Index
It is a beta-adrenergic agonist bronchodilator.
This is available as a sterile, non-pyrogenic aqueous solution, in vials, for subcutaneous administration.
Indications
Terbutaline sulfate injection is indicated to prevent and reverse bronchospasm in patients 12 years of age or older with asthma and reversible bronchospasm associated with bronchitis and emphysema.
Dosage and administration of Terbutaline
The vials should be used for subcutaneous administration only and not for intravenous infusion.
Sterility and accurate dosing cannot be guaranteed if the vials are not used according to the dosage and administration prescribed by your physician.
Discard the unused portion after single patient use.
The usual subcutaneous injection dose of terbutaline sulfate is 0.25 mg injected into the lateral deltoid area.
If no significant clinical improvement occurs within 15 to 30 minutes, the second dose of 0.25 mg may be administered.
Other therapeutic measures should be considered if the patient does not respond within another 15 to 30 minutes. The total dose within 4 hours should not exceed 0.5 mg.
Note: Parenteral medications should be visually inspected for particulate matter and discoloration before application, only if the container and solution allow such alterations.
Protect from light by storing vials in the original carton until the time of use.
Do not use it if the solution is colorless.
Discard the unused portion after single patient use.
Side effects
The adverse reactions with Terbutaline are similar to those with other sympathomimetic agents. These reactions are transient and generally do not require treatment.
Terbutaline interactions with other drugs
The combined use of Terbutaline with other sympathomimetic agents is not recommended, as the mixed effect on the cardiovascular system can be detrimental to the patient.
Monoamine oxidase inhibitors or tricyclic antidepressants
Terbutaline should be administered with extreme caution to patients undergoing treatment with monoamine oxidase inhibitors or tricyclic antidepressants.
There is also the option of applying them within two weeks after stopping these components since the effect of Terbutaline on the vascular system can be increased.
beta-blockers
Beta-adrenergic receptor blockers not only block the lung effect of beta-agonists, such as Terbutaline but can cause severe bronchospasm in asthmatic patients.
Therefore, patients with asthma should not usually be treated with beta-blockers.
However, under certain conditions, such as prophylaxis after myocardial infarction, there may be no acceptable alternatives to using beta-adrenergic blocking agents in asthmatic patients.
Cardioselective beta-blockers could be considered in this context, although they should be applied with caution.
Diuretics
Electrocardiogram changes and hypokalemia that may arise from the administration of potassium-sparing diuretics may be acutely worse with beta-agonists.
This tends to happen quite frequently in cases where the recommended beta-agonist dose is exceeded.
Although the clinical importance of these effects is unknown, caution is suggested in the combined application of beta-agonists with potassium-sparing diuretics.
Warnings
Worsening asthma
Asthma can become severe over hours or chronically over several days or more.
Use of anti-inflammatory components
Using beta-adrenergic agonist bronchodilators alone may not be suitable for controlling asthma in most patients.
The addition of anti-inflammatory agents, for example, corticosteroids, should be considered in advance.
Cardiovascular effects
Like all other beta-adrenergic agonists, Terbutaline can cause a clinically relevant cardiovascular sequela in some patients, measured by heart rate, blood pressure, and symptoms.
Although such effects are rare after administration of Terbutaline at recommended doses, the drug may need to be discontinued if they occur.
In addition, beta-agonists have been reported to cause electrocardiogram changes, such as flattening the T wave, prolonging the QT interval, and depression of the ST segment.
The clinical significance of these findings is unknown.
Seizures
There have been rare reports of seizures in patients receiving terbutaline sulfate; episodes did not recur in these patients after drug discontinuation.
Precautions
Tocolysis
Terbutaline has not been approved and should not be used for tocolysis. Severe adverse reactions may occur after administration to women in labor.
These include increased heart rate, transient hyperglycemia, hypokalemia, cardiac arrhythmias, pulmonary edema, and myocardial ischemia in the mother.
Increased fetal heart rate and neonatal hypoglycemia can occur due to maternal administration of Terbutaline.
General
Terbutaline, as well as other sympathomimetic amines, should be used with caution in patients with cardiovascular problems such as:
- Coronary insufficiency.
- Cardiac arrhythmias.
- Hypertension.
- Ischemic heart disease
It can also be applied in patients with hyperthyroidism or diabetes mellitus and in patients who are rarely receptive to sympathomimetic amines or seizure disorders.
Significant changes in systolic and diastolic blood pressure have been observed and are expected to occur in some patients after using any beta-adrenergic bronchodilator.
Hypersensitivity reactions and immediate exacerbations of bronchospasm have been reported after administering this drug.
Beta-adrenergic agonist medications could cause significant hypokalemia in some patients.
This probably happens through the intracellular bypass, which has the power to produce adverse cardiovascular effects.
The decrease is usually temporary and does not require additional supplements.
Large doses of intravenous Terbutaline have been reported to aggravate pre-existing diabetes mellitus and ketoacidosis.
The pregnancy
Teratogenic Effects: Pregnancy Category B
In a reproduction study in rats, Sprague-Dawley revealed that Terbutaline was not teratogenic when administered orally at doses up to 50 mg/kg.
A reproduction study in New Zealand white rabbits revealed that Terbutaline was not teratogenic when administered orally at doses up to 50 mg/kg.
However, there are no appropriate or well-controlled studies on pregnant women because animal reproduction studies are not always predictive of human responses.
Use on the day of delivery.
Due to the likelihood of beta-agonist interference with uterine contractility, the use of Terbutaline to relieve bronchospasm during labor should be restricted.
This only applies to those patients in whom the benefits outweigh the danger itself.
Nursing mothers
It is not known whether this drug is secreted with human milk. Therefore, Terbutaline should be applied during breastfeeding only if the benefit outweighs the possible risk to the newborn child.
Pediatric use
Terbutaline is not recommended for patients under 12 years of age due to insufficient clinical data to establish safety and effectiveness.
Geriatric use
The clinical studies of terbutaline sulfate injection did not include a sufficient number of subjects 65 years of age or older to determine whether they responded differently from younger subjects.
Other reported clinical experience has not identified differences in responses between older and younger patients.
In general, dose selection for an elderly patient should be cautious, generally starting at the lower end of the dosage range.
In this way, the greater frequency of decrease in liver, kidney, or heart function and concomitant disease or other pharmacological treatment is reflected.
Overdose
The median lethal dose of Terbutaline in mature rats was approximately 165 mg/kg.
Young rats’ median lethal dose of terbutaline sulfate was approximately 2,000 mg/kg.
The symptoms expected with overdose are those of excessive beta-adrenergic stimulation and appearance or exaggeration of any of the symptoms mentioned previously in this publication:
- Seizures
- Angina.
- Hypertension or hypotension.
- Tachycardia with rates of up to 200 beats per minute.
- Arrhythmias
- Nervousness.
- Headache.
- Temblor.
- Dry mouth.
- Palpitations
- Sickness.
- Dizziness
- Fatigue.
- Discomfort and insomnia.
Hypokalemia can also occur. There is no specific antidote. Treatment consists of stopping Terbutaline along with appropriate symptomatic therapy.
The judicious use of a cardioselective beta-receptor blocker may be considered, bearing in mind that such a drug may cause bronchospasm.
There is insufficient evidence to say whether dialysis is benign for terbutaline overdose.
