Antibiotic Slide Deck Flashcards

1
Q

What are common causes of drug resistance?

A
    • Overuse of broad-spectrum abx.
    • Over prescription of abx. for viral illnesses
    • Use of abx in animals that enter the food chain
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2
Q

Which type of bacteria has a cytoplasmic membrane surrounded by a touch rigid mesh cell wall?

A

Gram +

Ex: staph aureus, strep pneumoniae, clostridium - stain purple

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3
Q

Which type of bacteria has a thin cell wall surrounded by a second lipid membrane?

A

Gram -

Ex: E. coli, pseudomonas, H. pylori, Neisseria, gonerrhea, salmonella - stain pink

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4
Q

What type of antibiotic stops the bacteria from growing but does not kill it?

A

Bacteriostatic

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5
Q

What type of antibiotic kills the bacteria?

A

Bactericidal - important to use this type in patients that are immunocompromised

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6
Q

Important factors to keep in mind when prescribing antibiotics:

A
    • immune system function
    • renal and hepatic function
    • Age
    • Pregnancy/lactation
    • Risk for multi-drug-resistance organisms
    • Patient adherence: lowest frequency for the shortest duration
    • cost effective - for kids: taste good and most concentrated dose
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7
Q

What is the MOA of the penicillins?

A

Inhibit the biosynthesis of peptidoglycan bacterial cell wall

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8
Q

Penicillin V and Penicillin G Benzathine are active against what type of organisms?

Are they narrow or broad-spectrum?

A

Narrow spectrum

Most effective against gram +

Mostly:

  • S. pneumoniae, Group A strep (GABHS) –> bactericidal Pen V (oral) is best for group A beta-hemolytic strep - strep throat/pharyngitis
  • syphilis infection (T. pallidum) –> Pen G (IV) best for
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9
Q

Amoxicillin and Augmentin (Amox/Clavulanic Acid) are active against what type of organisms?

A

Broad spectrum, bactericidal

Gram +/-

  • Amoxicillin* - 1st line for AOM and sinusitis
  • Augmentin* (Amox/Clavulanic acid) - 1st line fx for bites, UTI in pregnancy
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10
Q

PCNs Adverse Drug Reactions (ADR)

A
  • serious allergic hx (anaphylaxis)
  • Rash - Stevens-Johnson syndrome
  • GI (N/V/D)
  • possible C.Diff associated diarrhea (CDAD)
  • Fungal overgrowth/candidiasis - Vaginitis
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11
Q

Cephalosporin MOA

A
  • Inhibit mucopeptide synthesis in the bacterial cell wall Bactericidal
  • 5 generation that is increasing in gram (-) coverage and less gm (+) coverage
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12
Q

Common Gm (+) and where the common infections they cause

A

•Staphylococcus aureus

  • Commonly causes skin infections
  • Can also cause endocarditis, sepsis, osteomyelitis, pneumonia
  • -Methicillin-resistant (MRSA) and methicillin-sensitive (MSSA)*

•Streptococcus Groups A,B,C,F,G

–Pyogenes (pharyngitis [GAS], impetigo, cellulitis)

–Pneumoniae (pneumonia, meningitis, sepsis)

–Agalactiae (meningitis, vaginitis [GBS], UTI, endocarditis, skin infection)

– Significant Macrolide resistance

•Enterococcus faecalis

–Anaerobic

–Can cause UTI, prostatitis, intra-abdominal infections, cellulitis, endocarditis

•Bacilli

–Lactobacilli -present in the mouth, vagina

–C. difficile

•Listeria

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13
Q

Common Gm (-) organisms and the infections they cause

A

•Escherichia coli

–Found in the intestines of humans and animals

–Responsible for:

  • f_ood-borne illness (traveler’s diarrhea)_
  • UTI
  • cholecystitis, sepsis

•Pseudomonas aeruginosa

–Most common in hospitalized patients

–Can cause otitis externa, pneumonia, wound infection, UTI, sepsis

Klebsiella pneumoniae

–Colonizes the human mouth and gut

–Commonly causes Pneumonia, UTI, sepsis

– Risks: ETOH use, DM

•Neisseria gonorrhoeae

•Haemophilus influenzae

Pneumonia, bronchitis, otitis media, c_ellulitis, infectious arthritis_

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14
Q

How does the spectrum of activity differ between generations of Cephalosporins?

A

-Earlier generations have good gram + coverage and less gram - coverage

-Later generations have better gram - coverage and less gram + coverage

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15
Q

Cephalosporins ADRs

A
  1. C. diff-associated infx in adults (Clostridioles)
  2. Hypersensitivity rx (most common) - cross rx PCN allergy (anaphylaxis, rash)
  3. Hemolytic anemia,
  4. Neutropenia, Leukopenia,
  5. Coagulation abnormalities (thrombocytopenia)
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16
Q

Cephalosporins cautions/CIs

A
  • hx of PCN allergy with anaphylaxis or hypersensitivity rx
  • -safe in pregnancy/lactation and pediatrics
  • The stronger the drug (later generation)-the more chance of a C. Diff infection
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17
Q

What drug is in the glycopeptide class?

A

Vancomycin (PO)

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18
Q

Vancomycin MOA and indication

A

MOA: inhibits cell wall synthesis by binding to the D-A1a-D-A1a protein in the cell wall; narrow, only Gm+

  • oral is not well absorbed so usually IV admin
  • stays in the GI tract

- used for C. diff. infection (given only orally for C.diff)

  • Corynebacterium, Listeria, Lactobicillus, Actinomyces, Clostridium
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19
Q

Vancomycin (oral) ADRs

A
  • ototoxicity
  • nephrotoxicity

** monitoring for hearing and renal function

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20
Q

Lincosamides Class (Clindamycin) active against/MOA

A

Clindamycin

narrow, Gm + , bacteriostatic

MOA: inhibits protein synthesis by binding to the 50S subunit of bacterial ribosome

Indications: MRSA skin infections, dental infections, acne (topical)

-Carries highest risk for C. Diff

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21
Q

Clindamycin: education

A
  • take w/ full glass of water
  • sit or stand for 30 minutes after dose
  • call the clinic if diarrhea occurs
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22
Q

Macrolides: MOA/indications

A

Azithromycin, Erythromycin, Clarithromycin

  • Gm + / - and atypical
  • Bacteriostatic @ low dose
  • Bacteriocidal @ high dose
  • Consider safe in pregnancy
  • Alternative to penicillin allergy
  • Consider macrolide-resistant S.pneumoniae if pt has taken a macrolide in the past 3 months
  • Convenient dosing (azithromycin[Z-pack]) only 5 days

MOA: inhibits RNA-dependent protein synthesis by binding to the 50S subunit

*Indications: *Think respiratory for this class**

  • 1st line CAP
  • 1st line pertussis
  • 1st line chlamydia (tx urethritis 2nd to chlamydia)

*

23
Q

Macrolides: ADRs

A

- potent CYP450 inhibitor (esp erythromycin and Clarithromycin [Biaxin])

–> many major drug interactions

  • Interacts with Statins, Ca Channel blockers, antiretrovirals, colchicine, carbamazepine
  • -combination with statins (increase serum statins, risk of myopathy, rhabdomyolysis, hepatitis)
  • skin rash (urticaria, bullous eruptions, eczema, SJS)
  • GI distress (esp. Erythomycin)

Azithromycin is most common well-tolerated macrolides (rare GI effects) - the risk of QT prolongation (cautions with pts with Dysrhythmias)

24
Q

Tetracyclines: MOA/indications

A

Tetracycline/Doxycycline

MOA: inhibit protein synthesis by reversibly binding to the 30S subunit of the bacterial ribosome

  • -Work against gm +/- and atypical
  • -BacterioSTATIC

Indications:

  • Doxy 1st line for Rocky Mountain spotted fever (RMSF) and Lyme dz
  • CAP (2nd line)
  • Mild to moderate respiratory tract infection (atypical), AECB, skin (acne, rosacea)
25
Q

Tetracyclines: Cautions/CI/ADRs

A
  • Avoid in pregnancy (Cat D), lactation, and children < 8 years old
  • d/t teeth discoloring

- Avoid antacids as they are Inactivated by Ca+ and aluminum

ADRs:

    • nephrotoxic
    • hepatotoxicity
    • photosensitivity (use hat sunblock)
26
Q

Tetracyclines: Education

A
  • Take with a full glass of water
  • Do not take with milk or milk products (binds to calcium)
    • Best to take 1 hr before or 2 hrs after a meal
    • or Take on an empty stomach
  • Can cause stomach upset/esophagitis
  • May decrease effectiveness of oral contraceptives
  • Wear sunglasses, hats, sunblock when expose
27
Q

Fluoroquinolones: MOA

A

Ciprofloxacin, Levofloxacin

MOA: interferes with bacterial enzymes required for the synthesis of bacterial DNA - breakage of DNA strands/Inhibit DNA synthesis

28
Q

Fluoroquinolones: INDICATIONS

A

Complicated severe infections

    • pyelonephritis (1st line)
    • complicated UTIs
  • CAP (3rd line) -
    • after tetracycline (2nd line)
29
Q

Fluoroquinolones: cautions/CIs/ADRs

A
  • BBW:
  • risk of tendon rupture and tendonitis
  • risk fo aortic dissection
  • risk of QT prolongation (avoid use with other QT-prolonging drugs like amiodarone, macrolides, TCA),

-dizziness, confusion, seizures, photosensitivity

  • high risk of superinfection (C.Diff, candida)
  • Increasing resistance - not to be used for minor uncomplicated infections

Contraindications:

  • children < 18 (unless pyelonephritis, anthrax, allergies to other meds)
  • pregnancy (Cat C) and lactation
  • elderly
  • hx of HTN, aneurysm, CVD
  • myasthenia gravis
30
Q

Sulfonamides/Trimethoprim (SMX/TMP) - MOA

A

Sulfonamides inhibit folic acid synthesis

Trimethoprim inhibits DNA synthesis

Excellent Broad spectrum, both gm +/-

31
Q

Sulfamethoxazole and Trimethoprim (Bactrim) Indications

A

- UTI

-Community-acquired MRSA

-excellent gram - (E.coli, Klebsiella, H. flu) and gram + (staph and strep) coverage,

-pneumocystis, chlamydia

32
Q

Sulfonamides and Trimethoprim: Cautions/CIs

A

Common hypersensitivity reactions:

  • rash, fever, SJS (more common in HIV + patients)

Contraindications

  • pregnancy (anti-folate effects) - esp in 1st trimester
  • pediatrics < 2 months old (risk of hyperbilirubinemia)

-Avoid concomitant** administration with **K+ sparing drugs (triamterene, ACE, ARB) d/t Hyperkalemia (reduces K+ excretion)

-Avoid with warfarin (increase risk of bleeding, increase INR)

33
Q

Nitrofurantoin: MOA/Indications

A

•Multifactorial MOA

•Bacteriostatic in low concentrations, Bactericidal in higher concentrations

-May inhibit acetyl coenzymes --> interferes with bacterial protein synthesis, cell wall synthesis, and aerobic energy metabolism Indications:

Indication:

  • uncomplicated UTI (1st line),
  • Not indicated in complicated infections/pyelonephritis
34
Q

Nitrofurantoin ADRs

A

neuropathy, pulmonary reactions

35
Q

Metronidazole [Flagyl]: MOA/Indications

A

MOA: Damage DNA structure – causing strand breakage, inhibition of protein synthesis, and cell death

  • BROAD-spectrum (gm +/- anaerobic bacteria and parasitic: protozoans, fungal)
  • Bacteriostatic

Indications:

  • C. diff,
  • bacterial vaginosis,
  • stool infections,
  • trichomoniasis (think below the belt infections), giardia
36
Q

Metronidazole ADRs

A
  • metallic taste
  • dark urine
  • hepatotoxicity
  • superinfections (rare)
37
Q

Metronidazole: cautions/CIs/pt education

A

- AVOID in the 1st trimester of pregnancy

  • take with food
  • Avoid ETOH during and for 2 days after tx (can cause disulfiram rx: N/V, H/A, flushing, dizziness, chest and abdominal discomfort)
  • BBW: potentially carcinogenic
38
Q

Tinidazole: MOA/indications

A

MOA: thought to cause cytotoxicity by damaging DNA and preventing DNA synthesis

- newer, more expensive

Indications: bacterial vaginosis, trichomoniasis - more for fungal, protozoan, parasitic infections - not as much bacterial

39
Q

Tinidazole cautions/CIs

A

- Avoid in pregnancy

- BBW: potentially carcinogenic

40
Q

Impetigo treatment

A
  1. Mupirocin (Bactroban; monoxycarbolic acid class) topically 3x/day for 5-14 days for up to 5 lesions
  2. Cephalexin [Keflex] or Cefadroxil [Duricef] (PO, a cephalosporin 1st gen) if there are 5 or more impetigo lesions
41
Q

Oral medication options for SKIN LESIONS

A
  • Cephalosporin 1st gen (Cephalexin, Cefadroxil), Augmentin, Bactrim (TMJ, SMZ)
    • moderate to severe impetigo (5 or more lesions), boils, perianal strep, cellulitis
  • CBD (cephalexin, bactrim, doxycycline)
    • Dicloxacillin If MRSA skin infection is suspected
42
Q

Oral Candidiasis treatment

A

Antifungal:

  • nystatin or clotrimazole lozenges
43
Q

Antifungal agents

A
  • used to treat vulvovaginal yeast infections
  • Topical
  • Miconazole and clotrimazole
  • Oral
  • Fluconazole oral (systemic) x 1 dose
44
Q

Topical treatment of tinea pedis (athlete’s foot) or tinea corporis (ringworm)

A
  • thin layer of terbinafine, miconazole, ketoconazole, clotrimazole
  • use BID

- wash hands well before and after use

45
Q

Topical HERPES simplex (Shingles) treatment

A
  • topical acyclovir (zovirax) , or penciclovir (denavir, and OTC docosanol (Abreva))
  • start as soon as possible
46
Q

Fluconazole (Oral) MOA/indications

A
  • interferes with fungal CYP 450 activity
  • inhibits cell membrane formation

- broad-spectrum, antifungal, systemic effect

Indications: candidiasis (vaginal, oropharyngeal, esophageal)

47
Q

Fluconazole: cautions/CIs

A

-Hard on liver –> Monitor hepatic function

  • CYP 3A4 and 2C9 inhibitor

-QT prolongation –> check EKG

-Avoid in pregnancy

48
Q

Itraconazole MOA/indications

A
  • interferes with fungal CYPE 450 activity
    • inhibits cell membrane formation
  • broad-spectrum systemic treatment

Indications: onychomycosis (nail fungus) but Terbinafine/Ciclopirox (topical) is first-line for Onychomycosis

49
Q

Itraconazole cautions/CIs

A
  • hard on the liver
  • QT prolongation

- avoid in pregnancy

- BBW: avoid in patients with HF/myocardial dysfunction

50
Q

Terbinafine/Ciclopirox (topical) : MOA/indications

A
  • synthetic allylamine derivative
  • inhibits squalene eposidase enzyme (a key enzyme in sterol biosynthesis in fungi
  • results in fungal cell death
  • metabolized by CYP450

Indication: onychomycosis (1st line)

  • Off label: extensive tinea fungal infection
51
Q

Terbinafine cautions/CIs

A

- arrhythmias (think QT)

- hepatic impairment

- avoid in pregnancy

52
Q

Terbinafine ADRs

A
  • hepatotoxicity hepatic failure
  • blood dyscrasias
53
Q

Amoxicillin

A
  • Broad spectrum beta-lactam penicillin
    • both Gm +/- but more effective against gram (-)
  • Bactericidal
  • PO 2-3x/day
  • Against
    • Group A strep, S. pneumo, staph, H. influenza
54
Q

Amoxicillin/Clavulanic acid [Augmentin]

A

For otitis media, sinusitis, lower RI, skin (cellulitis), bites