HES 033: General Pharmacology (2024-2025) SAS 6 PDF

HES 033: GENERAL PHARMACOLOGY Doctor of Optometry │ Third Year - First Semester │ Academic Year 2024 - 2025 SAS 6 - Sulfonamides- Antileprotic DrugsI Instructor: Dr. Jo-An Belotindos Sulfonamides, Trimethoprim & Quinolones, Antimycobacterial and AntiLeprotic drugs...

HES 033: GENERAL PHARMACOLOGY Doctor of Optometry │ Third Year - First Semester │ Academic Year 2024 - 2025 SAS 6 - Sulfonamides- Antileprotic DrugsI Instructor: Dr. Jo-An Belotindos Sulfonamides, Trimethoprim & Quinolones, Antimycobacterial and AntiLeprotic drugs SULFONAMIDES The basic formulas of the sulfonamides and their structural similarity to p-aminobenzoic acid (PABA). Sulfonamides with varying physical, chemical, pharmacologic, and antibacterial properties are produced by attaching substituents to the amido group (— SO2 — NH — R) or the amino group (— NH2) of the sulfanilamide nucleus. Sulfonamides are more soluble at alkaline than at acid pH. Most can be prepared as sodium salts, which are used Resistance Resistance to sulfonamides may for intravenous administration. develop when bacterial mutations result: Certain microbes require p-aminobenzoic acid (PABA) in 1. in PABA overproduction order to synthesize dihydrofolic acid which is required to 2. in a folic acid synthesizing enzyme produce purines and ultimately nucleic acids. protein that has low affinity for Sulfonamides, structural analogs of PABA, are sulfonamides competitive inhibitors of dihydropteroate synthase and 3. impair permeability to sulfonamides. folate production Classifications Oral absorbable sulfonamides are Sulfonamides inhibit both gram (+) bacteria and gm (-) of absorbed from the stomach and small enteric bacteria. Sulfonamides: intestine and widely distributed to tissues It is bacteriostatic, not bactericidal. 1. Oral and body fluids (including the CNS Combination of a sulfonamide with an inhibitor of absorbable /CSF), placenta and fetus. dihydrofolate reductase (trimethoprim or pyrimethamine) 2. Oral, Protein binding varies from 20% to provides synergistic activity because of sequential over 90%. Non-absorbable inhibition of folate synthesis. Sulfonamides and inactive 3. Topical metabolites are excreted by the kidney thru glomerular filtration. In renal failure, the dosage of sulfonamide must be reduced. The fixed-drug combination of TMP-SMZ is the drug of choice for infections such as Pneumocystis jiroveci (formerly P. carinii) pneumonia, toxoplasmosis, and nocardiosis. 1. Sulfadiazine in combination with 1. Oral pyrimethamine (antiprotozoal absorbable agent, dihydrofolate reductase Agents inhibitor) is first-line treatment for acute toxoplasmosis. 2. Sulfadoxine, a long-acting sulfonamide, is used in combination with pyrimethamine (Fansidar) as a second-line option for treating malaria 1  HES 033: GENERAL PHARMACOLOGY Doctor of Optometry │ Third Year - First Semester │ Academic Year 2024 - 2025 SAS 6 - Sulfonamides- Antileprotic DrugsI Instructor: Dr. Jo-An Belotindos 2. Oral, Sulfasalazine Sulfonamides may precipitate in Non-absorbabl (salicylazosulfapyridine) is used in urine producing crystalluria, e agents treating inflammatory bowel hematuria or even obstruction. disorders. 1. Sodium sulfacetamide ophthalmic 3. Topical solution/ointment is effective in the Agents treatment of bacterial conjunctivitis but considered as 2nd-line due to potential allergic reactions 2. Mafenide acetate is used topically but can be absorbed from burn sites. The drug and its primary metabolite Stevens-Johnson syndrome inhibit carbonic anhydrase and can cause metabolic acidosis Crystalluria is treated by administration of sodium bicarbonate to alkalinize the urine and fluids to increase 3. Silver sulfadiazine is a less toxic urine flow. topical sulfonamide and widely used Sulfonamides may provoke hemolytic reactions in for prevention of infection of burn patients with glucose-6-phosphate dehydrogenase wounds however, it may slow wound [G6-PD] deficiency. healing Sulfonamides taken near the end of pregnancy increase the risk of kernicterus in newborns. 1. SULFISOXAZOLE 2. SULFAMETHIZOLE 3. SULFACYTINE Member Drugs 4. SULFAMETHOXAZOLE 5. SULFASALAZINE 6. (SALICYLAZOSULFAPYRIDINE) 7. SODIUM SULFACETAMIDE 8. MAFENIDE 9. SULFADIAZINE 10. SULFAPYRIDINE 11. SULFADOXINE 12. CO-TRIMOXAZOLE Most Common: fever, skin rashes, Adverse exfoliative dermatitis, reactions of photosensitivity, urticaria, nausea, Sulfonamides vomiting, diarrhea, urinary tract problems following precipitation of drug in urine. Sulfonamides may cause Stevens-Johnson syndrome (