Action and Spectrum

Mechanism of action

salbutamol is a medication used as a bronchodilator to help manage asthma, chronic obstructive pulmonary disease (COPD), and other respiratory conditions. It works by relaxing the muscles in the airways, which helps to open up the air passages and make breathing easier

salbutamol is a type of medication called a short-acting beta-2 agonist. It works by binding to beta-2 receptors in the smooth muscle cells of the airways, causing the cells to relax and widen the air passages. This action helps improve airflow in and out of the lungs

Spectrum

The spectrum of activity of salbutamol is primarily focused on the respiratory system, where it can help to relieve symptoms of asthma, COPD, and other conditions that cause difficulty breathing. Salbutamol effectively treats bronchoconstriction, a tightening of the airway muscles that makes breathing harder. It can also be used to prevent exercise-induced bronchoconstriction

Drug Interaction

Adverse Reaction

Frequency defined:

>10%

Insomnia in children 6-12 years (11%)

Tremor (20%)

Nervousness (20%)

1-10%

Fever (1.6-9%)

Vomiting (7%)

Dizziness (1-7%)

Allergic reaction (4%)

Epistaxis in children (3%)

Urinary tract infections (3%)

Flatulence (<3%)

Pain (2.7%)

Hyperactivity (1-2%)

Lymphadenopathy (<2%)

Sweating (<2%)

Dysphonia (1%)

Nervousness

Nausea(10%)

Bronchospasm (8%)

Headache (4-7%)

Cough (5%)

Otitis media (3.3%)

Increased appetite (3%)

Dry mouth (<3%)

Increased sweating (<3%)

Dyspepsia (1-2%)

Chills

Ocular pruritis (<2%)

Conjunctivitis (1%)

Flu syndrome

<1%

Epistaxis in adults

Epigastric pain

Hyperactivity in children

Frequency undefined

Hypersensitivity

Increased blood glucose levels

Sleeplessness

Black Box Warning

Contraindication / Caution

Contraindications

• Allergic reactions: It should not be used in patients with a known allergy to salbutamol or any other ingredients in the medication
• Cardiovascular diseases: They may cause an increase in heart rate and blood pressure, so they should be used with caution in patients with heart disease, high blood pressure, or an irregular heartbeat
• Diabetes: It can increase blood sugar levels, so it should be used cautiously in patients with diabetes
• Thyroid disorders: It can cause a decrease in potassium levels in the blood, which may worsen symptoms in patients with thyroid disorders
• Pregnancy and breast-feeding: It should be used cautiously during pregnancy and breastfeeding

Caution

• Tremors: It can cause shaking or trembling in the hands, particularly in high doses or in patients who are particularly sensitive to the medication.
• Hypokalemia: It can cause a decrease in potassium levels in the blood
• Tachycardia: It can cause an increase in heart rate and palpitations, particularly in patients with pre-existing heart disease
• Hyperglycemia: It can cause an increase in blood sugar levels, particularly in patients with diabetes or other conditions that affect blood sugar
• Nervousness or anxiety: It can cause nervousness, restlessness, or anxiety, particularly in high doses or in patients who are particularly sensitive to the medication
• Drug interactions: It can interact with other medications, particularly beta-blockers and certain antidepressants, so it is essential to inform your healthcare provider of all medications you are taking

Pregnancy / Lactation

Pregnancy consideration: Insufficient data available

Lactation: Excretion of the drug in human breast milk is unknown

Pregnancy category:

Category A: well-controlled and Satisfactory studies show no risk to the fetus in the first or later trimester.

Category B: there was no evidence of risk to the fetus in animal studies, and there were not enough studies on pregnant women.

Category C: there was evidence of risk of adverse effects in animal reproduction studies, and no adequate evidence in human studies must take care of potential risks in pregnant women.

Category D: adequate data with sufficient evidence of human fetal risk from various platforms, but despite the potential risk, and used only in emergency cases for potential benefits.

Category X: Drugs listed in this category outweigh the risks over benefits. Hence these categories of drugs need to be avoided by pregnant women.

Category N: There is no data available for the drug under this category

Pharmacology

Pharmacology

It is a short-acting beta-2 adrenergic receptor agonist that relaxes the smooth muscle in the lungs’ airways, leading to bronchodilation. salbutamol is a selective beta-2 agonist, which means it targets the beta-2 receptors in the lungs and has little effect on the beta-1 receptors in the heart

The binding of salbutamol to the beta-2 receptors causes an increase in intracellular cyclic adenosine monophosphate (cAMP) levels in the smooth muscle cells, leading to relaxation and dilation of the airways

Pharmacodynamics

The pharmacodynamics of salbutamol is focused on its ability to selectively target and stimulate the beta-2 receptors in the lungs, leading to relaxation of the airway smooth muscle and improved airflow. This mechanism of action has made salbutamol a valuable medication for treating respiratory conditions such as asthma, COPD, and bronchitis.

Pharmacokinetics

Absorption

It can be administered by several routes, including inhalation, nebulization, and oral administration. The onset of action varies depending on the route of administration, with inhalation having the fastest onset (25 minutes for Ventolin HFA) and oral administration having the slowest onset (2-3 hours). The duration of action is generally 4-6 hours for oral administration, and the peak plasma time varies depending on the route of administration 

Distribution

It is relatively lipophilic and has a volume of distribution of approximately 90 liters. It is only 10% protein-bound, so it is highly distributed throughout the body

Metabolism

It is primarily metabolized in the liver by conjugation with glucuronic acid, and oxidative pathways metabolize a small percentage

Elimination/Excretion

The half-life of salbutamol varies depending on the route of administration, with inhalation having a half-life of 3-8 hours and oral administration having a half-life of 3.7-5 hours. It is eliminated from the body primarily through urine

Adminstartion

Administration

salbutamol can be administered through several routes, including inhalation, nebulization, and oral administration. The specific route of administration will depend on the condition being treated, the severity of symptoms, and the patient’s needs

Inhalation: Inhalation is the most common route of administration for salbutamol, especially for treating asthma and other respiratory conditions. Salbutamol can be delivered via a metered-dose inhaler (MDI) or a dry powder inhaler (DPI). The MDI is the most common method and delivers a fixed dose of salbutamol with each actuation. On the other hand, the DPI requires the patient to inhale a specific amount of powder.

In both cases, the patient should exhale completely, then inhale deeply while pressing down on the inhaler to release the medication. The patient should hold their breath for 10 seconds, then exhale slowly. The number of inhalations and frequency of use will depend on the patient’s specific condition and the severity of symptoms

Nebulization: Nebulization is another method of delivering salbutamol to the lungs. This method is often used in the hospital setting, especially for patients who cannot use an inhaler. A nebulizer converts the liquid medication into a fine mist that the patient can inhale through a mask or mouthpiece

Patient Information Leaflet

Patient information leaflet

Generic Name: salbutamol

Why do we use salbutamol?

salbutamol is a medication that is primarily used to treat and prevent symptoms of respiratory conditions, such as asthma, chronic obstructive pulmonary disease (COPD), and bronchitis

• Asthma: It is commonly used to treat asthma, a chronic respiratory condition characterized by airway inflammation and constriction, causing wheezing, shortness of breath, and coughing.
• COPD: It can also treat chronic obstructive pulmonary disease (COPD), a chronic inflammatory lung disease that causes airflow limitation.
• Bronchitis: It is sometimes used to treat acute bronchitis, inflammation of the bronchial tubes that can cause coughing, shortness of breath, and wheezing.
• Exercise-induced bronchoconstriction: It is also used to prevent and treat exercise-induced bronchoconstriction, a temporary narrowing of the airways during or after exercise.
• Preterm labor: It can also prevent preterm labor, relaxing the uterus and delaying contractions