Terbutaline
Encyclopedia
Terbutaline is a β2-adrenergic receptor agonist
.
Terbutaline is currently on the World Anti-Doping Agency
's list of prohibited drugs for Olympic athletes, except when administered by inhalation and a Therapeutic Use Exemption (TUE) has been obtained in advance.
Terbutaline is currently used to delay preterm labor for 48 hours to allow for fetal lung maturity through steroid injections. It should not be used to prevent preterm labor or delay labor past 48-72 hours. In February 2011, the Food and Drug Administration
has ordered to put a boxed warning on the drug's label. Pregnant women should not be given injections of the drug terbutaline for the prevention of preterm labor or for long-term (beyond 48-72 hours) management of preterm labor, and should not be given oral terbutaline for any type of prevention or treatment of preterm labor "due to of the potential for serious internal heart problems and death."
The American College of Obstetricians and Gynecologists also discourages the use of terbutaline for preventing preterm labor.
(often used as a short-term asthma treatment) and as a tocolytic
to delay premature labor. The inhaled form of terbutaline starts working within 15 minutes and can last up to 6 hours.
Terbutaline as a treatment for premature labor is an off-label use not approved by the FDA
. It is a pregnancy category
'B' medication and is routinely prescribed to stop contractions. After successful intravenous tocolysis, little evidence exists that oral terbutaline is effective. However, following uterine inversion in the third stage of pregnancy, Terbutaline (or either Halothane or magnesium sulfate) can be utilized to relax the uterus if necessary prior to uterine replacement.
into the appropriate 3,5-dibenzyloxybromoacetophenone, which is reacted with N-benzyl
-N-tert-butylamine, giving the aminoketone. Reduction of this product by hydrogen over a palladium catalyst leads to terbutaline.
Beta2-adrenergic receptor agonist
β2-adrenergic agonists, also known as β2-adrenergic receptor agonists, are a class of drugs used to treat asthma and other pulmonary disease states.-Uses:...
.
Terbutaline is currently on the World Anti-Doping Agency
World Anti-Doping Agency
The World Anti-Doping Agency , , is an independent foundation created through a collective initiative led by the International Olympic Committee . It was set up on November 10, 1999 in Lausanne, Switzerland, as a result of what was called the "Declaration of Lausanne", to promote, coordinate and...
's list of prohibited drugs for Olympic athletes, except when administered by inhalation and a Therapeutic Use Exemption (TUE) has been obtained in advance.
Terbutaline is currently used to delay preterm labor for 48 hours to allow for fetal lung maturity through steroid injections. It should not be used to prevent preterm labor or delay labor past 48-72 hours. In February 2011, the Food and Drug Administration
Food and Drug Administration
The Food and Drug Administration is an agency of the United States Department of Health and Human Services, one of the United States federal executive departments...
has ordered to put a boxed warning on the drug's label. Pregnant women should not be given injections of the drug terbutaline for the prevention of preterm labor or for long-term (beyond 48-72 hours) management of preterm labor, and should not be given oral terbutaline for any type of prevention or treatment of preterm labor "due to of the potential for serious internal heart problems and death."
The American College of Obstetricians and Gynecologists also discourages the use of terbutaline for preventing preterm labor.
Uses
Terbutaline is used as a fast-acting bronchodilatorBronchodilator
A bronchodilator is a substance that dilates the bronchi and bronchioles, decreasing resistance in the respiratory airway and increasing airflow to the lungs. Bronchodilators may be endogenous , or they may be medications administered for the treatment of breathing difficulties...
(often used as a short-term asthma treatment) and as a tocolytic
Tocolytic
Tocolytics are medications used to suppress premature labor . They are given when delivery would result in premature birth...
to delay premature labor. The inhaled form of terbutaline starts working within 15 minutes and can last up to 6 hours.
Terbutaline as a treatment for premature labor is an off-label use not approved by the FDA
Food and Drug Administration
The Food and Drug Administration is an agency of the United States Department of Health and Human Services, one of the United States federal executive departments...
. It is a pregnancy category
Pregnancy category
The pregnancy category of a pharmaceutical agent is an assessment of the risk of fetal injury due to the pharmaceutical, if it is used as directed by the mother during pregnancy. It does not include any risks conferred by pharmaceutical agents or their metabolites that are present in breast...
'B' medication and is routinely prescribed to stop contractions. After successful intravenous tocolysis, little evidence exists that oral terbutaline is effective. However, following uterine inversion in the third stage of pregnancy, Terbutaline (or either Halothane or magnesium sulfate) can be utilized to relax the uterus if necessary prior to uterine replacement.
Structure activity relationships
The tertiary butyl group in terbutaline makes it more selective for β2-receptors. Since there is no hydroxy group on the 4 position of the benzene ring - the molecule is less susceptible to metabolism by COMT enzyme.Side effects
- Maternal - tachycardiaTachycardiaTachycardia comes from the Greek words tachys and kardia . Tachycardia typically refers to a heart rate that exceeds the normal range for a resting heart rate...
, nervousnessAnxietyAnxiety is a psychological and physiological state characterized by somatic, emotional, cognitive, and behavioral components. The root meaning of the word anxiety is 'to vex or trouble'; in either presence or absence of psychological stress, anxiety can create feelings of fear, worry, uneasiness,...
, tremors, headacheHeadacheA headache or cephalalgia is pain anywhere in the region of the head or neck. It can be a symptom of a number of different conditions of the head and neck. The brain tissue itself is not sensitive to pain because it lacks pain receptors. Rather, the pain is caused by disturbance of the...
, hyperglycemiaHyperglycemiaHyperglycemia or Hyperglycæmia, or high blood sugar, is a condition in which an excessive amount of glucose circulates in the blood plasma. This is generally a glucose level higher than 13.5mmol/l , but symptoms may not start to become noticeable until even higher values such as 15-20 mmol/l...
, hypokalemiaHypokalemiaHypokalemia or hypokalaemia , also hypopotassemia or hypopotassaemia , refers to the condition in which the concentration of potassium in the blood is low...
, and rarely, pulmonary edemaPulmonary edemaPulmonary edema , or oedema , is fluid accumulation in the air spaces and parenchyma of the lungs. It leads to impaired gas exchange and may cause respiratory failure...
. - Fetal - tachycardiaTachycardiaTachycardia comes from the Greek words tachys and kardia . Tachycardia typically refers to a heart rate that exceeds the normal range for a resting heart rate...
and hypoglycemiaHypoglycemiaHypoglycemia or hypoglycæmia is the medical term for a state produced by a lower than normal level of blood glucose. The term literally means "under-sweet blood"...
.
Chemistry
It is synthesized by brominating 3,5-dibenzyloxyacetophenoneAcetophenone
Acetophenone is the organic compound with the formula C6H5CCH3. It is the simplest aromatic ketone. This colourless, viscous liquid is a precursor to useful resins and fragrances.-Production:Acetophenone can be obtained by a variety of methods...
into the appropriate 3,5-dibenzyloxybromoacetophenone, which is reacted with N-benzyl
Benzyl
In organic chemistry, benzyl is the term used to describe the substituent or molecular fragment possessing the structure C6H5CH2-. Benzyl features a benzene ring attached to a CH2 group.-Nomenclature:...
-N-tert-butylamine, giving the aminoketone. Reduction of this product by hydrogen over a palladium catalyst leads to terbutaline.