Ephedrine

Ephedrine is available in different forms used for different medical purposes — the right use depends on the specific product, route, and formulation.

• Low blood pressure during anesthesia (hypotension): Ephedrine Sulfate Injection, Akovaz, and Emerphed — all given intravenously — are used by healthcare providers to treat clinically significant drops in blood pressure that occur during anesthesia.
• Mild intermittent asthma symptoms: Bronkaid, Primatene, Ephedrine Hydrochloride tablets, and Ephedrine Sulfate tablets are taken by mouth to temporarily relieve wheezing, chest tightness, and shortness of breath in adults and children 12 and older who have been told by a doctor they have asthma.

Ephedrine is a sympathomimetic amine — meaning it mimics and boosts the body's own stress-response signals. It works two ways at once: it directly activates alpha- and beta-adrenergic receptors throughout the body, and it triggers the release of norepinephrine from nerve endings. In the heart and blood vessels, this combination increases heart rate, pumping strength, and blood pressure. In the lungs, activation of beta receptors relaxes and opens the airways (bronchodilation), making it easier to breathe.

One important limitation: with repeated doses, the body can become tolerant — a phenomenon called tachyphylaxis — and ephedrine's blood-pressure-raising effect may weaken. This is why injectable ephedrine is carefully dosed and monitored in clinical settings, and why oral tablets are intended only for occasional, mild asthma symptoms.

How and how often ephedrine is taken depends entirely on the product form. Injectable forms (Akovaz, Emerphed, Ephedrine Sulfate Injection) are given intravenously by trained healthcare providers in clinical settings — dosing is adjusted to achieve a blood pressure goal and is not something patients manage themselves.

• For asthma tablets (Bronkaid, Ephedrine Sulfate): one tablet every 4 hours as needed for adults and children 12 and older; no more than 6 tablets in 24 hours.
• For Ephedrine Hydrochloride and Primatene tablets: one to two tablets every 4 hours as needed; no more than 12 tablets in 24 hours.

Always follow the directions on your specific product label or your prescriber's instructions. Do not use more than the recommended amount.

The most commonly reported side effects with ephedrine include:

• Nausea and vomiting
• Fast heart rate (tachycardia)
• Heart palpitations (a pounding or racing feeling in the chest)
• Elevated blood pressure
• Dizziness
• Restlessness
• Difficulty sleeping
• Tremors or nervousness

More serious reactions to watch for include a rapid or irregular heartbeat, seizures, signs of a heart attack or stroke (chest pain, sudden weakness, slurred speech), or blood pressure that rises to a dangerous level. Seek emergency care immediately if any of these occur.

• Heart attack and stroke risk: Ephedrine raises blood pressure and heart rate. Using it — especially at higher doses or more frequently than directed — increases the risk of heart attack or stroke. This risk is higher if you already have heart disease or high blood pressure.
• Risk of high blood pressure when used preventively: Using ephedrine to prevent low blood pressure (rather than treat it) has been linked to a higher chance of developing dangerously elevated blood pressure.
• Dangerous interaction with oxytocic drugs: Combining ephedrine with drugs that stimulate uterine contractions (such as methylergonovine or ergonovine) can cause severe high blood pressure and stroke. Blood pressure must be carefully monitored in anyone who has received both.
• Tachyphylaxis (reduced effectiveness over time): Repeated doses of ephedrine can make it less effective. For injectable use, providers should have an alternative medication ready. For asthma tablets, relying on ephedrine more and more frequently may mean your asthma needs a different, stronger treatment.
• Asthma alert: These oral tablets are for mild, occasional asthma only. If your asthma is not better within 60 minutes, gets worse, or you're having attacks more than twice a week, see a doctor right away.

Ephedrine can interact with several medications and substances, sometimes in serious ways:

• MAOIs (monoamine oxidase inhibitors, used for depression or Parkinson's disease) — can powerfully amplify ephedrine's stimulant effects; do not use together or within 2 weeks of stopping an MAOI.
• Oxytocic drugs (such as methylergonovine or ergonovine, used after childbirth) — combination can cause dangerously high blood pressure and stroke.
• Clonidine, propofol, atropine — these increase ephedrine's blood-pressure-raising effect; blood pressure should be closely monitored.
• Alpha- and beta-blockers, reserpine, quinidine, mephentermine — these reduce ephedrine's effectiveness.
• Cardiac glycosides (such as digitalis) — raises the risk of dangerous heart rhythm problems (arrhythmias).
• Guanethidine — ephedrine may block its blood-pressure-lowering effect.
• Theophylline — using both together may worsen nausea, nervousness, and insomnia.
• Caffeine (in food, drinks, or supplements) — adds to stimulant effects; avoid while using oral ephedrine tablets.
• Other stimulant-containing products (including those with phenylephrine, pseudoephedrine, or ephedrine) — do not combine.

This is not a complete list of interactions. Always talk with your doctor or pharmacist before starting, stopping, or changing any medication.

• Do not use oral ephedrine tablets unless a doctor has told you that you have asthma.
• Do not use if you are currently taking an MAOI or have taken one within the past 2 weeks.
• Do not use if you have ever had an allergic reaction to ephedrine or any ingredient in the product.
• Tell your doctor if you have heart disease, high blood pressure, diabetes, thyroid disease, seizures, narrow-angle glaucoma, a psychiatric or emotional condition, or difficulty urinating due to an enlarged prostate.
• Tell your doctor if you have ever been hospitalized for asthma, as this may indicate more serious disease.
• Pregnancy: Ephedrine crosses the placenta. While human data have not confirmed major birth defects, newborns may need monitoring for a blood chemistry imbalance (metabolic acidosis). Discuss the risks and benefits with your doctor.
• Breastfeeding: Ephedrine is present in breast milk. The effects on a breastfed infant are not fully known. Talk to your healthcare provider before using.
• Children: Oral tablet forms should not be used in children under 12 (some brands say to ask a doctor first). The safety of injectable ephedrine in children has not been established.
• Older adults: May be more sensitive to side effects; kidney function should be considered, as ephedrine is cleared through the kidneys and reduced function slows its elimination.
• Kidney impairment: Ephedrine and its breakdown product are removed by the kidneys. Reduced kidney function means the drug stays in the body longer and side effects may be more likely.

Too much ephedrine — particularly with the injectable forms — can cause blood pressure to rise rapidly to a dangerous level. If an overdose is suspected, blood pressure should be carefully monitored, and a healthcare provider can administer intravenous medications to bring it down if needed. For oral tablet overdose, contact a Poison Control Center immediately or get emergency medical help right away.

Ephedrine's main effect on the body is raising blood pressure by increasing the heart's pumping strength, speeding up heart rate, and tightening blood vessels — all at once. It also relaxes the smooth muscle around the airways, which opens them up and makes breathing easier. As a secondary effect, it may increase resistance to urine flow by acting on smooth muscle in the bladder. With repeated use, these effects can diminish as the body adapts — this is called tachyphylaxis.

After oral use, ephedrine is broken down by the body into a metabolite called norephedrine, though the exact pathway is not fully understood. Both ephedrine and norephedrine are cleared from the body through the urine. The half-life — the time it takes the body to reduce drug levels by half — is about 6 hours after an oral dose. Ephedrine is also known to cross the placental barrier, meaning it can reach a developing baby during pregnancy.

EMERPHED (ephedrine sulfate injection) is a clear, colorless solution available as single-dose vials containing 5 mg/mL ephedrine sulfate, equivalent to 3. Store at 25°C (77°F); excursions permitted to 15°C to 30°C (59°F to 86°F) . Store in carton until time of use.