Adrenergic Drugs

Adrenergic drugs are medications that have been designed to stimulate specific nerves in your body. They bring about the release of two kinds of hormones – epinephrine and norepinephrine. They can as well copy the biologic functions of these two hormones in the body.

Cardiac arrest, asthma, allergic reaction, and shock are some of the life-threatening conditions that adrenergic drugs have found to be very useful in managing.

How do adrenergic drugs work?

Adrenergic drugs acts on the nerves in your body’s sympathetic nervous system to stimulate them. This system is involved in the regulation of your body’s response to emergency and stressful situations. Stress induces the release of epinephrine and norepinephrine from the adrenal gland. These hormones will now act on specific parts of the body including the heart, lungs, digestive system and sweat glands to bring about increased in heart rate, sweating, breathing rate, and decreased digestion. All of these responses are referred to as “fight or flight” response.

Adrenergic drugs have structures similar to epinephrine and norepinephrine. Certain receptors in the body called adrenergic receptors will be the recipient of epinephrine and norepinephrine including adrenergic drugs. The receptors will respond to adrenergic drugs the same way they will respond to epinephrine and norepinephrine. And theirresponse is termed “flight or fight” response

Adrenergic drugs are very useful in:

  • increasing heart rate
  • constricting blood vessels
  • increasing blood pressure
  • opening the airways of the lungs
  • stopping bleeding

Adrenergic drugs
Photo Credit: BBC


Types of adrenergic drugs and their uses

Different conditions need different adrenergic drugs. Every adrenergic drug has a particular receptor it targets.

It therefore implies that every adrenergic drug has a specific action it can produce. Adrenergic drugs can act directly as chemical messengers. They can also act indirectly by causing the release of needed chemical messengers.

Bronchodilators

Bronchodilators have the ability to keep open bronchial tubes. Bronchial tubes are air passages. Their site of action is the beta receptors. Their binding on these beta receptors will forceopen, the airways that lead to the lungs. Once the airways are opened,breathing will be easier for patients having respiratory disorders such as:

  • bronchitis
  • chronic obstructive pulmonary disease (COPD)
  • asthma
  • emphysema

Examples of bronchodilators are:

  • salmeterol
  • levalbuterol
  • albuterol
  • olodaterol
  • formoterol

Vasopressors

Vasopressors have four receptors they can act on – dopamine, beta-1, beta-2 and alpha-1 adrenergic receptors.

Vasopressor drugs induce the contraction of smooth muscle in blood vessels. Contraction of these blood vessels brings about their narrowing. Blood pressure will become increased by this action.

Increasing blood pressure can treat shock. Narrowing blood vessels can also bring an end to bleeding. It can as well keep anesthetics from spreading to surrounding blood vessels. Anestheticsare drugs that can make your body feel numbed.

Certain vasopressors have also been useful in treating colds and allergies. They have the ability to shrink swollen blood vessels found in the mucous membranes of the nose. This category of vasopressors is called nasal decongestants.

Examples of common vasopressors include:

  • phenylephrine
  • ephedrine
  • pseudoephedrine
  • dopamine
  • epinephrine
  • oxymetazoline

Cardiac stimulators

Cardiac stimulators have the potential of stimulating and restoring heart beat. Hence, they will be used on you if your heart suddenly stops beating due to drowning, electrocution, or suffocation.

Epinephrine is a cardiac stimulator. It will be injected directly into your heart so as to restore its beating.

Other considerations

If you are thinking of adrenergic drugs, you should as well think of their side effects and your own history (medical history). Side effects from adrenergic drugs depend on the specifictype being used.

Everyone will not experience the same side effects. Please note that all adrenergic drugs will not produce the same effect on everyone. Your health status other than what needs to be treated with an adrenergic drug determines the type of adrenergic drug that will be used. You doctor can help you make the right choice. Just speak to him or her about it.

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