(ephedrine sulfate) Injection, USP
Ephedrine is an alpha- and beta-adrenergic agonist and a norepinephrine-releasing agent. AKOVAZ (ephedrine sulfate injection) is a clear, colorless, sterile solution for intravenous injection. It must be diluted before intravenous administration. The chemical name of ephedrine sulfate is (1R,2S)-(-)-2- methylamine-1-phenylpropan-1-ol sulfate, and the molecular weight is 428.5 g/mol. Its structural formula is depicted below:
Ephedrine sulfate is freely soluble in water and ethanol, very slighly soluble in chloroform, and practically insoluble in ether. Each mL contains ephedrine sulfate 50 mg (equivalent to 38 mg ephedrine base) in water for injection. The pH is adjusted with sodium hydroxide and/or glacial acetic acid if necesssary. The pH range is 4.5 to 7.0.
DOSAGE AND ADMINISTRATION
General Dosage And Administration Instructions
Inspect parenteral drug products visually for particulate matter and discoloration prior to administration, whenever solution and container permit.
Sections or subsections omitted from the full prescribing information are not listed.
Dosing For The Treatment Of Clinically Important Hypotension In The Setting Of Anesthesia
The recommended dosages for the treatment of clinically important hypotension in the setting of anesthesia is an initial dose of 5 to 10 mg administered by intravenous bolus. Administer additional boluses as needed, not to exceed a total dosage of 50 mg.
- Adjust dosage according to the blood pressure goal (i.e., titrate to effect).
Prepare A 5 mg/mL Solution For Bolus Intravenous Administration
For bolus intravenous administration, prepare a solution containing a final concentration of 5 mg/mL of AKOVAZ (ephedrine sulfate injection):
- Withdraw 50 mg (1 mL of 50 mg/mL) of AKOVAZ (ephedrine sulfate injection) and dilute with 9 mL of 5% Dextrose Injection or 0.9% Sodium Chloride Injection.
- Withdraw an appropriate dose of the 5 mg/mL solution prior to bolus intravenous administration.
Dosage Forms And Strengths
AKOVAZ (ephedrine sulfate injection) is available as a single-dose 1 mL vial that contains 50 mg/mL ephedrine sulfate, equivalent to 38 mg ephedrine base.
Storage And Handling
AKOVAZ (ephedrine sulfate injection), 50 mg/mL, is supplied as follows:
|76014-005-25||50 mg/mL||1 mL clear glass vial; for single use (supplied in packages of 25)|
Vial stoppers are not manufactured with natural rubber latex. Store AKOVAZ (ephedrine sulfate injection), 50 mg/mL, at 25°C (77°F); excursions permitted to 15°C to 30°C (59°F to 86°F) [see USP Controlled Room Temperature]. Store in carton until time of use. For single use only. Discard unused portion.
Manufactured for: Avadel, Avadel Legacy Pharmaceuticals, LLC, Chesterfield, MO 63005. Revised: Nov 2016
The following adverse reactions associated with the use of ephedrine sulfate were identified in the literature. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to estimate their frequency reliably or to establish a causal relationship to drug exposure.
Gastrointestinal disorders: Nausea, vomiting
Nervous system disorders: Dizziness
Psychiatric disorders: Restlessness
|Interactions that Augment the Pressor Effect|
|Oxytocin and oxytocic drugs|
|Clinical Impact:||Serious postpartum hypertension has been described in patients who received both a vasopressor (i.e., methoxamine, phenylephrine, ephedrine) and an oxytocic (i.e., methylergonovine, ergonovine). Some of these patients experienced a stroke.|
|Intervention:||Carefully monitor the blood pressure of individuals who have received both ephedrine and an oxytocic.|
|Clonidine, propofol, monoamine oxidase inhibitors (MAOIs), atropine|
|Clinical Impact:||These drugs augment the pressor effect of ephedrine.|
|Intervention:||Carefully monitor the blood pressure of individuals who have received both ephedrine and any of these drugs.|
|Interactions that Antagonize the Pressor Effect|
|Clinical Impact:||These drugs antagonize the pressor effect of ephedrine.|
|Intervention:||Carefully monitor the blood pressure of individuals who have received both ephedrine and any of these drugs.|
|Examples:||a-adrenergic antagonists, P-adrenergic receptor antagonists, reserpine, quinidine, mephentermine|
|Other Drug Interactions|
|Clinical Impact:||Ephedrine may inhibit the neuron blockage produced by guanethidine, resulting in loss of antihypertensive effectiveness.|
|Intervention:||Clinician should monitor patient for blood pressor response and adjust the dosage or choice of pressor accordingly.|
|Clinical Impact:||Ephedrine may reduce the onset time of neuromuscular blockade when used for intubation with rocuronium if administered simultaneously with anesthetic induction.|
|Intervention:||Be aware of this potential interaction. No treatment or other interventions are needed.|
|Clinical Impact:||Ephedrine may decrease the efficacy of epidural blockade by hastening the regression of sensory analgesia.|
|Intervention:||Monitor and treat the patient according to clinical practice.|
|Clinical Impact:||Concomitant use of ephedrine may increase the frequency of nausea, nervousness, and insomnia.|
|Intervention:||Monitor patient for worsening symptoms and manage symptoms according to clinical practice.|
|Clinical Impact:||Giving ephedrine with a cardiac glycoside, such as digitalis, may increase the possibility of arrhythmias.|
|Intervention:||Carefully monitor patients on cardiac glycosides who are also administered ephedrine.|
Included as part of the PRECAUTIONS section.
Press Or Effect With Concomitant Oxytocic Drugs
Serious postpartum hypertension has been described in patients who received both a vasopressor (i.e., methoxamine, phenylephrine, ephedrine) and an oxytocic (i.e., methylergonovine, ergonovine) [see DRUG INTERACTIONS]. Some of these patients experienced a stroke. Carefully monitor the blood pressure of individuals who have received both ephedrine and an oxytocic.
Tolerance And Tachyphylaxis
Data indicate that repeated administration of ephedrine can result in tachyphylaxis. Clinicians treating anesthesia-induced hypotension with AKOVAZ (ephedrine sulfate injection) should be aware of the possibility of tachyphylaxis and should be prepared with an alternative pressor to mitigate unacceptable responsiveness.
Risk Of Hypertension When Used Prophylactically
When used to prevent hypotension, ephedrine has been associated with an increased incidence of hypertension compared with when ephedrine is used to treat hypotension.
Carcinogenesis, Mutagenesis, Impairment Of Fertility
Two-year feeding studies in rats and mice conducted under the National Toxicology Program (NTP) demonstrated no evidence of carcinogenic potential with ephedrine sulfate at doses up to 10 mg/kg/day and 27 mg/kg/day (approximately 2 times and 3 times the maximum human recommended dose on a mg/m basis, respectively).
Ephedrine sulfate tested negative in the in vitro bacterial reverse mutation assay, the in vitro mouse lymphoma assay, the in vitro sister chromatid exchange, and the in vitro chromosomal aberration assay.
Impairment Of Fertility
Studies to evaluate the effect of ephedrine on fertility have not been conducted.
Use In Specific Populations
Limited published data on the use of ephedrine sulfate are insufficient to determine a drug associated risk of major birth defects or miscarriage. However, there are clinical considerations [see Clinical Considerations]. Animal reproduction studies have not been conducted with ephedrine sulfate.
In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2 to 4% and 15 to 20%, respectively.
Fetal/Neonatal Adverse Reactions
Cases of potential metabolic acidosis in newborns at delivery with maternal ephedrine exposure have been reported in the literature. These reports describe umbilical artery pH of ≤ 7.2 at the time of delivery [see CLINICAL PHARMACOLOGY]. Monitoring of the newborn for signs and symptoms of metabolic acidosis may be required. Monitoring of infant's acid-base status is warranted to ensure that an episode of acidosis is acute and reversible.
Limited published literature reports that ephedrine is present in human milk. However, no information is available on the effects of the drug on the breastfed infant or the effects of the drug on milk production. The developmental and health benefits of breastfeeding should be considered along with the mother's clinical need for AKOVAZ (ephedrine sulfate injection) and any potential adverse effects on the breastfed child from AKOVAZ (ephedrine sulfate injection) or from the underlying maternal condition.
Safety and effectiveness in pediatric patients have not been established.
Clinical studies of ephedrine 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. This drug is known to be substantially excreted by the kidney, and the risk of adverse reactions to this drug may be greater in patients with impaired renal function. Because elderly patients are more likely to have decreased renal function, care should be taken in dose selection, and it may be useful to monitor renal function.
Ephedrine and its metabolite are excreted in urine. In patients with renal impairment, excretion of ephedrine is likely to be affected with a corresponding increase in elimination half-life, which will lead to slow elimination of ephedrine and consequently prolonged pharmacological effect and potentially adverse reactions. Monitor patients with renal impairment carefully after the initial bolus dose for adverse events.
Overdose of ephedrine can cause a rapid rise in blood pressure. In the case of an overdose, careful monitoring of blood pressure is recommended. If blood pressure continues to rise to an unacceptable level, parenteral antihypertensive agents can be administered at the discretion of the clinician.
Mechanism Of Action
Ephedrine sulfate is a sympathomimetic amine that directly acts as an agonist at α- and β-adrenergic receptors and indirectly causes the release of norepinephrine from sympathetic neurons. Pressor effects by direct alpha- and beta-adrenergic receptor activation are mediated by increases in arterial pressures, cardiac output, and peripheral resistance. Indirect adrenergic stimulation is caused by norepinephrine release from sympathetic nerves.
Ephedrine stimulates heart rate and cardiac output and variably increases peripheral resistance; as a result, ephedrine usually increases blood pressure. Stimulation of the α-adrenergic receptors of smooth muscle cells in the bladder base may increase the resistance to the outflow of urine. Activation of β- adrenergic receptors in the lungs promotes bronchodilation.
The overall cardiovascular effect from ephedrine is the result of a balance among α-1 adrenoceptormediated vasoconstriction, β-2 adrenoceptor-mediated vasoconstriction, and β-2 adrenoceptor-mediated vasodilatation. Stimulation of the β-1 adrenoceptors results in positive inotrope and chronotrope action.
Tachyphylaxis to the pressor effects of ephedrine may occur with repeated administration [see WARNINGS AND PRECAUTIONS].
Publications studying pharmacokinetics of oral administration of (-)-ephedrine support that (-)-ephedrine is metabolized into norephedrine. However, the metabolism pathway is unknown. Both the parent drug and the metabolite are excreted in urine. Limited data after IV administration of ephedrine support similar observations of urinary excretion of drug and metabolite. The plasma elimination half-life of ephedrine following oral administration was about 6 hours.
Ephedrine crosses the placental barrier [see Use in Specific Populations].
The evidence for the efficacy of ephedrine injection is derived from the published literature. Increases in blood pressure following administration of ephedrine were observed in 14 studies, including 9 where ephedrine was used in pregnant women undergoing neuraxial anesthesia during Cesarean delivery, 1 study in non-obstetric surgery under neuraxial anesthesia, and 4 studies in patients undergoing surgery under general anesthesia. Ephedrine has been shown to raise systolic and mean blood pressure when administered as a bolus dose following the development of hypotension during anesthesia.
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