ADH antagonists

Question 1

A patient has hyponatremia with low serum osmolarity and high urine osmolarity; name a drug that works by antagonizing the defective pathway

Answer 1

This is syndrome of inappropriate antidiuretic hormone secretion and can be treated by demeclocycline, which is an antidiuretic hormone antagonist

Question 2

Examples of ADH antagonists

Answer 2

• Conivaptan
• Tolvaptan
• Demeclocycline

Question 3

Block action of ADH at V₂–receptor

Answer 3

• Conivaptan
• Tolvaptan

Memory aid:

• _V_2 receptor antagonist
• _V_aptans

Question 4

Conivaptan

• SimD
• MOA
• Uses
• SE

Answer 4

• SimD
  
  • Tolvaptan, Lixivaptan
• MOA
  
  • Antagonist at V1, V2 receptors
• Uses
  
  • SIADH
  • Hyponatremia
• SE
  
  • Infusion site reactions
  • Hyperkalemia
• Memory aid:*
• VAptAN – VAsopressin ANtagonists

Question 5

Demeclocycline

• MOA
• Uses
• SE

Answer 5

• Class
  
  • ADH antagonist
  • Tetracycline
• MOA
  
  • Antagonist at V1, V2 receptors
• Uses
  
  • SIADH
  • Hyponatremia
• SE
  
  • Bone and teeth abnormalities
  • Renal failure