WAtosiban, sold under the brand name Tractocile among others, is an inhibitor of the hormones oxytocin and vasopressin. It is used as an intravenous medication as a labour repressant (tocolytic) to halt premature labor. It was developed by Ferring Pharmaceuticals in Sweden and first reported in the literature in 1985. Originally marketed by Ferring Pharmaceuticals, it is licensed in proprietary and generic forms for the delay of imminent preterm birth in pregnant adult women.
WBarusiban (INN) is a non-peptide drug which is among the most potent and selective oxytocin receptor antagonists known. It was trialed by Ferring Pharmaceuticals as a treatment of preterm labor but failed to demonstrate effectiveness and was not pursued any further.
WHexoprenaline is a selective β2 adrenergic receptor agonist used in the treatment of asthma. Hexoprenaline is also used in some countries as a tocolytic agent, with the most common trade name being Gynipral. It is not approved by U.S. FDA.
WIndometacin, also known as indomethacin, is a nonsteroidal anti-inflammatory drug (NSAID) commonly used as a prescription medication to reduce fever, pain, stiffness, and swelling from inflammation. It works by inhibiting the production of prostaglandins, endogenous signaling molecules known to cause these symptoms. It does this by inhibiting cyclooxygenase, an enzyme that catalyzes the production of prostaglandins.
WL-368,899 is a drug used in scientific research which acts as a selective antagonist of the oxytocin receptor, with good selectivity over the related vasopressin receptors. Unlike related drugs such as the peripherally selective L-371,257, the oral bioavailabity is high and the brain penetration of L-368,899 is rapid, with selective accumulation in areas of the limbic system. This makes it a useful tool for investigating the centrally mediated roles of oxytocin, such as in social behaviour and pair bonding, and studies in primates have shown L-368,899 to reduce a number of behaviours such as food sharing, sexual activity and caring for infants, demonstrating the importance of oxytocinergic signalling in mediating these important social behaviours.
WL-371,257 is a compound used in scientific research which acts as a selective antagonist of the oxytocin receptor with over 800x selectivity over the related vasopressin receptors. It was one of the first non-peptide oxytocin antagonists developed, and has good oral bioavailability, but poor penetration of the blood–brain barrier, which gives it good peripheral selectivity with few central side effects. Potential applications are likely to be in the treatment of premature labour.
WMagnesium citrate is a magnesium preparation in salt form with citric acid in a 1:1 ratio. The name "magnesium citrate" is ambiguous and sometimes may refer to other salts such as trimagnesium citrate which has a magnesium:citrate ratio of 3:2.
WNifedipine, sold under the brand name Adalat among others, is a medication used to manage angina, high blood pressure, Raynaud's phenomenon, and premature labor. It is one of the treatments of choice for Prinzmetal angina. It may be used to treat severe high blood pressure in pregnancy. Its use in preterm labor may allow more time for steroids to improve the baby's lung function and provide time for transfer of the mother to a well qualified medical facility before delivery. It is a calcium channel blocker of the dihydropyridine type. Nifedipine is taken by mouth and comes in fast and slow release formulations.
WQuinagolide (INN, BAN; brand name Norprolac) is a selective D2 receptor agonist that is used to reduce elevated levels of prolactin (hyperprolactinemia). It has also been found to be effective in the treatment of breast pain.
WRitodrine is a tocolytic drug used to stop premature labor. This drug has been removed from the US market, according to FDA Orange Book. It was available in oral tablets or as an injection and was typically used as the hydrochloride salt, ritodrine hydrochloride.
WTerbutaline, sold under the brand name Bricanyl among others, is a β2 adrenergic receptor agonist, used as a "reliever" inhaler in the management of asthma symptoms and as a tocolytic to delay preterm labor for up to 48 hours. This time can then be used to administer steroid injections to the mother which help fetal lung maturity and reduce complications of prematurity. It should not be used to prevent preterm labor or delay labor more than 48–72 hours. In February 2011, the Food and Drug Administration began requiring a black box 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 management of preterm labor, and should not be given oral terbutaline for any type of prevention or treatment of preterm labor "due to the potential for serious internal heart problems and death."