Myomine200 mg/5 ml

Myomine is an endogenous catecholamine used as a vasopressor and inotropic agent for the hemodynamic management of shock and severe hypotension. Indications are classified by strength of evidence below.

Established / FDA-approved uses

• Correction of hemodynamic imbalances (hypotension, low cardiac output, poor organ perfusion) present in the shock syndrome due to myocardial infarction, trauma, endotoxic septicemia, open-heart surgery, renal failure, and chronic cardiac decompensation (e.g. congestive heart failure).
• Improvement of blood pressure, cardiac output, and urine flow in patients who remain hypotensive after adequate fluid volume replacement (correction of hypovolemia).

Adjunct / combination-therapy use

• Myomine is used as an adjunct to, not a substitute for, volume replacement; in hypovolemic shock, whole blood, plasma, or appropriate fluids must be given first or concurrently.
• Often combined with other vasoactive or inotropic agents (e.g. norepinephrine, dobutamine) in refractory shock under intensive care supervision.

Not routinely recommended

• So-called "low-dose" or "renal-dose" Myomine for renal protection or prevention of acute kidney injury is not supported by current evidence and is not a recommended indication.

Each formulation contains Dopamine Hydrochloride as the active ingredient, supplied as a sterile concentrate for intravenous infusion, either alone or pre-mixed with dextrose (e.g. in 5% Dextrose Injection). Strength is typically expressed as mg of Dopamine Hydrochloride per mL of concentrate (e.g. 40 mg/mL) intended for further dilution before administration.

Myomine is the hydrochloride salt of dopamine, an endogenous catecholamine and immediate metabolic precursor of norepinephrine. It acts directly and indirectly (via norepinephrine release) on dopaminergic, beta-1 adrenergic, and alpha-1 adrenergic receptors in a dose-dependent manner.

Administered only as a continuous intravenous infusion after dilution, Myomine is used exclusively in hospital critical-care settings for short-term hemodynamic support in shock states and severe, fluid-refractory hypotension.

Myomine belongs to the therapeutic class of cardiac stimulants and vasopressor agents used in the treatment of shock; pharmacologically it is classified as a catecholamine/adrenergic and dopaminergic agonist.

Dopamine Hydrochloride produces dose-dependent hemodynamic effects by stimulating dopaminergic (D1), beta-1 adrenergic, and alpha-1 adrenergic receptors, and by promoting the release of norepinephrine from sympathetic nerve terminals.

Onset of action is rapid (within minutes) and effects dissipate quickly (plasma half-life approximately 2 minutes) after the infusion of Dopamine Hydrochloride is stopped, allowing rapid titration.

Administration of Myomine

• For intravenous infusion only, using an infusion pump for accurate rate control.
• Must be diluted before use in a compatible IV fluid; do not administer as an undiluted bolus.
• Preferably administered through a large vein or a secure central venous line to reduce the risk of extravasation.
• Requires continuous monitoring of blood pressure, heart rate, cardiac rhythm (ECG), and urine output in an intensive/critical care setting.
• Correct hypovolemia with appropriate fluids before or during administration of Myomine; it is not a substitute for volume replacement.
• If extravasation occurs, stop the infusion at that site immediately and manage per institutional protocol (e.g. local infiltration with an alpha-blocking agent) to prevent tissue necrosis.
• Do not use solutions that are discolored (pink, brown, or darkened) or contain particulate matter.
• Reduce the dose gradually when discontinuing therapy rather than stopping abruptly, to avoid a sudden marked fall in blood pressure.

Myomine has several well-documented, clinically significant drug interactions:

• Monoamine oxidase inhibitors (MAOIs): markedly potentiate and prolong the pressor effect of Myomine; patients who have received MAOIs require substantially reduced doses of Myomine (often to about one-tenth of the usual dose).
• Tricyclic antidepressants: may potentiate the cardiovascular pressor response to Myomine.
• Phenytoin: concurrent IV administration with Myomine has been associated with hypotension and bradycardia; use with caution.
• General anesthetics (e.g. halogenated hydrocarbons, cyclopropane): may sensitize the myocardium to the arrhythmogenic effects of Myomine, increasing the risk of ventricular arrhythmias.
• Alpha- and beta-adrenergic blocking agents: may antagonize or unpredictably alter the hemodynamic response to Myomine.
• Ergot alkaloids: concurrent use with Myomine may cause severe, prolonged vasoconstriction and risk of ischemia/gangrene.
• Diuretics: may have an additive or potentiating diuretic effect when combined with low-dose Myomine.

Adverse effects of Myomine are generally dose-related and occur most often at higher infusion rates.

Common

• Ectopic heartbeats, tachycardia, palpitations
• Anginal chest pain, dyspnea
• Headache, nausea, vomiting
• Hypotension (at low doses) or hypertension (at high doses)

Serious / less common

• Ventricular arrhythmias, marked increase in myocardial oxygen demand
• Peripheral ischemia/gangrene of the extremities with prolonged high-dose use
• Local tissue necrosis and sloughing if extravasation occurs at the infusion site (see Precautions and Warnings)
• Azotemia (rare, reversible on discontinuation)

Pregnancy: There are no adequate and well-controlled studies of Myomine in pregnant women. Myomine should be used during pregnancy only if the potential benefit to the mother justifies the potential risk to the fetus, and only under close medical supervision, as it is used solely in life-threatening maternal shock situations.

Lactation: It is not known whether Myomine is excreted in human breast milk. Because Myomine is used only for acute, short-term critical-care indications, a decision on breastfeeding should be individualized in consultation with a physician, weighing the clinical urgency of maternal treatment.

Monitored setting required: Myomine must be administered only in a closely monitored clinical environment (ICU/critical care), with continuous ECG, blood pressure, and urine output monitoring by trained personnel, and using an infusion pump for accurate dose control.

Extravasation risk: Myomine is a vesicant; extravasation can cause severe local tissue necrosis and sloughing. Administer via a secure, preferably central, intravenous line and inspect the infusion site frequently. If extravasation occurs, stop the infusion at that site immediately and treat promptly per institutional protocol.

Volume correction first: Hypovolemia should be corrected with appropriate fluid or blood replacement before or concurrently with Myomine, as it does not replace adequate volume repletion.

MAOI use: Patients recently treated with monoamine oxidase inhibitors require markedly reduced doses of Myomine (see Interactions).

Occlusive vascular disease: Use with caution in patients with a history of occlusive vascular disease (e.g. atherosclerosis, arterial embolism, Raynaud's phenomenon, cold injury, diabetic endarteritis, Buerger's disease), as the vasoconstrictive effect of Myomine at higher doses may exacerbate peripheral ischemia and increase risk of gangrene.

Cardiac arrhythmias: Use with caution in patients with pre-existing ventricular arrhythmias, as Myomine may provoke or worsen ectopic activity.

Abrupt discontinuation: Reduce the infusion rate gradually while monitoring for a marked drop in blood pressure; avoid stopping abruptly.

Overdosage of Myomine may present as excessive vasoconstriction, severe hypertension, ventricular arrhythmias, or excessive tachycardia due to its short half-life (approximately 2 minutes), overdose effects generally resolve quickly on reducing or stopping the infusion.

Management involves immediately reducing or discontinuing the Myomine infusion while continuing close hemodynamic and cardiac monitoring; general supportive measures should be instituted as clinically indicated. Because Myomine is used only in a hospital critical-care setting, any suspected overdose should be managed immediately by the attending medical team; if overdose is suspected outside a monitored setting, seek immediate emergency medical attention or contact a poison control center without delay.

Store Myomine at room temperature (below 30°C), protected from light, and do not freeze. Do not use if the solution is discolored (pink, purple, or darkened) or contains particulate matter, as this indicates degradation. Keep out of reach of children and use only under professional healthcare supervision.

Pediatric use

Myomine has been used in pediatric patients, including neonates, for shock refractory to fluid resuscitation, using weight-based mcg/kg/min dosing similar in principle to adults; however, safety and efficacy in children are less rigorously established than in adults, and use requires expert pediatric critical-care supervision.

Elderly

Elderly patients may be more sensitive to the cardiovascular effects of Myomine and are more likely to have pre-existing cardiac, renal, or vascular disease; use with caution, starting at the lower end of the dosing range and titrating carefully.

Renal and hepatic impairment

No formal dose-adjustment guidelines are well established; such patients may show altered sensitivity to Myomine and require closer hemodynamic monitoring during titration.

Myomine is intended for short-term use, continued only for as long as hemodynamic instability persists. It should be titrated continuously to the lowest effective dose and tapered gradually as the patient's condition stabilizes, rather than stopped abruptly.

Dopamine Hydrochloride is classified as a catecholamine, cardiac stimulant/inotropic agent, and vasopressor.

Dopamine Hydrochloride exerts dose-dependent, receptor-mediated cardiovascular effects: at low infusion rates it predominantly activates dopaminergic (D1) receptors causing vasodilation; at moderate rates it stimulates cardiac beta-1 adrenergic receptors, increasing contractility and cardiac output; at higher rates it activates alpha-1 adrenergic receptors, producing vasoconstriction and raising blood pressure. It also causes release of endogenous norepinephrine from storage sites, contributing to its inotropic and pressor effects.

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Myomine may be used in pediatric patients, including neonates and infants, for shock unresponsive to adequate fluid resuscitation, dosed on a weight-based mcg/kg/min basis analogous to adult dosing and titrated to hemodynamic response. Safety and efficacy have not been as extensively established in children as in adults, and Myomine should be used in pediatric patients only under close intensive-care supervision with continuous cardiac and hemodynamic monitoring.