1 / 104

Antibiotics

Antibiotics. Learning Objectives. Identify the major types of antibiotics by drug class. Know which auxiliary labels to use when dispensing major types of antibiotics. Define therapeutic effects, side effects, and administration routes of major antibiotics.

reina
Download Presentation

Antibiotics

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. Antibiotics

  2. Learning Objectives • Identify the major types of antibiotics by drug class. • Know which auxiliary labels to use when dispensing major types of antibiotics. • Define therapeutic effects, side effects, andadministration routes of major antibiotics. • Use antibiotic and general drug terminology correctly in written and oral communications.

  3. Anti-Infective Agents Antibiotics: Sulfonamides Penicillins Cephalosporins Tetracyclines Aminoglycosides Quinolones Macrolides

  4. Antibiotics • Medications used to treat bacterial infections • Ideally, before beginning antibiotic therapy, the suspected areas of infection should be cultured to identify the causative organism and potential antibiotic susceptibilities.

  5. Antibiotics • Empiric therapy: treatment of an infection before specific culture information has been reported or obtained • Prophylactic therapy: treatment with antibiotics to prevent an infection, as in intra-abdominal surgery

  6. Antibiotics • Bactericidal: kill bacteria • Bacteriostatic: inhibit growth of susceptible bacteria, rather than killing them immediately; will eventually lead to bacterial death

  7. Types of Bacteria • Aerobic bacteria needs oxygen to survive • Anaerobic bacteria survives in the absence of oxygen

  8. Bacteria Shapes (a) Round cocci (b) Rod-like bacilli (c) Spiral-shaped spirochetes

  9. Gram’s Stain Results and Related Diseases

  10. Gram’s Stain Results and Related Diseases

  11. Gram’s Stain Results and Related Diseases

  12. How Antibiotics Work • Block protein formation

  13. How Antibiotics Work • Block protein formation • Macrolides • Tetracyclines • Aminoglycosides

  14. How Antibiotics Work • Block protein formation • Inhibit cell wall formation • Interfere with DNA formation

  15. How Antibiotics Work • Block protein formation • Inhibit cell wall formation • Interfere with DNA formation • Nalidixic acid

  16. How Antibiotics Work • Block protein formation • Inhibit cell wall formation • Interfere with DNA formation • Prevent folic acid synthesis

  17. How Antibiotics Work • Block protein formation • Inhibit cell wall formation • Interfere with DNA formation • Prevent folic acid synthesis • Sulfonamides

  18. Sulfonamides One of the first groups of antibасterial agents • sulfadiazine • sulfamethizole • sulfamethoxazole • sulfisoxazole

  19. Sulfonamides: Mechanism of Action • Bacteriostatic action • Prevent synthesis of folic acid required for synthesis of purines and nucleic acid • Does not affect human cells or certain bacteria—they can use preformed folic acid

  20. Structure of sulfonamides para-Aminobenzoic acid sulfonamide

  21. Classification of sulfonamides(accordingly to duration of action) • Short action: streptocid, sulfadimezine, aethazole, norsulfazole, urosulfan, sulfizoxazole, sulfacyl-sodium • Medium duration of action: sulfamethoxazole (is a part of co-trimoxazole) • Longlasting action:sulfadimethoxyn, sulfapirydazin, sulfamonomethoxyn • Super longlasting action: sulfalen, sulfadoxyn (is a part of fansidar)

  22. Sulfonamides: sulfamethoxazole Therapeutic Uses Azo-Gantanol • Combined with phenazopyridine (an analgesic-anesthetic that affects the mucosa of the urinary tract). • Used to treat urinary tract infections (UTIs) and to reduce the pain associated with UTIs. Bactrim • Combined with trimethoprim. • Used to treat UTIs, Pneumocystis carinii pneumonia, ear infections, bronchitis, gonorrhea, etc.

  23. Co-trimoxazole (Bactrim) • 480 - for adults • 960 - for adults • 120 – for children • 240 – for children Orally 2 times daily

  24. Co-trimoxazole = Bactrim (trimethoprim + sulfamethoxazole)

  25. Sulfonamides: sulfisoxazole Therapeutic Uses Azo-Gantrisin • Combined with phenazopyridine • Used for UTIs Pediazole • Combined with erythromycin • Used to treat otitis media

  26. Sulfonamides: Side Effects Body System Effect Blood Hemolytic and aplastic anemia, thrombocytopenia Integumentary Photosensitivity, exfoliative dermatitis, Stevens-Johnson syndrome, epidermal necrolysis

  27. Sulfonamides: Side Effects Body System Effect GI Nausea, vomiting, diarrhea, pancreatitis Other Convulsions, crystalluria, toxic nephrosis, headache, peripheral neuritis, urticaria

  28. Sulfonamides’ Dispensing Issues • Avoid the sun • Maintain adequate fluid intake

  29. Sulfonamides Penicillins Cephalosporins Tetracyclines Macrolides Ketolides Quinolones Streptogramins Aminoglycosides Cyclic Lipopetides Classes of Antibiotics

  30. Antibiotics: Penicillins • Natural penicillins • Penicillinase-resistant penicillins • Aminopenicillins • Extended-spectrum penicillins

  31. Antibiotics: Penicillins Natural penicillins • penicillin G, penicillin V potassium Penicillinase-resistant penicillins • cloxacillin, dicloxacillin, methicillin, nafcillin, oxacillin

  32. Antibiotics: Penicillins Aminopenicillins • amoxicillin, ampicillin, bacampicillin Extended-spectrum penicillins • piperacillin, ticarcillin, carbenicillin, mezlocillin

  33. Antibiotics: Penicillins • First introduced in the 1940s • Bactericidal: inhibit cell wall synthesis • Kill a wide variety of bacteria • Also called “beta-lactams”

  34. S H2N CH3 CH3 T L O N C O OH Nucleus of penicillin molecule L – beta-lactame ring, T – thiazoline ring

  35. Antibiotics: Penicillins • Bacteria produce enzymes capable of destroying penicillins. • These enzymes are known as beta-lactamases. • As a result, the medication is not effective.

  36. Antibiotics: Penicillins • Chemicals have been developed to inhibit these enzymes: • clavulanic acid • tazobactam • sulbactam • These chemicals bind with beta-lactamase and prevent the enzyme from breaking down the penicillin

  37. Antibiotics: Penicillins • Penicillin-beta-lactamase inhibitor combination drugs: • ampicillin + sulbactam = Unasyn • amoxicillin + clavulanic acid = Augmentin • ticarcillin + clavulanic acid = Timentin • piperacillin + tazobactam = Zosyn

  38. Unasyn (ampicillin/sulbactam)

  39. Penicillins: Mechanism of Action • Penicillins enter the bacteria via the cell wall. • Inside the cell, they bind to penicillin-binding protein. • Once bound, normal cell wall synthesis is disrupted. • Result: bacteria cells die from cell lysis. • Penicillins do not kill other cells in the body.

  40. Penicillins: Therapeutic Uses • Prevention and treatment of infections caused by susceptible bacteria, such as: • gram-positive bacteria • Streptococcus, Enterococcus, Staphylococcus species

  41. Penicillins: Adverse Effects • Allergic reactions occur in 0.7% – 8% of treatments • urticaria, pruritus, angioedema • 10% of allergic reactions are life-threatening and • 10% of these are fatal

  42. Penicillins: Side Effects • Common side effects: • nausea, vomiting, diarrhea, abdominal pain • Other side effects are less common

  43. Penicillins’ Dispensing Issues • Take on an empty stomach • Food slows absorption • Acids in fruit juices or colas could deactivate the drug

  44. Penicillin Resistance • Penicillinase-resistant penicillins work against gram-positive aerobes • Extended-spectrum penicillins are more resistant to gram-negative bacteria • Penicillin combinations improve effect

  45. Antibiotics: Cephalosporins • First Generation • Second Generation • Third Generation • Fourth Generation

  46. S H2N L D N CH2 O CO CH3 O O C OH Structure of cephalosporins L – beta-lactame ring, D – dihydrothiazine ring

  47. Antibiotics: Cephalosporins • Semisynthetic derivatives from a fungus • Structurally and pharmacologically related to penicillins • Bactericidal action • Broad spectrum • Divided into groups according to their antimicrobial activity

  48. Cephalosporins: First Generation • cefadroxil • cephalexin • cephradine • cefazolin • cephalothin • cephapirin • Good gram-positive coverage • Poor gram-negative coverage

  49. Cephalosporins • First-generation • Similar to penicillinase-resistant penicillins with greater gram-negative coverage • Used for • community-acquired infections • mild to moderate infections

  50. Cephalosporins: First Generation cefazolin cephalexin (Ancef and Kefzol) (Keflex and Keftab) IV and PO PO used for surgical prophylaxis, URIs, otitis media

More Related