Salbutamol: Indications, Side Effects, Administration, Mechanism of Action, Interactions and Contraindications

This drug works by activating beta2 adrenergic receptors in the body.

Consequently, the muscles surrounding the bronchial tubes in the airways relax.

This increases the size of the airway passages and makes breathing easier, which helps reduce symptoms of asthma and chronic obstructive respiratory disease (COPD) .

It starts to work quickly on your body, so it’s helpful for quickly relieving symptoms when they get worse.

Salbutamol is the generic name of the drug, which is the name of the active ingredient in the drug that has an effect on your body.

However, you may know it best by one of its brand names, the names given to it by the pharmaceutical companies that make each drug.

Brands of salbutamol include:

  • Airomir.
  • Asmol.
  • Ventolin.
  • Butamol (nebulae only).

How is salbutamol administered?

There are several forms of salbutamol. It can be administered with:

  • Metered Dose Inhaler (MDI) – pumps salmeterol propellant gas into your airways when you coordinate your breath with the push of the inhaler button.
  • Dry Powder Inhaler (DPI) – Delivers a powder containing salmeterol into your airways with a breath-activated device so that you inhale the powder as you inhale.
  • Nebulizer – delivers the medicine with an air compressor or water jet and is helpful if you need to take higher doses over a longer period of time.

What kind of medicine is it?

Salbutamol is a type of medicine known as a short-acting beta2 agonist.

This is a group of drugs that work in a similar way to activate beta2 adrenergic receptors and make the muscles around the airways relax so that air can pass through more easily.

Another example of a short-acting beta2 agonist is terbutaline .

There are also some medications known as long-acting beta2 agonists, such as eformeterol, indacaterol, and salmeterol.

These medications work the same way but continue to work for a longer period of time, so they can be used for different purposes, such as preventive treatment rather than relief of asthma and COPD symptoms.

Mechanism of action

Salbutamol works in the body by stimulating certain receptors, called beta2 adrenergic receptors.

When these adrenergic receptors are activated, the smooth muscles surrounding the bronchial tubes relax so that the airways can expand and allow air to pass through more easily. This is helpful in treating respiratory conditions like asthma and COPD.

Salbutamol works quickly but does not stay in the body after taking the last dose compared to other types of beta2 agonists.

This makes it a good option for relieving asthma or COPD symptoms, as it can quickly help make breathing easier, but is still causing significant side effects.

For what do you use it?

Because of the way salbutamol works, it is typically used as a reliever medication in the treatment of respiratory conditions such as asthma and COPD.

It is supposed to be used as needed, only when you experience symptoms like shortness of breath or before physical activity that can cause exercise-induced asthma.

It may be helpful for you to keep track of how often you need to take salbutamol to relieve respiratory symptoms.

If you rely on taking it too often, more than three times a week, it could be a sign that your asthma or COPD symptoms are not well controlled.

You may need to talk to your doctor about preventing symptoms with other medications, such as long-acting beta2-agonists and inhaled corticosteroids .

Side effects of salbutamol

Some people taking salbutamol may experience some side effects, especially if they take high doses.

Side effects can include:

  • Trembling in the hands.
  • Heart palpitations
  • Fast heart rate ( tachycardia ).
  • Headache.
  • Hyperglycemia
  • Muscle cramps.
  • Agitation.

Fortunately, the effects of salbutamol are relatively short-lived, and your body clears the medication quickly if you experience these side effects.

For this reason, if you have an asthma attack, it is generally preferable to take salbutamol to relieve symptoms, even if you experience some short-term side effects.

In either case, you should talk to your doctor about an action plan so that you know what to do if your symptoms get worse.

Drug interactions

Salbutamol can interact with other medications you may be taking, and it is important that you are aware of these interactions so that you can verify that the combination is okay.

  • Sympathomimetic amines (eg, ephedrine, phenylephrine, pseudoephedrine) : increased risk of side effects such as tremor, tachycardia, and headache.
  • Beta-blockers : They have the opposite effect on beta2-adrenoceptors in the body, so they are generally not used together.
  • Theophylline : increased risk of low potassium levels in the blood ( hypokalemia ), so you will need to monitor your potassium levels more closely than usual.

Pregnancy and breastfeeding

There is not much evidence to guarantee the safety of salbutamol for pregnant or breastfeeding women.

However, it is important that asthma symptoms can be relieved, which is why most women continue to take salbutamol as they did before becoming pregnant.

There is little information on the use of salbutamol for women who are breastfeeding, although it should be safe to use.

Contraindications and precautions

  • Hypersensitivity to salbutamol.
  • Tachyarrhythmias and tachycardia due to intoxication.
  • Patients with degenerative heart disease.
  • Use cautiously with patients with diabetes, as this can aggravate diabetes and ketoacidosis.
  • Use with caution in the elderly because they are more sensitive to the effects of the CNS.

Dosages

Adult

  • Oral: 2 or 4 mg (1-2 teaspoons of syrup) three or four times a day.
  • ER tablets: 4-8 mg every 12 hours.
  • Inhalation: 1 or 2 inhalations per second every 4-6 hours (1 aerosol dispenser = 90 mcg).
  • Prevention of exercise-induced bronchospasms: 2 inhalations 15 minutes before exercise.

Pediatric

  • Oral: 2 mg three or four times a day.
  • Inhalation: 10-15 kg, use 1.25 mg twice or three times a day by nebulization; more than 15 kg, use 2.5 mg twice or three times per nebulization.

Pharmacokinetics

  • Oral route: start – 30 minutes; peak – 2-2.5 hours; duration – 4-8 hours.
  • Inhalation route: start – 5 minutes; peak – 1.5-2 hrs; duration – 3-8 hours.