Ornipressin: a synthetic derivative of vasopressin




Figure 1. The structural formula of ornipressin

Ornipressin is a synthetic analogue of vasopressin, which is replaced by Ornipressin at residue 8 of the cyclic nonapeptide. As an effective vasoconstrictor, ornipressin plasma volume expansion to improve the effective arterial blood volume by albumin. And it originates deep vasoconstriction by contracting smooth-muscle cells in the vascular bed, particularly in capillaries, small arterioles, and venules. Ornipressin is most commonly used for the treatment of hemorrhagic esophageal varices.

Pharmacologic action

Ornipressin functions as hemostatic agent by arresting the blood flow. Hemostatics are absorbable, which can provide a mechanical substrate form an artificial clot to arrest bleeding, and then promote clotting when applied directly to the bleeding surface. These agents play a better role in the capillary but cannot block arterial or venous bleeding effectively under any significant intravascular pressure. On the other side, ornipressin mainly has a vasoconstriction effect on the volumetric blood vessels, leading to pale appearance at the injection site. When it comes to the local vasoconstrictor action, ornipressin is similar to adrenaline. Therefore, in order to reduce blood loss and construct a bloodless surgical area, ornipressin is used for generating local hemostasis.


From the perspective of local vasoconstrictor property, ornipressin is almost equivalent to epinephrine. Regardless of whether the anesthetic is used, ornipressin agents have been used for controlling bleeding in burn treatment, gynecologic procedures, scalp infiltration for neurosurgery procedures, and prostatic surgery. Esophageal varices are also treated with intravenous ornipressin. For hemostasis, solutions containing up to 5 U of ornipressin in 20 to 60 mL of 0.9% sodium chloride are penetrated into the area involved. In most cases, the appropriate amount of ornipressin is 0.01 IU/mL. However, this value has a wide variation practically. It's worth noting that the maximum total dose of ornipressin is 5 IU, above which ornipressin may cause vasodilation.

Pharmacokinetics and metabolism

Ornipressin is a synthetic derivative of vasopressin (arginine-8-vasopressin) in which ornithine is substituted for arginine at the 8 position. The pressor and anti-diuretic effect of ornipressin depend on the alkalinity of the amino-acid residue at position 8 of the molecule. With tissue infiltration, the onset of ornipressin activity occurs within three minutes. Topical application of ornipressin to debrided areas produces hemostasis within 20 seconds. The duration of ornipressin action continues about 45 to 120 minutes. Ultimately, it is metabolized in the liver and kidneys.


1. Berde, B., Boissonnas, R. A., Huguenin, R. L., Strumer, E., Vasopressin analogues with selective pressor activity. Experimentia, 1964, 20: 42-43.

2. Zingg, H. H., Vasopressin and oxytocin receptors. Bailliere's Clin Endocrinolog Metab, 1996, 10: 75-96.

3. Kam, P. C. A., Tay, T. M., The pharmacology of ornipressin (POR-8): a local vasoconstrictor used in surgery. European Journal of Anaesthesiology, 1998, 15(2): 133-139.

4. Clodius, L., Smahel, J., POR 8, a new vasoconstrictor substitute for adrenaline in plastic surgery. British Journal of Plastic Surgery, 1970, 23(1): 73-76.

5. Lamont, A. S., Yorke, P., Maximum safe dose of POR 8. Anaesth Intensive Care, 1987, 15(4): 467.

Creative Peptides has accumulated a huge library of peptide knowledge including frontier peptide articles, application of peptides, useful tools, and more!

Basic information Desmopressin is a synthetic analogue of the antidiuretic hormone vasopressin used in the treatment of centr ...

 The thymopentin is a small peptide consisting of 5 amino acid residues (Arg-Lys-Asp-Val-Tyr) from thymosin. It h ...

 Myristoyl pentapeptide-7, a cosmetic peptide, is a synthetic peptide containing lysine and threonine residues, w ...

  BIM 189 is one of the most potent bombesin antagonists known in the guinea pig and 3T3 cell systems but has 40% ...

 NFAT, the nuclear factor of activated T cells, is a family of transcription factors that play an important role ...

Contact Us



Tel: |




Copyright © 2024 Creative Peptides. All rights reserved.