Pregnancy Category: B
Management of reversible airway disease due to asthma or COPD; inhalation and subcut used for short-term control and oral agent as long-term control.Management of preterm labor (tocolytic) (the FDA has recommended that injectable terbutaline should not be used in pregnancy for the prevention or prolonged treatment [>48–72 hr] of preterm labor in either the inpatient or outpatient settings because of the potential for serious maternal heart problems and death; oral terbutaline should not be used for the prevention or any treatment of preterm labor because of a lack of efficacy and the potential for serious material heart problems and death).
Results in the accumulation of cyclic adenosine monophosphate (cAMP) at beta-adrenergic receptors.
Inhibits the release of mediators of immediate hypersensitivity reactions from mast cells.
Relatively selective for beta2(pulmonary)-adrenergic receptor sites, with less effect on beta1(cardiac)-adrenergic receptors.
Absorption: 35–50% absorbed following oral administration but rapidly undergoes first-pass metabolism. Well absorbed following subcut administration.
Distribution: Enters breast milk.
Metabolism and Excretion: Partially metabolized by the liver; 60% excreted unchanged by the kidneys following subcut administration.
Time/action profile (bronchodilation)
|PO||within 60–120 min||within 2–3 hr||4–8 hr|
|Subcut||within 15 min||within 0.5–1 hr||1.5–4 hr|
Contraindicated in: Hypersensitivity to adrenergic amines.
Use Cautiously in: Cardiac disease;Hypertension;Hyperthyroidism;Diabetes;Glaucoma; Geriatric: More susceptible to adverse reactions; may require dose ↓;Excessive use may lead to tolerance and paradoxical bronchospasm (inhaler); Obstetric / Lactation: Pregnancy (near term) and lactation.
Adverse Reactions/Side Effects
Central nervous system
- nervousness (most frequent)
- restlessness (most frequent)
- tremor (most frequent)
- pulmonary edema
- myocardial ischemia
Fluid and Electrolyte
Drug-Drug interactionConcurrent use with other adrenergics (sympathomimetic) will have additive adrenergic side effects.Use with MAO inhibitors may lead to hypertensive crisis.Beta blockers may negate therapeutic effect.Use with caffeine-containing herbs (cola nut, guarana, mate, tea, coffee) ↑ stimulant effect.
Oral (Adults and Children >15 yr) Bronchodilation—2.5–5 mg 3 times daily, given q 6 hr (not to exceed 15 mg/24 hr).
Oral (Children 12–15 yr) Bronchodilation–2.5 mg 3 times daily (given q 6 hr) (not to exceed 7.5 mg/24 hr).
Oral (Children <12 yr) Bronchodilation—0.05 mg/kg 3 times daily; may ↑ gradually (not to exceed 0.15 mg/kg 3–4 times daily or 5 mg/24 hr.
Subcutaneous (Adults and Children ≥12 yr) Bronchodilation—250 mcg; may repeat in 15–30 min (not to exceed 500 mcg/4 hr).
Subcutaneous (Children <12 yr) Bronchodilation—0.005–0.01 mg/kg; may repeat in 15–20 min.
Intravenous (Adults) Tocolysis—2.5–10 mcg/min infusion; ↑ by 5 mcg/min q 10 min until contractions stop (not to exceed 30 mcg/min). After contractions have stopped for 30 min, ↓ infusion rate to lowest effective amount and maintain for 4–8 hr (unlabeled).
Availability (generic available)
Tablets: 2.5 mg, 5 mg
Injection: 1 mg/mL
- Bronchodilator: Assess lung sounds, respiratory pattern, pulse, and BP before administration and during peak of medication. Note amount, color, and character of sputum produced, and notify health care professional of abnormal findings.
- Monitor pulmonary function tests before initiating therapy and periodically throughout therapy to determine effectiveness of medication.
- Preterm Labor: Monitor maternal pulse and BP, frequency and duration of contractions, and fetal heart rate. Notify health care professional if contractions persist or increase in frequency or duration or if symptoms of maternal or fetal distress occur. Maternal side effects include tachycardia, palpitations, tremor, anxiety, and headache.
- Assess maternal respiratory status for symptoms of pulmonary edema (increased rate, dyspnea, rales/crackles, frothy sputum).
- Monitor mother and neonate for symptoms of hypoglycemia (anxiety; chills; cold sweats; confusion; cool, pale skin; difficulty in concentration; drowsiness; excessive hunger; headache; irritability; nausea; nervousness; rapid pulse; shakiness; unusual tiredness; or weakness) and mother for hypokalemia (weakness, fatigue, U wave on ECG, arrhythmias).
- Lab Test Considerations: May cause transient ↓ in serum potassium concentrations with higher than recommended doses.
Symptoms of overdose include persistent agitation, chest pain or discomfort, decreased BP, dizziness, hyperglycemia, hypokalemia, seizures, tachyarrhythmias, persistent trembling, and vomiting.
- Monitor maternal serum glucose and electrolytes. May cause hypokalemia and hypoglycemia. Monitor neonate’s serum glucose, because hypoglycemia may also occur in neonates.
- Treatment includes discontinuing beta-adrenergic agonists and symptomatic, supportive therapy. Cardioselective beta blockers are used cautiously, because they may induce bronchospasm.
Potential Nursing DiagnosesIneffective airway clearance (Indications)
- Do not confuse Brethine (terbutaline) with Methergine (methylergonovine).
- Oral: Administer with meals to minimize gastric irritation.
- Tablet may be crushed and mixed with food or fluids for patients with difficulty swallowing.
- Subcutaneous: Administer subcut injections in lateral deltoid area. Do not use solution if discolored.
- pH: 3.0–5.0.
- Continuous Infusion: Diluent: May be diluted in D5W, 0.9% NaCl, or 0.45% NaCl.Concentration: 1 mg/mL (undiluted).
- Rate: Use infusion pump to ensure accurate dose. Begin infusion at 10 mcg/min. Increase dosage by 5 mcg every 10 min until contractions cease. Maximum dose is 80 mcg/min. Begin to taper dose in 5-mcg decrements after a 30–60 min contraction-free period is attained. Switch to oral dose form after patient is contraction-free 4–8 hr on the lowest effective dose.
- Y-Site Compatibility: insulin
- Instruct patient to take medication as directed. If on a scheduled dosing regimen, take a missed dose as soon as possible; space remaining doses at regular intervals. Do not double doses. Caution patient not to exceed recommended dose; may cause adverse effects, paradoxical bronchospasm, or loss of effectiveness of medication.
- Instruct patient to contact health care professional immediately if shortness of breath is not relieved by medication or is accompanied by diaphoresis, dizziness, palpitations, or chest pain.
- Advise patient to consult health care professional before taking any OTC medications or alcoholic beverages concurrently with this therapy. Caution patient also to avoid smoking and other respiratory irritants.
- Preterm Labor: Notify health care professional immediately if labor resumes or if significant side effects occur.
- Prevention or relief of bronchospasm.
- Increase in ease of breathing.
- Control of preterm labor in a fetus of 20–36 wk gestational age.
BricanylA beta-adrenergic receptor agonist used for patients with COPD.
Asthma, bronchitis, reversible bronchospasm.
Tremor, nervousness, palpitations, nausea, vomiting.