sulfonamides.pptx

sulfonamides.pptx

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  SULFONAMIDES
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  INTRODUCTION  Sulfonamides werethe first effective, synthetic antibacterial agents to be used systemically in man.  They were introduced by Domagk in 1935 and in the next few years several of them were synthesized and widely used. Currently their role in therapeutics is limited because of their toxicity, development of resistance availability of safer drugs.
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  CLASSIFICATION 1. Short acting:Sulfisoxazole, Sulfadiazine 2. Intermediate acting: Sulfamethoxazole 3. Long-acting: Sulfamethoxypyridazine, sulfadoxine 4. Poorly absorbed: Sulfasalazine 5. Topical: Sulfacetamide, mefedine Silver sulfadiazine.
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  S. no. Drugs Doses 1. Sulfadiazime3g followed by 1-1.5gm every 6hrs. 2. Sulfisoxazole 4-6gm /per day in divided doses 3. Sulfasalazine 1-2gm 4time in a day or 2gm/day in divided doses. 4. Sulmethazaz ole 160 – 800mg every 12 hrs. 5. Sulfamethazi ne 3-6gm every 6hrs
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  ANTIBACTERIAL SPECTRUM  Itis wide spectrum antibiotic.  It inhibits many gram positive and some gram negative bacteria including streptococci, H. influenza, Norcardia, E. coli, proteus, V. cholerae, some stains of staphylococci, gonococci, memingococci and pneumococci.  They are also effective against Chlamydia, plasmodium falciparum and toxoplasma gondii.
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  MECHANISM OF ACTION PABA(Para-aminobenzoic acid) Folic acid synthesis DIHYDROFOLIC ACID Bacteria synthesize their own folic acid from PABA with the help of the enzyme folic acid synthetase. Sulfonamides are structurally similar to PABA and competitively inhibiting the enzymes folic acid synthetase.  They inhibit the enzyme folic acid synthase so folic acid is not synthesized (which is essential bacterial growth). SULFONAMIDES
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  PHARMACOKINETICS  Sulfonamides arewell absorbed, extensively bound to plasma proteins and are well distributed to all tissues.  They are metabolized in the liver and excreted in urine.  They can cross placental barriers.
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  COMMON USES  SYSTEMICUSES : sulfamethoxazole is used in combination with cotrimoxazolein many bacterial infections.  It is the drug of choice in pneumocystitis in AIDS patient.  Treatment of nocardiosis, toxoplasmosis, ulcerative colitis and rheumatoid arthritis.  TOPICAL USES: ocular sulfacetamide sodium is used in trachoma/inclusion conjuctivitis.  Topical silver sulfadiazine is used for preventing infection on burn surfaces.  Mefinide is active in the presence of pus and against pseudomonas, clostridia which are not inhibited by topical sulfonamides.
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  USES  Because ofthe development of resistance and availability of better antimicrobials, which are more effective and less toxic, these are not commonly used now except in a few cases:  UTI  NOCARDIOSIS  TOXOPLASMOSIS  TRACHOMAAND INCLUSION CONJUCTIVITIS  MALARIA  TOPICAL  ULCERATIVE COLLITIS
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   Contraindication &Precautions: Children younger than 2yrs, Pregnant and breast feeding mother, Renal and hepatic diseases, Hypersensitivity to sulphonamides drug.  Adverse effect: Fever, Rash, Nausea/vomiting, Aplastic Anemia.
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  DRUG INTERACTIONS 1. Sulphonamidescan increasing the blood thinning effect of warfarin, possibly leading to abnormal bleeding. 2. Increases blood level of potassium may occur when Sulfamethoxazole trimethoprim is combined with ACE inhibitors. 3. Sulphonamides may increase the effectiveness of oral hypoglycemics drugs. 4. Sulphonamides may increase the effectiveness of hormonal contraceptives drugs.
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  NURSING IMPLICATIONS  Patientshould be advised to take plenty of water.  These drugs should be avoided during pregnancy.  The renal functions should be regularly monitored.  Patient should be advised to avoid direct sun exposure.  Patient should be regularly enquired about any side effects.