Ephedrine

Ephedrine: A comprehensive overview of effects and use

Ephedrine, a main alkaloid of the plant Ma Huang from the genus Ephedra, exists in various stereoisomeric forms and serves as an indirect sympathomimetic. It promotes the release of noradrenaline, which leads to an increase in blood pressure, dilation of the bronchi and increased heart rate. These properties make it an effective agent for low blood pressure, especially hypotension during epidural or spinal anesthesia.

Medical application

Ephedrine is used both to decongest the nasal mucosa in colds and in combination with other active ingredients in cold and asthma remedies. However, frequent use can reduce the effect due to a habituation effect.

Advantages and risks

Despite its stimulant properties, which increase alertness and act as an appetite suppressant, ephedrine is highly regulated in medical use. This is due to the potential for abuse and dependence.

Table: Main effects of ephedrine

Due to these potential risks, the use of ephedrine is severely restricted by special regulations in German pharmacies.

Introduction to ephedrine

Ephedrine is a naturally occurring alkaloid extracted from the plant Ephedra sinica. Structurally, it is similar to the body's own substances adrenaline and noradrenaline. These properties are decisive for its sympathomimetic effect, which occurs both directly at alpha and beta receptors and indirectly through the increased secretion of noradrenaline from the nerve endings of the sympathetic nervous system.

Ephedrine has a wide range of uses. It is often used to treat low blood pressure (hypotension) during anesthetic procedures. It is also used to reduce swelling of the nasal mucous membranes in rhinitis.

Ephedrine has a stimulating effect on the central nervous system and the cardiovascular system and also has an appetite-suppressing effect. These properties make it attractive, but also problematic, as ephedrine is classified as a banned doping substance due to its similarity to amphetamines.

Mechanisms of action of ephedrine

Ephedrine acts both directly and indirectly on the sympathetic nervous system. It binds to alpha and beta receptors and increases the release of noradrenaline at the nerve endings. This multifunctional effect leads to an increase in blood pressure and heart rate. The mechanism involves the activation of adenyl cyclase, which leads to the production of cyclic adenosine-3,5-monophosphate (AMP) and enhances the beta-adrenergic effect. At the same time, ephedrine inhibits the activity of adenyl cyclase, which explains the alpha-adrenergic effects. With frequent use, it can produce a habituation effect, whereby the effect diminishes (tachyphylaxis).

Influence on the cardiovascular system

Ephedrine has a direct sympathomimetic effect and increases heart rate and blood pressure. This improves cardiac output and peripheral resistance. Administered intravenously, it can increase cardiac output, but reflex bradycardia is possible at high doses. Ephedrine has a positive inotropic effect, thus increasing cardiac work and myocardial oxygen consumption. Due to its structural similarity to adrenaline, it can dilate the coronary vessels, which can increase coronary blood flow. Overall, the effects on the cardiovascular system are dose-dependent, with both positive and negative potential effects.

Effect on the respiratory tract

Ephedrine relaxes the smooth muscles of the bronchi, increases the diameter of the airways and has a bronchodilating effect. When taken orally, bronchodilation is slower and less pronounced than with subcutaneous injections or inhalation. In patients with bronchoconstriction, ephedrine can help to relieve mild bronchospasm, improve gas exchange and increase vital capacity. Administration reduces the residual volume of the lungs, which optimizes breathing. The bronchodilator effect is based on the activation of beta 2-adrenergic receptors.

Applications of ephedrine

Ephedrine is a versatile active ingredient with various medical applications. It provides a solution for low blood pressure during anesthesia, is used to treat certain respiratory diseases and is used as a supportive factor in fat reduction. The different properties of ephedrine make it valuable in various medical fields.

• Treatment of hypotension during anesthesia
• Decongestion of the nasal mucous membranes
• Appetite suppression

Ephedrine may not be used in sports competitions and is banned as a doping agent.

Treatment of asthma attacks

Ephedrine is used as a bronchodilator, particularly to treat asthma attacks. By relaxing the smooth muscles of the bronchi, the diameter of the airways is enlarged, allowing for improved breathing. In patients with bronchoconstriction, ephedrine can help to relieve mild bronchospasm, improve gas exchange and increase vital capacity. The onset of action is slower after oral administration, but lasts longer compared to subcutaneous injections or oral inhalations. Ephedrine is often used in combination with other agents to enhance bronchodilator properties and reduce breathlessness during asthma attacks.

Use in hypotensive states during anesthesia

Ephedrine is used in anesthesia for the rapid treatment of hypotension. During spinal, epidural or general anesthesia, it can raise blood pressure within less than a minute. The mechanism of action includes both direct sympathomimetic effects and indirect effects through the increased release of noradrenaline. Compared to other drugs such as dopamine, ephedrine offers a longer duration of action and is also less expensive. It can be administered intravenously as a bolus. However, long-term use should be carefully monitored as tachyphylaxis can occur, where repeated doses are less effective.

Support for fat reduction

Ephedrine can contribute to fat reduction through its appetite-suppressing effect and the promotion of fat burning. It increases body temperature and thus energy consumption. Ephedrine also improves mood and alertness, which can increase motivation to lose weight. In the past, it was used in Germany in preparations such as Vencipon N to support diets. However, abuse of ephedrine can lead to neurological side effects, including restlessness and insomnia. Higher doses carry the risk of confusion and hallucinations.

Despite the risks, ephedrine remains a useful tool in medical treatment, but requires responsible use and monitoring to realize its full benefits.

Side effects of ephedrine

Ephedrine is known for its stimulating effects, but there are several side effects to be aware of. The most common include:

• Nervousness
• Sleep disorders
• Trembling
• Dizziness
• Headache

In the event of an overdose, more serious symptoms such as severe anxiety, delirium, hallucinations and psychosis may occur.

Ephedrine can also lead to cardiovascular problems, including cardiac arrhythmia, increased blood pressure and accelerated heart rate. Other common side effects are nausea and vomiting.

Misuse of ephedrine increases the risk of additional symptoms such as restlessness, shortness of breath and renewed tremors.