terbutaline

REMS

Reversible airway disease due to asthma (SUBQ used for short-term control and oral agent as long-term control).

Unlabeled Use:

Preterm labor (tocolytic) (terbutaline injection may only be used for short-term [≤72 hr] management of preterm labor to prolong pregnancy and allow for the administration of antenatal steroids).

Action ⬆ ⬇

Results in the accumulation of cyclic adenosine monophosphate (cAMP) at beta-adrenergic receptors.
Produces bronchodilation.
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.

Therapeutic effects:

Bronchodilation.

Pharmacokinetics ⬆ ⬇

Absorption: 35–50% absorbed following oral administration but rapidly undergoes first-pass metabolism. Well absorbed following SUBQ administration.

Distribution: Unknown.

Metabolism/Excretion: Partially metabolized by the liver; 60% excreted unchanged by the kidneys.

Half-Life: 5.7 hr.

Time/Action Profile ⬆ ⬇

(bronchodilation)

ROUTE	ONSET	PEAK	DURATION
PO	within 60–120 min	within 2–3 hr	4–8 hr
SUBQ	within 15 min	within 0.5–1 hr	1.5–4 hr

Contraind./Precautions ⬆ ⬇

Contraindicated in:

Hypersensitivity to adrenergic amines.

Use Cautiously in:

Cardiac disease;
Hypertension;
Hyperthyroidism;
Diabetes;
Glaucoma;
OB: Use for bronchodilation in pregnancy only if potential maternal benefit justifies potential fetal risk;
Geri: Older adults are more susceptible to adverse reactions (may require dose ↓).

Adv. Reactions/Side Effects ⬆ ⬇

CV: angina, arrhythmias, hypertension, myocardial ischemia, tachycardia

Endo: hyperglycemia

F and E: hypokalemia

GI: nausea, vomiting

Neuro: nervousness, restlessness, tremor, headache, insomnia

Resp: pulmonary edema

Interactions ⬆ ⬇

Drug-drug:

Concurrent use with other adrenergics (sympathomimetics) will have additive adrenergic side effects.
MAO inhibitors may lead to hypertensive crisis.
Beta blockers may negate its therapeutic effect.

Drug-Natural Products:

Use with caffeine-containing herbs (cola nut, guarana, mate, tea, coffee) ↑ stimulant effect.

Route/Dosage ⬆ ⬇

Asthma

PO (Adults and Children >15 yr): 2.5–5 mg 3 times daily (given every 6 hr) (not to exceed 15 mg/24 hr).
PO (Children 12–15 yr): 2.5 mg 3 times daily (given every 6 hr) (not to exceed 7.5 mg/24 hr).
PO (Children <12 yr): 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).
SC (Adults and Children ≥12 yr): 250 mcg; may repeat in 15–30 min (not to exceed 500 mcg/4 hr).
SC (Children <12 yr): 0.005–0.01 mg/kg; may repeat in 15–20 min.

Tocolysis (Off-Label)

IV (Adults ): 2.5–10 mcg/min infusion; ↑ by 5 mcg/min every 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.

Availability ⬆ ⬇

(Generic available)

Tablets: 2.5 mg; 5 mg
Solution for injection: 1 mg/mL

Assessment ⬆ ⬇

Assess cardiac history and ECG at baseline.
Bronchodilator: Assess lung sounds, respiratory pattern, BP, and HR before administration and during peak of medication. Monitor for symptomatic improvement of asthma attack. Note amount, color, and character of sputum produced, and notify health care provider of abnormal findings.
Monitor pulmonary function tests before initiating therapy and periodically throughout therapy to determine effectiveness of medication.
Preterm Labor: Monitor maternal BP and HR, frequency and duration of contractions, and fetal HR. Notify health care provider if contractions persist or ↑ 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; weakness) and mother for hypokalemia (weakness, fatigue, U wave on ECG, arrhythmias).

Lab Test Considerations:

Monitor maternal serum glucose and electrolytes. May cause hypokalemia and hypoglycemia. Monitor neonate’s serum glucose, because hypoglycemia may also occur in neonates.

Toxicity and Overdose:

Symptoms of overdose include persistent agitation, chest pain or discomfort, ↓ BP, dizziness, hyperglycemia, hypokalemia, seizures, tachyarrhythmias, persistent trembling, and vomiting.
- Treatment includes discontinuing beta-adrenergic agonists and symptomatic, supportive therapy. Cardioselective beta blockers are used cautiously because they may induce bronchospasm.

Implementation ⬆ ⬇

PO: Administer with meals to minimize gastric irritation.
- Tablet may be crushed and mixed with food or fluids for patients with difficulty swallowing.
SC: Administer SUBQ injections in lateral deltoid area. Do not use solution if discolored.

IV Administration:

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. ↑ infusion rate by 5 mcg/min every 10 min until contractions cease. Maximum dose is 80 mcg/min. Begin to taper dose in 5 mcg/min 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 regular

Patient/Family Teaching ⬆ ⬇

Explain the purpose and side effects of terbutaline. 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. Do not share medication with others, even if they have similar symptoms; may be harmful. Keep out of children's reach. Advise patient to read Patient Information before starting and with each Rx refill in case of changes.
Instruct patient to contact health care provider immediately if shortness of breath is not relieved by medication or is accompanied by diaphoresis, dizziness, palpitations, or chest pain.
Asthma: Caution patient to avoid smoking and other respiratory irritants.
Advise patient to notify health care provider of all Rx or OTC medications, vitamins, or herbal products being taken and to consult with health care provider before taking other medications. Advise patient there are multiple significant drug-drug interactions for this drug.
Preterm Labor: Notify health care provider immediately if labor resumes or if significant side effects occur.
Rep:
Advise women of reproductive potential to notify health care provider if pregnancy is planned or suspected or if breastfeeding. Unintended tocolytic effects may occur. Serious adverse reactions, including death, have been reported after administration of terbutaline to pregnant women, including tachycardia, transient hyperglycemia, hypokalemia, arrhythmias, pulmonary edema, and myocardial ischemia. Transient fetal tachycardia or hypoglycemia may occur.

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Pronunciation ⬇

Classifications ⬆ ⬇

Indications ⬆ ⬇