According to the FDA-approved labeling (2024), Ephedrine Sulfate is specifically indicated for the treatment of clinically significant hypotension in the setting of anesthesia.
A study published in the Journal of Clinical Anesthesia (2022) confirmed that Ephedrine remains a first-line treatment for maintaining maternal blood pressure during spinal anesthesia for C-sections.
The World Health Organization (WHO) includes Ephedrine on its List of Essential Medicines for its role in emergency cardiovascular care.
Data from the National Institutes of Health (NIH, 2023) indicates that 70-90% of an Ephedrine dose is excreted unchanged in the urine within 24 hours.
The FDA (2004) banned the sale of dietary supplements containing ephedrine alkaloids due to an 'unreasonable risk of illness or injury.'
Clinical guidelines from the American Society of Anesthesiologists emphasize that repeated doses of Ephedrine can lead to tachyphylaxis, where the drug becomes less effective over time.
Research in the American Journal of Health-System Pharmacy (2021) highlights that Ephedrine's resistance to MAO metabolism gives it a longer duration of action than epinephrine.
The American College of Cardiology warns that Ephedrine use in patients with pre-existing heart disease significantly increases the risk of myocardial ischemia.
This page is for informational purposes only and does not replace medical advice. Before using any prescription or over-the-counter medication for Emerphed, you must consult a qualified healthcare professional.
Emerphed – Uses, Dosage, Side Effects & Warnings | MedInfo World | MedInfo World
Clinical Information
Detailed information about Emerphed
ℹ️Overview
Ephedrine is a sympathomimetic amine used primarily to treat hypotension (low blood pressure) during anesthesia. It acts as both a direct and indirect stimulant of alpha and beta-adrenergic receptors to increase heart rate and blood pressure.
💊Usage & Dosage
Adult Dosage
The dosage of Ephedrine must be highly individualized based on the patient's blood pressure response, heart rate, and the specific clinical situation.
For Anesthesia-Induced Hypotension (IV): The standard initial dose is 5 mg to 10 mg administered as an intravenous bolus. This may be repeated as needed every 5 to 10 minutes, with the goal of maintaining the desired blood pressure. The total dose typically does not exceed 50 mg in a single surgical session.
Intramuscular (IM) or Subcutaneous (SC): When IV access is not the primary route, 25 mg to 50 mg may be administered.
Oral Dosing (Historical/Respiratory): The typical dose for adults was 12.5 mg to 25 mg every 4 hours, not to exceed 150 mg in 24 hours. However, oral Ephedrine is rarely used as a first-line treatment today.
Pediatric Dosage
Ephedrine use in children is less common and requires extreme caution.
IV Administration: The typical pediatric dose for hypotension is 0.5 mg/kg of body weight.
IM/SC Administration: Similar weight-based dosing (0.5 mg/kg) is generally used.
Safety Note: Ephedrine is generally not recommended for children under the age of 12 for over-the-counter uses. Always consult a pediatric specialist for hospital-based administration.
Dosage Adjustments
Renal Impairment
Since Ephedrine is primarily excreted unchanged by the kidneys, patients with impaired renal function (kidney disease) may experience drug accumulation. Healthcare providers typically start with lower doses and monitor blood pressure and heart rate more frequently in these patients.
Hepatic Impairment
While hepatic (liver) metabolism is a minor pathway for Ephedrine, patients with severe liver disease should still be monitored closely, as their overall physiological stability may be compromised during anesthesia.
Elderly Patients
Patients over the age of 65 are more sensitive to the effects of sympathomimetic amines. There is a higher risk of experiencing severe hypertension, arrhythmias (irregular heartbeats), or central nervous system side effects like confusion or agitation. Dosing for elderly patients should usually start at the low end of the range.
How to Take Ephedrine
In most clinical scenarios, Ephedrine is administered by a healthcare professional (anesthesiologist or nurse) in a hospital setting. If you are using an oral form for respiratory issues:
Consistency: Take the medication exactly as prescribed. Do not increase the dose or frequency.
Timing: Avoid taking Ephedrine close to bedtime, as its stimulant properties can cause significant insomnia.
Administration: Tablets should be swallowed whole with a full glass of water. They can be taken with or without food, though taking them with food may reduce stomach upset.
Storage: Store at room temperature (68°F to 77°F) away from moisture, heat, and light. Keep out of reach of children and pets.
Missed Dose
In a hospital setting, missed doses are unlikely as the medication is given based on real-time monitoring. For oral use at home, if you miss a dose, take it as soon as you remember. If it is almost time for your next dose, skip the missed dose and return to your regular schedule. Never double the dose to catch up.
Overdose
An overdose of Ephedrine is a medical emergency. Signs of toxicity include:
Severe hypertension (dangerously high blood pressure)
Tachycardia (rapid heart rate) or palpitations
Seizures or tremors
Severe nausea and vomiting
Psychosis or extreme agitation
Respiratory depression (in severe cases)
In the event of a suspected overdose, contact emergency services or a poison control center immediately. Treatment usually involves supportive care, including the use of beta-blockers to control heart rate and vasodilators to lower blood pressure.
> Important: Follow your healthcare provider's dosing instructions. Do not adjust your dose without medical guidance. Misuse of Ephedrine can lead to serious cardiovascular complications.
⚠️Side Effects
Common Side Effects (>1 in 10)
Because Ephedrine stimulates the sympathetic nervous system, side effects are common and often mirror the body's 'fight or flight' response. These typically include:
Nervousness and Anxiety: Patients often report feeling 'jittery' or 'on edge.'
Insomnia: Difficulty falling or staying asleep is very common if the drug is taken late in the day.
Dizziness and Vertigo: A sensation of spinning or lightheadedness.
Headache: Often described as a throbbing sensation, likely due to changes in blood pressure.
Tachycardia: A noticeable increase in heart rate that may feel like the heart is racing.
🔴Warnings
Important Safety Information
Ephedrine is a potent medication that significantly alters cardiovascular dynamics. It should only be used when the benefits of raising blood pressure or opening airways clearly outweigh the risks of cardiac strain. Patients with a history of heart disease, high blood pressure, or thyroid disorders must be evaluated carefully before receiving this medication. Because it is a CNS stimulant, it can also exacerbate underlying psychiatric conditions or sleep disorders.
Black Box Warnings
No FDA black box warnings for Ephedrine. However, it is important to note that the FDA banned Ephedra alkaloids in dietary supplements in 2004 due to an unreasonable risk of illness or injury, including heart attack and stroke. Pharmaceutical Ephedrine remains available but is strictly regulated.
Major Precautions
Allergic Reactions: While rare, hypersensitivity to Ephedrine or other sympathomimetic amines (like pseudoephedrine) can occur. Symptoms range from mild rashes to life-threatening anaphylaxis.
🔄Interactions
Contraindicated Combinations (Do Not Use Together)
Certain medications should never be used in combination with Ephedrine due to the risk of life-threatening complications:
Monoamine Oxidase Inhibitors (MAOIs): Drugs like phenelzine, selegiline, or tranylcypromine prevent the breakdown of norepinephrine. Taking Ephedrine while on an MAOI, or within 14 days of stopping one, can lead to a hypertensive crisis (a sudden, extreme rise in blood pressure) that can cause a stroke or heart attack.
Linezolid: This antibiotic also has weak MAOI properties and can interact similarly to increase blood pressure to dangerous levels.
Serious Interactions (Monitor Closely)
Tricyclic Antidepressants (TCAs): Medications like amitriptyline or nortriptyline can potentiate (increase) the pressor response of Ephedrine, leading to severe hypertension.
🚫Contraindications
Absolute Contraindications
Ephedrine must NEVER be used in the following circumstances:
Hypersensitivity: A known allergy to Ephedrine Sulfate or any of the inactive ingredients in the formulation. Cross-sensitivity with other sympathomimetics (like pseudoephedrine or phenylephrine) is possible.
Narrow-Angle Glaucoma: Ephedrine causes mydriasis (dilation of the pupil), which can lead to a sudden and dangerous increase in intraocular pressure in patients with narrow-angle glaucoma.
Concurrent MAOI Use: As mentioned, using Ephedrine with or within 14 days of a Monoamine Oxidase Inhibitor is strictly contraindicated due to the risk of fatal hypertensive crisis.
Pheochromocytoma: A rare tumor of the adrenal gland that secretes catecholamines. Ephedrine can trigger a massive release of these chemicals, leading to severe hypertension.
👥Special Populations
Pregnancy
Ephedrine is frequently used in the obstetric setting. It is often the drug of choice for treating hypotension during spinal anesthesia for Cesarean section (C-section).
FDA Category: Previously classified as Category C. This means that while animal studies may have shown risk, or there are no adequate human studies, the potential benefits in a life-threatening situation (like maternal hypotension) may justify its use.
Fetal Effects: Ephedrine crosses the placenta. It can increase the fetal heart rate and may cause a slight decrease in fetal pH (acidosis), though studies generally show it is safe for the infant when used appropriately to maintain maternal blood pressure.
Labor and Delivery: If used to treat hypotension during labor, it does not typically interfere with the contractions of the uterus.
Breastfeeding
🧬Pharmacology
Mechanism of Action
Ephedrine is a sympathomimetic amine that acts on both alpha and beta-adrenergic receptors. Its mechanism is twofold:
1Direct Stimulation: It binds directly to $\alpha_1$-receptors (causing vasoconstriction), $\beta_1$-receptors (increasing heart rate and contractility), and $\beta_2$-receptors (causing bronchodilation).
2Indirect Stimulation: It triggers the release of norepinephrine from storage vesicles in the sympathetic nerve endings. This released norepinephrine then binds to the same receptors, amplifying the effect. This indirect action is why Ephedrine is less effective if the body's norepinephrine stores are depleted (e.g., in chronic stress or after repeated doses).
Pharmacodynamics
Frequently Asked Questions
Common questions about Emerphed
What is Ephedrine used for?
Ephedrine is primarily used in modern medicine to treat low blood pressure (hypotension) that occurs during surgery under anesthesia. It works by narrowing the blood vessels and increasing the heart's pumping force to restore normal blood pressure levels. Historically, it was also used to treat asthma and nasal congestion because it can open the airways and shrink swollen tissues in the nose. However, for respiratory issues, newer and more selective medications are now usually preferred over ephedrine. It is a potent stimulant and must be administered under the supervision of a healthcare professional in most cases.
What are the most common side effects of Ephedrine?
The most common side effects of Ephedrine include nervousness, anxiety, dizziness, and insomnia. Because it stimulates the sympathetic nervous system, many people feel 'jittery' or experience a racing heart (tachycardia) after taking it. Other frequent issues include headache, nausea, and increased sweating. Most of these effects are related to the drug's stimulant properties and usually resolve as the medication wears off. If these symptoms become severe or are accompanied by chest pain, you should seek medical attention immediately.
Can I drink alcohol while taking Ephedrine?
No, you should not drink alcohol while taking Ephedrine. Alcohol can interact with Ephedrine in unpredictable ways, often increasing the strain on your heart and cardiovascular system. While Ephedrine is a stimulant and alcohol is a depressant, they do not 'cancel each other out'; instead, they can lead to dangerous spikes or drops in blood pressure and an increased risk of heart arrhythmias. Furthermore, alcohol can mask the stimulant effects of Ephedrine, potentially leading to accidental overdose or severe physical distress. Always consult your doctor regarding any substance use while on medication.
Is Ephedrine safe during pregnancy?
Ephedrine is commonly used during pregnancy, specifically during Cesarean sections to treat low blood pressure caused by anesthesia. Clinical evidence suggests it is effective for maintaining the mother's blood pressure without causing significant harm to the baby. However, it does cross the placenta and can increase the baby's heart rate. Outside of the controlled hospital setting, Ephedrine should only be used during pregnancy if the potential benefit justifies the potential risk to the fetus. Your obstetrician or anesthesiologist will carefully weigh these factors during your care.
How long does it take for Ephedrine to work?
The time it takes for Ephedrine to work depends on how it is administered. When given intravenously (IV) in a hospital, the effects on blood pressure and heart rate are almost immediate, occurring within seconds to a couple of minutes. If given as an injection into the muscle (IM), it typically takes about 10 to 20 minutes to start working. For oral tablets, the onset is slower, usually taking between 15 and 60 minutes to feel the effects. The duration of the effect typically lasts between one and four hours depending on the route of administration.
Can I stop taking Ephedrine suddenly?
If you have been taking Ephedrine for a long period, you should not stop taking it suddenly without consulting your doctor. Abruptly stopping chronic use can lead to withdrawal symptoms, including extreme fatigue, mental depression, and a 'rebound' effect where your original symptoms (like nasal congestion) return worse than before. A healthcare provider will usually recommend a gradual reduction in dose to allow your body to adjust. For a single dose given during surgery, there is no need for a tapering period as the drug will naturally clear your system.
What should I do if I miss a dose of Ephedrine?
If you miss a dose of oral Ephedrine, take it as soon as you remember. However, if it is almost time for your next scheduled dose, skip the missed dose and continue with your regular timing. You should never take two doses at once to make up for a missed one, as this significantly increases the risk of dangerous side effects like high blood pressure or heart palpitations. If the medication was being given to you in a hospital setting, the medical staff would manage the timing based on your vital signs, so a missed dose is unlikely.
Does Ephedrine cause weight gain?
No, Ephedrine is not known to cause weight gain; in fact, it is more likely to cause weight loss. Because it is a stimulant, it often suppresses the appetite and increases the body's metabolic rate. Historically, this led to its misuse in weight loss supplements, which were eventually banned by the FDA due to safety risks. Using Ephedrine for weight loss is dangerous and can lead to severe heart problems, stroke, or death. Any weight loss experienced while taking Ephedrine for medical reasons should be reported to your doctor.
Can Ephedrine be taken with other medications?
Ephedrine has many significant drug interactions and should be used cautiously with other medications. It is especially dangerous to take with Monoamine Oxidase Inhibitors (MAOIs), as this can cause a life-threatening spike in blood pressure. It also interacts with certain antidepressants, heart medications like digoxin, and other stimulants (including caffeine). Because of these risks, it is vital to provide your healthcare provider with a complete list of all prescription drugs, over-the-counter medicines, and herbal supplements you are currently taking before starting Ephedrine.
Is Ephedrine available as a generic?
Yes, Ephedrine Sulfate is available as a generic medication, primarily in the form of an injectable solution used in hospitals. Generic versions are typically more cost-effective than brand-name versions like Akovaz or Corphedra while providing the same clinical efficacy. In some regions, oral ephedrine may also be available as a generic, though its availability is often restricted due to its potential use in the illegal manufacture of other substances. Always ensure you are obtaining your medication through a licensed pharmacy or healthcare provider.
Similar Medications
Other drugs with the same active ingredient (Ephedrine)
Palpitations: The feeling of skipped or extra heartbeats.
Sweating (Diaphoresis): Increased perspiration even in cool environments.
Urinary Retention: Difficulty starting urination or fully emptying the bladder, particularly in men with an enlarged prostate.
Tremor: Involuntary shaking, usually in the hands.
Dry Mouth (Xerostomia): A decrease in saliva production.
Rare Side Effects (less than 1 in 100)
Psychosis: In high doses or sensitive individuals, Ephedrine can cause hallucinations, paranoia, or extreme confusion.
Cardiac Arrhythmias: Serious irregularities in heart rhythm that may require medical intervention.
Hypokalemia: A drop in blood potassium levels, which can affect muscle and heart function.
Dyspnea: Shortness of breath or difficulty breathing.
Serious Side Effects — Seek Immediate Medical Attention
> Warning: Stop taking Ephedrine and call your doctor immediately if you experience any of these serious symptoms.
Chest Pain (Angina): This may indicate that the heart muscle is not getting enough oxygen due to the increased workload caused by the drug.
Severe Hypertension: Symptoms include a sudden, 'thunderclap' headache, blurred vision, or confusion. This can lead to a stroke or heart attack.
Seizures: Ephedrine can lower the seizure threshold in susceptible individuals.
Rapid/Irregular Heartbeat: If your pulse feels dangerously fast or completely irregular, it could indicate a life-threatening arrhythmia.
Signs of an Allergic Reaction: Hives, swelling of the face, lips, or tongue, and difficulty breathing (anaphylaxis).
Long-Term Side Effects
Prolonged or chronic use of Ephedrine (which is generally discouraged) can lead to several long-term issues:
Tolerance: The body becomes less responsive to the drug, requiring higher doses to achieve the same effect.
Dependence and Addiction: Because of its stimulant effects, some individuals may develop a psychological or physical dependence on Ephedrine.
Cardiovascular Strain: Chronic elevation of blood pressure and heart rate can lead to left ventricular hypertrophy (thickening of the heart muscle) or chronic heart failure.
Weight Loss: While sometimes sought after, the appetite-suppressant effects can lead to malnutrition or unhealthy weight loss when used inappropriately.
Black Box Warnings
There are currently no FDA Black Box Warnings specifically for Ephedrine Sulfate injection. However, the FDA has issued strong public health advisories against the use of Ephedra-containing dietary supplements. Furthermore, the drug carries significant clinical warnings regarding its potential for abuse and its risks in patients with pre-existing cardiovascular disease. Healthcare providers are cautioned to use the lowest effective dose for the shortest duration necessary to minimize these risks.
Report any unusual symptoms to your healthcare provider. Monitoring of vital signs is essential during and after the administration of Ephedrine.
Cardiovascular Risks: Ephedrine can cause a rapid rise in blood pressure and heart rate. This is particularly dangerous for patients with coronary artery disease, heart failure, or a history of stroke. It may precipitate a myocardial infarction (heart attack) in vulnerable patients.
Thyroid Disease: Patients with hyperthyroidism (overactive thyroid) are more sensitive to the effects of Ephedrine and are at a much higher risk of developing dangerous heart rhythms.
Diabetes: Ephedrine can increase blood glucose levels by stimulating the breakdown of glycogen in the liver. Diabetic patients may require more frequent blood sugar monitoring and adjustments to their insulin or oral medications.
Prostatic Hypertrophy: Men with an enlarged prostate may experience acute urinary retention (the inability to urinate), which is a medical emergency.
Monitoring Requirements
When Ephedrine is administered, particularly by injection, the following must be monitored continuously:
Blood Pressure: Frequent (every few minutes) or continuous monitoring via an arterial line.
Heart Rate and Rhythm: Continuous ECG monitoring to detect arrhythmias or signs of cardiac ischemia (lack of oxygen to the heart).
Oxygen Saturation: Monitoring to ensure adequate respiratory function.
Electrolytes: Occasional checks for potassium levels, as Ephedrine can cause hypokalemia.
Driving and Operating Machinery
Ephedrine can cause dizziness, nervousness, and tremors. It may also cause a 'rebound' effect where the patient feels excessively tired once the drug wears off. Do not drive or operate heavy machinery until you know how Ephedrine affects you. In a surgical setting, you will not be allowed to drive yourself home following the use of anesthesia and associated medications.
Alcohol Use
Combining alcohol with Ephedrine is dangerous. Alcohol can mask some of the stimulant effects of Ephedrine, leading to a false sense of sobriety, while the combination increases the strain on the heart and can lead to unpredictable changes in blood pressure. Avoid alcohol while taking Ephedrine.
Discontinuation
For patients taking oral Ephedrine chronically, stopping the drug suddenly can lead to a 'crash' characterized by extreme fatigue, depression, and rebound nasal congestion (if used as a decongestant). If you have been using Ephedrine for an extended period, your doctor will likely recommend a gradual tapering of the dose to avoid withdrawal symptoms.
> Important: Discuss all your medical conditions with your healthcare provider before starting Ephedrine. Be sure to mention if you have any history of heart rhythm problems or high blood pressure.
General Anesthetics: Certain anesthetic gases (like halothane or cyclopropane) sensitize the heart muscle to the effects of sympathomimetics. Using Ephedrine during anesthesia with these agents increases the risk of serious ventricular arrhythmias.
Digitalis Glycosides (Digoxin): Ephedrine increases the irritability of the heart muscle. When combined with digoxin, the risk of cardiac arrhythmias is significantly elevated.
Moderate Interactions
Beta-Blockers: Drugs like propranolol or metoprolol oppose the effects of Ephedrine. This can lead to a situation where the blood pressure-lowering effect of the beta-blocker is neutralized, or conversely, the Ephedrine may cause 'unopposed alpha stimulation,' leading to severe hypertension.
Theophylline: Combining these two stimulants can increase the risk of side effects like nausea, insomnia, and tremors.
Diuretics: Ephedrine may reduce the effectiveness of blood pressure-lowering diuretics (water pills).
Food Interactions
Caffeine: Consuming coffee, tea, energy drinks, or soda while taking Ephedrine can significantly increase heart rate and blood pressure, leading to palpitations and severe anxiety.
Acidic vs. Alkaline Foods: Foods that significantly change urinary pH can affect how fast Ephedrine leaves the body. Highly acidic foods may decrease the drug's half-life, while alkaline foods (like large amounts of citrus or certain vegetables) may increase it.
Alcohol: As noted previously, alcohol increases the cardiovascular risks associated with Ephedrine.
Herbal/Supplement Interactions
St. John's Wort: May increase the risk of high blood pressure when used with Ephedrine.
Guarana/Yohimbe: These herbal stimulants can have additive effects with Ephedrine, dangerously increasing heart rate and blood pressure.
Bitter Orange (Synephrine): Structurally similar to ephedrine, this can lead to excessive stimulation and cardiovascular strain.
Lab Test Interactions
Ephedrine may interfere with certain medical tests:
Amphetamine Screen: Ephedrine can sometimes cause a false-positive result on urine drug screens for amphetamines due to structural similarities.
Urinary Catecholamines: It may falsely elevate the results of tests measuring norepinephrine or epinephrine in the urine.
For each major interaction, the mechanism typically involves either pharmacodynamic synergy (both drugs increasing blood pressure) or pharmacokinetic interference (changing how the drug is cleared). Management usually involves avoiding the combination or performing intensive hemodynamic monitoring.
> Important: Tell your doctor about ALL medications, supplements, and herbal products you are taking. Do not start any new medication without consulting your healthcare provider first.
Relative Contraindications
In these cases, the healthcare provider will perform a careful risk-benefit analysis:
Severe Coronary Artery Disease: The increased heart rate and blood pressure can cause a mismatch between oxygen supply and demand in the heart muscle.
Hyperthyroidism: These patients are already in a hypermetabolic state and are extremely prone to Ephedrine-induced arrhythmias.
Severe Hypertension: Using a pressor agent in someone with already high blood pressure requires extreme caution and usually a different therapeutic approach.
Diabetes Mellitus: Due to the risk of hyperglycemia (high blood sugar).
Cross-Sensitivity
Patients who have had adverse reactions to other 'upper' or stimulant-type medications should be cautious. This includes reactions to:
Pseudoephedrine (Sudafed)
Phenylephrine
Amphetamines
Epinephrine
If you have experienced severe heart palpitations or dangerously high blood pressure with any of these substances, inform your anesthesiologist or prescribing physician immediately.
> Important: Your healthcare provider will evaluate your complete medical history before prescribing Ephedrine. Be honest about all your pre-existing conditions, especially those related to the heart, eyes, and thyroid.
Ephedrine is excreted into breast milk.
Risks: Nursing infants may experience irritability, crying, and disturbed sleep patterns if the mother is taking Ephedrine.
Considerations: If a single dose is given during surgery, the amount reaching the infant is likely minimal. However, chronic oral use by a nursing mother is generally discouraged. Consult your pediatrician if you need to take this medication while breastfeeding.
Pediatric Use
As noted in the dosage section, Ephedrine is not commonly used in children.
Safety: The safety and effectiveness of Ephedrine in pediatric patients have not been as extensively studied as in adults.
Growth Effects: There is no evidence that short-term use during surgery affects growth, but chronic use of stimulants in children is always a concern for growth suppression.
Conditions: It is NOT approved for use in infants or for over-the-counter use in children under 12 in many jurisdictions.
Geriatric Use
Elderly patients (65 and older) require special consideration:
Cardiovascular Sensitivity: Older adults are much more likely to have underlying heart disease or hypertension, making them more susceptible to the side effects of Ephedrine.
Renal Clearance: Since kidney function naturally declines with age, the drug may stay in the system longer, increasing the risk of toxicity.
Fall Risk: The dizziness and potential for blood pressure fluctuations increase the risk of falls in the elderly.
Renal Impairment
In patients with a reduced Glomerular Filtration Rate (GFR):
Dosing: Dose reductions are often necessary.
Monitoring: Close monitoring of urinary output and blood pressure is required to prevent accumulation.
Dialysis: It is not clearly established if dialysis effectively removes Ephedrine from the blood.
Hepatic Impairment
While the liver is not the primary site of clearance, patients with Child-Pugh Class B or C cirrhosis may have altered fluid volumes and cardiovascular responses. Ephedrine should be used with caution, focusing on the clinical response rather than standard dosing.
> Important: Special populations require individualized medical assessment. Always inform your medical team if you are pregnant, planning to become pregnant, or nursing.
Onset of Action
: When given IV, the effects are almost immediate. When given IM, it takes 10–20 minutes. Oral onset is 15–60 minutes.
Duration: The pressor (blood pressure raising) and cardiac effects last approximately 1 hour after IV administration and up to 4 hours after oral administration.
Tolerance: Tachyphylaxis (rapidly diminishing response) can occur with frequent, repeated doses.
Structure: It is a phenylisopropylamine derivative, structurally similar to epinephrine and methamphetamine, but with lower CNS potency than the latter.
Drug Class
Ephedrine is classified as a sympathomimetic amine and an adrenergic agonist. Within the therapeutic area of anesthesia, it is considered a 'pressor agent' or 'vasopressor.' It is related to other medications like pseudoephedrine (a stereoisomer) and phenylephrine.