Warnings for Dopamine
Contains sodium metabisulfite, a sulfite that may cause
allergic-type reactions including anaphylactic symptoms and life-threatening or
less severe asthmatic episodes in certain susceptible people. The overall
prevalence of sulfite sensitivity in the general population is unknown, and
probably low. Sulfite sensitivity is seen more frequently in asthmatic than in
nonasthmatic people.
Do NOT add dopamine HCl to any alkaline diluent solution
since the drug is inactivated in alkaline solution.
Patients who have been receiving MAO inhibitors prior to
the administration of dopamine HCl will require substantially reduced dosage.
See DRUG INTERACTIONS section.
Precautions for Dopamine
General
- Monitoring- Careful monitoring of the
following indices is necessary during dopamine HCl infusion, as with any
adrenergic agent: blood pressure, urine flow, and, when possible, cardiac
output and pulmonary wedge pressure.
- Hypovolemia- Prior to treatment with
dopamine HCl, hypovolemia should be fully corrected, if possible, with either
whole blood or plasma as indicated. Monitoring of central venous pressure of
left ventricular filling pressure may be helpful in detecting and treating
hypovolemia.
- Hypoxia, Hypercapnia, Acidosis- These
conditions which may also reduce the effectiveness and/or increase the
incidence of adverse effects of dopamine, must be identified and corrected
prior to, or concurrently with administration of dopamine HCl.
- Decreased Pulse Pressure- If a
disproportionate increase in diastolic pressure and a marked decrease in the
pulse pressure are observed in patients receiving dopamine HCl, the rate of
infusion should be decreased and the patient observed carefully for further
evidence of predominant vasoconstrictor activity, unless such an effect is
desired.
- Ventricular Arrhythmias- If an increased
number of ectopic beats are observed, the dose should be reduced if possible.
- Hypotension- At lower infusion rates, if
hypotension occurs, the infusion rate should be rapidly increased until
adequate blood pressure is obtained. If hypotension persists, dopamine HCl
should be discontinued and a more potent vasoconstrictor agent such as
norepinephrine should be administered.
- Extravasation - Dopamine HCl should be
infused into a large vein whenever possible to prevent the possibility of
extravasation into tissue adjacent to the infusion site. Extravasation may
cause necrosis and sloughing of surrounding tissue. Large veins of the
antecubital fossa are preferred to veins in the dorsum of the hand or ankle.
Less suitable infusion sites should be used only if the patient's condition requires
immediate attention. The physician should switch to more suitable sites as
rapidly as possible. The infusion site should be continuously monitored for
free flow.
- Occlusive Vascular Disease- Patients
with a history of occlusive vascular disease (for example, atheroscierosis,
arterial embolism, and Raynaud's disease, cold injury, diabetic endarteritis,
and Buergers disease) should be closely monitored for any changes in color or
temperature of the skin in the extremities. If a change in skin color or
temperature occurs and is thought to be the result of compromised circulation
to the extremities, the benefits of continued dopamine HCl infusion should be weighed
against the risk of possible necrosis. This condition may be reversed by either
decreasing the rate or discontinuing the infusion.
IMPORTANT - Antidote for Peripheral Ischemia - To
prevent sloughing and necrosis in is chemic areas, the area should be
infiltrated as soon as possible with 10 to 15 mL of saline solution containing
5 to 10 mg of phentolamine mesylate, an adrenergic blocking agent. A syringe
with a fine hypodermic needle should be used, and the solution liberally
infiltrated throughout the is chemic area. Sympathetic blockade with
phentolamine causes immediate and conspicuous local hyperemic changes if the
area is infiltrated within 12 hours. Therefore, phentolamine should be given as
soon as possible after the extravasation is noted.
- Weaning- When discontinuing the
infusion, it may be necessary to gradually decrease the dose of dopamine HCl
while expanding blood volume with intravenous fluids, since sudden cessation
may result in marked hypotension.
Carcinogenesis, Mutagenesis, Impairment Of Fertility
Long-term animal studies have not been performed to
evaluate carcinogenic potential of dopamine hydrochloride.
Dopamine hydrochloride at doses approaching maximal
solubility shows no clear genotoxic potential in the Ames test. Although there
was a reproducible dose-dependent increase in the number of revertant colonies
with strains TA100 and TA98, both with and without metabolic activation, the
small increase was considered inconclusive evidence of mutagenicity. In the
L5178Y TK+/- mouse lymphoma assay, dopamine hydrochloride at the highest
concentrations used of 750 mcg/mL without metabolic activation, and 3000 mcg/mL
with activation, was toxic and associated with increases in mutant frequencies
when compared to untreated and solvent controls; at the lower concentrations no
increases over controls were noted.
No clear evidence of clastogenic potential was reported
in the in vivo mouse or male rat bone marrow micronucleus test when the animals
were treated intravenously with up to 224 mg/kg and 30 mg/kg of dopamine
hydrochloride, respectively.
Pregnancy
Teratogenic Effects
Teratogenicity studies in rats and rabbits at dopamine
HCl dosages up to 6 mg/kg/day intravenously during organogenesis produced no
detectable teratogenic or embryotoxic effects, although maternal toxicity
consisting of mortalities, decrease body weight gain, and pharmacotoxic signs
were observed in rats. In a published study, dopamine HCl administered at 10
mg/kg subcutaneously for 30 days, markedly prolonged metestrus and increased mean
pituitary and ovary weights in female rats. Similar administration to pregnant
rats throughout gestation or for 5 days starting on gestation day 10 or 15 resulted
in decreased body weight gains, increased mortalities and slight increases in
cataract formation among the offspring. There are no adequate and
well-controlled studies in pregnant women, and it is not known if dopamine HCl
crosses the placental barrier. Dopamine HCl should be used during pregnancy only
if the potential benefit justifies the potential risk to the fetus.
Labor And Delivery
In obstetrics, if vasopressor drugs are used to correct
hypotension or are added to a local anesthetic solution, some oxytocic drugs
may cause severe persistent hypertension and may even cause rupture of a cerebral
blood vessel to occur during the postpartum period.
Nursing Mothers
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 dopamine HCl is administered to a nursing mother.
Pediatric Use
Safety and effectiveness in children have not been
established. Dopamine HCl has been used in a limited number of pediatric
patients, but such use has been inadequate to fully define proper dosage and limitations
for use.
Geriatric Use
Clinical studies of dopamine injection did not include
sufficient numbers of subjects aged 65 and over to determine whether they
respond differently from younger subjects. Other reported clinical experience
has not identified differences in responses between the elderly and younger
patients. In general, 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 drug therapy.