Antibiotics

1. Chapter 4
Antibiotics
BY :SANJAY
RAJPUROHIT

2. Chapter 4 Topics
• Bacteria
• How Antibiotics Work
• Classes of Antibiotics
• Antibiotics Independent of Classes
• Adjunct in Treating Sepsis
• Discussion Questions

3. 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.
• Use antibiotic and general drug terminology
correctly in written and oral communications.

4. Fighting Bacterial Infections
• Bacteria: microorganisms that cause
infection
• Bactericidal agent: kills the invading
organism
• Bacteriostatic agent: inhibits the growth or
multiplication of bacteria

5. Types of Bacteria
• Aerobic bacteria
• Anaerobic bacteria

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

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

8. Gram’s Stain Results and Related
Diseases
Shape Gram’s
Stain
Bacteria Related
Disease
rods gram-positive Corynebacteria endocarditis
gram-negative E. Coli UTI

9. Gram’s Stain Results and Related
Diseases
Shape Gram’s Stain Bacteria Related Disease
cocci gram-positive Staphylococcus toxic shock
syndrome
gram-negative Neisseria gonorrhea

10. Gram’s Stain Results and Related
Diseases
Shape Gram’s Stain Bacteria Related Disease
curved or
spiral rods
gram-negative Campylobacter septicemia
spirochetes gram-negative Treponema
palladium
syphilis

11. How Antibiotics Work
• Block protein formation

12. How Antibiotics Work
• Block protein formation
– Macrolides
– Tetracyclines
– Aminoglycosides

13. How Antibiotics Work
• Block protein formation
• Inhibit cell wall formation

14. How Antibiotics Work
• Block protein formation
• Inhibit cell wall formation
– Penicillins
– Cephalosporins

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

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

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

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

19. Antibiotic Dispensing Issues
• Mix exactly as directed by manufacturer
• Swab counting tray with alcohol between
drugs to prevent cross-contamination
Warning!

20. Antibiotic Side Effects
• Most antibiotics should be taken on an
empty stomach to attain faster absorption

21. Antibiotic Side Effects
• Most antibiotics should be taken on an
empty stomach to attain faster absorption
• Examples of exceptions
– nitrofurantoin (Macrobid, Macrodantin)
– cefuroxime (Ceftin, Zinacef)

22. Antimicrobial Resistance
• Developing largely because of
–overuse
–misuse

23. Antimicrobial Resistance
• Developing largely because of
– overuse
– misuse
• The Pharmacy Technician’s role
– Place an label on antibiotics advising the
patient to take all of the medication

24. Discussion
How might the widespread use of
antibacterial soaps affect the
population?

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

26. Sulfonamides
• AKA “sulfa drugs”
• Effective against a broad range of
microorganisms
• Block specific step in biosynthetic pathway
of folic acid
• Interfere with PABA and folic acid
formation, thereby destroying bacteria

27. Sulfonamides and
Related Drugs
• nitrofurantoin (Macrobid, Macrodantin)
• sulfamethoxazole-trimethoprim (Bactrim
DS, Septra DS)
• sulfisoxazole (Gantrisin)
Drug List

28. Sulfonamides
• If patient is allergic to sulfa….

29. Sulfonamides
• If patient is allergic to sulfa….
nitrofurantoin (Macrobid, Macrodantin)

30. Therapeutic Uses of Sulfonamides
• Urinary tract infections (UTIs)
• Otitis media
• Ulcerative colitis
• Lower respiratory infections
• Prophylaxis in Pneumocystis carinii
pneumonia in immunocompromised
patients

31. Sulfonamides’ Side Effects
• Rash
• Nausea
• Drug fever
• Vomiting
• Jaundice
• Blood complications
• Kidney damage

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

33. Penicillins
• Low toxicity
• Effective derivatives created from
manipulating drug’s basic molecular
structure
• Kills bacteria by preventing them from
forming the rigid cell wall
• Because human cells do not have cell walls,
they are not affected

34. Penicillins
• amoxicillin (Amoxil, Trimox)
• amoxicillin-clavulanate (Augmentin)
• ampicillin (Principen)
• ampicillin-sulbactam (Unasyn)
• carbenicillin (Geocillin)
Drug List

35. • dicloxacillin
• nafcillin
• oxacillin
• penicillin G (various)
• penicillin V (Veetids)
• piperacillin
Penicillins
Drug List

36. • piperacillin-tazobactam (Zosyn)
• ticarcillin (Ticar)
• ticarcillin-clavulanate (Timentin)
Penicillins
Drug List

37. Therapeutic Uses of Penicillins
• Abscesses
• Beta-hemolytic streptococcus
• Meningitis
• Otitis media
• Pneumonia
• Respiratory infections
• Tooth and gum infections
• Venereal diseases (syphilis and gonorrhea)
• Endocarditis due to streptococci

38. Penicillins’ Side Effects
• Diarrhea
• Allergies in 7% to 10% of population

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

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

41. Cephalosporins
• Have a mechanism of action similar to
penicillins
• A person allergic to penicillin, about 10%
chance of being allergic

42. Cephalosporins
Alert the Pharmacist if a patient
allergic to penicillins is receiving
a cephalosporin prescription.
Warning!

43. Cephalosporins
• First-generation

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

45. Cephalosporins
• Second-generation

46. Cephalosporins
• Second-generation
– Increased activity, especially against
Haemophilus influenzae
– Used for
• Otitis media in children
• Respiratory infections
• UTIs

47. Cephalosporins
• Third-generation

48. Cephalosporins
• Third-generation
– Active against a wide spectrum of gram-
negative organisms
– Long half-life, so once-a-day dosing for some
– Used for
• Ambulatory patients
• Children (dosing before or after school)

49. Cephalosporins Side Effects
• Share side effects of penicillin
• Few may initiate unique toxic reactions
• Lower frequency of toxicity than many
other antibiotics

50. Cephalosporins
All of the cephalosporins look
alike when written in the generic
form. Watch for dosing and
indications for use.
Warning!

51. • cefaclor (Ceclor)
• cefadroxil (Duricef)
• cefazolin (Ancef)
• cefdinir (Omnicef)
• cefditoren (Spectracef)
• cefepime (Maxipime)
Cephalosporins
Drug List

52. • cefotaxime (Claforan)
• cefotetan (Cefotan)
• cefoxitin (Mefoxin)
• cefpodoxime (Vantin)
• cefprozil (Cefzil)
• ceftazidime (Fortaz)
• ceftibuten (Cedax)
Cephalosporins
Drug List

53. • ceftizoxime (Cefizox)
• ceftriaxone (Rocephin)
• cefuroxime (Ceftin, Zinacef)
• cephalexin (Keflex)
• cephradine (Velosef)
Cephalosporins
Drug List

54. Tetracyclines
• Broad-spectrum bacteriostatic antibiotics
• Inhibit protein synthesis in bacteria by
binding to ribosomes
• Suppress the infection and require
phagocytes to complete the eradication of
the bacteria

55. Therapeutic Uses of Tetracyclines
• Acne
• Chronic bronchitis
• Lyme disease
• Mycoplasma pneumoniae infection
• Rickettsia infection
• Some venereal diseases, such as Chlamydia
infection
• Traveler’s diarrhea

56. Tetracyclines’ Side Effects
• Gastrointestinal upset with nausea and
vomiting

57. Tetracyclines’ Dispensing Issues
• Avoid antacids to avoid chelation with
minerals
• Photosensitization
• To be avoided by pregnant women and
children
• Expired drugs are dangerous

58. • demeclocycline (Declomycin)
• doxycycline (Vibramycin)
• minocycline (Minocin)
• tetracycline (Sumycin)
Tetracyclines
Drug List

59. Macrolides
• Inhibit protein synthesis by combining with
ribosomes
• Used primarily to treat pulmonary
infections

60. Macrolides
Drugs of choice for the following illnesses
and specific bacteria:
– Chlamydia
– Group A beta-hemolytic streptococcus
– H. influenzae
– Legionnaire’s disease
– M. pneumoniae
– S. pneumoniae

61. Macrolides’ Dispensing Issues
Although most antibiotics should be taken on
an empty stomach, erythromycins usually
cause severe GI distress, so should be taken
with food

62. Macrolides
Erythromycin and azithromycin
can be misread, but the dosing
should help.
Warning!

63. • azithromycin (Zithromax, Z-PAK)
• clarithromycin (Biaxin)
• dirithromycin (Dynabac)
• erythromycin base (Eryc, Ery-Tab)
• erythromycin ethylsuccinate (E.E.S., EryPed)
• erythromycin lactobionate (Erythrocin)
• erythromycin stearate (Erythrocin)
• erythromycin-sulfisoxazole (Pediazole)
Macrolides
Drug List

64. Ketolides
• Block protein synthesis by binding to ribosomal
subunits
• May inhibit the formation of newly forming
ribosomes
• Bacteria resistant to macrolides, lincomycin
derivatives, and streptogramins are also resistant
• Used to treat bacterial infections in the lungs and
sinuses

65. • telithromycin (Ketek)
Ketolides
Drug List

66. Quinolones
• Strong, rapid bactericidal action against
most gram-negative and many gram-
positive bacteria
• Antagonize the enzyme responsible for
coiling and replicating DNA, causing DNA
breakage and cell death

67. Therapeutic Uses of Quinolones
• Bone and joint infections caused by gram-
negative organisms
• Infectious diarrhea
• Ophthalmic infections
• Some sexually transmitted diseases
• Upper respiratory infections
• UTIs

68. Quinolones’ Side Effects
• Primarily gastrointestinal, with nausea and
vomiting
• Dizziness
• Unpleasant taste
• Can cause joint problems such as swelling
and malformations
• Patients taking them have a tendency to
injure tendons

69. Quinolones’ Dispensing Issues
• Not to be given with theophylline
• Antacids interfere with absorption
• Avoid exposure to sun

70. • ciprofloxacin (Ciloxan, Cipro)
• gatifloxacin (Tequin)
• gemifloxacin (Factive)
• levofloxacin (Levaquin)
• moxifloxacin (Avelox, Vigamox)
• norfloxacin (Noroxin)
• ofloxacin (Floxin, Ocuflox)
Quinolones
Drug List

71. Streptogramins
• Inhibit protein synthesis within the bacterial
ribosomes
• Alternative to vancomycin
• Side effects similar to quinolones
nausea and vomiting
joint swelling
dizziness

72. • quinupristin-dalfopristin (Synercid)
Streptogramins
Drug List

73. Aminoglycosides
• Treat serious infections
• Inhibits bacterial protein synthesis by
binding to ribosomal subunits

74. Aminoglycosides’ Side Effects
• Nephrotoxicity, destructive to kidney
• Ototoxicity
– Tinnitus
– Permanent deafness
– Equilibrium problems
• Neuromuscular blockade

75. Aminoglycosides
• Less frequent dosing may help reduce
toxicity
– Less drug accumulates in the kidney and ear
– Simplified drug monitoring
• Levels should be checked prior to
administration of second dose to confirm
drug elimination

76. • amikacin
• gentamicin (Garamycin, Genoptic)
• kanamycin (Kantrex)
• neomycin (Myciguent, Neo-Fradin)
• streptomycin (none)
• tobramycin (Nebcin)
Aminoglycosides
Drug List

77. Cyclic Lipopetides
• Bind bacterial membranes and cause the
cell membrane to depolarize
• Leads to
– Inhibition of DNA and RNA synthesis
– Bacterial death

78. • daptomycin (Cubicin)
Do not take with statins.
Warning!
Cyclic Lipopetides
Drug List

79. Antibiotics Independent of Classes
These antibiotics are independent of other
classes and each other due to structural
differences.

80. • chloramphenicol (Chloromycetin)
• clindamycin (Cleocin)
• linezolid (Zyvox)
• metronidazole (Flagyl)
• pentamidine (NebuPent, Pentam)
• vancomycin (Vancocin)
Antibiotics Independent
of Classes
Drug List

81. Antibiotics Independent of Classes
vancomycin (Vancocin)
Bacterial resistance is increasing
due to overuse.
Warning!

82. Antibiotics Independent of Classes
Uses of clindamycin (Cleocin)
– Acne
– Alternative to penicillin in dental prophylaxis
– Anaerobic pneumonia
– Bone infections
– Bowel infections
– Female genital infections
– Intra-abdominal infections

83. Antibiotics Independent of Classes
clindamycin (Cleocin)
If patient develops diarrhea, the
drug must be discontinued.
Warning!

84. Antibiotics Independent of Classes
metronidazole (Flagyl)
Place a do not drink alcohol warning sticker
on this medication.

85. Adjunct in Treating Sepsis
• Sepsis is a life-threatening result of serious
infections.
• Properties of drotrecogin alfa (Xigris)
– Anticoagulant
– Anti-inflammatory

86. • drotrecogin alfa (Xigris)
Adjunct in Treating Sepsis
Drug List

87. Discussion
Why is resistance developing to
antibiotics? Is this a problem? What
role can the pharmacy technician play
in regards to this problem?