23031-32-5

Crystalline Powder

A B-Adrenergic receptor agonist. A Bronchodilator

Anti Asthmatic

betaadrenergic agonist, bronchodilator

Terbutaline is the N-t-butyl analogue of metaproterenol and, as such, would be expected to have a more potent β2-selectivity. When compared to metaproterenol, terbutaline has a threefold greater potency at the β2-receptor. Like metaproterenol, it is resistant to COMT and slowly metabolized by MAO, therefore having good oral bioavailability with similar onset and duration. Terbutaline is available as tablets and solutions for injection and inhalation. Adverse effects are similar to other direct-acting β2-selective agonists, however, with a greater incidence of palp

Bricanyl,Pharma-Stern,W. Germany,1971

ChEBI: Terbutaline sulfate is an ethanolamine sulfate salt. It is functionally related to a terbutaline.

To a solution of 32 g of benzyl-t-butylamine in 300 ml of absolute ethanol at reflux temperature was added 32 g of 3,5-dibenzyloxy-?-bromoacetophenone in 10 ml of dry benzene. The mixture was refluxed for 20 hours and then evaporated. When absolute ether was added to the residue, benzyl-tbutylamine hydrobromide was precipitated. The precipitated compound was filtered off and to the filtrate was added an excess of 2 N sulfuric acid. This caused precipitation of the hydrogen sulfate of 3,5-dibenzyloxy-?-(benzyl-tbutylamino)- acetophenone which was recrystallized from acetone/ether. If the product is crystallized from different organic solvents, the melting point will vary with the type and amount of solvent of crystallization, but the product can be used directly for hydrogenation.
15 g of 3,5-dibenzyloxy-?-(benzyl-t-butylamino)-acetophenone hydrogen sulfate in 200 ml of glacial acetic acid were hydrogenated in a Parr pressure reaction apparatus in the presence of 1.5 g of 10% palladium charcoal at 50°C and 5 atmospheres pressure. The reaction time was 5 hours. The catalyst was filtered off, the filtrate was evaporated to dryness and the hydrogen sulfate of 1-(3',5'-dihydroxyphenyl)-2-(t-butylamino)-ethanol was received. This compound is hygroscopic, but it can be transformed into a nonhygroscopic sulfate in the following manner.
The hydrogen sulfate was dissolved in water and the pH of the solution was adjusted to 5.6 (pH-meter) with 0.1 N sodium hydroxide solution. The water solution was evaporated to dryness and the residue dried with absolute ethanol/benzene and once more evaporated to dryness. The remaining crystal mixture was extracted in a Soxhlet extraction apparatus with absolute methanol. From the methanol phase the sulfate of 1-(3',5'-dihydroxyphenyl)- 2-(t-butylamino)-ethanol crystallized. Melting point 246°C to 248°C.

Terbutaline is INN and BAN.

Bronchodilator

Beta2 -adrenoceptor agonist:
Reversible airways obstruction

Terbutaline is used as a bronchodilating agent in the adjunctive treatment of cardiopulmonary diseases (including tracheobronchitis, collapsing trachea, pulmonary edema, and allergic bronchitis) in small animals. It may be of some benefit in treating bradyarrhythmias in dogs and cats.
Terbutaline has been used occasionally in horses for its bronchodilating effects, but adverse effects, short duration of activity after IV administration and poor oral absorption have limited its use. It has been shown to be useful as a diagnostic agent to diagnose anhidrosis in horses after intradermal injection.
Oral and intravenous terbutaline has been used successfully in humans for the inhibition of premature labor clinical signs.

Potentially hazardous interactions with other drugs
Effect may be diminished by beta-blockers.
Theophylline: increased risk of hypokalaemia.

Terbutaline undergoes extensive first-pass metabolism by sulphate (and some glucuronide) conjugation in the liver and the gut wall. It is excreted in the urine and faeces partly as the inactive sulphate conjugate and partly as unchanged terbutaline, the ratio depending upon the route by which it is given.