Terbutaline

• (RS)- 2-tert- butylamino -1 - (3,5- dihydroxyphenyl ) ethanol
• DL-2- tert- butylamino -1 - (3,5- dihydroxyphenyl ) ethanol
• Rac- 2-tert- butylamino -1 - (3,5- dihydroxyphenyl ) ethanol
• Latin: Terbutalinum

• 23031-25-6
• 23031-32-5 ( sulfate 2:1)

• R03AC03
• R03CC03

β2 -agonists

Water: 213 g · l-1 at 25 ° C

Hemisulfate

Risk

205 mg · kg -1 ( LD50, Mouse, oral, sulfate)

Template: Infobox chemical / molecular formula search available

Terbutaline is a drug, specifically a sympathomimetic agent, which is used for the acute treatment of those forms of breathlessness, which are characterized by a reversible narrowing of the airways, ie especially bronchial asthma and chronic obstructive pulmonary disease. Because of its effect on the smooth muscle of the uterus, it is also used for inhibition of uterine contractions ( tocolysis ).

As a selective β2 -sympathomimetic is a bronchodilator, which is administered mainly " by inhalation ".

Indications

Indications are:

• The symptomatic treatment of acute asthma attack
• Prophylactic treatment of bronchial asthma with exercise-induced
• Chronic obstructive bronchitis
• As parenteral application for tocolysis in risk of preterm delivery

Mechanism of Action

According to its characteristics as a β2 mimetic terbutaline acts more on the β2 - adrenergic receptors and thus the smooth muscle of the bronchia, of the uterus, blood vessels, and as to the β1 - receptors of the heart muscle. Thus, the effect of a relaxation of the muscles to lead to an expansion of Endbronchien and thus reduce the respiratory resistance and to facilitate the respiratory activity generally or to inhibit uterine contractions explained.

By long intake can be observed that the effect of the drug decreases due to a down-regulation of receptors.

Side effects

Due to the β2 - selectivity, the effects on heart activity, especially following inhalation of the substance is low. An increase in heart rate can also be interpreted as a counter-regulation for the expansion of peripheral blood vessels. May, however, occur palpitations, which, like a feinschlägiges muscle tremors and tonic spasms of sympathomimetic amines typical. A decrease in serum potassium is possible and forces for the determination of potassium before starting treatment.

While the inhalational administration of terbutaline leads to fewer systemic side effects than oral or parenteral use, allergic reactions when inhaled frequently are: angioneurotic edema, urticaria, rash, hypotension and collapse states are possible, but very rare.

The U.S. Food and Drug Administration warned recently in front of a prolonged use of terbutaline for inhibition of contractions. In one application of the substance for the prevention of preterm delivery of more than 72 hours, the cardiac risks outweigh considerably.

Chemistry

Stereochemistry

Terbutaline is a chiral drug and contains a stereocenter. Accordingly, there are two stereoisomers, (R)- terbutaline and (S) - terbutaline. The pharmacologically active isomer is the (R) terbutaline. Therapeutically, however, is the racemate, ie, the 1:1 mixture of both isomers used.

Trade names

Aerodur (D), Bricanyl (D, A, CH ), various generics (D)