Uterine relaxant

The uterine relaxants are medicines used when there is a risk of premature childbirth. As their name suggests, they are used to relax the muscle fibres of the uterus and block their contractions.

The different uterine relaxants

The uterine relaxants act on the smooth muscle cell of the uterus. Some only act on this cell. They are antagonists of oxytocin, the hormone directly responsible for uterine contractions. Others have effects on all smooth muscle cells such as lung cells. They are beta-2 stimulants. Their action is therefore not specific to the uterus. They have limited efficacy over time. On average they last for 48 hours. Note that the calcium blockers can also be used for their uterine relaxing properties. No medicine in this class, however, has marketing authorisation (MA) in France for an indication specific to pregnancy.

Source : Interview with Dr Philippe Deruelle, gynaecologist at the Lille University Hospital, 8 July 2011