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Brethine Side Effects

Generic Name: terbutaline

Note: This document contains side effect information about terbutaline. Some of the dosage forms listed on this page may not apply to the brand name Brethine.

For the Consumer

Applies to terbutaline: oral elixir, oral tablet

Other dosage forms:

Along with its needed effects, terbutaline (the active ingredient contained in Brethine) may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur while taking terbutaline:

More common
  • Shakiness in the legs, arms, hands, or feet
  • trembling or shaking of the hands or feet
Less common
  • Extra heartbeat
  • feeling faint, dizzy, or lightheadedness
  • feeling of warmth or heat
  • flushing or redness of the skin, especially on the face and neck
  • headache
  • sweating
  • Burning, crawling, itching, numbness, prickling, "pins and needles", or tingling feelings
  • excessive muscle tone
  • muscle stiffness
  • muscle tension or tightness

Get emergency help immediately if any of the following symptoms of overdose occur while taking terbutaline:

Symptoms of overdose
  • Arm, back, or jaw pain
  • blurred vision
  • chest pain or discomfort
  • chest tightness or heaviness
  • confusion
  • convulsions
  • decreased urine
  • dizziness
  • dizziness, faintness, or lightheadedness when getting up suddenly from a lying or sitting position
  • dry mouth
  • fainting
  • fast, pounding, or irregular heartbeat or pulse
  • general feeling of discomfort or illness
  • increased thirst
  • loss of appetite
  • mood changes
  • muscle pain or cramps
  • nausea or vomiting
  • nervousness
  • numbness or tingling in the hands, feet, or lips
  • pounding in the ears
  • seizures
  • shortness of breath
  • sleeplessness
  • slow or fast heartbeat
  • trouble sleeping
  • unable to sleep
  • unusual tiredness or weakness

Some side effects of terbutaline may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

More common
  • Sleepiness or unusual drowsiness
Less common Rare
  • Fever
  • rash
  • redness, soreness, or itching skin
  • seeing, hearing, or feeling things that are not there
  • sores, welting, or blisters

For Healthcare Professionals

Applies to terbutaline: compounding powder, inhalation aerosol, inhalation aerosol with adapter, injectable solution, oral tablet


Common adverse effects include palpitations, chest pain, rapid heart rate, tremor or nervousness.[Ref]


Changes in heart rate of approximately 30% may be observed following 5 mg of terbutaline (the active ingredient contained in Brethine) given orally. Aggravation of angina may be due to the tachycardia induced by terbutaline. Prolongation of the QT interval occurred in ten healthy males given a bolus injection of 0.25 mg terbutaline followed by an infusion of 5 mcg/min. Supraventricular ectopic beats and ventricular tachycardia have also been reported. Higher dosages of terbutaline should be used with caution in patients with cardiac disease, arrhythmias, or hypertension. All of these effects are dose-related and lower doses may be tolerated.

In one case-control study a positive association was found between the use of oral terbutaline for longer than 9 days and peripartum cardiomyopathy. Further study is needed to determine if a causative relationship exists.[Ref]

Very common (10% or more): Palpitations (up to 22.9%)
Common (1% to 10%): Tachycardia, extrasystoles ventricular, vasodilation, decrease in diastolic pressure, hypotension
Rare (less than 0.1%): Arrhythmias, e.g. atrial fibrillation, supraventricular tachycardia and extrasystoles; peripheral vasodilation; myocardial ischemia
Frequency not reported: Ectopic beats
Postmarketing reports: An increased tendency to bleeding in connection with caesarean section[Ref]

Nervous system

Very common (10% or more): Tremor (up to 38%), nervousness (up to 35 %), drowsiness (up to 11.7%), dizziness (up to 10.2%)
Common (1% to 10%): Headache
Uncommon (0.1% to 1%): Paresthesia
Postmarketing reports: Behavioral disturbances, such as agitation and restlessness[Ref]


Common (1% to 10%): Sweating
Uncommon (0.1% to 1%): Rash
Frequency not reported: Exanthema
Postmarketing reports: Urticaria[Ref]


Common (1% to 10%): Nausea, vomit
Uncommon (0.1% to 1%): Dry mouth
Frequency not reported: Bad taste, diarrhea
Postmarketing reports: Mouth, throat irritation[Ref]


Common (1% to 10%): Pain at the injection site[Ref]


Common (1% to 10%): Hypokalemia
Rare (less than 0.1%): Lactic acidosis, hyperglycemia[Ref]

Infusions of terbutaline, 25 mcg/min, in women in premature labor has caused decreases in serum potassium of up to 1.6 to 2 mEq/L. Another study in ten healthy males produced a mean decrease in serum potassium of 0.9 mEq/L following a bolus injection of 0.25 mg terbutaline, followed by an infusion of 5 mcg/min. A decrease in magnesium of 0.08 mmol/L was produced in these same patients.

This fall in potassium is presumably due to an intracellular shift of potassium secondary to hyperglycemia and hyperinsulinemia.[Ref]


Common (1% to 10%): Weakness, flashed feeling, asthenia[Ref]


Common (1% to 10%): Dyspnea, chest discomfort
Uncommon (0.1% to 1%): Pulmonary edema
Rare (less than 0.1%): Wheezing immediately after inhalation
Postmarketing reports: Paradoxical bronchospasm[Ref]


Uncommon (0.1% to 1%): Muscle cramps, hypertonia
Frequency not reported: Muscle twitching[Ref]


Rare (less than 0.1%): Elevation of liver enzymes[Ref]


Rare (less than 0.1%): Hypersensitivity vasculitis
Postmarketing reports: Hypersensitivity reactions including angioedema, bronchospasm, hypotension and collapse[Ref]


Common (1% to 10%): Somnolence, insomnia
Uncommon (0.1% to 1%): Anxiety, hallucinations
Postmarketing reports: Sleep disorders, hyperactivity[Ref]


1. Cerner Multum, Inc. "UK Summary of Product Characteristics." O 0

2. Cerner Multum, Inc. "Australian Product Information." O 0

3. "Product Information. Terbutaline Sulfate (terbutaline)." Athenex LLC, Buffaol, NY.

Some side effects of Brethine may not be reported. Always consult your doctor or healthcare specialist for medical advice. You may also report side effects to the FDA.

Disclaimer: Every effort has been made to ensure that the information provided is accurate, up-to-date and complete, but no guarantee is made to that effect. In addition, the drug information contained herein may be time sensitive and should not be utilized as a reference resource beyond the date hereof. This material does not endorse drugs, diagnose patients, or recommend therapy. This information is a reference resource designed as supplement to, and not a substitute for, the expertise, skill , knowledge, and judgement of healthcare practitioners in patient care. The absence of a warning for a given drug or combination thereof in no way should be construed to indicate safety, effectiveness, or appropriateness for any given patient. does not assume any responsibility for any aspect of healthcare administered with the aid of materials provided. The information contained herein is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. If you have questions about the substances you are taking, check with your doctor, nurse, or pharmacist.