Sulphonamides - antimicrobial

Question 1

What is the MOA of sulphonamides and trimethoprim (TMS)?

Answer 1

folate synthesis inhibitors

Question 2

Side effects/contraindications?

Answer 2

• Sulphonamides have been around for a long time so have to be aware of widespread resistance and should do a necropsy culture
• TOXICITY
  1/ crystalluria (beware during dehydration)
  2/ dry eye
  3/ hepatic necrosis

Question 3

PK quirks?

Answer 3

• wide distribution (bone, CNS, joints) Combine of sulphonimides with TMS to potentiate the antibacterial effects and make them bactericidal

Question 4

Representative drugs

Answer 4

Trimethoprim potentiated sulphonamides:

• Sulfadiazine trimethoprim - a whiteluid that can go IV
• sulfadimine, Trimethoprim
• sulfadimidine, Trimethoprim - used for colds in horses
• Wound dressing: Silver sulphadiazine, chlorhexidine - used for burns
• sulfasalazine - an inactive antibiotic + aspirin metabolite. Gets the aspirin to the colon, used for IBS in dogs.