Terbuta Uses, Dosage, Side Effects and more

Terbuta is a relatively selective β2-adrenergic bronchodilator that has little or no effect on alpha-adrenergic receptors. The drug has exerts a preferential effect on β2-adrenergic receptors but stimulates beta-adrenergic receptors less selectively than relatively selective β2-agonists. Terbuta appears to have a greater stimulating effect on beta-receptors of the bronchial, vascular, and uterine smooth muscles (β2 receptors) than on the beta-receptors of the heart (β1 receptors). This drug relaxes smooth muscle and inhibits uterine contractions, but may also cause some cardiostimulatory effects and CNS stimulation.

The pharmacologic effects of terbutaline are at least in part attributable to stimulation through beta-adrenergic receptors of intracellular adenyl cyclase, the enzyme that catalyzes the conversion of adenosine triphosphate (ATP) to cyclic- 3',5'- adenosine monophosphate (c-AMP). Increased c-AMP levels are associated with relaxation of bronchial smooth muscle and inhibition of release of mediators of immediate hypersensitivity from cells, especially from mast cells.

Terbuta is a beta-2 adrenergic receptor agonist indicated to treat reversibly bronchospasm in asthmatic patients with bronchitis and emphysema. It has a short duration as the inhaled form is taken up to three times daily, and the therapeutic window is wide.

Trade Name	Terbuta
Availability	Prescription only
Generic	Terbutaline
Terbutaline Other Names	Terbutalin, Terbutalina, Terbutaline, Terbutalinum
Related Drugs	Dupixent, Xolair, ProAir Digihaler, albuterol, dexamethasone, methylprednisolone, nifedipine, Symbicort, Breo Ellipta, Ventolin
Type
Formula	C12H19NO3
Weight	Average: 225.2842 Monoisotopic: 225.136493479
Protein binding	Terbutaline is not highly bound to protein in plasma.
Groups	Approved
Therapeutic Class	Short-acting selective β2-adrenoceptor stimulants
Manufacturer
Available Country	Hong Kong
Last Updated:	January 7, 2025 at 1:49 am

Uses

Used to open up the airways in people with asthma, bronchitis and other breathing problems.Used to relieve trouble breathing upon exertion.For the prevention and reversal of bronchospasm in patients 12 years of age and older with reversible, obstructive airway disease.Symptomatic management of reversible bronchospasm associated with bronchitis and emphysema.

Terbuta is also used to associated treatment for these conditions: Asthma, Bronchospasm, Chronic Cough (CC), Chronic Obstructive Pulmonary Disease (COPD), Cough, Premature Labour, Productive cough, Airway secretion clearance therapy

How Terbuta works

Terbuta is a selective beta-2 adrenergic receptor agonist. Agonism of these receptors in bronchioles activates adenylyl cyclase, increasing intracellular cyclic adenosine monophosphate (cAMP). Increased cAMP decreases intracellular calcium, activating protein kinase A, inactivating myosin light-chain kinase, activating myosin light-chain phosphatase, and finally relaxing smooth muscle in the bronchiole.

Dosage

The recommended adult dose for treating asthma, emphysema or bronchitis is 2.5-5 mg 3 times daily approximately 6 hours apart while awake. The maximum dosage is 15 mg/day. Shake the inhaler several times and uncap the mouthpiece. Breathe out fully. For best results, hold the inhaler 1 to 2 inches in front of your open mouth or attach a spacer to the inhaler and place the spacer in your mouth, above your tongue and past your teeth. Take a deep, slow breath as you push down on the canister. Hold your breath for 10 seconds, then exhale slowly. Use nebulizer machine for better response.

Side Effects

Dry mouth, irritated throat, nausea, dizziness, headache, heartburn, loss of appetite, altered taste sensation, restlessness, anxiety, nervousness, trembling, and sweating may occur but should subside as your body adjusts to the medication.

Toxicity

Patients experiencing an overdose may present with abdominal pain, agitation, palpitations, seizures, angina, hypertension, hypotension, tachycardia, arrhythmias, nervousness, headache, tremor, dry mouth, nausea, dizziness, fatigue, malaise, insomnia. Discontinue treatment with terbutaline and initiate symptomatic and supportive therapy.

Precaution

Before you use this drug, tell your doctor if you have: any allergies, heart disease, high blood pressure, an overactive thyroid gland, seizures, diabetes. Tell your doctor if you ever had a bad reaction to albuterol, bitolterol, ephedrine, epinephrine, isoetharine, isoproterenol, metaproterenol, pseudoephedrine, or pirbuterol or other similar agents. Tell your doctor if you are pregnant before using this medication. Terbuta is excreted into breast milk. Consult with your doctor before breast-feeding. Terbuta is not recommended for children under the age of 6. Caution is advised in the elderly.

Interaction

Tell your doctor of all nonprescription and prescription medications you take, including: beta-blockers (e.g., propranolol, timolol), all asthma drugs, antidepressants, MAO inhibitors (e.g., furazolidone, linezolid, phenelzine, selegiline, tranylcypromine), diuretics (e.g., hydrochlorothiazide). Many nonprescription medications contain pseudoephedrine or ephedrine, so check the labels carefully. Do not take any of these medications without consulting your doctor. Do not start or stop any medicine without doctor or pharmacist approval.

Food Interaction

No interactions found.

Terbuta Hypertension interaction

[Moderate] Adrenergic bronchodilators can stimulate cardiovascular beta- 1 and beta- 2 receptors, resulting in adverse effects such as tachycardia, palpitation, peripheral vasodilation, blood pressure changes, and ECG changes (e.g., flattening of the T wave; prolongation of the QT interval; ST segment depression).

Direct stimulation of cardiac tissues is mediated by beta- 1 receptors and thus less likely to occur with beta-2-selective agents such as albuterol.

However, beta-2-selectivity is not absolute and can be lost with larger doses.

High dosages of these agents have been associated with precipitation or aggravation of angina, myocardial ischemia, and cardiac arrhythmias.

Therapy with adrenergic bronchodilators should be administered cautiously in patients with sensitivity to sympathomimetic amines, hyperthyroidism, and

The recommended dosages should not be exceeded.

Drug Interaction

Moderate: epinephrine, furosemide, promethazine, oxytocin, budesonide / formoterolUnknown: aspirin, diphenhydramine, misoprostol, carboprost, ipratropium, methylergonovine, naloxone, acetaminophen, metoclopramide, rho , tiotropium, cyanocobalamin, ascorbic acid, cholecalciferol, phytonadione

Disease Interaction

Moderate: cardiovascular, diabetes, hypokalemia, seizures

Volume of Distribution

Terbuta has a mean volume of distribution of 1.6 L/kg.

Elimination Route

A 0.5 mg subcutaneous dose of terbutaline reaches a mean C_max of 9.6 ± ng/mL, with a median T_max of 0.5 hours, and a mean AUC of 29.4 ± 14.2 h*ng/mL. A 5 mg oral terbutaline tablet reaches a mean C_max of 8.3 ± 3.9 ng/mL with a median T_max of 2 hours, and a mean AUC of 54.6 ± 26.8 h*ng/mL. A 5 mg oral terbutaline solution reaches a mean C_max of 8.6 ± 3.6 ng/mL, with a median T_max of 1.5 hours, and a mean AUC of 53.1 ± 23.5 h*ng/mL.

Oral terbutaline has an oral bioavailability of 14-15%.

Half Life

An oral dose of terbutaline has an elimination half life of 3.4 hours, while a subcutaneous dose has an elimination half life of 2.9 hours.

Clearance

The average clearance of terbutaline is 3.0 mL/min/kg.

Elimination Route

An oral dose of terbutaline is 40% eliminated in the urine after 72 hours. The major metabolite in the urine was the sulphate conjugated form of terbutaline. Parenteral doses of terbutaline are 90% eliminated in the urine, with approximately 2/3 as the unchanged parent drug. Less than 1% of a dose of terbutaline is eliminated in the feces.

Pregnancy & Breastfeeding use

Although no teratogenic effects have been observed in animals or in patients, Terbuta should only be administered with caution during the first trimester of pregnancy. Terbuta is secreted via breast milk, but effect on the infant is unlikely at therapeutic doses.

Contraindication

Do not use Terbuta if

• You are allergic to any ingredient in Terbuta or to a sympathomimetic amine (eg, epinephrine, albuterol).
• You need to treat prolonged (more than 48 to 72 hours) premature labor.

Special Warning

Terbuta is not approved for use by children younger than 6 years of age.

Storage Condition

Store at room temperature between 15 to 30° C. Keep away from moisture and sunlight. Do not puncture. Keep away from the reach of children.

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