Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Boards II > Pharm Antimicrobials > Flashcards

Pharm Antimicrobials Flashcards

1
Q

Drug groups

  • cell wall inhibitors
  • protein synthesis inhibitors
  • bacterial DNA interference
A

CW: pens, cephs, bacitracin

PS: aminoglycosides & tetracyclines (30S), chloramphenicol, macrolides, & clindamycin (50S)

DNA: sulfonamides, TMP, & pyrimethamine (folic acid), fluoroquinolones (DNA gyrase and topo IV)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

For most class of oral antibiotics, __ effects are common and should be kept in mind when prescribing/educating

A

GI - nausea, vomiting, bloating, decr appetite, diarrhea

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Cell wall inhibitors

  • building blocks of cell walls
  • glue/mortar that holds blocks together
  • drugs that work on each
A

Peptidoglycan

Transpeptidase

Pep-can = bacitracin
Transpep = pens, cephs
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Bacitracin

  • MOA
  • clinical indications
  • dosing
A

Inhibits transfer of peptidoglycans (mucopeptides) into the growing cell wall

ONLY gram(+)
Blepharitis

Ung only
QD to TID

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What components make up

  • Polysporin
  • Neosporin
A

P: Bacitracin (+) and Polymyxin B (-)

N: Polysporin and neomycinq

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Penicillins

  • drug names (2)
  • MOA
  • clinical indications
A

Amoxicillin (Principen)
Dicloxacillin (Dynapen)

Inhibits transpeptidase (glue/mortar)

A&D both have good gram (+)
A has better gram (-); combined with clav acid to become resistant to pcnase (Augmentin)
D is resistant to penicillinase (as is oxacillin, cloxacillin)
-DOC for methicillin-sensitive staph infections (esp MSSA), however is NOT EFFECTIVE AGAINST MRSA
A&D: combat bacterial infections of the eyelid (e.g. hordeola, preseptal cell) that are most often caused by S. aureus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Pencillins

  • dosing
  • adverse effects
  • pregnancy
A

Augmentin: 500, 875, or 1000mg tablets BID x 1 week
Dicloxacillin: 250mg QID x 1 week

Hypersensitivity rxns: urticaria & anaphylaxis (IgE type 1), contact derm (type 4)
Stevens-Johnson syndrome from amoxicillin

Generally very safe in all trimesters

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Penicillin and Cephalosporin cross-sensitivity

A

Both have beta-lactam rings

  • P = 5-member
  • C = 6

(+)PCN allergy = 1% chance also allergic to 1st gen cephs

Both contraindicated in pts with hx of IgE type 1 HSRxn (urticaria, anaphylaxis)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Cephalosporins

  • drug names (2)
  • MOA
  • clinical indications & dosing
A

Cephalexin (Keflex)
Ceftriaxone (Rocephin)

Inhibits transpeptidase (glue/mortar)

All have good gram (+)
3rd and 4th gen have better gram (-) coverage

Cephalexin (Keflex): 1st gen; commonly rx’d for skin infxn - dacryoadenitis, dacryocystitis, preseptal; do not use in isolation for MRSA suspect; 250-500mg BID to QID

Cephtriaxone (Rocephin): 3rd gen; intravenous ceftriaxone is the TOC for gonococcal conjunctivitis and orbital cellulitis
Gono conjitis: if cornea-involving 1g IV every 12-24hrs with varying duration (usually 3-5 days); if not involving cornea single 1g IM injection
Orbital: 1g IV QD x 1 week

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Cephalosporins

-adverse rxns

A

Hypersensitivity

May destroy the normal intestinal microflora, altering absorption of vit K = excessive thinning of the blood in pts taking warfarin (vit K antag)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Aminoglycosides

  • drug names (2)
  • MOA
  • clinical indications & dosing
  • adverse effects
A

Gentamicin (Garamycin)
Tobramycin (Tobrex)

Bind to 30S to inhibit protein synthesis

Effective against gram (+) and (-), with better (-)
Previously used 1st line against ocular bact infxns (now use fluoros)
T: available in topical ophthalmic and ung form
G&T: available in fortified concentrations and rx’d with fortified cefazolin (1st gen) for sight-threatening corneal ulcers

SPK, delayed corneal re-epithelialization

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

TobraDex

  • components
  • clinical indications
A

Tobramycin 0.3% (30S/aminoglycoside)
Dexamethasone 0.1%

QID for inflammatory conditions with associated bacterial infxn: staph marginal keratitis, corneal infiltrates

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Tetracyclines

  • drug names (3)
  • MOA
A

Tetracycline
Doxycycline
Minocycline

Bind to 30S to inhibit protein synthesis & prevent access of aminoacyl tRNA
Bacteriostatic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Tetracyclines

-clinical indications & dosing

A

Minocycline: low dose for long-term mx of acne vulgaris

Doxycycline: alters the configuration of oil glands & decr the release of irritating free fatty acids

  • meibomianitis: 50 or 100mg BID x 4-8 weeks (or until symptom relief) then QD 3-6mo
  • acne rosacea: 100mg BID until symptoms relief (2-6 weeks) then taper to 100 QD for several weeks; some pts require long-term tx with Periostat = low-dose 20mg tablet; Metronidazole (MetroGel) topical gel 1% can be used for pts with chronic acne rosacea
  • chlamydia conjitis:
  • RCEs:
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Tetracyclines

  • pharmacokinetics
  • adverse effects
A

Absorption in the GI tract is impaired by cations in dairy, antacids, and iron-containing compounds
Primary route of excretion is kidney - contraindicated in renal failure
Doxycycline is an exception: can be taken with food, is eliminated in fecal matter, is safe for renal failure

Contraindicated in pregnancy and children
Pseudotumor cerebri, bone growth retardation, discoloring teeth
Minocyline: blue sclera, pigmented cysts on conj

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Chloramphenicol

  • brand name
  • MOA
  • adverse effects
A

Chloroptic

Bind to 50S to inhibit protein synthesis
Effective against gram (+) and (-)

Topical use has caused fatal aplastic anemia
Extended tx can cause optic neuritis

17
Q

Macrolides

  • drug names
  • MOA
A

Erythromycin
Azithromycin (Zithromax, Azasite)
Clarithromycin (Biaxin)

Bind to 50S to inhibit protein synthesis

18
Q

Macrolide clinical indications & dosing

A

Oral azithro (Zithromax): chlamydial infxns (trachoma, adult inclusion) = single 1g, taken on empty stomach

  • also available in Z-pak: six 250mg (2 capsule day 1, 1 capsule remaining 4 days)
  • Tri-pak: three 500mg

Topical ophthalmic azithro (Azasite): bacterial conjitis and blepharitis

  • conjitis: BID x 2 days, then DQ x 5 days
  • bleph: BID x 2 days, then QD until symptom relief (often several months)
  • preserved with BAK, d/c CLS wear during use

Topical ophthalmic erythro ung: prophylaxis (gonococcal ophthalmia neonatorum in place of silver nitrate); not usually used for active infxns due to poor resistance profile; dosed at night

Oral clarithro: respiratory infxns

19
Q

Lincomycin, Clindamycin

  • brand name
  • MOA
  • clinical indications
A

C: Cleocin

Reversibly binds to 50S inhibiting protein synthesis

MRSA and anaerobic infxns

20
Q

Antibiotics used for MRSA

A

“Bacteria Can’t Decide”
Bactrim (TMP-SMX)
Clindamycin
Doxycycline

21
Q

Sulfonamides

  • drug names (4)
  • MOA
A

Sulfisoxazole (Gantrisin)
Sulfacetamide (Sulamyd)
Sulfamethoxazole (Gantanol)
Sulfadiazine (Microsulfan)

Inhibit dihydropteroate synthase (enzyme that converts PABA to dihydrofolic acid for the 1st step in folic acid synth)
Bacteriostatic
Gram (+) and (-)

22
Q

Sulfonamides

  • ophthalmic indications & adverse effects
  • systemic indications & adverse effects
A

Ophthalmic:

  • topical sulfisoxazole and sulfacetamide were commonly used for bleph/conjitis, but are now rarely used
  • most common SE: burning, stinging, contact derm, photosensitization (sunburn on the eyelid margin)

Systemic:

  • sulfadiazine + pyrimethamine = tx toxoplasmosis
  • sulfamethoxazole + trimethoprim = Bactrim
  • SE: orals can cause kernicterus in infants due to bilirubin accumulation in the brain (contraindicated during pregnancy); may induce a myopic shift; topical ophthalmics and orals may cause Stevens-Johnson syndrome
23
Q

What is Stevens-Johnson syndrome

A

Fever, lesions on skin/mucus membranes -> sloughing over 10% or less of the body surface area, conj lesions (85%)

Most commonly assoc with medications (sulfonamids (incl bactrim), amoxicillin, allopurinol) and infections

24
Q

Trimethoprim, Pyrimethamine

  • brand names
  • MOA
  • clinical indications
  • adverse effects
A

Trimethoprim (Primsol)
Pyrimethamine (Daraprim)

Inhibit dihydrofolate reductase (enzymes that converts dihydrofolic acid into tetrahydrofolic acid in 2nd step of folic acid synth)

Idications

  • Topical ophthalmic trimethoprim: effective against gram (+) and (-), but not pseudomonas; available with poly b as Polytrim
  • Oral pyrimethamine: ocular toxoplasmosis infections

SE:

  • Oral TMP: bone marrow suppression (Treats Marrow Poorly) -> aplastic anemia, leukopenia, granulocytopenia
  • Pyrimethamine can have similar toxicity
25
Q

Ocular TRUST study demonstrated what

A

Trimethoprim and (to a lesser extent) tobramycin are the most potent topical ophthalmic antibiotics against MRSA

Other studies have shown besifloxacin and vancomycin are also effective

26
Q

Polytrim

-clinical indication & dosage

A

Bacterial conjunctivitis

QID x 5-7 days

27
Q

Fluoroquinolones

-drug names, generations (6)

A

2nd gen: ciprofloxacin (Ciloxan, Cipro) & ofloxacin (Ocuflox)

3rd gen: levofloxacin (Quixin)

4th gen: gatifloxacin (Zymar), moxifloxacin (Vigamox, Avelox), & besifloxacin (Besivance)

3rd and 4th gen have improved effectiveness against gram (+)

28
Q

Fluoroquinolones

  • MOA
  • topical ophthalmic indications
A

Rapidly inhibit DNA synth by inhibiting DNA gyrase & topoisomerase IV

CLS-related corneal ulcers
Corneal abrasions
Bacterial conjunctivitis
*all topical ophthalmics except levo are approved for use in pts 1+ years

29
Q

Antibiotic dosing for

  • infectious corneal ulcers
  • corneal abrasions and erosions
A

Ulcers: loading dose of Q15min x 1 hour, then Q1h with daily F/U

Abrasion/erosion: QID for prophylaxis

30
Q

Fluoroquinolones

  • systemic indications
  • adverse effects
A

Cipro: gram (-) urinary and GI infections
Moxi: pneumonia, sinusitis, intra-abdominal and skin infections

Oral fluoroquinoLONES can hurt attachments to your BONES = tendinitis
Orals contraindicated in pregnancy, children, adolescents <18 due to damage in cartilage formation and inhibition of bone growth

31
Q 
Bacteriostatic agents (4)
Bacteriocidal agents (5)
A

Static: tetracyclines, TMP, sodium sulfacetamide, erythromycin

Cidal: pens, cephs, bacitracin, aminoglycosides, fluoros

Boards II (5 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions