NBEO Pharmacology

3 M/action of antibiotics

Inhibition of cell wall synthesis (peptidoglycan)
Inhibition of protein synthesis (30s+50s)
Interference of bacterial DNA (folic acid)

What AB drug classes inhibit cell wall synthesis?

Bacitracin
Penicillins
Cephalosporins

What AB drug classes inhibit protein synthesis?

buy AT 30, CEL at 50
Aminoglycosides + Tetracyclines: 30S
Chloramphenicol, Erythromycin (macrocodes) , cLindamycin: 50S

Which AB drug classes interfere with bacterial DNA?

Sulfonamides, trimethoprim, pyrimethamine: folic acid inhibition

Fluoroquinolones: inhibit DNA gyrate and topoisomerase IV

Most oral antibiotics have the side affect of ______

GI upset

M/Action of Bacitracin:

Inhibit peptidoglycan in cell wall formation (logs of a log cabin)

Classify Bacitracin: (gram status and vehicle)

Antibiotic ointment, effective against gram positive only

Bacitracin is often prescribed for the treatment of:

blepharitis

Bacitracin is often combined with __________________________ to form Polysporin (gram + and -).

Polymyxin B

What is Polysporin?

Antibiotic: Bacitracin + Polymyxin B- effective against both gram + and gram -

What is Neosporin?

Antibiotic: Polysporin + Neomycin

M/Action of Penicillins:

Inhibit transpeptidase in cell wall formation (glue of the log cabin)

M/Action of Cephalosporins:

Inhibit transpeptidase in cell wall formation (glue of the log cabin)

Penicillins and cephalosporins are similar in that they both have a

beta lactam ring-- potential for cross sensitivity reaction

What is Augmentin?

Fortified antibiotic: Amoxicillin + clavulonic acid (penicillinase inhibitor)

Classify Dicloxacillin: (class and gram)

Penicillin antibiotic, mostly effective against gram +

Is Dicloxacillin resistant to penicillinase?

Yes

Is Amoxicillin resistant to penicillinase?

No (that's why Augmentin is used more often)

Amoxicillin is often combined with ___________________________ to form Augmentin, which is a fortified antibiotic.

Clavulonic acid (penicillinase inhibitor)

Classify Amoxicillin: (class and gram)

Penicillin antibiotic, effective against both gram + and gram -

Is Dicloxacillin effective against MRSA?

NO

Are Penicillins safe in pregnancy?

Yes

which penicillin is better for use of eyelid infections? (hordeolum, preseptal, etc)

dicloxacillin

Common side effects of Penicillins:

Hypersensitivity reactions (type 1)-- anaphylaxis
Stevens-Johnson syndrome

Penicillins and Cephalosporins are contraindicated in patients with a history of:

IgE Type 1 hypersensitivity reactions (urticaria, anaphylaxis)

T/F: if pt is allergic to PCN, do NOT give cephalosporins

true

________ and _________ generation Cephalosporins are effective against both gram-positive AND gram-negative bacteria.

3rd
4th

Common uses for Cephalexin (Keflex):

Hordeolum, preseptal cellulitis, dacryoadenitis, dacryocystitis

Cephalexin is a ____ generation and ceftriaxone is a ____ generation

1st(+) and 3rd (+/-)

Cephalexin is a gram_____

gram +

Classify Ceftriaxone: (class/gen, gram spectrum)

3rd-gen Cephalosporin- IV is treatment of choice for gonococcal conjunctivitis & orbital cellulitis (gram + and -)

Drug of choice for treatment of gonococcal conjunctivitis:

IV Ceftriaxone

Drug of choice for treatment of orbital cellulitis:

IV Ceftriaxone

Common side effects of Cephalosporins:

Hypersensitivity reactions
Vitamin K reduction (blood thinning)

Which drug classes bind the 30s subunit to inhibit bacterial protein synthesis?

Aminoglycosides & Tetracyclines

what drugs make up the ahminoglycosides class?

Tobramycin
Gentamicin

Classify Gentamicin: (class and gram spectrum)

Aminoglycoside antibiotic, effective against both Gram-positive and gram-negative bacteria

M/Action of Gentamicin:

Bind 30s subunit to inhibit bacterial protein synthesis

Classify Tobramycin: (class and gram spectrum)

Aminoglycoside antibiotic, effective against both Gram-positive and gram-negative bacteria

M/Action of Tobramycin:

Bind 30s subunit to inhibit bacterial protein synthesis

What is TobraDex?

Tobramycin + Dexamethasone ophthalmic preparation

Common side effects of topical aminoglycosides, including tobradex:

SPK (enhances drug penetration)
Delayed corneal re-epithelialization

What drugs make up the Tetracycline class?

Tetracycline
doxycycline
minocycline

Classify Tetracycline: (class and gram spectrum)

Tetracycline antibiotic, effective against both Gram-positive and gram-negative bacteria

Classify Doxycycline: (class and gram spectrum)

Tetracycline antibiotic, effective against both Gram-positive and gram-negative bacteria

Classify Minocycline: (class and gram spectrum)

Tetracycline antibiotic, effective against both Gram-positive and gram-negative bacteria

M/Action of Tetracycline:

Bind 30s subunit to inhibit bacterial protein synthesis

M/Action of Doxycycline:

Bind 30s subunit to inhibit bacterial protein synthesis. Also decreases inflammation in sebaceous glands.

M/Action of Minocycline:

Bind 30s subunit to inhibit bacterial protein synthesis

Common uses for Doxycycline:

Meibomianitis, acne rosacea
Chlamydial infections (trachoma, inclusion)

Antibiotic Drug classes that are contraindicated in pregnancy:

Never FAT:
Fluoroquinolones
Aminoglycosides
Tetracyclines

Antibiotic Drug classes that are recommended in pregnancy:

PAC:
Penicillins
Azithromycin
Cephalosporins

Tetracycline antibiotics are contraindicated in:

Renal failure (EXCEPT Doxycycline)
Pregnancy
Children

Which Tetracycline is OK for patients with renal failure?

Doxycycline

Tetracyclines should NOT be taken with

dairy

Common side effects of Tetracyclines:

Pseudotumor cerebri
Bone growth retardation
Tooth discoloration

what are the 4 drugs that can cause pseudotumor cerebri?

CANT
contraceptives
accutane
nalidoxic acid
tetracyclines

Common side effects of Minocycline:

Blue sclera
Pigmented conjunctival cysts
(PTC, bone retardation, tooth discoloration)

M/Action of Chloramphenicol:

Bind 50s subunit to inhibit bacterial protein synthesis

M/Action of Macrolide antibiotics:

Bind 50s subunit to inhibit bacterial protein synthesis

what drugs make up the Macrolide class?

erythromycin
azythromycin
clarithromycin

M/Action of Lincomycin/Clindamycin:

Reversibly Bind 50s subunit to inhibit bacterial protein synthesis

M/Action of Erythromycin:

Bind 50s subunit to inhibit bacterial protein synthesis

M/Action of Azithromycin:

Bind 50s subunit to inhibit bacterial protein synthesis

M/Action of Clarithromycin:

Bind 50s subunit to inhibit bacterial protein synthesis-

Classify Erythromycin:

Macrolide antibiotic

Classify Azithromycin:

Macrolide antibiotic

Classify Clarithromycin:

Macrolide antibiotic

Classify Chloramphenicol: (class and gram spectrum)

Antibiotic: effective against both gram-positive and gram-negative bacteria

Side effects of topical Chloramphenicol:

Fatal aplastic anemia
Optic neuritis

what 2 drugs cause aplastic anemia?

Acetazolamide (diamox)
Chloramphenicol

List the Macrolide antibiotics:

"-thromycin"
Erythromycin
Azithromycin
Clarithromycin

Drug of choice for chlamydial/trachoma infections:

Oral Azithromycin (single 1 gram dose is convenient)

Common uses for Topical Azithromycin:

Bacterial conjunctivitis
Blepharitis

Is azithromycin safe to use in pregnant women?

YES

Common uses for Erythromycin:

prophylaxis for gonococcal neonatorum?

Before Erythromycin ointment, what was used for prophylaxis of gonococcal ophthalmia neonatorum?

Silver nitrate

Common uses for Clindamycin:

MRSA

Drugs recommended for treatment of MRSA:

Clindamycin
Bactrim
Doxycycline

Classify Sulfisoxazole: (class and gram spectrum)

Sulfonamide antibiotic: effective against both gram-positive and gram-negative bacteria

Classify Sulfacetamide: (class and gram spectrum)

Sulfonamide antibiotic: effective against both gram-positive and gram-negative bacteria

Classify Sulfamethoxazole: (class and gram spectrum)

Sulfonamide antibiotic: effective against both gram-positive and gram-negative bacteria

Classify Sulfadiazine: (class and gram spectrum)

Sulfonamide antibiotic: effective against both gram-positive and gram-negative bacteria

M/Action of Sulfonamide antibiotics:

Inhibit Step 1 of folate synthesis (dihyeropteroate SYNTHASE) to interfere with bacterial DNA synthesis

M/Action of Sulfisoxazole:

Inhibit Step 1 of folate synthesis (dihyeropteroate SYNTHASE) to interfere with bacterial DNA synthesis

M/Action of Sulfacetamide:

Inhibit Step 1 of folate synthesis (dihyeropteroate SYNTHASE) to interfere with bacterial DNA synthesis

M/Action of Sulfamethoxazole:

Inhibit Step 1 of folate synthesis (dihyeropteroate SYNTHASE) to interfere with bacterial DNA synthesis

M/Action of Sulfadiazine:

Inhibit Step 1 of folate synthesis (dihyeropteroate SYNTHASE) to interfere with bacterial DNA synthesis

Sulfadiazine is prescribed in combination with Pyrimethamine to treat:

Toxoplasmosis (DI goes with PY!!!)

Sulfadiazine is prescribed in combination with __________________________________ to treat Toxoplasmosis.

Pyrimethamine

What is in Bactrim?

Sulfamethoxazole + trimethoprim (METHs go together)

What is Bactrim commonly used to treat?

MRSA

Sulfamethoxazole combined with ___________________________ makes Bactrim.

Trimethoprim (METHs go together)-- Bactrim good for MRSA infections

Common side effects of Sulfonamide antibiotics:

Myopic shift
Stevens-Johnson syndrome

Medications commonly associated with Stevens-Johnson syndrome:

Sulfonamide antibiotics
Amoxicillin

M/Action of Trimethoprim:

Inhibit Step 2 of folate synthesis (dihyeropteroate REDUCTASE) to interfere with bacterial DNA synthesis

M/Action of Pyrimethamine:

Inhibit Step 2 of folate synthesis (dihyeropteroate REDUCTASE) to interfere with bacterial DNA synthesis

Classify Trimethoprim:

Antibiotic- inhibits folic acid

Classify Pyrimethamine:

Antibiotic- inhibits folic acid

Trimethoprim is combined with __________________________ to make Polytrim ophthalmic.

Polymyxin B