Adrenergic or sympathomimetic drugs are medicines that stimulate the sympathetic nervous system (SNS). This part of the automatic nervous system helps regulate the body’s ability to react to stress. During a stressful situation, the SNS releases neurotransmitters, or chemicals that act on the body to increase your heart rate, breathing rate and sweating speed. This body response is also known as the “fight or flight” response.

What Are the Common Adrenergic Drugs?

The body has several types of receptors or nerve endings that respond to adrenergic drugs. The effects of these drugs depend on the specific type of receptors that are stimulated. Alpha receptors react with some drugs that can increase heart rate, dilate the pupils of the eyes and contract the muscles. Beta receptors, when stimulated, can cause opening up of the airways in the lungs.

Common Adrenergic Drugs

Here are some of the adrenergic drugs commonly used:



Albuterol (ex. Alupent, Ventolin)

Improves breathing; taken as oral medication or nasal spray.

Dobutamine (ex. Dobutrex)

Stimulates the heart; used after a heart attack; cardiac arrest; or during surgery.

Dopamine (ex. Intropin)

Increases cardiac output, elevates blood pressure, and improves urine flow; used for treating patients in circulatory shock.

Epinephrine (ex. Adrenalin)

Used as local injection to control bleeding during surgery; used to stimulate the heart during circulatory shock; used also as a nasal decongestant to reduce symptoms of conjunctivitis (or red eye). It may be added to a local anesthetic to prolong the anesthetic effect and prevent its spread.


Used to reduce breathing problems such as asthma and chronic lung disease; also used to control irregular heartbeats

Phenylephrine (ex. Neo-Synephrine)

Used to treat low blood pressure and circulatory shock; also used as nose drops/ spray to relieve colds and allergies with nasal congestion

Phenylephrine (ex. Neo-Synephrine)

Used to treat circulatory shock by increasing blood pressure and cardiac output

What Are the Effects of Adrenergic Drugs?

Adrenergic drugs work by stimulating the adrenergic nerves, just like the natural neurotransmitters (ex. Norepinephrine) that the body produces. When stressful situations arise, norepinephrine stimulates the adrenergic receptors. In the same way, adrenergic drugs act directly on the same receptors as the neurotransmitter.

Adrenergic Drug Effects

Effects of adrenergic drugs on the body include:

  • increase in blood pressure

  • constriction of blood vessels

  • opening of airways in the lungs

  • increase in heart rate

  • prevention from bleeding

What Are the Side Effects of Adrenergic Drugs?

Just like any medicine, adrenergic drugs have side effects. These depend on the type of adrenergic drug taken. The most common of these are agitation, nervousness, and wakefulness. However, these side effects do not occur during surgery or when the drugs are combined with local anesthetics.

Common Side Effects

Common side effects occur when adrenergic drugs are used to treat patients with nasal congestion due to infections or allergies. These include: 

  • Ÿ   rapid heartbeat

  • Ÿ   irregular heart beat

  • Ÿ   nervousness

  • Ÿ   increased sweating

  • Ÿ   hallucinations

  • Ÿ   paleness

  • Ÿ   dizziness

  • Ÿ   sleep disturbances

  • Ÿ   high blood pressure

  • Ÿ   chest pain

  • Ÿ   headache

  • Ÿ   dry mouth

  • Ÿ   flushing

  • Ÿ   weakness

  • Ÿ   nausea

  • Ÿ   vomiting

These are not the only side effects that may occur. Anyone who experiences unusual symptoms after taking adrenergic drugs must contact a doctor right away.

What Should Be Noted When Taking Adrenergic Drugs?

It is important to note that adrenergic drugs may interact with other drugs or supplements a patient is taking. They may also affect other medical conditions a patient may have. Consult a doctor or pharmacist before taking adrenergic drugs with other drugs or supplements.

Drug Interactions

Adrenergic drugs may interact with various drugs. Discuss the use of adrenergic drugs with your doctor or pharmacist before using other over-the-counter medications that also contain adrenergic animes for your colds and allergies.

 Medications that may interact with adrenergic drugs include:

  • tricyclic antidepressants such as Adapin, Aventyl, Asendin, Elavil, Endep, Pamelor, Norpramin, Sinequan, Surmontil, Vivactil, Tofranil

  • furazolidone (Furoxone)

  • methyldopa (Aldomet)

  • guanethidine (Ismelin)



Herbal supplements that may interact with adrenergic drugs include:

  • ephedra (ma huang), which is often contained in over-the-counter weight loss products

  • St. John's wort, which is used as a remedy for anxiety and depression

  • Alfalfa

  • angelica (dong quai)

  • hibiscus

  • ginseng

  • yohimbe


Medical Conditions

Some medical problems may be affected by your intake of adrenergic drugs. Be sure to tell your physician if you have any of these conditions:

  • liver disease

  • narrow-angle glaucoma

  • enlarged heart

  • disorders affecting the brain’s blood supply

  • disorders affecting the arteries and veins


Please Log In or add your name and email to post the comment.