How much ephedrine do you give for tachycardia?
Ephedrine is given as an intravenous bolus of 5 to 10 mg. It is effective in the same dose range when administered intramuscularly, albeit with slower onset and longer duration. When given in repeated doses, tachyphylaxis occurs, probably because of depleted norepinephrine stores.
What happens if you take too much ephedrine?
When given in repeated doses, tachyphylaxis occurs, probably due to depletion of norepinephrine stores. Ephedrine causes an increase in systolic, diastolic, and mean arterial pressures. It increases myocardial contractility, heart rate, and cardiac output (see Table 22-1 ).
What is the mechanism of action of ephedrine?
Mechanism of Action Ephedrine, a stereoisomer to better-known pseudoephedrine, is a sympathomimetic amine that has unique effects due to its indirect mechanism compared to other sympathomimetic agents like pseudoephedrine and phenylephrine.[11] Ephedrine acts as both a direct and indirect sympathomimetic.
What class of drug is ephedrine?
Ephedrine is a medication used in the management and treatment of clinically significant hypotension. It is in the sympathomimetic class of medications. This activity illustrates the indications, action, and contraindications for ephedrine as a valuable agent in the treatment of clinically significant hypotension.
Does ephedrine have Tachyphylaxis?
Ephedrine also has central nervous system stimulant effects. Tachyphylaxis to the effects of ephedrine may also occur after use for a short while possibly due to the depletion of noradrenaline stores. Pharmacokinetic data for ephedrine following intravenous administration is limited.
What is the mechanism of action of ephedrine?
Ephedrine is a direct and indirect sympathomimetic amine. As a direct effect, ephedrine activates alpha-adrenergic and beta-adrenergic receptors. As an indirect effect, it inhibits norepinephrine reuptake and increases the release of norepinephrine from vesicles in nerve cells.
Which receptors does ephedrine stimulate?
Ephedrine produces norepinephrine release, stimulating mostly A1 and B1 receptors; the effects resemble those of epinephrine although they are less intense. Increases in systolic blood pressure, diastolic blood pressure, heart rate, and cardiac output are noted.
When is ephedrine contraindicated?
Ephedrine is contraindicated in patients with closed-angle glaucoma. Use ephedrine with caution in patients with hypertension, cardiac disease (including coronary artery disease, angina pectoris, and patients receiving cardiac glycosides), cardiac arrhythmias, or unstable vasomotor system.
What drugs cause Tachyphylaxis?
Over-the-counter ophthalmic decongestant drops, such as Visine (Pfizer), are another category of drugs that induce tachyphylaxis. In particular, these medications contain alpha-adrenergic amines—such as tetrahydrozoline, naphazoline or phenylephrine—that act as vasoconstrictors.
What's the difference between epinephrine and ephedrine?
As a vasoconstrictor, epinephrine is 100 to 1,000 times more potent than ephedrine. 1 Mix-ups between these two drugs have resulted in serious patient harm. The Closed Claims Project of the American Society of Anesthesiologists found that errors involving epinephrine are particularly dangerous.
What is the mechanism of action of epinephrine?
Mechanism of Action Through its action on alpha-1 receptors, epinephrine induces increased vascular smooth muscle contraction, pupillary dilator muscle contraction, and intestinal sphincter muscle contraction.
Is ephedrine a vasodilator or vasoconstrictor?
Ephedrine and pseudoephedrine thus exert a vasoconstrictive effect on the vessels, which underlies the relief they procure in nasal congestion.
Why is ephedrine given during surgery?
What is this medication? EPHEDRINE (e FED rin) is used to treat low blood pressure in patients who receive anesthesia during surgery.
Can you overdose on ephedrine?
According to the manufacturer's prescribing information, an overdose of ephedrine can cause a rapid rise in blood pressure. In the case of an overdose, careful monitoring of blood pressure is recommended.
What are the long term effects of ephedrine?
The results showed that long-term exposure to ephedrine had potential neurotoxic effects. Withdrawal after 8 weeks of ephedrine exposure leads to neurotoxicity, neurobehavioral disorders and accompanied by up-regulation of CRF in the prefrontal cortex and hippocampus in rhesus macaques.
What class of drug is ephedrine?
Ephedrine is a prescription medicine used to treat the symptoms of low blood pressure during anesthesia (Hypotension). Ephedrine may be used alone or with other medications. Ephedrine belongs to a class of drugs called Alpha/Beta Adrenergic Agonists.
What is the mechanism of action of epinephrine?
Mechanism of Action Through its action on alpha-1 receptors, epinephrine induces increased vascular smooth muscle contraction, pupillary dilator muscle contraction, and intestinal sphincter muscle contraction.
Is ephedrine a vasodilator or vasoconstrictor?
Ephedrine and pseudoephedrine thus exert a vasoconstrictive effect on the vessels, which underlies the relief they procure in nasal congestion.
What type of drug is ephedrine?
Ephedrine is a prescription medicine used to treat the symptoms of low blood pressure during anesthesia (Hypotension). Ephedrine may be used alone or with other medications. Ephedrine belongs to a class of drugs called Alpha/Beta Adrenergic Agonists.
What is the mechanism of action of norepinephrine?
Mechanism of action It stimulates α1 and α2 adrenergic receptors to cause blood vessel contraction, thus increases peripheral vascular resistance and resulted in increased blood pressure. This effect also reduces the blood supply to gastrointestinal tract and kidneys.
What is ephedrine used for?
Ephedrine is a medication used in the management and treatment of clinically significant hypotension . It is in the sympathomimetic class of medications. This activity illustrates the indications, action, and contraindications for ephedrine as a valuable agent in the treatment of clinically significant hypotension. This activity will highlight the mechanism of actions, adverse event profile, and other key factors pertinent to interprofessional healthcare team members involved in the care of patients with clinically significant hypotension and related conditions.
What is the most concerning effect of ephedrine overdose?
The most concerning effect of ephedrine overdose is the manifestation of excessive hypertension . If blood pressure rises to unacceptable levels, a parenteral administration of antihypertensive medication is necessary. There is no specific agent recommended, and the choice depends on clinical judgment. Treatments for excessive hypertension include nitrates, labetalol, esmolol, nicardipine, and nitroglycerine. A less common effect experienced mostly by illicit users of ephedrine and its derivatives is the development of radiolucent urological ephedrine containing stones and paranoid schizophrenia. [23][24]
How long does ephedrine last?
However, if given intramuscularly, the vasopressor effects typically remain for 60 to 90 minutes.[12] These effects are of particular importance on the labor and delivery ward where patients often receive intramuscular injections of ephedrine following spinal block to attenuate the sympathectomy and nausea that frequently accompany spinal blockade. The effects of an IM injection may last much longer than the procedure itself, and nurses and techs should not rely on hypotension as the primary indicator of postpartum hemorrhage as IM ephedrine may mask this sign.
Is ephedrine safe for tachycardia?
Ephedrine is contraindicated in a patient with acute hypertension or tachycardia. Ephedrine increases both chronotropy and inotropy and therefore increases myocardial oxygen demand, and its use requires caution in patients with ischemic heart disease or heart failure. Additionally, it should be avoid ed in situations where tachycardia would be undesirable, such as aortic stenosis . Alpha-adrenergic stimulation caused by ephedrine results in contraction of the smooth muscle at the base of the bladder, resulting in resistance to urine outflow, and caution is necessary for patients with urinary retention and prostatic hyperplasia.[14] The use of ephedrine should be avoided or used with caution within 14 days of MAOI therapy due to excessive norepinephrine availability at the synapse, which could cause a hypertensive crisis through the indirect sympathomimetic effect of ephedrine. [12][19]
Is pseudoephedrine a sympathomimetic amine?
Ephedrine, a stereoisomer to better-known pseudoephedrine, is a sympathomimetic amine that has unique effects due to its indirect mechanism compared to other sympathomimetic agents like pseudoephedrine and phenylephrine. [11] Ephedrine acts as both a direct and indirect sympathomimetic. It binds directly to both alpha and beta receptors; however, its primary mode of action is achieved indirectly, by inhibiting neuronal norepinephrine reuptake and by displacing more norepinephrine from storage vesicles.[12] This action allows norepinephrine to be present in the synapse longer to bind postsynaptic alpha and beta receptors.[13] Ephedrine’s indirect mechanism results in a sustained or even increased heart rate due to norepinephrine’s ability to bind both alpha and beta receptors, whereas more direct sympathomimetics like phenylephrine result in reflex bradycardia. While the indirect effect is most profound on the arterial blood pressure, the direct vasoconstricting action functions more on the venous system. It is, therefore, effective in elevating central venous pressure when the patient is fluid challenged. [12]
When planning to use ephedrine, should the pharmacist verify the dose and that there are no significant drug?
When planning to use ephedrine, the pharmacist should verify the dose and that there are no significant drug-drug interactions, and report these findings to the clinical team . Nursing must be cognizant of the adverse effects of the drug, and be prepared to inform the clinician regarding their observations. Nursing will also commonly be involved in administration, so they must collaborate with the pharmacist on dosing and administration. These examples show how all members of the interprofessional team working together can optimize ephedrine therapy when it is necessary while mitigating its adverse effects. [Level 5]
Is ephedrine hepatotoxic?
[16][17]Additionally, ephedrine may be hepatotoxic, but there seems to be unclear evidence for such. This idea stems from case reports where ephedra species containing several compounds resulted in liver damage as opposed to a direct correlation. [18]
What are the side effects of ephedrine?
Check with your doctor or nurse immediately if any of the following side effects occur while taking ephedrine: Incidence not known. Blurred vision. dizziness. fast, pounding, or irregular heartbeat or pulse. headache. nervousness. pounding in the ears.
Does ephedrine need immediate medical attention?
Side effects not requiring immediate medical attention. Some side effects of ephedrine may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects.
What are some examples of ephedrine?
Examples: α-adrenergic antagonists, β-adrenergic receptor antagonists, reserpine, quinidine, mephentermine.
What is ephedrine sulfate used for?
Ephedrine sulfate injection is indicated for the treatment of clinically important hypotension occurring in the setting of anesthesia.
How much ephedrine sulfate should be in a bolus?
For bolus intravenous administration, prepare a solution containing a final concentration of 5 mg/mL of ephedrine sulfate injection:
Is ephedrine sulfate safe for pregnant women?
Available data from randomized studies, case series, and reports of ephedrine sulfate use in pregnant women have not identified a drug-associated risk of major birth defects, miscarriage, or adverse maternal or fetal outcomes. However, there are clinical considerations due to underlying conditions (see Clinical Considerations). In animal reproduction studies, decreased fetal survival and fetal body weights were observed in the presence of maternal toxicity after normotensive pregnant rats were administered 60 mg/kg intravenous ephedrine sulfate (12 times the maximum recommended human dose (MRHD) of 50 mg/day). No malformations or embryofetal adverse effects were observed when pregnant rats or rabbits were treated with intravenous bolus doses of ephedrine sulfate during organogenesis at doses 1.9 and 7.7 times the MRHD, respectively [See data].
Can ephedrine cause tachyphylaxis?
Data indicate that repeated administration of ephedrine can result in tachyphylaxis. Clinicians treating anesthesia-induced hypotension with ephedrine sulfate injection should be aware of the possibility of tachyphylaxis and should be prepared with an alternative pressor to mitigate unacceptable responsiveness.
Is ephedrine in milk?
A single published case report indicates 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.
Does Ephedrine decrease the efficacy of epidural blockade?
Ephedrine may decrease the efficacy of epidural blockade by hastening the regression of sensory analgesia.
How to analyze response to Oxytocin?
The response to oxytocin was analyzed as follows: hemodynamic data were averaged for 30 s before the administration of oxytocin. As for the vasopressors, the subsequent data were plotted against time to ascertain the time to maximum effect of oxytocin (taken as the highest value of CO), and the maximum response to oxytocin was estimated by averaging the data for 5 s before and after this point. In the 20 patients randomized to receive either oxytocin or the oxytocin-phenylephrine mixture, the change in hemodynamic variables was compared. A sample size of five patients in each group would have 90% power to detect a difference in mean CO of 25% assuming that the common SD is 10%, using a two group t test with a 0.05 two-sided significance level. Therefore, 10 patients were included in each group.
Does bolus phenylephrine lower CO?
Bolus phenylephrine reduced maternal CO, and decreased CO when compared with ephedrine during elective spinal anesthesia for Cesarean delivery. CO changes correlated with heart rate changes after vasopressor administration, emphasizing the importance of heart rate as a surrogate indicator of CO. Coadministered phenylephrine obtunded hemodynamic responses to oxytocin.
Does ephedrine affect CD?
The effects of the two commonly used vasopressors, ephedrine and phenylephrine, on neonatal acid base status, a surrogate marker for neonatal wellbeing, have been extensively studied during SA for CD. Recent work shows that ephedrine is associated with a greater degree of neonatal acidosis than phenylephrine, probably on the basis that ephedrine crosses the placenta and causes a β- adrenergically mediated increase in fetal metabolic rate. This, together with a lower incidence of maternal symptoms, has led to a change in practice and a resurgence of the use of phenylephrine for spinal hypotension. 1 There have been very few investigations comparing the effects of the two vasopressors on maternal cardiovascular indices other than HR and blood pressure during SA for CD. Only one previously published study, employing intermittent suprasternal Doppler flow measurements, has compared CO changes using the two vasopressors during SA for CD. In this study, which compared bolus doses of the vasopressors, bradycardia in the phenylephrine group was treated with atropine, which makes the results difficult to interpret. 2 The primary outcome variable in this study was umbilical artery pH, and not maternal hemodynamic changes. There have been no investigations using beat-by-beat CO measurements. There is currently a condition of equipoise with regards to the use of the two vasopressors, as far as the restoration of maternal blood pressure is concerned. Our hypothesis, based on the limited literature and a study on patients with severe preeclampsia during SA for CD in our institution, 3 is that phenylephrine, but not ephedrine, decreases CO when administered in response to hypotension during SA for CD. Thus phenylephrine might be the better agent to restore systemic vascular resistance (SVR) to normal when hypotension is associated with vasodilation and a partial compensatory increase in CO in response to SA. 4 Ephedrine may be a better choice should severe hypotension and bradycardia occur, reflecting decreased CO. The primary outcome of our prospective randomized, double-blind study was thus a comparison of the time-based effects on maternal CO of bolus administration of the vasopressors phenylephrine and ephedrine during SA for CD. The LiDCO plus monitor (LiDCO, Cambridge, United Kingdom), which employs pulse wave form analysis calibrated with lithium dilution, was employed for the study. In addition, a monitor of transthoracic bioimpedance changes was also used in each patient to corroborate the results.
Does phenylephrine affect hemodynamics?
This prospective randomized comparison of the effects of phenylephrine and ephedrine on maternal hemodynamics during SA for CD showed that an 80-μg bolus of phenylephrine caused a significantly lower maternal CO when compared to a 10-mg bolus dose of ephedrine, during the 150 s after vasopressor administration. However, the mean postphenylephrine CO values remained above baseline ( tables 3 and 4 ), since CO values immediately before vasopressor administration were higher than baseline. The two CO monitors used, based upon pulse wave form analysis and transthoracic bioimpedance changes, recorded similar trends in changes in CO after vasopressor administration. The maximum change in HR was also significantly different between groups. There was a strong correlation between HR and CO in both groups after vasopressor administration. The peak changes in CO and MAP after phenylephrine occurred significantly earlier than those after ephedrine. SVR changes after the vasopressors suggested a marked rise in afterload after phenylephrine. After ephedrine administration, there was a sequence of a transient increase in afterload, followed by a transient decrease (possibly β 2 -mediated) and then a sustained increase in SVR (probably mediated by noradrenaline release) ( fig. 2, A and B ).
What is the function of ephedrine?
Often referred to as a “mixed acting” sympathomimetic, ephedrine causes the release of norepinephrine from storage vesicles in sympathetic neurons and directly stimulates alpha and beta adrenoceptors.
What is ephedrine used for?
In the acute care setting, ephedrine is used primarily to treat mild hypotension and bradycardia associated with general or regional anesthesia. Previously, ephedrine was the first-line therapy for parturients with hypotension secondary to spinal or epidural anesthesia based on studies in pregnant ewes suggesting that ephedrine preserved uterine blood flow compared with other vasopressors. 92 These data have been challenged recently; phenylephrine appears to be as good or better in preserving uterine blood flow and does not cause or worsen maternal tachycardia. 93,94
What are the effects of ephedra alkaloids?
Common symptoms include hyperactivity, tremulousness, agitation, anxiety, and palpitations.
How much ephedrine is given?
Ephedrine is given as an intravenous bolus of 5 to 10 mg. It is effective in the same dose range when administered intramuscularly, albeit with slower onset and longer duration.
How long after selegiline can you give ephedrine?
Ephedrine should not be administered within 2 weeks of a patient receiving a monoamine oxidase inhibitor, e.g. selegiline.
How many isomers are in ephedrine?
Having two chiral centers, ephedrine consists of four isomers: l-ephedrine (1R,2S-ephedrine), d-ephedrine (1S,2R-ephedrine), l-pseudoephedrine (1R,2S-pseudoephedrine), and d-pseudoephedrine (1S,2R-pseudoephedrine). It is used clinically to prevent bronchospasm during surgical procedures, to treat acute hypotension, and as a nasal decongestant.
Is ephedrine a genetically modified cell?
Ephedrine has been studied in cultured cells, genetically modified cell lines, in in vivo animal models, and in isolated tissues. In the past, it has been difficult to determine which effects of ephedrine are caused by direct stimulation of adrenergic receptors and which are caused by ephedrine-induced norepinephrine or dopamine release.