Antimicrobial Therapy Flashcards
1
Q
Combinations
A
- Additive
- Synergistic
- Antagonistic
- Potentiation
2
Q
Penicillin + Aminoglycoside
A
Synergistic
3
Q
Penicillin + Tetracycline
A
Antagonistic
4
Q
Penicillin + Clavulanic Acid
A
Potentiation
5
Q
Cell Wall Synthesis Inhibitors
— ALL cell wall inhibitors are BACTERICIDAL
A
• Penicillin • Cephalosporins • Other Beta Lactams - Monobactams - Carbapenems - Glycopeptide - Bacitracin
6
Q
- MOA: X Transpeptidation
- Alexander Fleming
- Penicillin — Penicilloic Acid
- Bactericidal
A
Penicillin
7
Q
Stability of Penicillin
A
- Crystalline/ powder form
- Solutions/ Suspension must be freshly prepared
- Suspensions 14 days — ✔️ ref
7 days — ✖️ ref
- Suspensions 14 days — ✔️ ref
- Amber colored bottles
8
Q
Special precautions for Penicillins
A
Cross-reactivity w/ Cephalosporins
9
Q
Drug-Drug Interactions of Penicillin
A
• Ampicillin + Allopurinol = Rash
• Penicillin + B blocker = Hypersensitivity
• Penicillin + Probenecid = ⬆️ Penicillin levels
— blocks the tubular secretion of Penicillin
10
Q
Pharmacokinetics of Penicillin
A
- Absorption varies greatly
- Food retards absorption (except Amoxicillin)
- Distribution: Poor penetration
- Excretion: Kidney
15
Q
Natural Penicillins
A
- Pen G – acid labile
* Pen V – acid stable
16
Q
Beta lactamase resistant
— narrow spectrum
A
- Methicillin
- Oxacillin
- Cloxacillin
- Nafcillin
- Dicloxacillin
17
Q
Extended Spectrum
A
- Aminopenicillins
- Carboxypenicillins — Antipseudomonal
- Ureidopenicillins — Antipseudomonal
18
Q
Aminopenicillins
A
- Ampicillin
- Amoxicillin
- Bacampicillin
19
Q
Carboxypenicillin
A
- Carbenicillin
* Ticarcillin
20
Q
Ureidopenicillin
A
- Mezlocillin
- Azlocillin
- Piperacillin
21
Q
- G (+), G (-), anaerobes, spirochetes
- Aqueous Pen G
- Procaine Pen G
- Benzathine Pen G
A
Pen G
22
Q
Prophylaxis of rheumatic fever and tx of syphilis
A
Pen G
23
Q
- Phenoxymethyl Penicillin
- Oral — Vivig
A
Pen V
24
Q
- X active against G (-)
- Antistaphylococcal
A
Beta lactamase resistant
25
Q
Special precautions of Cephalosporins
A
- Pseudomembranous colitis
- Coagulation abnormality
- Nephrotoxicity
26
Q
Pharmacokinetics of Cephalosporins
A
- Absorbed in GIT
- Delayed by food
27
Q
Drug-Drug Interactions of Cephalosporins
A
- 2nd/3rd Gen + Ethanol= Disulfiram Like effect
- Aminoglycosides = severe nephrotoxicity
- Anticoagulants = bleeding
- Probencid = ⬆️ T 1/2
28
Q
1st Gen
A
“Ceph-“
— EXCEPTION: Cefazolin, Cefalexin, Cefadroxil, Cefradine
29
2nd Gen
"Cef-"
— ✖️ end with "-one" and "-ime"
— EXCEPT: Cefuroxime
— Alternatively, most 2nd gen are "Cef" + vowel
30
3rd Gen
"Cef-"
— Most end with"-one" and "-ime"
— EXCEPT: Cefditoren, Cefdinir, Moxalactam, Ceftibuten
—Most 3rd gen are "Cef" + consonant
31
3rd Gen can cross BBB except:
- Ceftibuten
- Cefixime
- Cefpodoxime
- Cefoperazone
32
4th Gen
• Cefipime
• Cefpirome
— associate w/ "pi"
33
Other Beta Lactams
* Monobactams
* Carbapenenem
* Glycopeptides
* Bacitracin
34
- Reserved for serious infections
- G (-)
- Resistant to beta lactamase
Monobactams
| — Aztreonam
35
Carbapenems
- Imipenem
- Meropenem
- Ertapenem
36
- Strep. orientalis
- ✔️ MRSA
- If VRSA — Daptomycin or Linezolid
- AE: Red Man Syndrome
Vancomycin
| Glycopeptides
37
- G(+)
- Nephrotoxic
- Topical only
Bacitracin
38
Protein Synthesis Inhibitors
| "Buy AT 30 CELLS for 50"
* Tetracyclins
* Aminoglycosides
* Chloramphenicol
* Macrolides
* Limcosamides
* Linezolid
* Streptogrammins
39
- MOA: ✖️ 30s
- Absorption: Impaired by food
EXCEPT: Doxycycline and Minocycline
- Excretion: Kidney
- Indications: Cholera, Mycoplasma, Chlamydia, Rickettsia,
Demeclocycline — SIADH
Tetracyclines
40
Warnings for Tetracyclines
- Photosensitivity, esp. Demeclocycline
- Hepatotoxic
- Nephrotoxic, except: Doxycycline — excreted in the urine
- Yellow discoloration in teeth, bone deformities in children
41
- MOA: ✖️ 30s
- G (-)
- Bactericidal
- ✖️anaerobes
- ✖️ absorbed in GIT
Aminoglycosides
42
AE of Aminoglycosides
* Ototoxic — Neomycin, Amikacin, Kanamycin
* Nephrotoxic — Neomycin, Gentamicin, Tobramycin
* Vestibulotoxic — Streptomycin, Gentamicin
43
Interactions of Aminoglycosides
* + Cephalosporins = Nephrotoxic
| * + NMJ Blockers = Paralysis
44
- MOA: ✖️ 50s
- Bacteriostatic
- DOC: Typhoid
Chloramphenicol
45
AE of Chloramphenicol
- Grey baby syndrome (Neonates)
- Bone marrow suppression (Dose-related)
- Aplastic anemia (non-dose related)
- Avoid in G6PD deficient patient (hemolytic anemia)
46
- MOA: ✖️ 50s
- G (-), G (+), anaerobes
- inhibit CYP450 enzymes
- most common AE: GI disturbances
Macrolides
47
- isolated from soil in IloIlo
- Estolate salt (best preparation)
- DOC: CAP, Chlamydia, Corynebacterium
Erythromycin/ Ilothycin
48
- for Toxoplasma and Mycobacteria
| - ✔️ Eythromycin-resistant Staph and Strep
Clarithromycin
49
- excreted in the bile
| - ✔️ renally impaired px
Azithromycin
50
- MOA: ✖️ 50s
Lincosamides
51
- Streptomyces lincolnensis
| - similar activity to macrolides
Lincomycin
52
- AE: Pseudomembranous colitis
Clindamycin
53
- MOA: ✖️ 50s
| - For VRSA, VREF
Linezolid
54
- MOA: ✖️ 50s
- For VREF
- Synercid = Quinopristine + Dalfopristin
Streptogrammins
55
Nucleic Acid Synthesis Inhibitors
* Sulfonamides
* Trimethoprim
* Co-trimoxazole
* Quinolones
56
- MOA: ✖️ dihydropteroate synthesis
- similar structure to PABA
- indication: PCP, Toxoplasma
Sulfonamides
57
Forms of Sulfonamides
* Oral absorbable - Sulfisoxazole
* Oral nonabsorbable - Sulfasalazine
* Topical - Silver Sulfasalazine
58
- MOA: ✖️ dihydrofolate reductase
| - AE: Megaloblastic anemia (macrocystic)
Trimethoprim
59
- Bactrim
- Trimethoprim + Sulfamethoxazole
- Indications: UTI, PCP, Pyrlonephritis
- ✖️ Pregnancy
Co-trimoxazole
60
- MOA: ✖️ DNA gyrase
- Bactericidal
- Well absorbed orally
- Indications: UTI, PCP, G (-) infections
- AE: tendonitis
Quinolones
61
1st Gen
Nalidixic Acid
62
2nd Gen
- Ciprofloxacin
- Ofloxacin
- Norfooxacin
63
3rd Gen
- Levofloxacin
| - Sparfloxacin — Active for Strep.
64
4th Gen
- Moxifloxacin
| - Travafloxacin
65
Anaerobic Inhibitors
* Metronidazole
| * Clindamycin
66
- MOA: In aerobes: converted to free radicals
- Antiprotozoal: Trichomonas, Entamoeba, Giardiasis
- Antibacterial: PUD, Pseudomembranous colitis — DOC
Metronidazole
67
Drugs for Mycobacteria
- Drugs for TB/ Anti Koch's Drugs
| - Drugs for Leprosy/ Anti Hansen Drugs
68
Drugs for TB/ Anti Koch's Drugs
* Isoniazid
* Rifampicin
* Pyrazinamide
* Ethambutol
* Streptomycin
69
- Tuberculocidal — Rapidly dividing
- MOA: ✖️ mycolic acid synthesis
- for intracellular, extracellular bacteria
- penetrates all body fluids
- AE: peripheral neuropathy, hepatitis
Isoniazid
70
- Tuberculocidal
- MOA: ✖️ RNA synthesis
- Active for slow dividing bacteria
- Hepatic enzyme inducer
- from Streptomyces mediterranei
- AE: red discoloration of body fluids
Rifampicin
71
- Tuberculocidal
- MOA: ✖️ ETC in mycobacteria
- good penetration to meninges
- ✔️ TB meningitis
Pyrazinamide
72
AE for Pyrazinamide
- Hepatotoxicity
- Gout
- Vertigo and Hearing loss
73
- Tuberculostatic
- ✖️ Arabinogalactan synthesis (cell wall component)
- ✖️ penetrate meninges
- AE: Optic neuritis
Ethambutol
74
- only parenteral 1st line drug (poor GI absorption)
| - DOC: Tularemia and infections of bubonic plague
Streptomycin
75
Inactivated by beta lactamase
Extended Spectrum
76
- Highest BA
| - Prodrug: Bacampicillin
Ampicillin
77
- Antipseudomonal
- ✔️ for serious infections
- Tazocin = Piperacillin + Tazobactam
Carboxypenicillin and Ureidopenicillin
78
- More stable against Beta lactamase
- X active Listeria & Enterococcus
- Bactericidal
- Pregnancy Category: B
Cephalosporins
79
1st Line — TB
| TB — MDRTB
RIPES
| HRZE
80
2nd Line — TB
| MDRTB — XDRTB
- Ethionamide
- Aminoglycosides
- Fluoroquinolones
- Cycloserine
- Linezolid
- P-aminosalicylic acid
81
- Usually 2 months
- Use Tuberculocidal, INH, Rifampicin, PRZA
- Kill actively and rapidly dividing bacteria (large population killed)
First Phase/ Intensive Phase
82
- 4 months
| - aim to kill slowly dividing bacteria
Second/ Maintenance Phase
83
Tx failure
If px is still (+) after 5 months of tx
84
- min. of 9 months tx
- intensive: 2-3 months
- maintenance: 7-9 months
Extrapulmonary TB
85
Drugs for Leprosy/ Anti Hansen Drugs
* Dapsone
* Rifampicin
* Clofazimine
86
- Structurally related to sulfonamides
- MOA: ✖️ Folic acid synthesis
- Indications: PCP, intermediate & Tuberculoid Leprosy
Dapsone
87
- Sulfone-resistent therapy
- Fat soluble
- AE: skin discoloration
Clofazimine
88
- Tx: 6 months
Dapsone
Rifampicin
Tuberculoid
89
- Tx: 24 months
Dapsone
Rifampicin
Clofazimine
Lepromatous
