DOBUCIN

Indications

• Acute heart failure
• Cardiogenic shock
• Cardiac arrest during positive end-expiratory pressure ventilation

Dosage

Children: In paediatric patients, refer to the BNF for Children for specific dosing recommendations, as it varies based on the child's weight and clinical condition.

Adults: For adults, Dobutamine is usually administered as a continuous intravenous infusion, with the initial dose commonly starting at 2-5 micrograms/kg/min, adjusted based on clinical response and tolerance.

Mechanism of action

Dobutamine directly stimulates beta-1 receptors of the heart, resulting in increased myocardial contractility and stroke volume, which collectively enhance cardiac output. It acts primarily on beta-1 adrenergic receptors, producing mild chronotropic and hypertensive effects while avoiding the release of endogenous norepinephrine.

Pharmacodynamics

Dobutamine is a direct-acting inotropic agent whose primary activity arises from stimulation of beta-adrenoceptors in the heart. It produces comparatively mild effects on heart rate, blood pressure, and arrhythmia, with the primary focus on increasing myocardial contractility. Its selectivity for beta-1 receptors results in limited interaction with beta-2 or alpha receptors.

Pharmacokinetics

Dobutamine is administered intravenously and has a rapid onset of action, with peak effects occurring within 10 minutes. Its duration of action is typically 1-2 hours. The drug is rapidly metabolized primarily by catechol-O-methyltransferase (COMT) and sulfation, resulting in inactive metabolites excreted through the urine. Its pharmacokinetic profile is influenced by factors such as the patient's renal function and the presence of other medications.

Contra-indications

• Hypersensitivity to dobutamine or any of its components
• Idiopathic hypertrophic subaortic stenosis
• Severe hypotension
• Obstructive hypertrophic cardiomyopathy

Adverse effects

• Tachycardia
• Arrhythmias
• Hypotension
• Nausea
• Headache
• Palpitations
• Injection site reactions

Interactions

• Increased risk of arrhythmias when administered with other sympathomimetics
• Potentially increased effects when given with monoamine oxidase inhibitors (MAOIs)
• May interact with beta-blockers, potentially opposing the effects of dobutamine

Precautions

• Caution in patients with a history of arrhythmias
• Monitor heart rate and blood pressure regularly during treatment
• Use with caution in patients with ischemic heart disease
• Avoid extravasation as it may cause tissue necrosis

Pregnancy

No evidence of harm in animal studies; however, use should be considered only if the potential benefit justifies the potential risk to the fetus.

Breast-feeding

Use with caution; no information available on excretion in human milk.

Storage

Store at room temperature, away from light. Protect from freezing.

Formulations

• Dobutamine 250 mg/50 mL solution for infusion
• Dobutamine 12.5 mg/mL concentrate for solution for infusion
• Dobutamine 5 mg/mL injection

Mechanism of action

Dobutamine directly stimulates beta-1 receptors of the heart to increase myocardial contractility and stroke volume, resulting in increased cardiac output.

Pharmacodynamics

Dobutamine is a direct-acting inotropic agent whose primary activity results from stimulation of the beta-adrenoceptors of the heart while producing comparatively mild chronotropic, hypertensive, arrhythmogenic, and vasodilative effects. Dobutamine acts primarily on beta-1 adrenergic receptors, with negligible effects on beta-2 or alpha receptors. It does not cause the release of endogenous norepinephrine, as does dopamine.