Carboprost tromethamine
[CAS# 58551-69-2]

Identification

• Classification: API >> Hormone and endocrine-regulating drugs >> Prostaglandins
• Name: Carboprost tromethamine
• Synonyms: (Z)-7-[(1R,2S,3R,5S)-3,5-Dihydroxy-2-[(E,3S)-3-hydroxy-3-methyl-oct-1-enyl]cyclopentyl]hept-5-enoic acid 2-amino-2-(hydroxymethyl)propane-1,3-diol
• Molecular Formula: C₂₁H₃₆O₅.C₄H₁₁NO₃
• Molecular Weight: 489.64
• CAS Registry Number: 58551-69-2
• EC Number: 638-806-5
• SMILES: CCCCC[C@@](C)(/C=C/[C@H]1[C@@H](C[C@@H]([C@@H]1C/C=CCCCC(=O)O)O)O)O.C(C(CO)(CO)N)O

Properties

• Solubility: water: 100mM (Expl.)

Safety Data

• Hazard Symbols: GHS08 Danger
• Risk Statements: H360
• Safety Statements: P203-P280-P318-P405-P501

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Reproductive toxicity	Repr.	1A	H360
Reproductive toxicity	Repr.	1B	H360
Skin sensitization	Skin Sens.	1	H317
Acute toxicity	Acute Tox.	4	H302
Specific target organ toxicity - single exposure	STOT SE	3	H335

Discovery and Applications

Carboprost tromethamine is a synthetic analogue of prostaglandin F_2α (PGF_2α), chemically designed to retain potent uterotonic activity while improving stability and solubility. It is the tromethamine (tris(hydroxymethyl)aminomethane) salt of carboprost, which enhances water solubility and allows preparation of sterile aqueous formulations for parenteral administration. The compound retains the cyclopentane core and omega-side chain typical of PGF_2α analogues, but with a 15-methyl modification on the prostaglandin backbone that confers resistance to enzymatic degradation, prolonging its biological activity.

Carboprost tromethamine acts primarily as an agonist at the FP prostanoid receptor, inducing strong uterine contractions. It is used clinically in obstetrics for the management of postpartum hemorrhage and for termination of pregnancy, particularly in the second trimester, where it stimulates myometrial contraction and facilitates expulsion of uterine contents. Its chemical stability and tromethamine salt form make it suitable for intramuscular or intravaginal administration, allowing predictable pharmacokinetics and dosing.

The pharmacological activity of carboprost tromethamine involves binding to FP receptors in the myometrium, resulting in increased intracellular calcium and sustained uterine contractions. These effects reduce postpartum bleeding by promoting uterine tone and also facilitate medical abortion by inducing expulsion of fetal and placental tissue. Unlike native PGF_2α, the 15-methyl modification reduces rapid metabolic inactivation, enabling prolonged therapeutic action without requiring frequent dosing.

Clinical studies have confirmed the efficacy of carboprost tromethamine in controlling postpartum hemorrhage and inducing abortion, demonstrating high rates of uterine contraction and effective hemostasis. Common adverse effects include gastrointestinal symptoms such as nausea, vomiting, and diarrhea, as well as fever, flushing, and transient hypotension. Its use is contraindicated in patients with hypersensitivity to prostaglandins, severe cardiac, pulmonary, or renal disease, and in situations where uterine stimulation is undesirable.

Carboprost tromethamine exemplifies the development of prostaglandin analogues with chemical modifications designed to enhance therapeutic utility while maintaining receptor specificity. By combining structural modifications with the tromethamine salt form, the compound achieves a balance of potency, stability, and solubility suitable for clinical obstetric applications.

References

Bai J, Sun Q & Zhai H (2014) A comparison of oxytocin and carboprost tromethamine in the prevention of postpartum hemorrhage in high‑risk patients undergoing cesarean delivery. Experimental and Therapeutic Medicine 7 46–50 DOI: 10.3892/etm.2013.1379

Wei C, Chang X‑Y, Dong J‑H, Zhou Q‑H (2020) Remifentanil for carboprost‑induced adverse reactions during cesarean delivery under combined spinal–epidural anesthesia. Frontiers in Pharmacology 11 980 DOI: 10.3389/fphar.2020.00980

Saloni, Agrawal M (2024) Postpartum haemorrhage and carboprost for its prevention: a narrative review. Cureus 16(6) e62875 DOI: 10.7759/cureus.62875