1 / 48

SULFONAMIDES

SULFONAMIDES. Now largely superceded by antibiotics and trimethoprim-sulfamethoxazole. They continue to occupy a small place in therapy. Wheel of Bugs. Gram-negative. H. influenzae. Neissseria spp. E. Coli (coliforms). Bacteroides spp. P. aeruginosa. Anaerobic. Clostridium spp.

joelle
Download Presentation

SULFONAMIDES

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. SULFONAMIDES • Now largely superceded by antibiotics and trimethoprim-sulfamethoxazole. • They continue to occupy a small place in therapy.

  2. Wheel of Bugs Gram-negative H. influenzae Neissseria spp E. Coli (coliforms) Bacteroides spp P. aeruginosa Anaerobic Clostridium spp S. aureus Streptococcus spp Enterococcus spp Gram-positive

  3. 2HN SO2NH2 FOLIC ACID BIOSYNTHESIS DIHYDROPTERIDINE 2 ATP PYROPHOSPHATE DERIVATIVE Dihydropteroate Synthetase 2HN COOH DIHYDROPTEROIC ACID Glutamic Acid DIHYDROFOLIC ACID

  4. BLOOD Protein Bound Kidney Metabolites Oral X Topical Parenteral Other-Sweat, Free Saliva, Prostatic fluid, Stool Body Fluids & Tissues CSF

  5. KERNICTERUS IN THE NEWBORN • Displacement of bilirubin from plasma protein binding sites.

  6. O 3HC C N METABOLISM H SO2N R Acetylated sulfonamides-inactive, toxic, and less soluble

  7. EXCRETION • They are excreted in the urine partly as the parent and partly as the metabolite. • Some sulfonamides are very insoluble in the acid urine.

  8. EXCRETION • Half life of the sulfonamides depends on renal function. • Dosage should be modified or the sulfonamides should not be used in renal failure.

  9. SULFONAMIDE PREPARATIONS • Rapidly absorbed and rapidly eliminated (prototype- sulfisoxazole). • Poorly absorbed sulfonamides (sulfasalazine). • Topical sulfonamides (sulfacetamide, silver sulfadiazine). • Long-acting sulfonamides (sulfadoxine)

  10. CONTRAINDICATIONS

  11. DRUG-DRUG INTERACTIONS • Inhibit metabolism of some drugs. • Displace certain drugs from plasma albumin.

  12. TRIMETHOPRIM-SULFAMETHOXAZOLE OCH3 2HN CH OCH3 2 OCH3 80 mg TRIMETHOPRIM 2HN SO2NH N CH3 O 400 mg SULFAMETHOXAZOLE

  13. COTRIMOXAZOLE • Optimal ratio of the two drugs is 5:1 sulfa :trimethoprim.

  14. Synergism

  15. ADVANTAGES • Expanded number of organisms inhibited. • Bactericidal . • Decreased resistance. • Decreased toxicity.

  16. THERAPEUTIC USES

  17. hcd2.bupa.co.uk/.../ html

  18. PNEUMOCYSTIS PNEUMONIA (PCP)

  19. PNEUMOCYSTIS PNEUMONIA (PCP) www.learningradiology.com/

  20. PNEUMOCYSTIS PNEUMONIA (PCP) • The most common opportunistic infection in advanced AIDS (80% of AIDS patients have at least one episode). • Now considered a fungus (P.jurovecii). • Multiple infections are often present simultaneously with the PCP.

  21. PROPHYLAXIS • Routine prophylaxis has been successful in improving survival. • PCP prophylaxis is indicated if the patient has a CD4 T lymphocyte count lower than 200 cells/mm3, or has oral candidiasis regardless of the CD4 count.

  22. TREATMENT OF PCP • Early therapy is essential as success of therapy is related to severity of the disease at the time of initiation of therapy.

  23. TMP-SMX • Treatment of choice. • Oral form used for mild-moderate cases or after initial response to IV therapy and for prophylaxis.

  24. TMP-SMX • Excellent tissue penetration. • Produces a rapid clinical response.

  25. DRUG INTERACTIONS • Same as with sulfonamides

  26. RESISTANCE • Results from multiple mechansims. • Altered dihydropteroate synthetase. • Cross-resistance among all sulfonamides.

  27. SULFONAMIDE TRIMETHOPRIM PABA + Pteridine Dihydropteroate Synthetase DIHYDROPTEROIC ACID Dihydrofolate Synthetase DIHYROFOLIC ACID Dihydrofolate Reductase TETRAHYDROFOLIC ACID

  28. ADVERSE EFFECTS • Hypersensitivity reactions -common • allergic rashes • photosensitivity • drug fever • Stevens-Johnson syndrome

  29. CRYSTALLINE AGGREGATES, HEMATURIA, OBSTRUCTION

  30. ADVERSE EFFECTS • Headache, nausea, vomiting and diarrhea. • Hematological effects -anemia, agranulocytosis.

  31. ADVERSE REACTIONS • Dermatological reactions including skin rashes. • GI (nausea and vomiting).

More Related