Ephedrine

Ephedrine is a medication that belongs to the class of sympathomimetic agents. It is primarily used to manage and treat clinically significant hypotension, particularly during anesthesia[4]. Additionally, it is indicated for the treatment of allergic conditions, bronchial asthma, and nasal congestion[1][3].

Mechanism of Action

Ephedrine acts as both a direct and indirect sympathomimetic. It is an alpha- and beta-adrenergic receptor agonist, which means it stimulates both alpha and beta receptors in the body. This leads to various physiological effects, including vasoconstriction, increased heart rate and contractility, and bronchodilation[1][2].

Uses

Ephedrine is used for temporary relief of shortness of breath, chest tightness, and wheezing due to bronchial asthma. It may also be used for other conditions as determined by a doctor[3]. In chemical synthesis, ephedrine is used in bulk quantities as a chiral auxiliary group[2].

Adverse Effects

Ephedrine can produce a range of adverse effects, including cardiovascular, dermatological, gastrointestinal, genitourinary, nervous system, respiratory, and miscellaneous effects. Cardiovascular effects include tachycardia, cardiac arrhythmias, angina pectoris, and vasoconstriction with hypertension. Dermatological effects include flushing and sweating. Gastrointestinal effects include nausea. Genitourinary effects include decreased urination due to vasoconstriction of renal arteries. Nervous system effects include restlessness, confusion, insomnia, mild euphoria, mania/hallucinations (rare except in previously existing psychiatric conditions), delusions, formication (may be possible, but lacks documented evidence), paranoia, hostility, panic, and agitation. Respiratory effects include dyspnea and pulmonary edema. Miscellaneous effects include dizziness, headache, tremor, hyperglycemic reactions, and dry mouth[2].

Contraindications and Interactions

Ephedrine is contraindicated in patients with acute hypertension or tachycardia. It should not be used by individuals who are allergic to this medication, do not have a diagnosis of asthma, have a diagnosis of asthma but use prescription asthma medications, have ever been hospitalized for asthma, or are taking a monoamine oxidase (MAO) inhibitor[3]. Ephedrine may interact with various medications, including beta-blockers, cocaine, indomethacin, methyldopa, MAO inhibitors, linezolid, oxytocic medicines, rauwolfia derivatives, tricyclic antidepressants, ergot alkaloids, bromocriptine, catechol-O-methyltransferase (COMT) inhibitors, digoxin, guanadrel, guanethidine, mecamylamine, methyldopa, or reserpine[3][4].

Dosage and Administration

The dose of ephedrine should be initiated at the low end of the dosing range, considering the higher frequency of decreased hepatic, renal, or cardiac function. For the treatment of asthma, 25 mg tablets are used every four hours as needed, and the maximum dose should not exceed 150 mg in 24 hours. For adults, bolus dose recommendations are 5 to 10 mg, and intramuscular doses for a prolonged desired effect are 25 to 50 mg. Ephedrine requires dilution before intravenous administration[4].

Pregnancy and Breastfeeding

Ephedrine has not been adequately studied in pregnant women or in women who are breastfeeding. As a result, its use in these populations should be approached with caution[5].

Removal from the U.S. Market

On April 14, 2004, the FDA warned that over-the-counter products and supplements containing ephedrine are unsafe and may cause side effects such as headache, dizziness, heart irregularities, seizures, and possibly death. All products containing ephedrine have been removed from the U.S. market[5].

Citations:

[1] https://go.drugbank.com/drugs/DB01364

[2] https://en.wikipedia.org/wiki/Ephedrine

[3] https://www.drugs.com/ephedrine.html

[4] https://www.ncbi.nlm.nih.gov/books/NBK547661/

[5] https://www.medicinenet.com/ephedrine-oral/article.htm