Core pharmacology

Class Group

Vasopressin Analogue

Legacy Cicm Level

Level 2

Introduction

Synthetic analogue of 8-arginine vasopressin (ADH)

Antidiuretic peptide drug

displays enhanced antidiuretic potency, fewer pressor effects due to V2-selective actions, and a prolonged half-life and duration of action compared to endogenous ADH

Indications Uses

Central DI – ADH replacement (Intranasal/parenteral)
Nocturnal polyuria (intranasal).
Haemostasis in Haemophilia with fVIII def or Type 1 Von Willebrand disease during surgical procedures and postoperatively to maintain hemostasis (parenteral).

Chemical Pharmaceutics

Deamino Arginine Vasopressin

Presentation

sublingual tablet, intra nasal spray, IV/IM

Main Action

Acts at the GPCR Vasopressin receptors

Mechanism of action

Acts at the GPCR Vasopressin receptors
V1 on vascular smooth muscle – vasoconstrictive – markedly less than ADH (1500x less than ADH)
V1 on platelets - increase platelet aggregation – more potent than ADH
V2 on the nephron - expressed in the renal collecting duct (CD) - antidiuretic actions (10x ADH)

Physiological effects

Vasoconstriction (less)
Increased platelet aggregation
Antidiuretic (more)

Adverse Effects Toxicity

OD – Hyponatremia (Seizure, altered mental state, arrythmias, edema)

Absorption

BA
SL: 0.25%
PO: 0.08-0.16%
Intranasal: 10%

Protein binding

20%

Volume of distribution

0.2-0.32 L/kg

Metabolism

Minimal hepatic metabolism

Excretion

65% unchanged in urine

Half-life

2-3hrs

Route And Dose

sublingual tablet, intra nasal spray, IV/IM
0.1 to 1.2 mg divided into 2 or 3 doses