Each ml contains Norepinephrine bitartrate monohydrate equivalent to Norepinephrine 1 mg
Norepinephrine is a sympathomimetic amine, which acts primarily by direct effect on and receptors in the heart. That is what causes peripheral vasoconstriction (-adrenergic action), and positive inotropic effects on the heart and coronary artery dilation (-adrenergic action). This action results in an increase in systemic blood pressure and coronary artery blood flow. In myocardial infarction accompanied by hypotension, norepinephrine usually increases aortic blood pressure, coronary artery blood flow, and myocardial oxygenation, thereby helping to limit areas of ischemia and myocardial infarction. Venous return is increased and the heart tends to return to a more normal rate and rhythm than in the hypotensive state. In persistent hypotension after correction of the deficient blood volume, norepinephrine helps increase blood pressure to optimal levels and results in more adequate circulation. However, the effect of norepinephrine on the 1 receptor is less when compared with epinephrine or isoproterenol. It is believed that the -adrenergic effect results from inhibition of the production of cyclic adenosine-3′,5′-monophosphate (AMP) by inhibiting the enzyme adenyl cyclase, whereas the -adrenergic effect results from the stimulation of adenyl cyclase activity.
Oral norepinephrine is impaired in the gastrointestinal tract, and absorption is low after subcutaneous injection. After IV administration, there is a rapid pressor response. This drug has a short duration of action, and its pressor action ceases within 1-2 minutes after the infusion is stopped.
Norepinephrine is mainly located in the sympathetic nervous system. This drug can cross the placenta but cannot cross the blood brain barrier.
The pharmacological action of norepinephrine is primarily mediated by uptake and metabolism at sympathetic nerve endings. It is metabolized in the liver and other tissues by a combination of reactions involving the enzymes catechol-O-methyltransferase (COMT) and monoamine oxidase (MAO). The main metabolites are normetanephrine and 3-methoxy-4-hydroxy mandelic acid (vanillymandelic acid, VMA), both of which are inactive metabolites. Other inactive metabolites are 3-methoxy-4hydroxyphenyl glycol, 3,4-dihydroxymandelic acid, and 3,4-dihydroxyphenylglycol. Norepinephrine metabolites are excreted in the urine, mainly as sulfate conjugates and to a lesser extent as glucuronide conjugates. Only small amounts of norepinephrine are excreted intact.
– To control blood pressure in acute hypotensive conditions (such as pheochromocytomectomy, sympathectomy, poliomyelitis, spinal anesthesia, myocardial infarction, septicemia, blood transfusion, and drug reactions).
– As adjunctive therapy in cardiac arrest and severe hypotension.
– To correct and maintain adequate blood pressure after effective heart rate and ventilation have been achieved by other means.
Dosage and Administration:
Norepinephrine injection is a concentrated, potent drug which must be dissolved in a solution containing dextrose before being infused. Norepinephrine infusion should be given into a large vein (“see caution”).
- Restoration of blood pressure in acute hypotension
Reduction in blood volume should always be corrected as soon as possible before a vasopressor is administered. If, as an emergency measure, intra-aortic pressure must be maintained to prevent cerebral or coronary artery ischemia, norepinephrine can be given before and at the same time as blood volume replacement.
Norepinephrine should be diluted in 5% dextrose injection or 5% dextrose and sodium chloride injection. This dextrose-containing liquid will significantly protect against potential loss due to oxidation. It is not recommended to administer norepinephrine in sodium chloride solution alone. Whole blood or plasma, if indicated to increase blood volume, should be administered separately (eg by using Y-tubes and separate containers if given concurrently).
Add 4 ml (4 mg) of the Norepinephrine ampoule to 1,000 ml of the 5% dextrose-containing solution. Each ml of this dilution contains 4 mcg of Norepinephrine base. Give this solution by intravenous infusion. Insert a plastic intravenous catheter through a needle that is properly inserted into the vein and attached with a tape, if possible, avoid the catheter tie-in technique, as this technique can easily cause static. An IV drip chamber or other suitable measuring device is required to accurately measure the flow rate in drops per minute. After observing the response to an initial dose of 2-3 ml (of 8-12 mcg base) per minute, adjust the flow rate to achieve and maintain Normal low blood pressure (usually 80-100 mmHg systolic pressure) is sufficient to maintain circulation to vital organs. In patients with a history of hypertension, it is recommended to increase blood pressure no more than 40 mmHg below the previous systolic pressure. The average maintenance dose is 0.5 – 1 ml per minute (2 mcg to 4 mcg alkaline).
- Adjunct treatment in cardiac arrest
Norepinephrine infusions are usually given intravenously during cardiac resuscitation to restore and maintain adequate blood pressure once the heart rate has been effective and cardiac ventilation has been maintained by other means. [Norepinephrine’s strong ability to stimulate -adrenergics is also thought to increase the strength and effectiveness of the systolic contractions that occur].
To maintain systemic blood pressure during the management of cardiac arrest, norepinephrine is used in the same way as described in “blood pressure restoration in acute hypotension”.
Prior to use, parenteral drug products should be visually observed for particles and discoloration, if the nature of the solution and container allows.
Do not use the solution, if the color is slightly reddish (pink) or darker than light yellow or if the preparation contains a precipitate. Avoid contact with ferrous salts, alkalis or oxidizing agents.
Store below 300C and protected from light.
After the Norephinephrine Injection is diluted, the solution can be stored for 24 hours at room temperature.
GUPRIN® Box, 5 ampoules @ 4 ml Reg. Number. : DKL1908026243A1
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