carboprost tromethamine
Hemabate

Available forms
Available by prescription only
Injection: 250 mcg/ml carboprost and 83 mcg/ml tromethamine

Indications and dosages
 To abort pregnancy between weeks 13 and 20 of gestation. Adults: Initially, 250 mcg by deep I.M. injection. Subsequent 250-mcg doses at intervals of 11/2 to 31/2 hours depending on uterine response. Dose may be increased to 500 mcg if contractility is inadequate after several 250-mcg doses. Total dose shouldn’t exceed 12 mg, and therapy shouldn’t continue for longer than 2 days.
 Postpartum hemorrhage from uterine atony that hasn’t responded to conventional management. Adults: 250 mcg by deep I.M. injection. May repeat doses at 15- to 90-minute intervals. Maximum total dose is 2 mg.

Pharmacodynamics
Oxytocic action: Exact mechanism unknown. Stimulates myometrial contractions in the gravid uterus similar to the contractions of term labor. Effect may be due to one or more of the following: direct stimulation, regulation of cellular calcium transport, or regulation of intracellular levels of cAMP. Uterine response increases with the length of the pregnancy. Facilitates cervical dilation by softening the cervix. The mean abortion time is 16 hours.

Pharmacokinetics
Absorption: Administered I.M.
Distribution: No information available.
Metabolism: Primary site of oxidation appears to be liver.
Excretion: Excreted primarily as metabolites in urine.

Contraindications and precautions
Contraindicated in patients hypersensitive to drug and in those with acute pelvic inflammatory disease or active cardiac, pulmonary, renal, or hepatic disease. Use cautiously in patients with history of asthma; hypotension or hypertension; CV, renal, or hepatic disease; anemia; jaundice; diabetes; epilepsy; compromised uterus; or chorioamnionitis.

Interactions
Drug-drug. Oxytocin, other oxytocics: Enhances effects of these drugs; however, cervical laceration and trauma have been reported with use of oxytocin. Use together cautiously.

Adverse reactions
CNS: headache, anxiety, hot flashes, paresthesia, syncope, weakness, fever.
CV: chest pain, arrhythmias, flushing.
EENT: blurred vision, eye pain.
GI: vomiting, diarrhea, nausea.
GU: endometritis, uterine rupture, uterine or vaginal pain.
Musculoskeletal: backache.
Respiratory: cough, wheezing.
Skin: rash, diaphoresis.
Other: chills, breast tenderness, leg cramps.

Effects on lab test results
None reported.

Overdose and treatment
Signs and symptoms of overdose are extensions of the adverse reactions.
 Because drug is metabolized rapidly, treatment of overdose involves stopping drug and providing supportive care.

Special considerations
• Administer only in hospitals in which intensive care and surgical facilities are available.
• Confirmation of fetal death is imperative before administration when used for missed abortion or intrauterine fetal death.
• Premedicate patient with antiemetics and antidiarrheals to minimize GI effects.
• Meperidine may be helpful to reduce abdominal cramps.
• Store drug in refrigerator. (Carboprost is stable at room temperature for 9 days.)
• If fever occurs, differentiate between drug-induced fever and endometritis pyrexia.
• If incomplete abortion occurs, use other measures to ensure complete abortion.

Patient education
• Advise patient of expected adverse reactions.

Reactions may be common, uncommon, life-threatening, or COMMON AND LIFE THREATENING.
◆ Canada only
◇ Unlabeled clinical use