TERBUTALINE SULFATE
(ter-byoo'te-leen)
Brethaire, Brethine, Bricanyl
Classifications: autonomic nervous system agent; beta-adrenergic agonist; bronchodilator
Prototype: Albuterol
Pregnancy Category: B

Availability

2.5 mg, 5 mg tablets; 0.2 mg aerosol; 1 mg/mL injection

Actions

Synthetic adrenergic stimulant with selective beta2- and negligible beta1-agonist (cardiac) activity. Exerts preferential effect on beta2 receptors in bronchial smooth muscles, inhibits histamine release from mast cells, and increases ciliary motility.

Therapeutic Effects

Relieves bronchospasm in chronic obstructive pulmonary disease (COPD) and significantly increases vital capacity. Promotes relaxation of vascular smooth muscle, contraction of GI and urinary sphincters, increase in renin, pancreatic beta-cell secretion, and serum HDL-cholesterol concentration. Increases uterine relaxation (thereby preventing or abolishing high intrauterine pressure).

Uses

Orally or subcutaneously as a bronchodilator in bronchial asthma and for reversible airway obstruction associated with bronchitis and emphysema.

Unlabeled Uses

To delay delivery in preterm labor.

Contraindications

Known hypersensitivity to sympathomimetic amines; severe hypertension and coronary artery disease; tachycardia with digitalis intoxication; within 14 d of MAO inhibitor therapy; angle-closure glaucoma. Used only after evaluation of risk-benefit ratio in pregnancy (category B) and lactation.

Cautious Use

Angina, stroke, hypertension; diabetes mellitus; thyrotoxicosis; history of seizure disorders; cardiac arrhythmias; older adults; kidney and liver dysfunction.

Route & Dosage

Bronchodilator
Adult: PO 2.5–5 mg t.i.d. at 6 h intervals (max: 15 mg/d) SC 0.25 mg q15–30min up to 0.5 mg in 4 h Inhaled 2 inhalations separated by 60 sec q4–6h
Adolescent: PO 12–15 y, 2.5 mg t.i.d. at 6 h intervals (max: 7.5 mg/d) SC 0.25 mg q15–30min up to 0.5 mg in 4 h Inhaled 2 inhalations separated by 60 sec q4–6h
Child: PO <12 y, 0.05 mg/kg q8h, gradually increase up to 0.15 mg/kg q8h (max: 5 mg/d) SC 0.005–0.01 mg/kg (max: 0.4 mg) q15–20min times 2 doses

Premature Labor
Adult: PO 2.5 mg q4–6h

Administration

Oral
Subcutaneous

Adverse Effects (1%)

CNS: Nervousness, tremor, headache, light-headedness, drowsiness, fatigue, seizures. CV: Tachycardia, hypotension or hypertension, palpitation, maternal and fetal tachycardia. GI: Nausea, vomiting. Body as a Whole: Sweating, muscle cramps.

Diagnostic Test Interference

Terbutaline may increase blood glucose and free fatty acids.

Interactions

Drug: Epinephrine, other sympathomimetic bronchodilators may add to effects; mao inhibitors, tricyclic antidepressants potentiate action on vascular system; effects of both beta-adrenergic blockers and terbutaline antagonized.

Pharmacokinetics

Absorption: 33–50% absorbed from GI tract. Onset: 30 min PO; <15 min SC; 5–30 min inhaled. Peak: 2–3 h PO; 30–60 min SC; 1–2 h inhaled. Duration: 4–8 h PO; 1.5–4 h SC; 3–4 h inhaled. Distribution: Distributed into breast milk. Metabolism: Metabolized in liver. Elimination: Excreted primarily in urine, 3% in feces. Half-Life: 3–4 h.

Nursing Implications

Assessment & Drug Effects

Patient & Family Education


Common adverse effects in italic, life-threatening effects underlined; generic names in bold; classifications in SMALL CAPS; Canadian drug name; Prototype drug