VPT 311: General and Systemic Veterinary Pharmacology (2+1)

XANTHINES AND MERCURIALS

Xanthines

• These drugs stimulate cardiac functions. Their diuretic activity may stem from the resultant increase in renal blood flow and thereby an increase in glomerular filtration rate.
• They also exert a direct action on the renal tubule. Renal response is manifested by an increase in levels of sodium and chloride in urine.
• There is no significant change in the urine pH and potassium excretion appears to be relatively unaffected.
• Examples are: Caffeine, Theophylline

Mercurials

• Diuretic action of mercurials is associated with sulphydryl groups and so they inactivate the sodium transport mechanism of the nephron.
• For clinical use, mercurials are obsolete