Antidiuretics help control fluid balance by reducing urination. They are divided into three categories: antidiuretic hormone and analogues like vasopressin; natriuretics like thiazides that cause sodium excretion and water retention; and miscellaneous agents like carbamazepine. Antidiuretic hormone and analogues work by binding to V1 and V2 receptors, promoting water reabsorption and vasoconstriction/vasodilation. Natriuretics inhibit sodium transporters. Miscellaneous agents enhance antidiuretic hormone effects. Common uses include treating diabetes insipidus. Side effects of antidiuretic hormone include headaches and gastrointestinal issues.

1. ANTIDIURETICS
3 rd YEAR PHARM.D
PHARMACOLOGY II

2. DEFINITION:
An antidiuretic is a substance that helps to
control fluid balance in our body by reducing
urination, opposing diuresis.
Antidiuretics reduce urine volume, particularly
in diabetes insipidus, which is one of their
main indications.

3. CLASSIFICATION:
These agents are divided into three categories,
• Antidiuretic hormone and its analogues
• Natriuretics
• Miscellaneous

4. EXAMPLES
ANTIDIURETIC HORMONE AND ITS ANALOGUES:
• Vasopressin
• Desmopressin
• Lypressin
• Terlipressin
• Oxytocin

5. NATRIURETICS:
• Thiazides
• Amiloride
MISCELLANEOUS:
• Carbamazepine
• Chlorpropamide
• Indomethacin

6. M.O.A
1 ADH AND ITS ANALOGUES:

7. 2 NATRIURETICS:
• These drugs cause excretion of sodium alone
in the urine but causes retention of water in
the body.
• They inhibit NaCl co transporter in renal distal
convoluted tubule. The antidiuretic action of
thiazides is secondary to increased sodium
excretion.

8. 3 MISCELLANEOUS:
• These agents induce the release of or
enhance the action of Anti Diuretic Hormone,
at least partially by reducing the production of
prostaglandins in the kidney.
• These agents are useful as antidiuretics in
diabetic patients.

9. PHARMACOLOGICAL ACTIONS:
• ADH and its analogues leads to
vasoconstriction and cause an increase in
arterial pressure.
• It promotes re absorption of water from renal
tubular epithelium.
• Used to treat diabetes insipidus, increased
thirst and urination.

10. • ADH binds at V1 receptors and causes
constriction of blood vessels and leads to raise
in B.P.
• At V2 receptors it promotes endothelium
dependent NO production and causes
vasodilation.
• ADH on GIT – increased peristalsis,
evacuation and expulsion of gases.
• ADH induces platelet aggregation and hepatic
glycogenolysis.

11. • Thiazides helps to prevent our body from
absorbing too much salt, which can cause fluid
retention.
ADR for ADH and its analogues:
• Transient headache and flushing
• Nasal irritation, Congestion, Rhinitis
• Belching, Nausea, Vomiting
• Abdominal cramps, Pallor, Backache,
Contraction of uterus in females.

12. ROLE OF THIAZIDES IN TREATING
DIABETES INSIPIDUS:

13. CONTRAINDICATIONS FOR ADH AND
ITS ANALOGUES:
• Ischemic heart disease
• Hypertension
• Chronic nephritis
• Psychogenic polydipsia