Terbutaline Sulfate (terbutaline sulfate)

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Terbutaline sulfate is administered orally or subcutaneously (usually into the lateral deltoid area).

Terbutaline sulfate also has been used IV+ in selected patients to inhibit uterine contractions in preterm labor+ (tocolysis).

The drug also has been administered by IV infusion+ for the emergency treatment of acute asthma exacerbations in young children. However, administration of parenteral terbutaline sulfate by routes or methods other than subcutaneous injection (e.g., IV) is not recommended by the manufacturer.

No dosing information is available for this tab.

No dosing information is available for this tab.

There is no enhanced messaging for this drug.

Contraindicated Drug Combination: This drug combination is contraindicated and generally should not be dispensed or administered to the same patient.

Sympathomimetics/Dihydroergotamine

SEVERITY LEVEL: 1-Contraindicated Drug Combination: This drug combination is contraindicated and generally should not be dispensed or administered to the same patient.

MECHANISM OF ACTION: Concurrent use of dihydroergotamine and sympathomimetics may result in additive or synergistic effect on peripheral blood vessels.(1)

CLINICAL EFFECTS: Concurrent use of dihydroergotamine and sympathomimetics may result in increased blood pressure due to peripheral vasoconstriction.(1)

PREDISPOSING FACTORS: None determined.

PATIENT MANAGEMENT: Dihydroergotamine is contraindicated with sympathomimetics because the combination may result in additive or synergistic elevation of blood pressure.(1)

DISCUSSION: Significant elevation in blood pressure has been reported in patients treated with dihydroergotamine.(1) Sympathomimetics can be expected to have additional effects on blood pressure.

Severe Interaction: Action is required to reduce the risk of severe adverse interaction.

Agents That Affect Catecholamines/Iobenguane I 123

SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction.

MECHANISM OF ACTION: Many compounds that reduce catecholamine uptake or that deplete catecholamine stores may interfere with iobenguane uptake into cells.(1)

CLINICAL EFFECTS: Compounds that reduce catecholamine uptake or that deplete catecholamine stores may interfere with imaging completed with iobenguane.(1)

PREDISPOSING FACTORS: None determined.

PATIENT MANAGEMENT: Discuss the use of agents that affect catecholamines. Discontinue drugs that reduce catecholamine uptake or deplete catecholamine stores prior to imaging with iobenguane. Before imaging with iobenguane, discontinue agents that affect catecholamines for at least 5 biological half-lives, as clinically tolerated.(1)

DISCUSSION: Many agents may reduce catecholamine uptake or deplete catecholamine stores.(1) Examples include: - CNS stimulants or amphetamines (e.g. cocaine, methylphenidate, dextroamphetamine) - norepinephrine and dopamine reuptake inhibitors (e.g. phentermine) - norepinephrine and serotonin reuptake inhibitors (e.g. tramadol) - monoamine oxidase inhibitors (e.g. phenelzine, linezolid) - central monoamine depleting drugs (e.g. reserpine) - non-select beta adrenergic blocking drugs (e.g. labetalol) - alpha agonists or alpha/beta agonists (e.g. pseudoephedrine, phenylephrine, ephedrine, phenylpropanolamine, naphazoline) - tricyclic antidepressants or norepinephrine reuptake inhibitors (e.g. amitriptyline, bupropion, duloxetine, mirtazapine, venlafaxine) - botanicals that may inhibit reuptake of norepinephrine, serotonin or dopamine (e.g. ephedra, ma huang, St. John's Wort, yohimbine)

Agents That Affect Catecholamines/Iobenguane I 131

SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction.

MECHANISM OF ACTION: Many compounds that reduce catecholamine uptake or that deplete catecholamine stores may interfere with iobenguane uptake into cells.(1)

CLINICAL EFFECTS: Compounds that reduce catecholamine uptake or that deplete catecholamine stores may impact the dosimetry calculations or effectiveness of iobenguane.(1)

PREDISPOSING FACTORS: None determined.

PATIENT MANAGEMENT: Discuss the use of agents that affect catecholamines. Discontinue drugs that reduce catecholamine uptake or deplete catecholamine stores for at least 5 half-lives before administration of either the dosimetry or a therapeutic dose of iobenguane. Do not administer these drugs until at least 7 days after each iobenguane dose.(1)

DISCUSSION: Many agents may reduce catecholamine uptake or deplete catecholamine stores.(1) Examples include: - CNS stimulants or amphetamines (e.g. cocaine, methylphenidate, dextroamphetamine) - norepinephrine and dopamine reuptake inhibitors (e.g. phentermine) - norepinephrine and serotonin reuptake inhibitors (e.g. tramadol) - monoamine oxidase inhibitors (e.g. phenelzine, linezolid) - central monoamine depleting drugs (e.g. reserpine) - non-select beta adrenergic blocking drugs (e.g. labetalol) - alpha agonists or alpha/beta agonists (e.g. pseudoephedrine, phenylephrine, ephedrine, phenylpropanolamine, naphazoline) - tricyclic antidepressants or norepinephrine reuptake inhibitors (e.g. amitriptyline, bupropion, duloxetine, mirtazapine, venlafaxine) - botanicals that may inhibit reuptake of norepinephrine, serotonin or dopamine (e.g. ephedra, ma huang, St. John's Wort, yohimbine) - calcium channel blockers

Beta-2 Agonists/Non-Cardioselective Beta-Blockers

SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction.

MECHANISM OF ACTION: Non-cardioselective beta-blockers and beta-2 agonists may antagonize the effects of each other.

CLINICAL EFFECTS: Diminished response to either the beta-agonist, beta-blocker, or both may occur. Beta-blockers may also induce bronchospasm.

PREDISPOSING FACTORS: Patients receiving beta-2 agonists for the treatment of asthma may be more at risk for bronchospasm.

PATIENT MANAGEMENT: If possible, avoid beta-blocker therapy in asthmatic patients requiring beta-2 agonist therapy. If beta-blocker therapy is required, use a cardio-selective beta-blocker. For timolol ophthalmic drops, counsel patients to apply pressure to the inner corner of the eye after administration to prevent systemic absorption. Monitor patients for decreased effects of either agent, such as increased need for/use of beta-2 agonists or increased heart rate or blood pressure.

DISCUSSION: Many patients with asymptomatic or mild reactive airways disease tolerate beta-blockers well. Most patients with COPD do not have bronchospastic component to their illness and may be given beta-blockers. Heart failure treatment guidelines recommend beta-blockers in the presence of COPD. Non-selective beta-blockers have been shown to have a negative effect on lung function (FEV1) and airway hyperresponsiveness (AHR) in patients with asthma and COPD.(1) An open-label study using the nonselective beta blocker nadolol showed no effect on salbutamol in 10 patients with mild asthma not on controller therapy.(2) A study in 8 healthy men showed that long acting propranolol (160 mg) only effected airway dilation at the 200 mcg salbutamol dose. The 800 mcg and 1600 mcg dose were unaffected. However, penbutolol prevented any significant airway dilation with all doses of salbutamol.(3) In a double blind, three-way, crossover study, 44% (7/16 patients) of patients taking metoprolol showed a greater than 20% decrease in FEV1 compared to 19% (3 patients) after dilevalol and 6% (1 patient) after placebo. Dilevalol and metoprolol significantly inhibited isoproterenol response compared to placebo.(4) A double-blind, randomized, crossover study in 10 asthmatic patients showed that intravenous propranolol produced marked symptomatic bronchoconstriction. Only a slight but significant inhibition of bronchomotor sensitivity to isoproterenol was noted during esmolol infusion.(5) In 18 patients with reversible bronchial asthma, labetalol caused a significant increase in FEV1 and metoprolol caused a significant decrease in FEV1. Concurrent administration of isoproterenol and labetalol caused a further increase in FEV1. The effect of isoproterenol was decreased by metoprolol (100, 200mg).(6) In one study propranolol (0.06mg/kg IV) was shown to almost completely block the effects of isoproterenol in asthmatics. Metoprolol (0.12mg/kg IV) did not affect isoproterenol.(7) Studies have shown that cardioselective beta-blockers are safe for patients with asthma and COPD.(8,9,10) Nebivolol and celiprolol significantly decreased FEV1. Inhalation of albuterol (up to 800mcg) significantly improved FEV1, but the values after nebivolol and celiprolol administration were lower than the initial values.(11) Administration of metoprolol did not cause any respiratory problems in 9 asthmatic patients. There was no significant difference between the metoprolol and placebo groups in the respiratory response to an isoproterenol aerosol in 24 asthmatic patients.(12) Eight male asthmatic patients were given 10 mg bisoprolol, 20 mg bisoprolol, and 100 mg metoprolol. Both bisoprolol and metoprolol caused bronchoconstriction measured by a significant fall in PEFR (peak expiratory flow rate). Terbutaline was able to reverse bronchoconstriction in all patients.(13) A double blind, placebo-controlled study analyzed the use of atenolol 100mg, metoprolol 100mg, or acebutolol 400 mg in 8 asthmatic patients before and after exercise. All three drugs reduced significantly FEV1 and PEFR. Administration of terbutaline improved all respiratory indices.(14) A double-blind crossover trial in 10 asthmatic patients showed that a single IV dose of atenolol 3mg caused slight impairment of ventilatory function. A dose of salbutamol by inhalation was able to reverse the bronchial effect of atenolol.(15) Propranolol (80mg/day), oxprenolol (80mg/day), atenolol (100mg/day), and celiprolol 200mg/day were given to 10 asthmatic patients in a randomized, crossover design with a two week washout period between each drug. The non-beta 1 selective beta blockers (propranolol, oxprenolol) caused a significant reduction in FEV1 and inhibited the bronchodilator response to inhaled salbutamol. Atenolol and celiprolol (beta1 selective beta blockers) did not significantly affect respiratory function or antagonize salbutamol effects.(16) A double blind, randomized, within patient, placebo-controlled study compared the cardioselective beta-blocker atenolol to the non-selective propranolol. Atenolol caused a significantly less drop in FEV1 compared to propranolol. The effect of isoprenaline plus the beta blockers were also studied. Both atenolol and propranolol effected isoprenaline FEV1 dose response curves but the greatest displacement was seen with propranolol.(17) The pulmonary effects of celiprolol 200 mg, celiprolol 400mg, propranolol 40mg, atenolol 100 mg were evaluated in 34 asthmatic patients. Propranolol and atenolol caused significant reductions in pulmonary function. Propranolol pretreatment caused a significant reduction in the effect of the bronchodilator. Celiprolol did not antagonize the bronchodilators.(18) A double-blind, placebo controlled, randomized, crossover design study studied the effects of propranolol 80mg or celiprolol 200 or 400mg on pulmonary function. Propranolol produced a significant decrease in FEV1 and FVC. Celiprolol and placebo had similar results. The effect of aerosolized terbutaline was also measured. Even at supratherapeutic doses, terbutaline was unable to restore pulmonary function parameters to baseline levels after treatment with propranolol. Terbutaline caused further bronchodilation after administration of celiprolol.(19) Eleven asthmatic patients showed significant bronchoconstriction in small airways after propranolol 40mg and pindolol 2.5mg in a double blind, randomized trial. Large airways only showed bronchoconstriction with propranolol. Terbutaline 0.5mg subcutaneous was given after pretreatment with propranolol and pindolol. The bronchodilator effect of terbutaline on large airways was diminished after both propranolol and timolol.(20)

Selected Direct-Acting Sympathomimetics/Tricyclic Compounds

SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction.

MECHANISM OF ACTION: Unknown. However, it is speculated that direct-acting sympathomimetic amines have an enhanced effect due to tricyclic blockage of norepinephrine reuptake.

CLINICAL EFFECTS: Increased effect of direct acting sympathomimetics.

PREDISPOSING FACTORS: None determined.

PATIENT MANAGEMENT: Consider avoiding the concurrent use of direct-acting sympathomimetics and tricyclic compounds. If concurrent use of direct-acting sympathomimetics and tricyclic compounds is warranted, the initial dose of the sympathomimetic should be lowered and the patient should be monitored for adverse cardiovascular effects. Use of tricyclic compounds and other sympathomimetics should be approached with caution.

DISCUSSION: Epinephrine and other direct-acting sympathomimetic amines exert enhanced cardiovascular effects (e.g., arrhythmias, hypertension, and tachycardia) in individuals concurrently receiving or previously treated with tricyclic antidepressants. Other direct and mixed acting sympathomimetic amines have also been reported to interact with tricyclic antidepressants. These include norepinephrine, phenylephrine, dopamine, and methoxamine. Protriptyline, amitriptyline, and desipramine have also been reported to interact with direct-acting sympathomimetics.

Sympathomimetics/Ergot Alkaloids

SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction.

MECHANISM OF ACTION: Concurrent use of ergot alkaloids and sympathomimetics may result in additive or synergistic effect on peripheral blood vessels.

CLINICAL EFFECTS: Concurrent use of ergot alkaloids and sympathomimetics may result in increased blood pressure due to peripheral vasoconstriction.

PREDISPOSING FACTORS: None determined.

PATIENT MANAGEMENT: When possible, avoid the concurrent use of ergot alkaloids and sympathomimetics. If concurrent use is warranted, monitor blood pressure and for signs of vasoconstriction. Decreasing the dose of one or both drugs may be necessary.

DISCUSSION: There have been reports of severe vasoconstriction resulting in gangrene in patients receiving intravenous ergonovine with dopamine or norepinephrine.

Sympathomimetics/Selected Inhalation Anesthetic Agents

SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction.

MECHANISM OF ACTION: The exact mechanism is unknown. The anesthetics produce conduction changes that increase impulse re-entry into the myocardial tissue.(1) The anesthetics' ability to precipitate arrhythmias is enhanced by elevated arterial blood pressure, tachycardia, hypercapnia, and/or hypoxia, events that stimulate the release of endogenous catecholamines.(1)

CLINICAL EFFECTS: Concurrent use of inhalation anesthetic agents and sympathomimetics may result in ventricular arrhythmias or sudden blood pressure and heart rate increase during surgery.(2)

PREDISPOSING FACTORS: None determined.

PATIENT MANAGEMENT: Monitor blood pressure and avoid use of sympathomimetics in patients being treated with anesthetics on the day of surgery.(2) Intravenous use of epinephrine during surgery with halothane and related halogenated general anesthetics should be strongly discouraged. When intravenous epinephrine is necessary, nitrous oxide anesthesia supplemented with ether, muscle relaxants, or opioids should be used instead of halothane.(3,4) Epinephrine may safely be used subcutaneously with the following precautions: the patient is adequately ventilated to prevent hypoxia or respiratory acidosis; the total dose of epinephrine is limited to 100 mcg/10 minute period or 300 mcg/hour in adults, 3.5 mcg/Kg in infants, 2.5 mcg/Kg in children up to two years of age, and 1.45 mcg/Kg in children over two years of age; a minimum effective concentration of anesthetic is maintained; the drugs are not co-administered in patients with hypertension or other cardiovascular disorders; and the cardiac rhythm is continuously monitored during and after injection.(3-10) If arrhythmias occur after the administration of the epinephrine, the drugs of choice are lidocaine or propranolol, depending on the type of arrhythmia.(1)

DISCUSSION: Administration of epinephrine during halothane anesthesia may may lead to serious ventricular arrhythmias.(3-6,11-18) This has occurred when epinephrine was administered intravenously,(6) when it was administered with lidocaine as a dental block,(11,14) or when it was administered supraperiosteally.(5) Norepinephrine has been shown to interact with halothane in a manner similar to epinephrine.(1) In two case reports, patients were given terbutaline (0.25 to 0.35 mg) for wheezing following induction of anesthesia with halothane. One patient's heart rate increased from 68 to 100 beats/minute, and the ECG showed premature ventricular contractions and bigeminy, while the other patient developed multiple unifocal premature ventricular contractions and bigeminy. The arrhythmias resolved in both patients following lidocaine administration.(19) Although not documented, isoproterenol causes effects on the heart similar to terbutaline(20) and would probably interact with halothane in a similar manner. Other inhalation anesthetics that increase the incidence of arrhythmias with epinephrine include chloroform,(20) methoxyflurane,(20) and enflurane.(12) A similar interaction may be expected between the other inhalation anesthetics and sympathomimetics.

Moderate Interaction: Assess the risk to the patient and take action as needed.

Beta-Agonists; Anticholinergics; Theophylline/Methacholine

SEVERITY LEVEL: 3-Moderate Interaction: Assess the risk to the patient and take action as needed.

MECHANISM OF ACTION: Beta-agonists, anticholinergics, and theophylline may inhibit the action of methacholine on the airway.(1)

CLINICAL EFFECTS: The result of the methacholine challenge test may not be accurate.(1)

PREDISPOSING FACTORS: None determined.

PATIENT MANAGEMENT: The following drugs should be held before a methacholine challenge for the the duration indicated:(1) - short-acting beta-agonists: 6 hours - long-acting beta-agonists: 36 hours - short-acting anti-cholinergics: 12 hours - long-acting anti-cholinergics: at least 168 hours (7 days) - oral theophylline: 12-48 hours

DISCUSSION: Beta-agonists, anticholinergics, and theophylline may inhibit the action of methacholine on the airway and cause inaccurate test results.

*Prolonged or maintenance tocolysis (terbutaline injection).

*Acute or maintenance tocolysis (terbutaline tablets).

*Hypersensitivity to sympathomimetic amines or any component of the drug product.

• Compression of umbilical cord
• Myocardial ischemia
• Placental abruption

• Cardiac arrhythmia
• Chronic myocardial ischemia
• Hypertension
• Hypokalemia
• Pulmonary edema

• Diabetes mellitus
• Hyperthyroidism
• Ketoacidosis
• Seizure disorder

The most common adverse effects of terbutaline sulfate tablets reported in >=1% of patients include nervousness, tremor, somnolence, dizziness, anxiety, insomnia, palpitations, tachycardia, ventricular extrasystoles, vasodilation, nausea, dry mouth, headache, asthenia, and sweating.

The most common adverse effects of terbutaline sulfate injection reported in >=2% of patients include tremor, nervousness, dizziness, headache, drowsiness, palpitations, tachycardia, dyspnea, nausea/vomiting, flushed feeling, and sweating.

Rare or Very Rare

• Acute myocardial infarction
• Cardiac arrhythmia
• Chest pain
• Hyperglycemia
• Hypertension
• Hypokalemia
• Myocardial ischemia
• Paradoxical bronchospasm
• Pulmonary edema
• Tachycardia

More Frequent

• Nervousness
• Tremor

Less Frequent

• Cramps
• Dizziness
• Drowsy
• General weakness
• Hyperhidrosis
• Insomnia
• Nausea
• Vomiting

No enhanced messaging available.

The manufacturer does not recommend terbutaline sulfate for patients younger than 12 years of age because of insufficient clinical data to establish safety and effectiveness.

There are no adequate and well-controlled studies of terbutaline sulfate in pregnant women. Published animal studies in rats showed alterations in behavior and brain development in the offspring, including decreased cellular proliferation and differentiation, when dams were treated subcutaneously with terbutaline during the late stage of pregnancy and lactation period.

Oral terbutaline sulfate has not been approved and should not be used for acute or maintenance tocolysis. Terbutaline injection has not been approved and should not be used for prolonged tocolysis (beyond 48-72 hours). In particular, terbutaline sulfate should not be used for tocolysis in the outpatient or home setting. Serious adverse reactions, including death, have been reported after administration of terbutaline sulfate to pregnant women. In the mother, these adverse reactions include increased heart rate, transient hyperglycemia, hypokalemia, cardiac arrhythmias, pulmonary edema, and myocardial ischemia. Increased fetal heart rate and neonatal hypoglycemia may occur as a result of maternal administration.

Terbutaline crosses the placenta. After administration of a single IV dose of terbutaline to 22 women in late pregnancy who required elective Cesarean section due to clinical reasons, umbilical blood levels of terbutaline were found to range from 11-48% of the maternal blood levels. Because of the potential for beta-agonist interference with uterine contractility, use of terbutaline sulfate for relief of bronchospasm during labor should be restricted to those patients in whom the benefits clearly outweigh the risk.

It is not known whether terbutaline is excreted in human milk. The drug should be used during nursing only if the potential benefit justifies the possible risk to the infant.

The manufacturer makes no specific dosage recommendations for geriatric patients. In general, dose selection for an elderly patient should be cautious, usually starting at the low end of the dosing range, reflecting the greater frequency of decreased hepatic, renal, or cardiac function, and of concomitant disease or other drug therapy.

Clinical studies of terbutaline sulfate did not include sufficient numbers of patients 65 years of age and older to determine whether they respond differently from younger subjects. Other reported clinical experience has not identified differences in responses between the elderly and younger patients. In general, dose selection for an elderly patient should be cautious, usually starting at the low end of the dosing range, reflecting the greater frequency of decreased hepatic, renal, or cardiac function, and of concomitant disease.