Chelafrin - General Information
The active sympathomimetic hormone from the adrenal medulla in most species. It stimulates both the alpha- and beta- adrenergic systems, causes systemic vasoconstriction and gastrointestinal relaxation, stimulates the heart, and dilates bronchi and cerebral vessels. It is used in asthma and cardiac failure and to delay absorption of local anesthetics.
Pharmacology of Chelafrin
Chelafrin is indicated for intravenous injection in treatment of acute hypersensitivity, treatment of acute asthmatic attacks to relieve bronchospasm, and treatment and prophylaxis of cardiac arrest and attacks of transitory atrioventricular heart block with syncopal seizures (Stokes-Adams Syndrome). The actions of epinephrine resemble the effects of stimulation of adrenergic nerves. To a variable degree it acts on both alpha and beta receptor sites of sympathetic effector cells. Its most prominent actions are on the beta receptors of the heart, vascular and other smooth muscle. When given by rapid intravenous injection, it produces a rapid rise in blood pressure, mainly systolic, by (1) direct stimulation of cardiac muscle which increases the strength of ventricular contraction, (2) increasing the heart rate and (3) constriction of the arterioles in the skin, mucosa and splanchnic areas of the circulation. When given by slow intravenous injection, epinephrine usually produces only a moderate rise in systolic and a fall in diastolic pressure. Although some increase in pulse pressure occurs, there is usually no great elevation in mean blood pressure. Accordingly, the compensatory reflex mechanisms that come into play with a pronounced increase in blood pressure do not antagonize the direct cardiac actions of epinephrine as much as with catecholamines that have a predominant action on alpha receptors.
Chelafrin for patients
Epinephrine should be used cautiously in patients with hyperthyroidism, hypertension and cardiac arrhythmias. All vasopressors should be used cautiously in patients taking monoamine oxidase (MAO) inhibitors.
Epinephrine should not be administered concomitantly with other sympathomimetic drugs (such as isoproterenol) because of possible additive effects and increased toxicity.
Combined effects may induce serious cardiac arrhythmias. They may be administered alternately when the preceding effect of other such drug has subsided.
Administration of epinephrine to patients receiving cyclopropane or halogenated hydrocarbon general anesthetics such as halothane which sensitize the myocardium, may induce cardiac arrhythmia.. When encountered, such arrhythmias may respond to administration of a beta-adrenergic blocking drug. Epinephrine also should be used cautiously with other drugs (e.g., digitalis, glycosides) that sensitize the myocardium to the actions of sympathomimetic drugs.
Diuretic agents may decrease vascular response to pressor drugs such as epinephrine.
Epinephrine may antagonize the neuron blockade produced by guanethidine resulting in decreased antihypertensive effect and requiring increased dosage of the latter.
Epinephrine is contraindicated in patients with known hypersensitivity to sympathomimetic amines, in patients with angle closure glaucoma, and patients in shock (nonanaphylactic). It should not be used in patients anesthetized with agents such as cyclopropane or halothane as these may sensitize the heart to arrhythmic action of sympathomimetic drugs.
Epinephrine should not ordinarily be used in those cases where vasopressor drugs may be contraindicated, e.g., in thyrotoxicosis, diabetes, in obstetrics when maternal blood pressure is in excess of 130/80 and in hypertension and other cardiovascular disorders.
Additional information about Chelafrin
Chelafrin Indication: Used to treat anaphylaxis and sepsis.
Mechanism Of Action: Chelafrin works via the stimulation of alpha and beta-1 adrenergic receptors, and a moderate activity at beta-2 adrenergic receptors.
Drug Interactions: Acebutolol Hypertension, then bradycardia
Alseroxylon Increased arterial pressure
Amitriptyline The tricyclic increases the sympathomimetic effect
Amoxapine The tricyclic increases the sympathomimetic effect
Atenolol Hypertension, then bradycardia
Betaxolol Hypertension, then bradycardia
Bevantolol Hypertension, then bradycardia
Bisoprolol Hypertension, then bradycardia
Carteolol Hypertension, then bradycardia
Carvedilol Hypertension, then bradycardia
Clomipramine The tricyclic increases the sympathomimetic effect
Desipramine The tricyclic increases the sympathomimetic effect
Deserpidine Increased arterial pressure
Doxepin The tricyclic increases the sympathomimetic effect
Entacapone Entacapone increases the effect and toxicity of sympathomimetics
Methylergonovine Possible marked increase of arterial pressure
Nortriptyline The tricyclic increases the sympathomimetic effect
Protriptyline The tricyclic increases the sympathomimetic effect
Imipramine The tricyclic increases the sympathomimetic effect
Esmolol Hypertension, then bradycardia
Guanethidine The agent decreases the effect of guanethidine
Isocarboxazid Increased arterial pressure
Labetalol Hypertension, then bradycardia
Linezolid Possible increase of arterial pressure
Methyldopa Increased arterial pressure
Metoprolol Hypertension, then bradycardia
Midodrine Increased arterial pressure
Moclobemide Moclobemide increases the sympathomimetic effect
Nadolol Hypertension, then bradycardia
Penbutolol Hypertension, then bradycardia
Oxytocin Possible marked increase of arterial pressure
Phenelzine Increased arterial pressure
Pindolol Hypertension, then bradycardia
Practolol Hypertension, then bradycardia
Propranolol Hypertension, then bradycardia
Rasagiline Increased arterial pressure
Reserpine Increased arterial pressure
Sotalol Hypertension, then bradycardia
Timolol Hypertension, then bradycardia
Tranylcypromine Increased arterial pressure
Trimipramine The tricyclic increases the sympathomimetic effect
Ergonovine Possible marked increase of arterial pressure
Oxprenolol Hypertension, then bradycardia
Pargyline Increased arterial pressure
Food Interactions: Not Available
Generic Name: Epinephrine
Synonyms: Adrenalina; Adrenalin; Adrenalin Chloride; Adrenaline; Adrenalinum; D-Adrenaline; D-Epifrin; D-Epinephrine; Epinefrin [Czech]; Epinefrina [Inn-Spanish]; Epinephran; Epinephrine Bitartrate; Epinephrinum [Inn-Latin]; L-Adrenalin; L-Adrenaline; L-Adrenaline Base; L-Epinephine; L-Epinephrine; L-Epirenamine; Levoepinephrine; Levoadrenaline; Racepinefrinum [inn-latin]; Racepinephrine; Racepinefrine; Racepinefrina [inn-spanish]; ADR Adrenaline
Drug Category: Vasoconstrictor Agents; Mydriatics; Bronchodilator Agents; Adrenergic alpha-Agonists; Adrenergic beta-Agonists; Adrenergic Agonists; Sympathomimetics
Drug Type: Small Molecule; Approved
Absorption: Usually this vasodilator effect of the drug on the circulation predominates so that the modest rise in systolic pressure which follows slow injection or absorption is mainly the result of direct cardiac stimulation and increase in cardiac output.
Toxicity (Overdose): Skin, LD50 = 62 mg/kg (rat)
Protein Binding: Not Available
Biotransformation: Epinephrine is rapidly inactivated in the body and is degraded by enzymes in the liver and other tissues. The larger portion of injected doses is excreted in the urine as inactivated compounds and the remainder either partly unchanged or conjugated. The drug becomes fixed in the tissues and is inactivated chiefly by enzymatic transformation to metanephrine or normetanephrine either of which is subsequently conjugated and excreted in the urine in the form of sulfates and glucuronides. Either sequence results in the formation of 3-methoxy-4-hydroxy-mandelic acid which also is detectable in the urine.
Half Life: 2 minutes
Dosage Forms of Chelafrin: Solution / drops Oral
Solution / drops Ophthalmic
Solution Respiratory (inhalation)
Chemical IUPAC Name: 4-[(1R)-1-hydroxy-2-methylaminoethyl]benzene-1,2-diol
Chemical Formula: C9H13NO3
Epinephrine on Wikipedia: https://en.wikipedia.org/wiki/Epinephrine
Organisms Affected: Humans and other mammals