Dopamine Hydrochloride

Dopamine HCl Injection is indicated to improve hemodynamic status in patients in distributive shock or shock due to reduced cardiac output. Dopamine HCl Injection is a catecholamine indicated to improve hemodynamic status in patients in shock. ( 1 )

The following strengths of Dopamine HCL, USP, are supplied in single-dose vials (the solution is clear practically colorless):

• 200 mg/5 mL (40 mg/mL)
• 400 mg/10 mL (40 mg/mL) The following strengths of Dopamine HCL, USP, are supplied in single-dose vials: ( 3 )
• 200 mg/5 mL (40 mg/mL)
• 400 mg/10 mL (40 mg/mL)

Dopamine is contraindicated in patients with pheochromocytoma. Dopamine is contraindicated in patients with pheochromocytoma. ( 4 )

• Tissue ischemia: Severe peripheral and visceral vasoconstriction can occur. Address hypovolemia prior to use, monitor extremities, and infuse into large vein. ( 5.1 )
• Cardiac arrhythmias: Monitor closely. ( 5.2 )
• Hypotension after abrupt discontinuation: Gradually reduce infusion rate while expanding blood volume with intravenous fluids. ( 5.3 )
• Severe hypersensitivity reactions due to sodium metabisulfite excipient: May cause anaphylaxis including life‑threatening or less severe asthmatic episodes in susceptible individuals. ( 5.4 )

5.1 Tissue Ischemia Administration of dopamine to patients who are hypotensive from hypovolemia can result in severe peripheral and visceral vasoconstriction, decreased renal perfusion and hypouresis, tissue hypoxia, lactic acidosis, and poor systemic blood flow despite “normal” blood pressure. Address hypovolemia prior to initiating Dopamine HCl Injection [see Dosage and Administration (2.2) ] . Gangrene of the extremities has occurred in patients with occlusive vascular disease or who received prolonged or high dose infusions. Monitor for changes to the skin of the extremities in susceptible patients. Extravasation of Dopamine HCl Injection may cause necrosis and sloughing of surrounding tissue. To reduce the risk of extravasation, infuse into a large vein [see Dosage and Administration (2.1) ] , check the infusion site frequently for free flow, and monitor for signs of extravasation. Emergency Treatment of Extravasation To prevent sloughing and necrosis in areas in which extravasation has occurred, infiltrate the ischemic area as soon as possible, using a syringe with a fine hypodermic needle with:

• 5 to 10 mg of phentolamine mesylate in 10 to 15 mL of 0.9% Sodium Chloride Injection in adults
• 0.1 to 0.2 mg/kg of phentolamine mesylate up to a maximum of 10 mg per dose in pediatric patients. Sympathetic blockade with phentolamine causes immediate and conspicuous local hyperemic changes if the area is infiltrated within 12 hours.

5.2 Cardiac Arrhythmias Dopamine may cause arrhythmias. Monitor patients with arrhythmias and treat appropriately.

5.3 Hypotension after Abrupt Discontinuation Sudden cessation of the infusion may result in marked hypotension. Gradually reduce the infusion rate while expanding blood volume with intravenous fluids.

5.4 Severe Hypersensitivity Reactions due to Sodium Metabisulfite Excipient Dopamine HCl Injection 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.

The following adverse reactions are described elsewhere in the labeling:

• Tissue Ischemia [see Warnings and Precautions (5.1) ]
• Cardiac Arrhythmias [see Warnings and Precautions (5.2) ]
• Hypotension [see Warnings and Precautions (5.3) ]
• Severe Hypersensitivity Reactions [see Warnings and Precautions (5.4) ] The following adverse reactions have been identified during postapproval use of dopamine. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure. Cardiac Disorders: anginal pain, palpitation Gastrointestinal Disorders: nausea, vomiting Metabolism and Nutrition Disorders: azotemia Nervous System Disorders: headache, anxiety Respiratory Disorders: dyspnea Skin and Subcutaneous Tissue Disorders: piloerection Vascular Disorders: hypertension The most common adverse reaction is localized vasoconstriction due to extravasation. ( 6 ) To report SUSPECTED ADVERSE REACTIONS, contact Pfizer Inc. at 1-800-438-1985 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch.

See Table 1 for clinically significant drug interactions with dopamine. Table 1: Clinically Significant Drug Interactions with Dopamine Halogenated Anesthetics Clinical Impact: Concomitant use may increase cardiac autonomic irritability and can sensitize the myocardium to the action of dopamine which may lead to ventricular arrhythmias and hypertension. Intervention: Monitor cardiac rhythm. Examples: desflurane, enflurane, isoflurane, and sevoflurane. MAO Inhibitors Clinical Impact: Because dopamine is metabolized by monoamine oxidase (MAO), inhibition of this enzyme prolongs and potentiates the effect of dopamine which may result in severe hypertension and cardiac arrhythmia. Intervention: Reduce the recommended starting dosage to no greater than one‑tenth (1/10) of the recommended dose in patients who have been treated with MAO inhibitors within two to three weeks prior to the administration of Dopamine HCl Injection. Examples: isocarboxazid, phenelzine, tranylcypromine, rasagiline, selegiline, linezolid. Tricyclic Antidepressants Clinical Impact: Concomitant use may potentiate the cardiovascular effects of dopamine (e.g., hypertension). Intervention: Monitor blood pressure. Examples: amitriptyline, desipramine, doxepin, imipramine, nortriptyline. Vasopressors Clinical Impact: Concomitant use may result in severe hypertension. Intervention: Monitor blood pressure. Examples: norepinephrine, epinephrine, oxytocin.

• Halogenated anesthetics: Can sensitize the myocardium to the effects of dopamine and can produce ventricular arrhythmias and hypertension. ( 7 )
• MAO inhibitors: Risk of severe hypertension. Reduce recommended Dopamine HCl Injection dosage. ( 7 )
• Tricyclic antidepressants: Risk of hypertension. Monitor blood pressure. ( 7 )
• Vasopressors: Risk of severe hypertension. Monitor blood pressure. ( 7 )

8.1 Pregnancy Risk Summary There are no human data with dopamine use in pregnant women. There are risks to the mother and fetus from hypotension associated with shock, which can be fatal if left untreated ( see Clinical Considerations ). In animal reproduction studies, adverse developmental outcomes were observed with intravenous dopamine HCl administration in pregnant rats during organogenesis at doses, on a mcg/m 2 basis, of one‑third the human starting dose of 2 mcg/kg/minute (90 mcg/m 2 /minute). The background risk of major birth defects and miscarriage for the indicated population is unknown. All pregnancies carry some risk of birth defect, loss, or other adverse outcomes. In the U.S. general population, the background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2‑4% and 15‑20%, respectively. Clinical Considerations Disease-Associated Maternal and/or Embryo/Fetal risk Hypotension associated with distributive shock, or shock due to reduced cardiac output are medical emergencies in pregnancy which can be fatal if left untreated. Delaying treatment in pregnant women with hypotension associated with distributive shock, or shock due to reduced cardiac output may increase the risk of maternal and fetal morbidity and mortality. Life-sustaining therapy for the pregnant woman should not be withheld due to potential concerns regarding the effects of dopamine on the fetus. Labor or Delivery Vasopressor drugs, including dopamine, may cause severe maternal hypertension when used concomitantly with some oxytocic drugs [see Drug Interactions (7) ] . Data Animal Data Animal reproduction studies in rats and rabbits at dopamine HCl dosages up to 6 mg/kg/day intravenously (on a mcg/m 2 basis, one third and two thirds, respectively, the human starting dosage of 2 mcg/kg/minute) during organogenesis produced no detectable teratogenic or embryotoxic effects, although maternal toxicity consisting of mortalities, decreased body weight gain, and pharmacotoxic signs were observed in rats. In a published study, administration of 10 mg/kg/day dopamine HCl (on a mcg/m 2 basis, two-thirds the human starting dosage of 2 mcg/kg/minute) to pregnant rats throughout gestation or for 5 days starting on gestation day 10 or 15 resulted in decreased body weight gain, increased mortality, and slight increase in cataract formation among the offspring.

8.2 Lactation Risk Summary There are no data regarding the presence of dopamine in human milk, the effects of dopamine on the breastfed infant, or the effects of the drug on milk production.

8.4 Pediatric Use Dopamine HCl infusions have been used in pediatric patients from birth through adolescence. Most reports in pediatric patients describe dosing that is similar (on a mcg/kg/minute basis) to that used in adults [see Dosage and Administration (2.2) ] . Except for vasoconstrictive effects caused by inadvertent infusion of dopamine into the umbilical artery, adverse reactions unique to pediatric patients have not been identified, nor have adverse reactions identified in adults been found to be more common in pediatric patients.

8.5 Geriatric Use Clinical studies of dopamine 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 start at the low end of the dosing range, reflecting the frequency of decreased hepatic, renal or cardiac function, and of concomitant disease or other drug therapy.

Dopamine is a natural catecholamine formed by the decarboxylation of 3,4 dihydroxyphenylalanine (DOPA). It is a precursor to norepinephrine in noradrenergic nerves and is also a neurotransmitter in certain areas of the central nervous system, especially in the nigrostriatal tract, and in a few peripheral sympathetic nerves. Dopamine elicits its pharmacological action by activating dopamine D1 and D2 receptors, beta 1 receptors and alpha 1 receptors. The activation of different receptors leading to its effects are dependent on dopamine dose.