Brethine 2.5mg Tablets
WARNING: Severe and sometimes deadly side effects, like fast heartbeat, an abnormal heartbeat, high blood sugar, low potassium, fluid in the lungs, or heart attack, have happened when this drug was given during pregnancy. It may also cause fast heartbeat or low blood sugar in the fetus or newborn if given to during pregnancy. This drug is not approved to treat or prevent premature labor. Talk with the doctor. @ COMMON USES: It is used to open the airways in lung diseases where spasm may cause breathing problems. It may be given to you for other reasons. Talk with the doctor.
Drug Class
Bronchodilator
Pharmacologic Class
Selective Beta-2 Adrenergic Agonist
Pregnancy Category
Category B
FDA Approved
Sep 1974
DEA Schedule
Not Controlled
Overview
What is this medicine?
Terbutaline is a medicine that helps open up the airways in your lungs, making it easier to breathe. It's used to treat conditions like asthma and COPD that cause wheezing and shortness of breath.
How to Use This Medicine
Taking Your Medication
To use this medication correctly, follow your doctor's instructions and read all the information provided. You can take this medication with or without food.
Storing and Disposing of Your Medication
Keep your medication at room temperature in a dry place, avoiding storage in a bathroom. Store all medications in a safe location, out of the reach of children and pets. When disposing of unused or expired medication, do not flush it down the toilet or pour it down the drain unless instructed to do so. Instead, consult your pharmacist for guidance on proper disposal. You may also want to explore local drug take-back programs.
Missing a Dose
If you miss a dose, take it as soon as you remember. However, if it's close to the time for your next scheduled dose, skip the missed dose and resume your regular dosing schedule. Do not take two doses at the same time or take extra doses to make up for a missed one.
To use this medication correctly, follow your doctor's instructions and read all the information provided. You can take this medication with or without food.
Storing and Disposing of Your Medication
Keep your medication at room temperature in a dry place, avoiding storage in a bathroom. Store all medications in a safe location, out of the reach of children and pets. When disposing of unused or expired medication, do not flush it down the toilet or pour it down the drain unless instructed to do so. Instead, consult your pharmacist for guidance on proper disposal. You may also want to explore local drug take-back programs.
Missing a Dose
If you miss a dose, take it as soon as you remember. However, if it's close to the time for your next scheduled dose, skip the missed dose and resume your regular dosing schedule. Do not take two doses at the same time or take extra doses to make up for a missed one.
Lifestyle & Tips
- Take this medication exactly as prescribed by your doctor. Do not take more or less than directed.
- This medication is for maintenance treatment and is not meant for sudden, severe breathing problems (acute asthma attacks). You should have a fast-acting inhaler (rescue inhaler) for those situations.
- Avoid activities that trigger your breathing problems (e.g., allergens, smoke).
- If you smoke, quitting can significantly improve your lung health.
Available Forms & Alternatives
Available Strengths:
Generic Alternatives:
Dosing & Administration
Adult Dosing
Standard Dose:
2.5 mg or 5 mg three times a day (every 6-8 hours)
Dose Range:
2.5 - 5 mg
Condition-Specific Dosing:
bronchospasm:
Initial dose 2.5 mg three times a day. May increase to 5 mg three times a day if needed and tolerated. Maximum daily dose 15 mg.
Pediatric Dosing
Neonatal:
Not established
Infant:
Not established
Child:
Not generally recommended for children under 12 years for chronic asthma due to lack of established efficacy and safety compared to inhaled options. If used, 2.5 mg three times a day for children 12-15 years. Not recommended for children under 12 years.
Adolescent:
12-15 years: 2.5 mg three times a day. Over 15 years: Adult dosing.
Dose Adjustments
Renal Impairment:
Mild:
No specific adjustment recommended, monitor for adverse effects.
Moderate:
Consider dose reduction (e.g., 2.5 mg twice daily) and monitor for adverse effects.
Severe:
Consider significant dose reduction (e.g., 2.5 mg once daily) and monitor closely due to primary renal excretion.
Dialysis:
Not well studied, but likely requires dose adjustment. Monitor for adverse effects.
Hepatic Impairment:
Mild:
No specific adjustment recommended.
Moderate:
No specific adjustment recommended, as metabolism is primarily by conjugation, not hepatic CYP450.
Severe:
No specific adjustment recommended, as metabolism is primarily by conjugation, not hepatic CYP450.
Pharmacology
Mechanism of Action
Terbutaline is a selective beta-2 adrenergic agonist. It acts by stimulating beta-2 adrenergic receptors in bronchial smooth muscle, leading to activation of adenyl cyclase, increased intracellular cyclic AMP (cAMP), and subsequent relaxation of bronchial smooth muscle. This results in bronchodilation and relief of bronchospasm. It also inhibits the release of mediators from mast cells in the airways.
Pharmacokinetics
Absorption:
Bioavailability:
30-50%
Tmax:
1-2 hours
FoodEffect:
Food may delay the rate of absorption but does not significantly affect the extent of absorption.
Distribution:
Vd:
1.6 L/kg
ProteinBinding:
Approximately 25%
CnssPenetration:
Limited
Elimination:
HalfLife:
3-4 hours
Clearance:
Not readily available, but primarily renal excretion.
ExcretionRoute:
Renal (urine)
Unchanged:
Approximately 60% of an oral dose is excreted unchanged in urine.
Pharmacodynamics
OnsetOfAction:
Within 30 minutes
PeakEffect:
2-3 hours
DurationOfAction:
4-8 hours
Confidence:
Medium
Safety & Warnings
Side Effects
Serious Side Effects: Seek Medical Attention Immediately
Although rare, this medication can cause severe and potentially life-threatening side effects. If you experience any of the following symptoms, contact your doctor or seek medical help right away:
Signs of an allergic reaction, such as:
+ Rash
+ Hives
+ Itching
+ Red, swollen, blistered, or peeling skin with or without fever
+ Wheezing
+ Tightness in the chest or throat
+ Trouble breathing, swallowing, or talking
+ Unusual hoarseness
+ Swelling of the mouth, face, lips, tongue, or throat
Signs of high blood pressure, including:
+ Severe headache
+ Dizziness
+ Fainting
+ Changes in eyesight
Signs of high blood sugar, such as:
+ Confusion
+ Feeling sleepy
+ Unusual thirst or hunger
+ Frequent urination
+ Flushing
+ Rapid breathing
+ Fruity-smelling breath
Signs of low potassium levels, including:
+ Muscle pain or weakness
+ Muscle cramps
+ Abnormal heartbeat
Chest pain or pressure
Fast or abnormal heartbeat
Seizures
Other Possible Side Effects
Like all medications, this drug can cause side effects. While many people may not experience any side effects or only minor ones, it's essential to discuss any concerns with your doctor. If you experience any of the following side effects or any other symptoms that bother you or do not go away, contact your doctor:
Feeling nervous and excitable
Shakiness
Restlessness
Headache
Dizziness or drowsiness
This is not an exhaustive list of possible side effects. If you have questions or concerns about side effects, consult your doctor. You can also report side effects to the FDA at 1-800-332-1088 or online at https://www.fda.gov/medwatch.
Although rare, this medication can cause severe and potentially life-threatening side effects. If you experience any of the following symptoms, contact your doctor or seek medical help right away:
Signs of an allergic reaction, such as:
+ Rash
+ Hives
+ Itching
+ Red, swollen, blistered, or peeling skin with or without fever
+ Wheezing
+ Tightness in the chest or throat
+ Trouble breathing, swallowing, or talking
+ Unusual hoarseness
+ Swelling of the mouth, face, lips, tongue, or throat
Signs of high blood pressure, including:
+ Severe headache
+ Dizziness
+ Fainting
+ Changes in eyesight
Signs of high blood sugar, such as:
+ Confusion
+ Feeling sleepy
+ Unusual thirst or hunger
+ Frequent urination
+ Flushing
+ Rapid breathing
+ Fruity-smelling breath
Signs of low potassium levels, including:
+ Muscle pain or weakness
+ Muscle cramps
+ Abnormal heartbeat
Chest pain or pressure
Fast or abnormal heartbeat
Seizures
Other Possible Side Effects
Like all medications, this drug can cause side effects. While many people may not experience any side effects or only minor ones, it's essential to discuss any concerns with your doctor. If you experience any of the following side effects or any other symptoms that bother you or do not go away, contact your doctor:
Feeling nervous and excitable
Shakiness
Restlessness
Headache
Dizziness or drowsiness
This is not an exhaustive list of possible side effects. If you have questions or concerns about side effects, consult your doctor. You can also report side effects to the FDA at 1-800-332-1088 or online at https://www.fda.gov/medwatch.
Seek Immediate Medical Attention If You Experience:
- Worsening breathing problems despite taking the medication.
- Chest pain or discomfort.
- Severe or persistent dizziness, nervousness, or tremor.
- Fast or irregular heartbeat (palpitations).
- Muscle cramps or weakness (signs of low potassium).
Before Using This Medicine
Before Taking This Medication: Important Information to Share with Your Doctor
It is essential to inform your doctor about the following:
Any allergies you have, including allergies to this medication, its components, or other substances, such as foods or drugs. Be sure to describe the allergic reaction you experienced, including any symptoms that occurred.
If you have a history of fast or abnormal heartbeats.
* If you are currently experiencing preterm labor or having a miscarriage.
This list is not exhaustive, and it is crucial to discuss all your medications, including prescription and over-the-counter drugs, natural products, and vitamins, with your doctor and pharmacist. Additionally, share any existing health problems to ensure safe use of this medication.
To guarantee your safety, do not start, stop, or modify the dosage of any medication without first consulting your doctor. It is vital to verify that this medication can be taken safely with all your other medications and health conditions.
It is essential to inform your doctor about the following:
Any allergies you have, including allergies to this medication, its components, or other substances, such as foods or drugs. Be sure to describe the allergic reaction you experienced, including any symptoms that occurred.
If you have a history of fast or abnormal heartbeats.
* If you are currently experiencing preterm labor or having a miscarriage.
This list is not exhaustive, and it is crucial to discuss all your medications, including prescription and over-the-counter drugs, natural products, and vitamins, with your doctor and pharmacist. Additionally, share any existing health problems to ensure safe use of this medication.
To guarantee your safety, do not start, stop, or modify the dosage of any medication without first consulting your doctor. It is vital to verify that this medication can be taken safely with all your other medications and health conditions.
Precautions & Cautions
Important Warnings and Cautions for Patients Taking This Medication
If you are taking this medication, it is essential to inform all your healthcare providers, including doctors, nurses, pharmacists, and dentists, about your treatment.
Immediately contact your doctor if you experience any of the following:
- Your normal dose is not providing adequate relief
- Your symptoms worsen
- You need to use this medication more frequently than prescribed
Adhere strictly to your doctor's prescribed dosage. Taking more than the recommended amount can significantly increase your risk of severe side effects.
Before using any other medications or inhalers for breathing problems, consult with your doctor to ensure safe and effective treatment.
If you have diabetes (high blood sugar), discuss this with your doctor, as this medication may cause an increase in blood sugar levels. Monitor your blood sugar as instructed by your doctor.
Patients aged 65 and older should exercise caution when using this medication, as they may be more susceptible to side effects.
If you are pregnant, planning to become pregnant, or are breastfeeding, consult your doctor to discuss the potential benefits and risks to both you and your baby.
Special Considerations for Children
Different formulations of this medication are approved for use in children of various ages. Before administering this drug to a child, consult with their doctor to ensure the appropriate form and dosage are used.
If you are taking this medication, it is essential to inform all your healthcare providers, including doctors, nurses, pharmacists, and dentists, about your treatment.
Immediately contact your doctor if you experience any of the following:
- Your normal dose is not providing adequate relief
- Your symptoms worsen
- You need to use this medication more frequently than prescribed
Adhere strictly to your doctor's prescribed dosage. Taking more than the recommended amount can significantly increase your risk of severe side effects.
Before using any other medications or inhalers for breathing problems, consult with your doctor to ensure safe and effective treatment.
If you have diabetes (high blood sugar), discuss this with your doctor, as this medication may cause an increase in blood sugar levels. Monitor your blood sugar as instructed by your doctor.
Patients aged 65 and older should exercise caution when using this medication, as they may be more susceptible to side effects.
If you are pregnant, planning to become pregnant, or are breastfeeding, consult your doctor to discuss the potential benefits and risks to both you and your baby.
Special Considerations for Children
Different formulations of this medication are approved for use in children of various ages. Before administering this drug to a child, consult with their doctor to ensure the appropriate form and dosage are used.
Overdose Information
Overdose Symptoms:
- Exaggerated beta-adrenergic stimulation
- Seizures
- Angina
- Hypertension or hypotension
- Tachycardia (heart rate up to 200 beats/minute)
- Arrhythmias
- Nervousness
- Headache
- Tremor
- Dry mouth
- Palpitations
- Nausea
- Dizziness
- Fatigue
- Malaise
- Insomnia
- Hypokalemia
- Hyperglycemia
- Metabolic acidosis
What to Do:
Seek immediate medical attention. Call 911 or Poison Control at 1-800-222-1222. Treatment is supportive and symptomatic. Consider cautious use of a cardioselective beta-blocker for severe cardiac effects, but only with extreme caution in patients with bronchospasm.
Drug Interactions
Major Interactions
- Beta-blockers (e.g., propranolol, metoprolol): May antagonize the bronchodilating effects of terbutaline and produce severe bronchospasm in asthmatic patients. Avoid concomitant use.
- Monoamine Oxidase Inhibitors (MAOIs) and Tricyclic Antidepressants (TCAs): May potentiate the cardiovascular effects of terbutaline (e.g., increased heart rate, blood pressure). Use with extreme caution.
Moderate Interactions
- Diuretics (e.g., loop or thiazide diuretics): May exacerbate ECG changes and/or hypokalemia induced by beta-agonists, especially at higher doses. Monitor potassium levels.
- Digoxin: Terbutaline may decrease serum digoxin levels. Monitor digoxin levels if co-administered.
Monitoring
Baseline Monitoring
Heart Rate and Blood Pressure
Rationale: Terbutaline can cause cardiovascular effects (tachycardia, palpitations, hypertension).
Timing: Prior to initiation of therapy.
Serum Potassium
Rationale: Beta-2 agonists can cause transient hypokalemia, especially at high doses or with concomitant diuretics.
Timing: Prior to initiation, especially in patients at risk for hypokalemia.
Routine Monitoring
Symptom Control (e.g., shortness of breath, wheezing)
Frequency: Regularly, at each visit or as needed by patient
Target: Improved respiratory symptoms, reduced need for rescue inhalers.
Action Threshold: Worsening symptoms, increased frequency of use, or lack of efficacy may indicate need for dose adjustment or alternative therapy.
Adverse Effects (e.g., tremor, nervousness, palpitations, tachycardia)
Frequency: Regularly, at each visit or as needed by patient
Target: Minimization of side effects.
Action Threshold: Persistent or severe adverse effects may require dose reduction or discontinuation.
Serum Potassium
Frequency: Periodically, especially if on concomitant diuretics or high doses.
Target: 3.5-5.0 mEq/L
Action Threshold: Hypokalemia (<3.5 mEq/L) may require potassium supplementation or dose adjustment.
Symptom Monitoring
- Worsening shortness of breath
- Increased wheezing
- Chest tightness
- Increased use of rescue inhalers
- Palpitations
- Tremor
- Nervousness
- Dizziness
- Muscle cramps
Special Patient Groups
Pregnancy
Terbutaline is classified as Pregnancy Category B. Animal studies have not shown harm to the fetus, but there are no adequate and well-controlled studies in pregnant women. It should be used during pregnancy only if clearly needed and the potential benefit justifies the potential risk to the fetus.
Trimester-Specific Risks:
First Trimester:
No specific increased risk identified.
Second Trimester:
No specific increased risk identified.
Third Trimester:
May inhibit uterine contractions (tocolytic effect) and cause maternal and fetal tachycardia, hyperglycemia, and hypokalemia. Use with caution near term.
Lactation
Terbutaline is excreted in breast milk. While the amount is generally small, caution is advised. Monitor breastfed infants for signs of beta-adrenergic effects such as irritability, tremor, or changes in heart rate.
Infant Risk:
Low to moderate risk (L3).
Pediatric Use
Oral terbutaline tablets are generally not recommended for chronic treatment of asthma in children under 12 years of age due to limited efficacy data and the availability of more effective and safer inhaled therapies. For adolescents 12-15 years, the dose is 2.5 mg three times a day. Safety and efficacy in children under 12 years have not been established.
Geriatric Use
Elderly patients may be more sensitive to the adverse effects of beta-agonists, particularly cardiovascular effects (e.g., tachycardia, palpitations, tremor). Start with the lowest effective dose (e.g., 2.5 mg three times a day) and titrate cautiously based on response and tolerability. Monitor closely for adverse effects.
Clinical Information
Clinical Pearls
- Terbutaline tablets are primarily used for maintenance treatment of bronchospasm and are not recommended for the relief of acute bronchospasm, for which inhaled short-acting beta-agonists (SABAs) are preferred.
- Patients should be advised to carry a rescue inhaler (e.g., albuterol) for acute symptoms.
- Tolerance to the bronchodilator effect may develop with chronic use.
- Caution should be exercised in patients with cardiovascular disorders (e.g., coronary insufficiency, arrhythmias, hypertension), hyperthyroidism, diabetes mellitus, or convulsive disorders.
- Paradoxical bronchospasm, though rare with oral forms, can occur with beta-agonists; if it occurs, discontinue immediately and institute alternative therapy.
Alternative Therapies
- Inhaled Short-Acting Beta-Agonists (SABAs) like Albuterol (preferred for acute relief)
- Inhaled Long-Acting Beta-Agonists (LABAs) like Salmeterol, Formoterol (for maintenance)
- Inhaled Corticosteroids (ICS) like Fluticasone, Budesonide (first-line for persistent asthma)
- Leukotriene Receptor Antagonists (LTRAs) like Montelukast
- Anticholinergics (e.g., Ipratropium, Tiotropium)
- Methylxanthines (e.g., Theophylline)
Cost & Coverage
Average Cost:
$15 - $40 per 30 tablets (2.5mg or 5mg generic)
Generic Available:
Yes
Insurance Coverage:
Tier 1 or Tier 2 (Generic)
General Drug Facts
If your symptoms or health issues persist or worsen, it's essential to contact your doctor for further guidance. To ensure your safety, never share your medication with others or take someone else's medication. Some medications may come with an additional patient information leaflet, so be sure to check with your pharmacist for more information. If you have any questions or concerns about this medication, don't hesitate to reach out to your doctor, nurse, pharmacist, or other healthcare provider. In the event of a suspected overdose, immediately call your local poison control center or seek medical attention. When seeking help, be prepared to provide details about what was taken, the amount, and the time it occurred.