Ornipressin

Summary

Ornipressin (POR-8) is a synthetic vasopressin analogue used primarily as a vasoconstrictor in local anesthesia to prolong anesthetic effect and reduce bleeding, and in the management of portal hypertension-related bleeding. It has greater selectivity for V1 vascular receptors compared to vasopressin and shorter duration of antidiuretic effect.

Mechanism of Action

Selective agonist of vasopressin V1 receptors on vascular smooth muscle, causing vasoconstriction by increasing intracellular calcium via Gq/phospholipase C signaling; reduces splanchnic and peripheral blood flow with minimal antidiuretic (V2) activity.

Routes of Administration

Goals & Uses

• Local vasoconstriction adjunct to anesthesiaSurgical/anestheticHigh
• Control of variceal bleedingGastroenterologyModerate
• Reduction of intraoperative blood lossSurgicalModerate
• Management of circulatory shockCritical CareLow

Contraindications

• Hypertension (uncontrolled)CardiovascularModerate
• PregnancyPopulationHighPotential fetal risk or insufficient safety data
• Severe cardiovascular diseaseCardiovascularHigh
• Hypersensitivity to ornipressin or vasopressin analoguesAllergy/ImmunologyHigh
• Severe peripheral vascular diseaseVascularHigh

Adverse Effects

• HypertensionCardiovascularCommonHigh blood pressure
• Nausea and vomitingGastrointestinalUncommon
• Pallor and peripheral ischemiaVascularCommon
• Tissue necrosis at injection siteLocal/DermatologicalUncommon
• Cardiac arrhythmiasCardiovascularUncommon
• BradycardiaCardiovascularCommon

Drug Interactions

• Halogenated inhalation anesthetics (e.g., halothane)High
• Beta-blockersModerate
• Tricyclic antidepressantsModerate
• NSAIDsLowMay increase renal risk in susceptible patients

Population Constraints

• Renal impairmentOrgan ImpairmentRelative
• Pediatric patientsAgeRelative
• Hepatic impairment/cirrhosisOrgan ImpairmentRelative
• Elderly patientsAgeRelative

Regulatory Status

• European UnionApprovedApproved: Adjunct vasoconstrictor in local/regional anesthesia, Control of bleeding in surgeryApproved in several EU member states; availability varies by country.
• United StatesUnapprovedNot FDA-approved; not available for clinical use in the United States.
• United KingdomUnknownLimited information on current UK regulatory status post-Brexit; historically available in some European markets.

Approved in several European countries and other jurisdictions for use as a local vasoconstrictor adjunct. Not FDA-approved in the United States. Used in clinical practice in Europe, Latin America, and parts of Asia.

Evidence & Sources

No sources recorded yet.