Carboprost

Carboprost tromethamine injection is approved for two main purposes across its available products:

• Second-trimester pregnancy termination — ending a pregnancy between weeks 13 and 20 of gestation
• Failed expulsion with another method — when another abortion method has not worked
• Membrane rupture complications — premature rupture of membranes during an intrauterine procedure with loss of drug and insufficient uterine activity, or inadvertent rupture in the presence of a previable fetus
• Need for repeat treatment — when a repeat intrauterine instillation is required for fetal expulsion
• Postpartum hemorrhage due to uterine atony — Hemabate and Carboprost Tromethamine injection are indicated for severe postpartum bleeding when the uterus fails to contract after delivery, and only after oxytocin, uterine massage, and (unless contraindicated) ergot medicines have not controlled the bleeding

Carboprost tromethamine is a synthetic prostaglandin — a hormone-like compound — that causes the uterine muscle to contract forcefully. During pregnancy termination, these contractions expel the pregnancy. After delivery, the same contractions compress the blood vessels at the site where the placenta was attached, helping to stop hemorrhage. The drug also stimulates smooth muscle elsewhere in the body: in the gastrointestinal tract (causing nausea, vomiting, and diarrhea), in the airways (potentially causing bronchoconstriction — airway narrowing — in some patients), and in blood vessels (which can temporarily raise blood pressure at higher doses).

The drug can also raise body temperature at clinical doses, and some patients experience a temporary fever that resolves after the injections are stopped.

Carboprost tromethamine is given only as a deep intramuscular injection by trained medical staff in a hospital. The number of injections and the spacing between them depend entirely on how the uterus responds — your care team adjusts the schedule as needed.

• For pregnancy termination, doses are typically spaced 1½ to 3½ hours apart; treatment should not continue for more than two days
• For postpartum hemorrhage, most patients responded to a single injection in clinical trials; if needed, repeat doses may be given at intervals of 15 to 90 minutes at the physician's discretion

There are maximum total dose limits for both uses, and the prescribing team will manage these carefully. Do not attempt to adjust or repeat doses on your own — this drug is always administered under direct medical supervision.

The most common side effects of carboprost tromethamine are related to its effect on the gastrointestinal tract:

• Vomiting (about two-thirds of patients)
• Diarrhea (also very common)
• Nausea (about one-third of patients)
• Flushing or hot flashes
• Chills or shivering
• Temporary fever or rise in body temperature
• Headache
• Dizziness
• Coughing or wheezing
• Injection site pain

Doctors routinely give anti-nausea and anti-diarrheal medicines alongside carboprost to help manage these effects. More serious reactions — including uterine rupture, pulmonary edema (fluid in the lungs), septic shock, and severe allergic reactions — require immediate medical attention.

• Hospital use only: Carboprost must be given in a facility with intensive care and emergency surgical capabilities. It is never appropriate outside that setting.
• Potent uterine stimulant: Like all strong oxytocic drugs, the dose must be followed exactly — deviating from the recommended regimen can cause serious harm.
• Not a feticidal agent: Carboprost does not directly cause fetal death. A previable fetus may show brief signs of life after the procedure. If the drug fails to terminate the pregnancy, the process must be completed by another method.
• Viability limit: Carboprost should not be used once the fetus has reached the stage of viability (the point at which it could survive outside the womb).
• Benzyl alcohol: This product contains benzyl alcohol, which has been linked to a fatal condition called Gasping Syndrome in premature infants.
• Allergic reactions: Severe allergic reactions including anaphylaxis (a life-threatening whole-body reaction) and angioedema (severe swelling) have been reported and are a contraindication to use.

Carboprost tromethamine has one key drug interaction to be aware of:

• Other oxytocic agents (drugs that stimulate uterine contractions, such as oxytocin or ergot preparations): carboprost can amplify their effects, which could cause excessively strong or prolonged uterine contractions. Combining them is not recommended.

This is not a complete list of interactions. Always talk with your doctor or pharmacist before starting, stopping, or changing any medication.

• Do not use if you have ever had a severe allergic reaction — including anaphylaxis or angioedema (severe swelling) — to carboprost tromethamine
• Do not use if you have active pelvic inflammatory disease (an ongoing pelvic infection)
• Do not use if you have active heart, lung, kidney, or liver disease
• Not appropriate once the fetus has reached viability (the ability to survive outside the womb)
• Tell your care team about all medications you are taking, especially other uterine-stimulating drugs
• The product contains benzyl alcohol — this is a safety concern for premature infants who may be nearby or exposed
• Any failed termination attempt with carboprost must be completed by another method; discuss the plan with your provider

Carboprost tromethamine causes strong contractions of the uterine muscle, similar to those seen at the end of full-term labor. When used after delivery, these contractions compress the blood vessels at the placental site and help stop hemorrhage. The drug also stimulates smooth muscle in the gastrointestinal tract, which explains why vomiting and diarrhea are so common. It can transiently raise body temperature, and in some patients it causes bronchoconstriction (airway narrowing). At large doses — larger than those used clinically — it can raise blood pressure by contracting vascular smooth muscle, though this effect has not been clinically significant at recommended doses.

After an intramuscular injection, carboprost tromethamine is absorbed into the bloodstream relatively quickly, with blood levels peaking within about 15 to 30 minutes in most patients. With repeated injections spaced two hours apart, peak levels rise slightly with each dose but then fall again before the next dose is given. In women treated postpartum with a single injection, the highest blood levels were seen between 15 and 60 minutes after the dose. The drug is measured in the blood using a technique called radioimmunoassay; the label does not specify a formal half-life or route of elimination.

Store refrigerated between 2° and 8°C (36° and 46°F).