Action and Spectrum

Actions and spectrum:

terbutaline is a medication that belongs to the class of beta-2 adrenergic receptor agonists. It is primarily used as a bronchodilator to treat and prevent symptoms of asthma and chronic obstructive pulmonary disease (COPD). It works by relaxing the smooth muscles in the airways, which allows the air to flow more easily in and out of the lungs.

In addition to its bronchodilator effect, terbutaline can also stimulate the heart and increase blood pressure, and as a result, it is used to treat certain conditions such as arrhythmias and heart failure. Terbutaline may also be used off-label for the treatment of preterm labor by relaxing the uterus and delaying delivery.

Drug Interaction

Adverse Reaction

Frequency undefined:

Nervousness

Transient hyperglycemia

Trembling

HTN

Dizziness

Drowsiness

Insomnia

Nausea

Bad taste in mouth

Weakness

Cardiac arrhythmias

Myocardial ischemia

Increased fetal heart rate

Restlessness

Transient hypokalemia

Tachycardia

Pounding heartbeat

Lightheadedness

Headache

Dry mouth

Vomiting

Muscle cramps

Diaphoresis

Pulmonary edema

Myocardial infarction

Hypoglycemia

Black Box Warning

Black Box Warning

The risk of significant adverse effects outweighs the possible benefit for pregnant women undergoing prolonged terbutaline injection (i.e., >48-72 hr) or acute or chronic oral terbutaline medication.

Death and major adverse reactions have been reported after pregnant women were given oral or injectable terbutaline for an extended period.

Contraindication / Caution

Contraindication/Caution

Contraindication

• Patients with a known hypersensitivity to terbutaline or any of the other components of the product
• Patients with a history of hypersensitivity to sympathomimetic amines
• Patients with uncontrolled hypertension
• Patients with tachyarrhythmias or other cardiac arrhythmias
• Patients with coronary artery disease
• Patients with pre-existing diabetes mellitus
• Patients with hyperthyroidism
• Patients with pheochromocytoma

Caution

• Cardiovascular disease: terbutaline may cause an increase in heart rate and blood pressure, so it should be used in patients with cardiovascular diseases with caution, such as hypertension, coronary artery disease, and arrhythmias.
• Hyperthyroidism: terbutaline can exacerbate the symptoms of hyperthyroidism, so caution should be exercised when using it in patients with this condition.
• Diabetes: terbutaline can cause an increase in blood glucose levels, so it should be used with caution in patients with diabetes.
• Seizure disorders: terbutaline can lower the seizure threshold, so it should be used in patients with a history of seizures with caution.
• Hypokalemia: terbutaline can cause a decrease in serum potassium levels, so it should be used with caution in patients with hypokalemia or those taking medications that can cause hypokalemia.
• Pregnancy: terbutaline should be used with caution during pregnancy, especially during the first trimester, due to the increased risk of adverse effects on the fetus.
• Breastfeeding: terbutaline should be used with caution in breastfeeding women, as it can pass into breast milk. 

Comorbidities

• Cardiovascular disease: terbutaline can cause an increase in heart rate and blood pressure, so it should be used cautiously in patients with underlying cardiovascular diseases such as hypertension, arrhythmias, coronary artery disease, or heart failure.
• Diabetes mellitus: terbutaline can cause hyperglycemia (high blood sugar), so it should be used with caution in patients with diabetes mellitus.
• Hyperthyroidism: terbutaline can worsen hyperthyroidism, so it should be used cautiously in patients with this condition.
• Seizure disorders: terbutaline can lower the seizure threshold, so it should be used in patients with seizure disorders with caution.
• Hypokalemia: terbutaline can cause hypokalemia (low blood potassium), so it should be used in patients with this condition.

Pregnancy / Lactation

Pregnancy consideration: Pregnancy Category: C

Lactation: not recommended in lactation as it passes into breast milk 

Pregnancy category:

• Category A: Satisfactory and well-controlled studies show no risk to the fetus in the first or later trimester.
• Category B: There is no evidence of risk to the fetus found in animal reproduction studies and there are not enough studies on pregnant women.
• Category C: Adverse effects on the fetus found with evidence in animal reproduction studies and no adequate evidence for an effect in humans, care must be taken for potential risks in pregnant women
• Category D: There is adequate data available with sufficient evidence of human fetal risk from various platforms, but despite potential risks may be used only in emergency cases for potential benefits.
• Category X: Drugs listed in this category outweigh risks over benefits These category drugs should be prohibited for pregnant women.
• Category N: There is no data available for the drug under this category.

Pharmacology

Pharmacology

terbutaline is a beta-2 adrenergic agonist that stimulates beta-2 adrenergic receptors in the lungs and uterus. It is a bronchodilator that relaxes the smooth muscle in the airways and allows for increased airflow. In addition, it can also relax the smooth muscle of the uterus and inhibit contractions, making it useful for delaying premature labor.

terbutaline is a selective beta-2 adrenergic agonist, which means it primarily targets beta-2 receptors and has little effect on beta-1 receptors. This selectivity results in fewer cardiovascular side effects than non-selective beta-agonists.

Pharmacodynamics

terbutaline is a beta-2 adrenergic receptor agonist. It works by stimulating beta-2 adrenergic receptors in the smooth muscles of the bronchi, uterus, and blood vessels. This results in the relaxation of these muscles, leading to bronchodilation, uterine relaxation, and vasodilation.

terbutaline also increases the production of cyclic AMP (cAMP) by stimulating the adenylate cyclase enzyme. Increased cAMP levels lead to the activation of protein kinase A (PKA), which then mediates the relaxation of the smooth muscles.

pharmacokinetics

terbutaline is rapidly absorbed after oral or subcutaneous administration, with peak plasma concentrations reached within 30 to 60 minutes. The onset of action occurs within 5 to 15 minutes after subcutaneous administration and within 30 minutes after oral administration. The drug gets metabolized by the liver and excreted in the urine, with a half-life of 4 to 6 hours in adults. The pharmacokinetics of terbutaline may be altered in patients with hepatic impairment, renal impairment, or congestive heart failure.

Adminstartion

Administration

terbutaline can be administered in various forms, including oral tablets, subcutaneous injections, and inhalation via metered-dose inhalers or nebulizers. The specific route of administration and dosing regimen may vary depending on the condition being treated, the patient’s age, and other factors.

Patient Information Leaflet

Patient information leaflet

Generic Name: terbutaline

Pronounced: (ter-bue-ta-leen-)

Why do we use terbutaline?

terbutaline is a medication primarily used to treat bronchospasm in conditions such as asthma, chronic obstructive pulmonary disease (COPD), and bronchitis. It is a beta-2 agonist, which means it acts by relaxing smooth muscles in the airway, allowing for easier breathing.

In addition to its use in respiratory conditions, terbutaline is also used to delay premature labor by relaxing the uterine smooth muscle. It can also be used to treat high blood pressure and other conditions where the relaxation of smooth muscle is beneficial.