TERBUTALINE SULFATE

Terbutaline sulfate USP is a beta-adrenergic agonist bronchodilator available as tablets of 2.5 mg (2.05 mg of the free base) and 5 mg (4.1 mg of the free base) for oral administration. Terbutaline sulfate is ±-α-[( tert –butylamino) methyl]-3,5-dihydroxybenzyl alcohol sulfate (2:1) (salt). The molecular formula is (C 12 H 19 NO 3 ) 2 • H 2 SO 4 and the structural formula is Terbutaline sulfate USP is a white to gray-white crystalline powder. It is odorless or has a faint odor of acetic acid. It is soluble in water and in 0.1N hydrochloric acid, slightly soluble in methanol, and insoluble in chloroform. Its molecular weight is 548.65. Inactive Ingredients: lactose monohydrate, pregelatinized starch, microcrystalline cellulose, povidone, and magnesium stearate. image description

Terbutaline sulfate is indicated for the prevention and reversal of bronchospasm in patients 12 years of age and older with asthma and reversible bronchospasm associated with bronchitis and emphysema.

Adults The usual oral dose of terbutaline sulfate for adults is 5 mg administered at approximately six-hour intervals, three times daily, during the hours the patient is usually awake. If side effects are particularly disturbing, the dose may be reduced to 2.5 mg three times daily, and still provide a clinically significant improvement in pulmonary function. The total dose within 24 hours should not exceed 15 mg. Children Terbutaline sulfate is not recommended for use in children below the age of 12 years. A dosage of 2.5 mg three times daily is recommended for children 12-15 years of age. The total dose within 24 hours should not exceed 7.5 mg. If a previously effective dosage regimen fails to provide the usual relief, medical advice should be sought immediately as this is often a sign of seriously worsening asthma that would require reassessment of therapy.

1. Tocolysis Oral terbutaline sulfate has not been approved and should not be used for acute or maintenance tocolysis. [see Boxed Warning: Tocolysis . ] 2. Hypersensitivity Terbutaline sulfate is contraindicated in patients known to be hypersensitive to sympathomimetic amines or any component of this drug product.

Adverse reactions observed with terbutaline sulfate are similar to those commonly seen with other sympathomimetic amines. All of these reactions are generally transient in nature and usually do not require treatment. The frequency of these side effects appears to diminish with continued therapy. The following table lists the adverse reactions seen in 199 patients treated with terbutaline sulfate tablets during six double-blind crossover studies and four double-blind parallel studies (short- and long-term) performed in the United States. Percent Incidence of Adverse Reactions (Total Daily Dosage Range 5 to 15 mg) Terbutaline N=199 Reaction % Nervous System Nervousness 35.0 Tremor 15.0 Somnolence 5.5 Dizziness 3.5 Anxiety 1.0 Insomnia 1.5 Cardiovascular Palpitations 5.0 Tachycardia 3.5 Extrasystoles ventricular 1.5 Vasodilations 1.0 Digestive Nausea 3.0 Dry mouth 1.5 Body as a Whole Headache 7.5 Asthenia 2.0 Skin and Appendages Sweating 1.0 The following adverse effects each occurred in fewer than 1% of patients: hallucinations, rash, paresthesia, hypertonia, (muscle cramps), vomiting. There have been rare reports of elevations in liver enzymes and of hypersensitivity vasculitis.

The concomitant use of terbutaline sulfate with other sympathomimetic agents is not recommended, since the combined effect on the cardiovascular system may be deleterious to the patient. However, this does not preclude the use of an aerosol bronchodilator of the adrenergic-stimulant type for the relief of an acute bronchospasm in patients receiving chronic oral therapy with terbutaline sulfate.