Ergonovine

Ergonovine, also known as ergometrine and lysergic acid propanolamide, is a medication used to cause contractions of the uterus to treat heavy vaginal bleeding after childbirth. It can be used either by mouth, by injection into a muscle, or injection into a vein.

Common side effects include high blood pressure, vomiting, seizures, headache, and low blood pressure. Other serious side effects include ergotism.

Ergonovine was discovered in 1932. It is on the World Health Organization's List of Essential Medicines. Ergonovine is controlled in some countries because it can be used to make the psychedelic drug lysergic acid diethylamide (LSD). It is also known to produce psychedelic effects itself at high doses.

Ergonovine has a medical use in obstetrics to facilitate delivery of the placenta and to prevent bleeding after childbirth by causing smooth muscle tissue in the blood vessel walls to narrow, thereby reducing blood flow. It is usually combined with oxytocin (Syntocinon) as syntometrine. It begins working within 15 minutes when taken by mouth and is faster in onset when used by injection. Its duration is between 45 and 180 minutes.

It can induce spasm of the coronary arteries. It is used to diagnose variant (Prinzmetal's) angina.

Possible side effects include nausea, vomiting, abdominal pain, diarrhea, headache, dizziness, tinnitus, chest pain, palpitation, bradycardia, transient hypertension and other cardiac arrhythmias, dyspnea, rashes, and shock. An overdose produces a characteristic poisoning, ergotism or "St. Anthony's fire": prolonged vasospasm resulting in gangrene and amputations; hallucinations and dementia; and abortions.

Gastrointestinal disturbances such as diarrhea, nausea, and vomiting, are common. The drug is contraindicated in pregnancy, vascular disease, and psychosis.

Ergonovine stimulates the uterus and other smooth muscles. It targets α-adrenergic, dopaminergic, and serotonin receptors (the 5-HT₂ receptor). Its uterotonic effect has not been identified with a specific receptor type.^{[citation needed]} The drug has been found to bind to and activate the rat and human serotonin 5-HT_2A receptor with similar affinity as lysergic acid diethylamide (LSD). Ergonovine is an agonist of the serotonin 5-HT_2B receptor and has been associated with cardiac valvulopathy. A computer-predicted binding profile of ergonovine at an array of serotonin, dopamine, and other receptors has been published. It was predicted to bind to most of the serotonin receptors with moderately high affinity, albeit lower than LSD.