Drugs acting on posterior pituitary Flashcards
What are the conditions during which oxytocin and ADH are released?
Increase in plasma osmolarity, Parturition, Increase in blood volume & redistribution of blood
ADH is structurally related to what hormone?
Oxytocin
What are the two roles of ADH?
Vasopressor and anti-diuretic property
What are the receptors that respond to in changes in plasma osmolarity, blood volume?
Osmoreceptors (present in hypothalamus) & Baroreceptors (veins, atria & Carotids)
On what receptors does vasopressin act that are located on blood vessels of liver & smooth muscles?
V1 receptors
What effect does vasopressin have on V1 receptors?
Vasoconstriction
On what receptors does vasopressin act that are located on DCT & Collecting ducts of nephron?
V2 receptors
What effect does vasopressin have on V2 receptors?
Reabsorption of H2O &b production of concentrated urine
What are the adverse effects of natural vasopression?
Water intoxication and Hyponatremia
What is the drug that belongs to Synthetically Modified Selective V2 receptor agonsit?
Desmopressin
Desmopressin is used in the treatment of?
Diabetes Insipidus & Nocturnal Enuresis (Nocturnal involuntary urination/bedwetting)
Desmopressin is contraindicated in which patients?
Children for enuresis that causes seizures
Name the condition where an elevated level of Vasopressin is seen
Syndrome of Inappropriate ADH
What are the choice of drugs in SIADH?
Vasopressor receptor Antagonist and Demeclocycline
What drugs fall under Vasopressin receptors Antagonist?
Conivaptan & Tolvaptan
