| Class | Vasopressin receptor agonist |
|---|---|
| Chemistry |
Benzazepine |
| Routes of administration |
IV, oral |
| Absorption |
Oral bioavailability 40% |
| Solubility |
pKa 11.4; slightly soluble in water |
| Distribution |
VOD=0.5L/kg; 99% protein bound |
| Metabolism |
99% metabolised in the liver, mainly by CYP3A |
| Elimination |
Half life is 5 hours |
| Time course of action |
Duration of effect is about 12 hours |
| Target receptor |
Has affinity for both V2 and V1A receptors |
| Mechanism of action |
By decreasing the insertion of aquaporins into the apical membrane of collecting duct cells, prevents the reabsorption of water. This distal site of action means this class of drugs is free from electrolyte-depleting side effects (i.e. only water is excreted) |
| Clinical effects |
Hypernatremia, hyperkalemia, diuresis |
| Literature reference |
FDA PI data sheet |
| CICM details of understanding | Not specifically listed in the CICM syllabus |
| Mentioned around Deranged Physiology | |
| Related SAQs |