Antimicrobial .pptx of diploma in pharmacy

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1. SULFONAMIDES Sulfonamides (sulfa  drugs ) are drugs that are derived from sulfanilamide, a sulfur-containing chemical. The antibacterial sulfonamides agents that contain the  sulfonamide group and other non-antimicrobial compound e.g. Sulfonylureas and  thiazide diuretics  are newer drug groups based upon the antibacterial sulfonamides Sulfonamides are structural analogs of  para -aminobenzoic acid ( PABA ) 

2. Mechanism of action It inhibit two sequential step in the synthesis of tetrahydrofolic acid, sulfamethoxazole inhibit the incorporation of PABA into dihydrofolic acid and trimethoprim prevents reduction of dihydrofolate to tetrahydrofolate

3. I ndication: Lung infections (pneumonia ) caused by a bacteria called  Pneumocystis jirovecii . Infections caused by a bacteria called Toxoplasma (toxoplasmosis). Urinary bladder or urinary tract infections Respiratory tract infections such as bronchitis. Ear infections such as otitis media. An infection called nocardiosis which can affect the lungs, skin and brain. Adverse-effects: Hyperkalaemia , Overgrowth of fungal, Headache, Nausea, vomiting, diarrhea, skin rashes, renal and hepatic impairment

4. Contraindications • Hypersensitivity to sulfonamides, trimethoprim, co-trimoxazole. • severe liver parenchymal damage. • severe renal insufficiency. • infants during the first 6 weeks of life. • Co-Trimoxazole should not be given to patients with acute porphyria Dose: Adult: Cotrimoxazole(160/ 800mg ) daily 7 days per weeks Child: Cotrimoxazole(80/ 400mg ) daily 7 days per weeks

5. Sulfacetamide Sulfacetamide is a sulfonamide antibiotic with bacteriostatic actions and broad-spectrum activity against most gram + ve and many gram - ve organisms. Mechanism of action: Sulfacetamide inhibit multiplication of bacteria by acting as competitive inhibitors of p-aminobenzoic acid in the folic acid metabolism cycle.

6. Indication: For bacterial eye infections (such as conjunctivitis)  For skin infections as a topical Contraindication & precaution: Hypersensitivity Corneal ulcer Adverse effect: -Skin reaction - corneal ulcer -irritation - conjunctival hypremia Dose: 10, 20, 30% concentration as a eye drop or ointment

7. Silver Sulfadiazine It is a sulfonamide antibiotic with bacteriocidal actions and broad-spectrum activity against most gram + ve and many gram - ve organisms as well as effective against yeast. Mechanism of action: Silver binds to surface membrane & proteins, causing proton leaks in the membrane leading cell death Sulfadiazine is competitive inhibitors of p-aminobenzoic acid in the folic acid metabolism cycle.

8. Indication: It is used on the skin for 2 nd or 3 rd degree burns. Contraindication: Hypersensitivity enzyme deficiency ( G6PD or glucose-6-phosphate dehydrogenase deficiency) Side effect: brownish gray discoloration of skin, nails or clothing Pain, burning, or itching of the treated skin may occur Application to large areas or to severe burns may lead to systemic absorption and lead to adverse effects similar to those of other sulfonamides. Dose: 1% cream topically

9. SULFASALAZINE It exerts anti-inflammatory activity in the bowel and is useful in ulcerative colitis. In addition, it suppresses the disease in significant number of RA patients Mechanism of action It spilt into colon by bacteria into 5- aminosalicylic acid (5-ASA) and sulfapyridine (SP). 5-ASA is COX (I & II) inhibitor which block the production of prostaglandins and leukotrienes. Sulfapyridine shows anti-bacterial activity. Indication: ulcerative colitis rheumatoid arthritis Crohan’s disease

10. Contraindications and precautions: hypersensitivity to sulfasalazine, sulfonamides or salicylates intestinal or urinary obstruction Adverse effects: anorexia, headache, nausea, vomiting, gastric distress Hepatotoxicity Dose: The usual maintenance dose for ulcerative colitis is 2 grams daily. The daily dosage is then adjusted according to the patient’s response and tolerance NOTE: Take with adequate fluids. It may require supplements of folic acid or iron

11. PENICILLIN Penicillin, one of the first and still one of the most widely used antibiotic agents In 1929, Alexander Fleming isolated penicillin from a strain of Penicillium notatum It belongs to Beta- lactum antibiotic All penicillin works by inhibiting the bacterial enzymes responsible for cell wall synthesis in replicating microorganisms and by activating other enzymes to break down the protective wall of the microorganism. The several kinds of penicillin synthesized by various species of the mold  Penicillium  may be divided into two classes: the natural penicillin and  semisynthetic penicillin

12. Chemistry of Penicillin

13. Classification of Penicillin 1. Natural Penicillin: penicillin G Penicillin V 2. Beta lactamases Resistant Penicillin: Methicillin Oxacillin Cloxacillin 3. Aminopenicillins: These are extended s pectrum antibiotics. Ampicillin Amoxicillin 4. Carboxypenicillins: These are also extended spectrum antibiotics. Carcenicillin Ticarcillin 5. Ureidopenicillins: These are extended spectrum antibiotics. Mezlocillin Piperacillin

14. General Mechanism It inhibit bacterial growth by interfering with transpeptidation reaction It binds with penicillin binding protein ( PBP ) of bacteria and inhibit the enzyme DD-transpeptidase that is essential for for bacterial cell wall rigidity This lead weak cell wall formation undergo lysis. NOTE : Transpeptidation:- cross-linking of adjucent peptidoglycan standards

15. COMMONLY USED PENICILLIN BENZYL PENICILLIN ( penicillin G or crystalline penicillin) It is a beta-lactam penicillin that inhibits penicillin-binding protein 3 and thereby inhibits bacterial cell synthesis and results in cell lysis. INDICATION Used in the treatment of bacterial endocarditis, meningococcal meningitis, pneumococcal meningitis etc. CONTRAINDICATION AND PRECAUTIONS hypersensitivity heart failure, spirochete infection and neurotoxicity Hematological disorder

16. Adverse effects: 1. Hypersensitivity - Rashes -Urticaria -Serum sickness-like reactions 2. Hematological toxicities - Thrombocytocytopenia -Neutropenia - Haemolytic anaemia Angioedema Joint pain DOSE Adult: 2-4 gm every 4 hour Child: 150 mg/kg daily

17. PHENOXYMETHYL PENICILLIN( penicillin V ) It is natural penicillin having a narrow spectrum antibiotic. It binds to the penicillin- binding proteins inside the bacterial cell wall. It inhibits the third and last stage of bacterial cell wall synthesis Indication It is used in the treatment of mild to moderately severe bacterial infections. Contraindication and precautions: Contraindicated in patients with hypersensitive reaction Precaution should be taken by patients with penicillin allergy

18. Adverse effects: Nausea and vomiting Diarrhoea Increased capillary fragility Abdominal discomfort etc. Dose Adult: 250-500 mg TDS Child(>12 year): 125-250 mg TDs

19. Ampicillin It is a broad-spectrum, semi-synthetic, beta-lactam penicillin with bactericidal activity. It is stable against hydrolysis by a variety of B-lactamases therefore, can be used in combination with cloxacillin MOA It binds to and inactivates penicillin-binding proteins ( PBP ). Inactivation of PBPs interfers with the cross-linkage of peptidoglycan chains. This interrupts bacterial cell wall synthesis and results in the weakening of the bacterial cell wall and causes cell lysis. Indication -respiratory tract infections, - urinary tract infections, -meningitis, - salmonellosis, -endocarditis.

20. Contraindication and precautions hypersensitivity reaction and in allergy to other penicillins . increase the risk of bleeding with concurrent use of warfarin. Blood disorder Adverse effects: GI effects (diarrhea, nausea), rash Thrombocytopenia Leukopenia, neutropenia, anaemia , eosinophilia and agranulocytosis Seizures Dose: Adult: 250-500 mg QID orally; 1-2 QID IM/IV Child: 50-100 mg/kg/day

21. CLOXACILLIN It is semisynthetic antibiotic that is chlorinated derivatives of oxacillin It is also used in combination with ampicillin or amoxicillin This is best absorbed when taken on an empty  stomach  (1 hour before or 2 hours after meals) MOA By binding to specific penicillin-binding proteins ( PBPs ) located inside the bacterial cell wall, cloxacillin inhibits the third and last stage of bacterial cell wall synthesis

22. Indication: treatment of beta-hemolytic streptococcal, pneumococcal, and staphylococcal infections S/E; Nausea, diarrhea, stomach upset Allergic reaction Contraindication: Hypersensitivity Renal impairment Dose: Adult: 250-500 mg QID orally; 1-2 QID IM/IV Child: 50-100 mg/kg/day

23. AMOXICILLIN Amoxicillin is a board-spectrum semi synthetic antibiotic. MOA : Same as cloxacillin Indication: Amoxicillin is used to stop or treat certain bacterial infections, such as infections of the ear, nose , throat, urinary tract and skins. Adverse Effects: - Rashes - Exfoliative dermatitis - diarrhea - Nausea and vomiting - agitation - Insomnia - Muscle weakness - Bleeding

24. NEW GENERATION PENICILLINS MEROPENEM Meropenem is a broad-spectrum antibiotic which is active against gram +ve and gram - ve bacteria. MOA Meropenem exerts its action by penetrating bacterial cells readily and interfering with the synthesis of vital cell wall components, which leads to cell death. Indication febrile neutropenia. complicated skin and skin structure infections, complicated intra abdominal infections and bacterial meningitis

25. Contraindication and Precautions: Contraindicated in patients with hypersensitivity Precaution should be taken by patients with history of hypersensitivity to Beta- lactum antibiotics, neurological disorder, renal insufficiency etc. Adverse Effects: Anaphylaxis Pseudomembranous colitis Stevens- johnson syndrome Nausea and vomiting Abdominal pain Diarrhoea Constipation

26. Dose: Adult: 0.5 to 1 gm 8 hourly Child: <7 days: 20 mg/kg 12 hourly; 7-28 days: 20 mg/kg 8 hourly; 1-3 month: 10 mg/kg 8 hourly;>3 month and <50 kg: 10-20 mg/kg 8 hourly.

27. CARBAPENEM It is naturally derived product of Streptomyces cattleya . Indication: Abdominal infections urinary tract infections Pneumonia Bloodstream Infections Contraindication: hypersensitivity allergic reactions to B-lactam antibiotics

28. Adverse effects: Serious and occasionally fatal allergic reactions Seizures are a dose-limiting toxicity for both carbepenem and meropenem Clostridium difficile-related diarrhea Those with an allergy to penicillin may develop a cross sensitivity to carbapenems Dose: 500 mg 8 hourly (infusion in 1 hour) 5-14 days.