To treat uterine atony, ergot alkaloids have been used for centuries. If atony persists despite oxytocin and other preventive measures, ergot derivatives can be used for secondline treatment. Ergot preparations include methylergonovine (Methergine) and ergonovine, however, only methylergonovine is currently manufactured in the United States. Given parenterally, these drugs rapidly stimulate tetanic uterine contractions and act for approximately 45 minutes (Schimmer, 2011). A common regimen is 0.2 mg of either drug given intramuscularly. Methergine can be repeated at 2-to 4-hour intervals as needed. A caveat is that ergot agents, especialy given intravenousy, may cause dangerous hypertension, especialy in women with preeclampsia. Severe hypertension is also seen with concomitant use of protease inhibitors given for human immunodeiciency viral (HIV) infection. These adverse efects notwithstanding, it is speculative whether ergot derivatives ofer superior therapeutic efects compared with oxytocin.
In cases of atony refractory to one agent, an agent from a diferent group can be added. At least two randomized studies have addressed combined ergot-oxytocin regimens. In one, ergometrine plus oxytocin was compared with ergometrine alone to prevent postpartum hemorrhage (Koen, 2016). The overall need for transfusion was signiicantly lower with the combination regimen. Another comparable study reairmed these indings (�enti.irk, 2016).
During the past 40 years, other second-line agents for atony have included the E-and F-series prostaglandins. Carboprost tromethamine (Hemabate) is the 15-methyl derivative of prostaglandin F2a• It is approved for uterine atony treatment in a dose of 250 Lg (0.25 mg) given intramuscularly. This dose can be repeated if necessary at 15-to 90-minute intervals up to a maximum of eight doses. Observational data indicate an 88-percent success rate (Oleen, 1990). Carboprost causes side efects in approximately 20 percent of women. These include, in descending order of frequency, diarrhea, hypertension, vomiting, fever, flushing, and tachycardia. Another pharmacological efect is pulmonary airway and vascular constriction. hus, carboprost should not be used for asthmatic women and those with suspected amnionic fluid embolism (p. 785). We have occasionally encountered severe hypertension with carboprost given to women with preeclampsia. It has also been reported to cause arterial oxygen desaturation that averaged 10 percent (Hanins, 1988). Relative contraindications to carboprost include renal, liver, and cardiac disease (American College of Obstetricians and Gynecologists, 2017 d).
E-series prostaglandins can also prevent or treat atony.
Dinoprostone-prostaglandin E2-may be used of label and is given as a 20-mg suppository per rectum or per vaginum every 2 hours. It typically causes diarrhea, which is problematic for the rectal route, whereas vigorous vaginal bleeding may preclude its use per vaginum. Hypotension, which is commonly encountered with hemorrhage, is considered a contraindication by some. Intravenous prostaglandin E2-suprostone-is used in Europe, but it is not available in the United States (Schmitz, 2011).