Adult: 2.5-10 mcg/kg/min. Dose range of 0.5-40 mcg/kg/min may be given. Adjust according to patient's BP, heart rate, cardiac and urine output. Child: Neonates to 18 yr Initially, 5 mcg/kg/min, adjust to 2-20 mcg/kg/min according to response.
Intravenous Cardiac stress test
Adult: 5 mcg/kg/min for 8 min via infusion pump using a soln containing 1 mg/mL. Increase dose by increments of 5 mcg/kg/min up to max 20 mcg/kg/min, w/ each dose being infused for 8 min before the next increase. Child:
Reconstitution
Dilute to a concentration of 0.5-1 mg/mL (max 5 mg/mL, if fluid restricted) w/ glucose 5% or NaCl 0.9%.
Patient w/ hyperthyroidism, active myocardial ischaemia or recent MI, cardiogenic shock complicated by severe hypotension, DM, closed angle glaucoma. Correct hypovolaemia prior to treatment. Childn, including neonates. Pregnancy and lactation.
Adverse Reactions
Increased heart rate, ectopic heartbeats, angina, chest pain, palpitation, elevations in BP, skin rash, fever, eosinophilia, bronchospasm, paraesthesia, nausea, vomiting, tingling sensation, dyspnoea, fever, headache, mild leg cramps; pruritus of the scalp; phlebitis at the inj site. Rarely, ventricular tachycardia, hypokalaemia.
Monitor BP, ECG, cardiac output and pulmonary wedge pressure.
Overdosage
Symptoms: Nausea, vomiting, anorexia, headache, shortness of breath, anginal and non-specific chest pain, palpitations, anxiety, tremor, urinary incontinence, HTN, tachyarrhythmias, myocardial ischaemia, ventricular fibrillation, hypotension. Management: Protect patient’s airway and support ventilation and perfusion. May admin metoprolol, esmolol or other β-adrenergic blocking agents.
Drug Interactions
Risk of hypotension and tachycardia w/ α-blockers (e.g. phenoxybenzamine). May produce ventricular arrhythmias w/ cyclopropane, halothane and other halogenated anaesth. Increased risk of arrhythmias w/ quinidine and cardiac glycosides. Risk of HTN and arrhythmias w/ TCAs. May increase BP w/ antihypertensives. Risk of severe HTN and bradycardia w/ β-blocker esp non-selective β-blockers. Reduced cardiotonic effects w/ CaCl infusion. Increased risk of HTN w/ doxapram. Enhanced effects w/ entacapone. Risk of ergotism w/ ergotamine or ergometrine (ergonovine) or methysergide. Oxytocin may possibly enhance the pressor effect of dobutamine w/ or w/o HTN.
Action
Description: Dobutamine exerts positive inotropic effect on the myocardium by stimulating β1-adrenergic receptors, thereby increasing myocardial contractility, stroke vol and cardiac output. Onset: Approx 2 min. Duration: <10 min. Pharmacokinetics: Absorption: Inactivated when given orally. Metabolism: Hepatically metabolised; converted to 3-O-methyldobutamine by COMT and via conjugation by glucuronic acid. Excretion: Mainly via urine; via faeces (small amounts). Elimination half-life: Approx 2 min.
C01CA07 - dobutamine ; Belongs to the class of adrenergic and dopaminergic cardiac stimulants excluding glycosides. Used in the treatment of hypotension.
References
Anon. Dobutamine. Lexicomp Online. Hudson, Ohio. Wolters Kluwer Clinical Drug Information, Inc. https://online.lexi.com. Accessed 21/10/2015.Buckingham R (ed). Dobutamine Hydrochloride. Martindale: The Complete Drug Reference [online]. London. Pharmaceutical Press. https://www.medicinescomplete.com. Accessed 21/10/2015.Dobutamine Hydrochloride Injection, Solution, Concentrate (Hospira, Inc.). DailyMed. Source: U.S. National Library of Medicine. https://dailymed.nlm.nih.gov/dailymed/. Accessed 21/10/2015.Joint Formulary Committee. Dobutamine. British National Formulary [online]. London. BMJ Group and Pharmaceutical Press. https://www.medicinescomplete.com. Accessed 21/10/2015.McEvoy GK, Snow EK, Miller J et al (eds). Dobutamine Hydrochloride. AHFS Drug Information (AHFS DI) [online]. American Society of Health-System Pharmacists (ASHP). https://www.medicinescomplete.com. Accessed 21/10/2015.