How do alpha/beta agonists work?
Alpha/beta agonists are medications for treating bronchial conditions such as asthma and croup, and anaphylaxis, a serious multisystem allergic reaction. Alpha/beta agonists are also used in critical care to revive a person after a cardiac arrest.
Alpha/beta agonists are a synthetic formulation of epinephrine, a hormone naturally produced in our bodies by the adrenal gland. Alpha/beta agonists work by enhancing the activity of alpha and beta adrenergic receptors, which are protein molecules on cell surfaces that are activated by epinephrine, and norepinephrine, another hormone.
By stimulating alpha and beta receptors, alpha/beta agonists produce several effects in the body which include:
- An increase in heart rate and the force of heart contractions, which increases the cardiac output.
- Constriction of systemic blood vessels and increase in blood pressure.
- Relaxation of bronchial smooth muscles eases breathing.
How are alpha/beta agonists used?
Alpha/beta agonists are available in inhalers over the counter, but injectable solutions require a prescription. Alpha/beta agonists are administered through the following routes:
Inhalations: Inhaled using inhalers or nebulizers
Injections:
Subcutaneous (SC) and intramuscular (IM) injections using prefilled autoinjector or syringe
Intravenous (IV), intracardiac, or into the endotracheal tube in clinical settings
Alpha/beta agonists are used in the treatment of:
- Mild asthma
- Bronchial asthma
- Croup (infection of the upper airway that obstructs breathing)
- Cardiac arrest
- Hypotension associated with septic shock
- Anaphylaxis (serious allergic reaction)
- Symptomatic bradycardia (slow heartbeat)
- Mydriasis (dilation of pupils) during intraocular surgeries
What are side effects of alpha/beta agonists?
Side effects of alpha/beta agonists may include the following:
- Tachycardia (rapid heartbeat)
- Arrhythmia (irregular heartbeat)
- Hypertension (high blood pressure)
- Headache
- Nausea
- Sweating
- Flushing
- Vomiting
- Tremor
- Rebound airway edema
- Angina (chest pain)
- Autonomic hyperreflexia (overreaction of the involuntary nervous system to stimuli)
- Cardiac dysrhythmia (abnormal cardiac rate and rhythm)
- Ventricular fibrillation (irregular heartbeat in the ventricles)
- Cerebral hemorrhage
- Pulmonary edema
- Anxiety
- Apprehensiveness
- Nervousness
- Restlessness
- Dizziness
- Dyspnea (shortness of breath)
- Respiratory difficulties
- Pallor
- Palpitations
- Stress cardiomyopathy (temporary heart muscle weakness due to stress)
- Weakness
- Vasoconstriction (constriction of blood vessels)
- Necrotizing fasciitis (soft tissue death) and myonecrosis (muscle tissue death), also known as gas gangrene, are caused by Clostridium perfringens bacterial infection
Information contained herein is not intended to cover all possible side effects, precautions, warnings, drug interactions, allergic reactions, or adverse effects. Check with your doctor or pharmacist to make sure these drugs do not cause any harm when you take them along with other medicines. Never stop taking your medication and never change your dose or frequency without consulting your doctor.
