Salbutamol

BRAND NAMES:

Ventolin – Ventolin is an albuterol inhaler available with 200 sprays or 60 sprays used to treat bronchospasms aged above 4 years.

Asmatol – Asmatol contains salbutamol 2 mg/5 ml as the active ingredient available in syrup used in treating airway obstructions.

Asthalin – Asthalin is available in syrup which has salbutamol the major active ingredient that works by relaxing the airways.

Azmasol – Azmasol is an inhaler containing salbutamol sulfate as an active ingredient.

MECHANISM OF ACTION:

Salbutamol acts on beta-2 adrenergic receptors, inducing bronchial smooth muscle relaxation and inhibiting hypersensitivity mediator release from mast cells. Salbutamol also affects beta-1 androgenic receptors; the impact is minimal, exerting little effect on the heart rate. By utilizing immune liposomes to deliver salbutamol to oxytocin receptors, salbutamol can ease uterine contractions.

PHARMACOKINETICS:

Absorption: Approximately 2-3 hours after inhalation, a trace amount emerges in the blood. The time it took to achieve peak plasma concentration was longer with salbutamol (Tmax = 0.42 hours).

Distribution: The volume of distribution of salbutamol is 156 ± 38 L.

Metabolism: It undergoes hepatic metabolism. It goes through metabolic routes such as oxidative deamination and conjugation with glucuronide. Administrating salbutamol directly to the respiratory tract is the appropriate approach to bypassing first-time metabolism.

Excretion: 70% of salbutamol is excreted through urine, and 80% to 100% of salbutamol and its metabolites are excreted within 72 hours. 10% of salbutamol is excreted in the feces.

PHARMACODYNAMICS:

Salbutamol is a selective beta adrenergic receptor agonist; the binding increases the formation of intracellular through stimulation of adenylyl cyclase,  which helps in relaxing airway smooth muscle.

DOSAGE AND ADMINISTRATION:

Salbutamol is available in inhalers, inhalation powders, oral tablets, syrup, solutions for inhalation, intravenous injections, subcutaneous injections, and intramuscular injections. The dose recommended is different from patient to patient.

Salbutamol dry inhaler powder

• Salbutamol dry powder inhaler with strength 200 mcg per dose, 1 inhalation up to times per day, is recommended in adults over 12 years and children 4 to 1 years of age.

Salbutamol inhaler 100 mcg per dose

• In adults, 1 puff every 4 hours up to 4 times is recommended. In children, 1 puff is recommended for every 4 hours up to 4 times, and based on the condition, it can be increased to 2 puffs. 

Salbutamol tablets

• The recommended tablet dosage for adults is 4 mg 3 or 4 times once a day. It gradually increased up to 8mg three or four times a day. 
• For children over the age of 12, a dose of 2 to 4 mg should be given three or four times once a day. The suggested dose for children aged 6 to 12 years is 2mg, taken three or four times each day. The suggested dose for children aged 2 to 6 years is 1 to 2 mg, taken three or four times per day.

Salbutamol injection

• The suggested dose for a subcutaneous or intramuscular injection is 500 mg, repeated every 4 hours as needed.

Salbutamol respiratory solution for nebulizer:

• Adults receiving intermittent treatment are advised to use 0.5 to 1 milliliter (2.5 to 5 milligrams) of respiratory solution. It could take up to 2 ml for certain patients.
• The dosage for children between one month and one year is 0.5 to 1 ml (2.5 to 5 mg salbutamol) of respiratory solution. 
• In continuous treatment, the usual dose is 1 to 2 mg of salbutamol per hour. It can be obtained by diluting 1 or 2 ml of the respiratory solution to 100 ml with sterile saline solution to produce a solution containing 50 or 100 mg/ml of salbutamol and inhaling the mist from a nebulizer.

CONTRAINDICATIONS:

Salbutamol is contraindicated in patients with hypersensitivity and hypersensitivity to milk protein.

DRUG INTERACTIONS:

Salbutamol, when taken with other drugs, may cause some severe side effects. So below are the few drugs that interact with the salbutamol.

Irregular heartbeat medicines - Digoxin

• Diuretics - Furosemide
• Corticosteroids – Beclometasone dipropionate
• Depression medicines – Moclobemde, clomipramide, amitriptyline, phenelzine
• Tablets for asthma including xanthine derivatives -  Theophylline, aminophylline.
• Blood pressure – Atenolol

FOOD INTERACTIONS:

Limit intake of alcohol

ADVERSE EFFECTS:

• Fever
• Nausea
• Headache
• Palpitation
• Increased heart rate
• Dryness
• Tremor
• Muscle tightness
• Epistaxis
• Increased appetite
• Dyspepsia
• Nasal congestion

TOXICITY:

Overdose of salbutamol can cause some toxic effects

• Seizures
• Increase in liver aminotransferase
• Irregular heartbeat
• Chest pain