Known brand names include Pitocin.
A hospital injection of the hormone that makes the uterus contract. An IV drip starts or strengthens labor when there is a medical reason to deliver, and IV or IM doses after delivery control bleeding. It is given by pump with continuous monitoring of contractions and the baby's heart rate.
61 / 100
Oxytocin attaches to oxytocin receptors in the muscle of the uterus. This raises calcium inside the muscle cells, which switches on the proteins that make the muscle contract. The uterus grows many more of these receptors during pregnancy, with the most in early labor at term, so how strongly it responds differs a lot from person to person.
Dripped into a vein (1/7)
Given by IV drip in labor, oxytocin acts on the uterus almost at once.
Given by IV, it acts on the uterus almost at once and the effect fades within an hour, while a shot into a muscle works within 3 to 5 minutes and lasts 2 to 3 hours. Because the IV effect fades so quickly, an infusion that makes contractions too strong can be stopped and the push on the uterus soon wanes. It is chemically very close to vasopressin, so large doses can also raise blood pressure and make the body hold on to water. Small amounts probably reach the baby's bloodstream.
Oxytocin starts or strengthens labor contractions when there is a medical reason for the baby to be delivered vaginally, such as preeclampsia near term, diabetes in the mother, or waters that have broken early. It can also boost labor in some cases where the contractions are too weak to move labor along. After the baby is born, it makes the uterus contract and helps control heavy bleeding.
It is given by a health care provider in a hospital or clinic, either as an IV drip or as a shot into a muscle. To start or strengthen labor, it is given only by IV drip, with close medical supervision. It can also help empty the uterus, along with other treatment, after a miscarriage that is incomplete or cannot be stopped. It is not used to start labor just for convenience when there is no medical reason.
Nausea and vomiting can happen. The label treats contractions that come too strong or too close together as the main danger, because they can tear or rupture the uterus and reduce oxygen to the baby, causing a slow heart rate, brain injury, or death. It also warns about severe water retention with seizures and coma, heavy bleeding after delivery, dangerous blood pressure spikes and bleeding in the brain, heart rhythm problems, and serious allergic reactions.
This is the boxed warning, the warning the FDA label prints first.
Not indicated for elective induction of labor, meaning induction without a medical indication, because available data do not establish its benefits against its risks for that use.
Sources: [1]