem vasomotor area. It is used to stimulate respiration postanesthesia, for drug-induced CNS depression, and for chronic pulmonary disease associated with acute hypercapnia.
Uses
Short-term adjunctive therapy to alleviate postanesthesia and drug-induced respiratory depression. Also as a temporary measure (approximately 2 h) in hospitalized patients with COPD associated with acute respiratory insufficiency as an aid to prevent elevation of Paco2 during administration of oxygen. (Not used with mechanical ventilation.)
Unlabeled Uses
Neonatal apnea refractory to xanthine therapy.
Contraindications
Epilepsy and other convulsive disorders; of ventilatory mechanism due to muscle paresis, pulmonary fibrosis, flail chest, pneumothorax, airway obstruction, extreme dyspnea, or acute bronchial asthma; severe hypertension, coronary artery disease, uncompensated heart failure, CVA; MAOI; lactation; children <12 y.
Cautious Use
History of bronchial asthma, COPD; cardiac disease, severe tachycardia, arrhythmias, hypertension; hyperthyroidism; pheochromocytoma; head injury, cerebral edema, increased intracranial pressure; peptic ulcer, patients undergoing gastric surgery; acute agitation; pregnancy (category B).
Route & Dosage
| Postanesthesia Adult: IV 0.5–1 mg/kg single injection (not more than 1.5 mg/kg), may repeat q5min up to 2 mg/kg total dose; infusion of 0.5–1 mg/kg (up to 4 mg/kg total dose) Drug-Induced CNS Depression Adult: IV 1–2 mg/kg repeat in 5 min, then q1–2h until patient awakens [if relapse occurs, resume q1–2h injections (max: total dose 3 g), if no response after priming dose, may give 1–3 mg/min for up to 2 h until patient awakens] Chronic Obstructive Pulmonary Disease Adult: IV 0.5–2 mg/kg OR 1–2 mg/min for a max of 2 h (max: rate 3 mg/min) |
Administration
- IV administration to neonates: Verify correct IV concentration and rate of infusion with physician. Generally do not use in newborns because doxapram contains benzyl alcohol.
- Ensure adequacy of airway and oxygenation before initiation of doxapram therapy.
| Intravenous PREPARE: Direct: Give undiluted. IV Infusion for CNS Depression: Dilute 250 mg (12.5 mL) in 250 mL of D5W or NS. IV Infusion for COPD: Add 400 mg doxapram to 180 mL of D5W, D10W, or NS to yield 2 mg/mL. ADMINISTER: Direct for CNS Depression: Give undiluted over 5 min. IV Infusion for CNS Depression: Give at a rate of 1–3 mg/min, depending on patient response. Never exceed 3 mg/min. Infusion should not be administered for longer than 2 h. IV Infusion for COPD: Infuse at 0.5–1.5 mL/min. INCOMPATIBILITIES Solution/additive: Aminophylline, ascorbic acid, cephalosporins, carbenicillin, dexamethasone, diazepam, digoxin, dobutamine, folic acid, furosemide, hydrocortisone, ketamine, methylprednisolone, minocycline, thiopental, ticarcillin. Y-site: Clindamycin. |
- Store at 15°–30° C (59°–86° F) unless otherwise directed.
Adverse Effects (≥1%)
CNS: Dizziness, sneezing, apprehension, confusion, involuntary movements, hyperactivity, paresthesias; feeling of warmth and burning, especially of genitalia and perineum; flushing, sweating, hyperpyrexia, headache, pilomotor erection, pruritus, muscle tremor, rigidity, convulsions, increased deep-tendon reflexes, bilateral Babinski sign, carpopedal spasm, pupillary dilation, mild delayed narcosis. CV: Mild to moderate increase in BP, sinus tachycardia, bradycardia, extrasystoles, lowered T waves, PVCs, chest pains, tightness in chest. GI: Nausea, vomiting, diarrhea, salivation, sour taste. Urogenital: Urinary retention, frequency, incontinence. Respiratory: Dyspnea, tachypnea, cough, laryngospasm, bronchospasm, hiccups, rebound hypoventilation, hypocapnia with tetany. Other: Local skin irritation, thrombophlebitis with extravasation; decreased Hgb, Hct, and RBC count; elevated BUN; albuminuria.Interactions
Drug: mao inhibitors, sympathomimetic agents add to pressor effects.Pharmacokinetics
Onset: 20–40 s. Peak: 1–2 min. Duration: 5–12 min. Metabolism: Rapidly metabolized. Elimination: In urine as metabolites.Nursing Implications
Assessment & Drug Effects
- Monitor IV site frequently. Extravasation or use of same IV site for prolonged periods can cause thrombophlebitis (see Appendix F) or tissue irritation.
- Monitor carefully and observe accurately: BP, pulse, deep tendon reflexes, airway, and arterial blood gases. All are essential guides for determining minimum effective dosage and preventing overdosage. Make baseline determinations for comparison.
- Lab tests: Draw arterial Po2 and Pco2 and O2 saturation prior to both initiation of doxapram infusion and oxygen administration in patients with COPD, and then at least every 30 min during infusion.
- Discontinue doxapram if arterial blood gases show evidence of deterioration and when mechanical ventilation is initiated.
- Observe patient continuously during therapy and maintain vigilance until patient is fully alert (usually about 1 h) and protective pharyngeal and laryngeal reflexes are completely restored.
- Notify physician immediately of any adverse effects. Be alert for early signs of toxicity: Tachycardia, muscle tremor, spasticity, hyperactive reflexes.
- Note: A mild to moderate increase in BP commonly occurs.
- Discontinue if sudden hypotension or dyspnea develops.
Common adverse effects in italic, life-threatening effects underlined; generic names in bold; classifications in SMALL CAPS; 
Canadian drug name; 
Prototype drug