DOBUJECT 250 mg/5 ml infusion concentrate
equivalent to dobutamine 250 mg
Ascorbic acid 5 mg
Water for injection to 5 ml
Dobutamine is a sympathomimetic amine which has a strong stimulating effect on cardiac β1-receptors and a weak effect on β2- and α1- receptors. The intropic effect of dobutamine results from direct stimulation of cardiacβ1-receptors, unlike the effect of dopamine which is based mainly on endogenous noradrenalin release.
Dobutamine is suitable for short-term inotropic support of the heart in patients with insufficient cardiac output and high left ventricular filling pressure but only slightly or moderately decreased blood pressure. Dobutamine is not suitable for monotherapy of severe hypotension or shock requiring vasopressor effect. In these patients, the best result is propably obtained by concomitant use of dobutamine and dopamine.
Dobutamine exerts a dose-related positive inotropic effect at dose levels which involve no significant increase in heart rate. Tachycardia may occur only at high dosages (15 microg/kg/min). With dobutamine therapy the risk of tachycardia and cardiac arrythmia is relatively small.
The action of dobutamine is observable within 2 minutes after instituting intravenous infusion, but fill effect os obtained only after 10 minutes. The plasma half-life of dobutamine is about 3 minutes. The direct and prompt short-term stimulating effect of dobutamine on B1-receptors allows a flexible and individual support of myocardial contractility. This can easily be carried out by adjusting the infusion rate.
Inotropic support of the myocardium in the treatment of acute congestive heart failure or cardiogenic shock.
Note! For hospital use only.
As an intravenous infusion of 2.5-40 microg/kg/min. The usual dose is 2.5-10 microg/kg/min. The dosage should be adjusted individually according to the patient's heart rate and rhythm, blood pressure and diuresis. Partial tolerance may develop if infusion time exceeds 72 hours, and such cases may call for an increase in dosage.
Infusion concentrate 250 mg/5 ml:
In clinical studies, no evidence has been found of drug interactions between dobutamine and other drugs. Concomitant administration of dobutamine and nitroprusside increase cardiac output and usually reduces pulmonary capillary wedge pressure more than either of these drugs alone. Dobuject may prove ineffective in patients recently treated with β-adrenoreceptor blocking drugs. In such cases, peripheral vascular resistance may increase.
During treatment with Dobuject, ECG and blood pressure should be monitored continuosly. In addition, cardiac filling pressure and output should be monitored whenever possible. Hypovolaemia should always be corrected before instituting dobutamine therapy.
Dobutamine, like any catecholamine, may provoke chest pain in patiets with coronary heart disease. Therefore, the dosage should be carefully considered. Care should also be taken after acute myocardial infarction; excessive inotropism and tachycardia should be avoided as these may increase myocardial oxygen consumption and, consequently, infarct size.
Dobutamine usually causes a slight increase in systolic blood pressure (10-20 mmHg) and heart rate (5-10 beats/min). Unusually high blood pressure increases have been reported especially in patients with arterial hypertension. Sometimes excessive tachycardia may occur. Discontinuation of infusion or reduction of infusion rate usually normalize the situation rapidly. Dobutamine increases atrioventricular conduction. Therefore, care should be taken when determining the dosage for patients with atrial fibrillation. These patients should preferably be digitalized before dobutamine therapy is instituted. Dobutamine may provoke ventricular ectopic activity.
At overdosage, which manifests itself as excessive blood pressure changes or tachycardia, the infusion rate must be reduced or therapy discontinued until the patient is in balance.
Dobuject should not be mixed with alkaline solutions.
Storage and Shelf Life:
Shelf life 2 years, protected from light. Below 25oC. Diluted Dobuject infusion solution remains effective for 12 hours at room temperature and 24 hours in a refrigerator.Unused concentrate must be destroyed.
Infusion concentrate 5x5 ml and 10x5 ml, clear, clourless or slightly yellowish solution. The yellowish colour is caused by oxidation of ascorbic acid during storage. This does not affect the efficacy or safety of the product.
HARUS DENGAN RESEP DOKTER
Schering Oy, Finland