General: Avoid Hypertension: Because of the potency of norepinephrine and because of varying response to pressor substances, the possibility always exists that dangerously high blood pressure may be produced with overdoses of this pressor agent. Therefore, blood pressure should be recorded every 2 min from the time administration is started until the desired blood pressure is obtained, then every 5 min if administration is to be continued. The rate of flow must be watched constantly and the patient should never be left unattended while receiving norepinephrine. Headache may be a symptom of hypertension due to overdosage.
Site of Infusion: Whenever possible, infusions of norepinephrine should be given into a large vein, particularly on the antecubital vein, because of the risk of necrosis of the overlying skin from prolonged vasoconstriction, when administered into this vein, is apparently very slight. Some scientists have indicated that the femoral vein is also an acceptable route of administration. If possible, a catheter tie-in technique should be avoided, since the obstruction to blood flow around the tubing may cause stasis and increased local concentration of norepinephrine. Occlusive vascular diseases (eg, atherosclerosis, arteriosclerosis, diabetic endarteritis, Buerger's disease) are more likely to occur in the lower extremity than in the upper extremity. Therefore, avoid the veins of the leg in elderly patients or in those suffering from such disorders. It has been reported that gangrene occur in the lower extremity when infusions of norepinephrine were given in an ankle vein.
Extravasation: The infusion site should be checked frequently for free flow. Care should be taken to avoid extravasation of norepinephrine into the tissues, as local necrosis might ensue due to the vasoconstrictive action of Raivas. Blanching along the course of the infused vein, sometimes without obvious extravasation, has been attributed to vasa vasorum constriction with increased permeability of the vein wall, permitting some leakage. Although rare, this also may progress to superficial slough, particularly during infusion into leg veins in elderly patients or in those suffering from obliterative vascular disease. Hence, if blanching occurs, consideration should be given for periodically changing the infusion site at intervals to allow the effects of local vasoconstriction.
Antidote for Extravasation Ischaemia: To prevent sloughing and necrosis in areas in which extravasation has taken place, the area should be infiltrated as soon as possible with 10-15 mL of saline solution containing phentolamine 5-10 mg, an adrenergic-blocking agent. A syringe with a fine hypodermic needle should be used, with the solution being infiltrated liberally throughout the area, which is easily identified by its cold, hard and pallid appearance. Sympathetic blockade with phentolamine causes immediate and conspicuous local hyperaemic changes if the area is infiltrated within 12 hrs. Therefore, phentolamine should be given as soon as possible after extravasation is noted.
Carcinogenicity, Mutagenicity & Impairment of Fertility: Studies have not been established.
Use in pregnancy: Animal reproduction studies have not been conducted with norepinehrine. It is also not known whether noradrenaline can cause foetal harm when administered to a pregnant woman or can affect reproduction capacity. Norepinephrine should be given to a pregnant woman only if clearly needed.
Use in lactation: It is not known whether this drug is excreted in human milk. Because many drugs are excreted in human milk, caution should be exercised when norepinephrine is administered to a nursing mother.
Use in children: Safety and effectiveness in paediatric patients has not been established.
Use in the elderly: Clinical studies of norepinephrine did not include sufficient numbers of subjects ≥65 years to determine whether they respond differently from younger subjects. Although clinical experience has not identified differences in responses between the elderly and younger patients, dose selection for an elderly patient should be cautious, usually starting at the low-end of the dosing range, reflecting the greater frequency of decreased hepatic, renal or cardiac function, and of concomitant disease or other therapy. Norepinephrine infusions should not be administered into the veins in the leg in elderly patients.