Brethine 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
Beta-2 Adrenergic Agonist
Pregnancy Category
Category B
FDA Approved
Sep 1974
DEA Schedule
Not Controlled
Overview
What is this medicine?
Terbutaline is a medication that helps open up the airways in your lungs, making it easier to breathe. It's used to treat conditions like asthma and COPD (chronic obstructive pulmonary disease) by relaxing the muscles around your airways.
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 with your pharmacist for guidance on proper disposal. You may also want to check if there are drug take-back programs available in your area.
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 with your pharmacist for guidance on proper disposal. You may also want to check if there are drug take-back programs available in your area.
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 exactly as prescribed; do not take more often or in higher doses than recommended.
- Do not stop taking other asthma or COPD medications unless directed by your doctor.
- Avoid smoking, as it can worsen lung conditions and reduce the effectiveness of the medication.
- Report any worsening of breathing problems or frequent need for rescue inhalers to your doctor immediately.
- Limit caffeine intake, as it can increase side effects like nervousness or tremor.
Available Forms & Alternatives
Available Strengths:
Generic Alternatives:
Dosing & Administration
Adult Dosing
Standard Dose:
2.5 mg or 5 mg orally, three times daily (every 6-8 hours)
Dose Range:
2.5 - 5 mg
Condition-Specific Dosing:
bronchospasm:
Initial dose 2.5 mg three times daily; may increase to 5 mg three times daily if needed and tolerated. Max 15 mg/day.
Pediatric Dosing
Neonatal:
Not established
Infant:
Not established
Child:
0.05 mg/kg/dose orally, three times daily (every 6-8 hours), not to exceed 2.5 mg per dose. Max 7.5 mg/day.
Adolescent:
Same as adult dosing, 2.5 mg or 5 mg orally, three times daily.
Dose Adjustments
Renal Impairment:
Mild:
No specific adjustment recommended, monitor for adverse effects.
Moderate:
Consider reducing dose to 2.5 mg three times daily, monitor for adverse effects.
Severe:
Consider reducing dose to 2.5 mg three times daily, monitor for adverse effects. Use with caution.
Dialysis:
Not well studied; use with caution and monitor for adverse effects. Terbutaline is dialyzable.
Hepatic Impairment:
Mild:
No specific adjustment recommended.
Moderate:
No specific adjustment recommended.
Severe:
No specific adjustment recommended, as hepatic metabolism is not the primary elimination route. Use with caution and monitor for adverse effects.
Pharmacology
Mechanism of Action
Terbutaline is a selective beta-2 adrenergic agonist. It stimulates beta-2 adrenergic receptors in the smooth muscle of the bronchi, leading to relaxation of bronchial smooth muscle and bronchodilation. It also inhibits the release of mediators from mast cells in the airways.
Pharmacokinetics
Absorption:
Bioavailability:
10-15%
Tmax:
1-2 hours
FoodEffect:
Food may delay absorption but does not significantly affect the extent of absorption.
Distribution:
Vd:
Not available (high volume of distribution)
ProteinBinding:
25%
CnssPenetration:
Limited
Elimination:
HalfLife:
3-4 hours
Clearance:
Not available
ExcretionRoute:
Urine (primarily as inactive sulfate conjugates, some unchanged drug)
Unchanged:
Approximately 30-50% (oral dose)
Pharmacodynamics
OnsetOfAction:
30-60 minutes
PeakEffect:
2-3 hours
DurationOfAction:
4-8 hours
Safety & Warnings
BLACK BOX WARNING
Oral terbutaline should not be used for prolonged tocolysis (delaying labor for more than 48-72 hours) in pregnant women. Serious maternal cardiac adverse reactions, including death, have been reported after prolonged administration of terbutaline to pregnant women. In the setting of preterm labor, terbutaline should be used only for short-term (up to 48-72 hours) subcutaneous or intravenous administration in a hospital setting.
Side Effects
Urgent Side Effects: Seek Medical Help Immediately
While rare, some people may experience severe and potentially life-threatening side effects when taking this medication. If you experience any of the following symptoms, contact your doctor or seek medical attention 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
Most people taking this medication will not experience side effects, or they may be mild. However, if you experience any of the following side effects, or if they bother you or do not go away, contact your doctor:
Feeling nervous and excitable
Shakiness
Restlessness
Headache
Feeling dizzy or sleepy
Reporting Side Effects
This is not a comprehensive list of all possible side effects. If you have questions or concerns about side effects, contact your doctor. You can also report side effects to the FDA at 1-800-332-1088 or online at https://www.fda.gov/medwatch.
While rare, some people may experience severe and potentially life-threatening side effects when taking this medication. If you experience any of the following symptoms, contact your doctor or seek medical attention 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
Most people taking this medication will not experience side effects, or they may be mild. However, if you experience any of the following side effects, or if they bother you or do not go away, contact your doctor:
Feeling nervous and excitable
Shakiness
Restlessness
Headache
Feeling dizzy or sleepy
Reporting Side Effects
This is not a comprehensive list of all possible side effects. If you have questions or concerns about side effects, contact 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:
- Severe chest pain or discomfort
- Fast or irregular heartbeat (palpitations)
- Severe dizziness or fainting
- Worsening shortness of breath or wheezing after taking the medication (paradoxical bronchospasm)
- Severe headache
- Unusual muscle weakness or cramps (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 irregular or rapid heartbeat.
* If you are 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.
Remember, before starting, stopping, or changing the dose of any medication, including this one, consult with your doctor to confirm it is safe to do so in conjunction with 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 irregular or rapid heartbeat.
* If you are 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.
Remember, before starting, stopping, or changing the dose of any medication, including this one, consult with your doctor to confirm it is safe to do so in conjunction with your other medications and health conditions.
Precautions & Cautions
Important Information for Patients Taking This Medication
It is essential to inform all your healthcare providers, including doctors, nurses, pharmacists, and dentists, that you are taking this medication. If you experience any changes in your condition, such as your normal dose not working as well as expected, your symptoms worsening, or needing to use this medication more frequently than usual, contact your doctor immediately.
Dosage and Administration
Do not exceed the dosage prescribed by your doctor, as taking more than the recommended amount may increase your risk of severe side effects.
Interactions with Other Medications
Before using any other medications or inhalers for breathing, consult with your doctor to ensure safe and effective treatment.
Special Considerations
If you have diabetes (high blood sugar), discuss this with your doctor, as this medication may affect your blood sugar levels. Monitor your blood sugar as instructed by your doctor.
Age-Related Precautions
If you are 65 years or older, use this medication with caution, as you may be more susceptible to side effects.
Pregnancy and Breastfeeding
If you are pregnant, plan to become pregnant, or are breastfeeding, consult with your doctor to discuss the potential benefits and risks to you and your baby.
Pediatric Use
Different forms of this medication may be suitable for children of various ages. Before giving this medication to a child, consult with your doctor to ensure the correct formulation and dosage are used.
It is essential to inform all your healthcare providers, including doctors, nurses, pharmacists, and dentists, that you are taking this medication. If you experience any changes in your condition, such as your normal dose not working as well as expected, your symptoms worsening, or needing to use this medication more frequently than usual, contact your doctor immediately.
Dosage and Administration
Do not exceed the dosage prescribed by your doctor, as taking more than the recommended amount may increase your risk of severe side effects.
Interactions with Other Medications
Before using any other medications or inhalers for breathing, consult with your doctor to ensure safe and effective treatment.
Special Considerations
If you have diabetes (high blood sugar), discuss this with your doctor, as this medication may affect your blood sugar levels. Monitor your blood sugar as instructed by your doctor.
Age-Related Precautions
If you are 65 years or older, use this medication with caution, as you may be more susceptible to side effects.
Pregnancy and Breastfeeding
If you are pregnant, plan to become pregnant, or are breastfeeding, consult with your doctor to discuss the potential benefits and risks to you and your baby.
Pediatric Use
Different forms of this medication may be suitable for children of various ages. Before giving this medication to a child, consult with your doctor to ensure the correct formulation and dosage are used.
Overdose Information
Overdose Symptoms:
- Exaggerated beta-adrenergic stimulation
- Tachycardia
- Palpitations
- Arrhythmias
- Tremor
- Nervousness
- Headache
- Nausea
- Dizziness
- Hypotension or hypertension
- Seizures
- Angina
- Hypokalemia
- Hyperglycemia
What to Do:
Seek immediate medical attention. Treatment is supportive and symptomatic. Consider cautious use of a cardioselective beta-blocker (e.g., metoprolol) for severe cardiac symptoms, but only if there is no history of bronchospasm. Call 1-800-222-1222 (Poison Control).
Drug Interactions
Contraindicated Interactions
- Non-selective beta-blockers (e.g., propranolol, nadolol) - may antagonize bronchodilatory effect and cause severe bronchospasm.
Major Interactions
- MAO inhibitors (e.g., phenelzine, selegiline) - increased risk of cardiovascular effects (hypertension, tachycardia).
- Tricyclic antidepressants (e.g., amitriptyline, imipramine) - increased risk of cardiovascular effects.
- Other sympathomimetics (e.g., pseudoephedrine, epinephrine) - additive cardiovascular effects.
Moderate Interactions
- Diuretics (e.g., furosemide, hydrochlorothiazide) - increased risk of hypokalemia.
- Digoxin - hypokalemia induced by terbutaline may increase risk of digoxin toxicity.
- Theophylline - additive effects on CNS stimulation and cardiovascular effects; increased risk of hypokalemia.
Monitoring
Baseline Monitoring
Baseline heart rate and blood pressure
Rationale: Terbutaline can cause cardiovascular stimulation (tachycardia, palpitations, hypertension).
Timing: Prior to initiation of therapy.
Serum potassium
Rationale: Beta-2 agonists can cause transient hypokalemia.
Timing: Prior to initiation, especially in patients at risk for hypokalemia or on concomitant diuretics.
Routine Monitoring
Heart rate and blood pressure
Frequency: Periodically, especially during dose titration or if symptoms occur.
Target: Within patient's normal range, or acceptable clinical limits.
Action Threshold: Persistent tachycardia (>120 bpm), significant hypertension/hypotension, or symptomatic palpitations.
Pulmonary function tests (e.g., FEV1)
Frequency: As clinically indicated to assess bronchodilator response.
Target: Improvement in FEV1 or other lung function parameters.
Action Threshold: Lack of improvement or worsening of lung function.
Serum potassium
Frequency: Periodically, especially in patients with risk factors for hypokalemia or on concomitant diuretics.
Target: 3.5-5.0 mEq/L
Action Threshold: <3.0 mEq/L or symptomatic hypokalemia.
Symptom Monitoring
- Chest pain
- Palpitations
- Tremor
- Nervousness
- Dizziness
- Headache
- Muscle cramps
- Worsening shortness of breath or wheezing (paradoxical bronchospasm)
Special Patient Groups
Pregnancy
Terbutaline was historically Pregnancy Category B. While not approved for tocolysis, it has been used off-label. However, due to serious maternal cardiac adverse reactions, including death, associated with prolonged use for tocolysis, its use for this purpose is strongly discouraged. For bronchodilation, use only if the potential benefit justifies the potential risk to the fetus.
Trimester-Specific Risks:
First Trimester:
Limited data, but generally avoided unless clearly needed.
Second Trimester:
Risk of maternal cardiovascular effects (tachycardia, palpitations, arrhythmias) and hyperglycemia. Potential for fetal tachycardia.
Third Trimester:
Risk of maternal cardiovascular effects, hyperglycemia, and hypokalemia. Potential for fetal tachycardia and neonatal hypoglycemia (if used close to delivery).
Lactation
Terbutaline is excreted into breast milk. The amount is small, and adverse effects on the infant are unlikely with therapeutic doses. However, monitor the infant for signs of irritability, tremor, or changes in feeding patterns. Use with caution.
Infant Risk:
Low risk (L3)
Pediatric Use
Oral terbutaline is approved for children 6 years of age and older. Dosing is weight-based. Children may be more sensitive to the central nervous system effects (nervousness, tremor). Close monitoring is required.
Geriatric Use
Elderly patients may be more susceptible to the cardiovascular and CNS adverse effects of terbutaline (e.g., tremor, nervousness, tachycardia, palpitations). Start with lower doses and titrate carefully. Monitor for underlying cardiovascular disease.
Clinical Information
Clinical Pearls
- Oral terbutaline (Brethine) is largely replaced by inhaled beta-agonists due to slower onset and higher systemic side effects.
- The Black Box Warning for prolonged tocolysis is critical and highlights a significant safety concern for an off-label use.
- Patients should be educated on the difference between maintenance therapy and rescue therapy; terbutaline oral tablets are for maintenance, not acute bronchospasm.
- Monitor for hypokalemia, especially in patients on diuretics or corticosteroids.
- Paradoxical bronchospasm, though rare with oral forms, can occur and requires immediate discontinuation.
Alternative Therapies
- Inhaled short-acting beta-agonists (SABAs) like albuterol (preferred for acute relief)
- Inhaled long-acting beta-agonists (LABAs) like salmeterol or formoterol (for maintenance, often in combination with inhaled corticosteroids)
- Inhaled corticosteroids (ICS) for asthma control
- Leukotriene receptor antagonists (e.g., montelukast)
- Anticholinergics (e.g., ipratropium, tiotropium)
Cost & Coverage
Average Cost:
$15 - $50 per 30 tablets (5mg)
Generic Available:
Yes
Insurance Coverage:
Tier 1 (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 the medication, including the amount taken and the time it happened, to ensure you receive the best possible care.