Antimicrobial Pharmacology Practice Flashcards

Practice flashcards reviewing antimicrobial concepts, drug classes, mechanisms, adverse effects, and targets based on lecture notes.

What is an antimicrobial?

A drug that acts against microorganisms.

What does bactericidal mean?

Kills bacteria.

What does bacteriostatic mean?

Stops bacteria from reproducing.

What is spectrum of activity?

The number of different types of bacteria affected by an antimicrobial.

What are the 4 basic bacterial shapes?

Coccus, bacillus, spiral, and square.

What is a coccus?

A spherical-shaped bacterium.

What is a bacillus?

A rod-shaped bacterium.

What is a spirillum?

A rigid spiral-shaped bacterium.

What is a spirochete?

A flexible, undulating spiral-shaped bacterium.

What are the major targets of antimicrobials?

Cell wall, cell membrane, ribosomes, cell metabolism, and DNA/RNA.

What antimicrobial classes are bactericidal?

Penicillins, cephalosporins, aminoglycosides, trimethoprim/sulfonamides, nitrofurans, metronidazole, and quinolones.

What antimicrobial classes are bacteriostatic?

Tetracyclines, chloramphenicol, macrolides, lincosamides, spectinomycin, and sulfonamides.

What should antimicrobial selection be based on?

A definitive diagnosis.

When possible, should you use a narrow- or broad-spectrum antibiotic?

Narrow-spectrum.

Are tetracyclines bactericidal or bacteriostatic?

Bacteriostatic.

How do tetracyclines work?

They bind to bacterial ribosomes and prevent tRNA from linking.

Are tetracyclines broad or narrow spectrum?

Broad spectrum.

What diseases can tetracyclines treat?

Rickettsial diseases, Ehrlichiosis, Hemobartonella, Lyme disease, Mycoplasma, and Chlamydial infections.

What suffix is associated with tetracyclines?

-cycline

What should tetracyclines NOT be given with?

Food, milk products, or antacids.

What mineral can tetracyclines bind to?

Calcium.

What can tetracyclines do to developing teeth?

Cause brown staining of tooth enamel.

Should tetracyclines be used in pregnant animals?

No.

Name 3 tetracyclines.

Tetracycline, doxycycline, and minocycline.

Is chloramphenicol bacteriostatic or bactericidal?

Bacteriostatic at low doses and bactericidal at high doses.

What serious adverse effect is associated with chloramphenicol?

Aplastic anemia.

Where does chloramphenicol have good drug levels?

Eye, CNS, and prostate.

What is florfenicol used for?

Respiratory disease.

What is the brand name for florfenicol?

Nuflor.

Name 2 lincosamides.

Lincomycin and clindamycin.

Name 3 macrolides.

Erythromycin, tylosin, and tilmicosin.

How do lincosamides and macrolides work?

They inhibit bacterial protein synthesis.

What type of bacteria do lincosamides/macrolides mainly affect?

Gram-positive bacteria.

Which animals should NOT receive lincosamides?

Rabbits, hamsters, guinea pigs, horses, and ruminants.

What can oral macrolides cause in horses?

Fatal diarrhea.

Why is Micotil (tilmicosin) dangerous?

It can cause death in monogastrics, including humans.

What type of antibiotic is spectinomycin?

Aminocyclitol antibiotic.

What does spectinomycin have little activity against?

Anaerobes and Pseudomonas.

What is an important adverse effect of spectinomycin?

Neuromuscular blockade.

What are polymyxin B and bacitracin mainly used for?

Topical skin and ophthalmic use.

What is an important adverse effect of polymyxin B?

Nephrotoxicity.

What is the most common nitrofuran?

Nitrofurazone.

What are nitrofurans used for?

Bactericidal treatment of skin wounds.

Can nitrofurans be used in food animals?

No.

Are penicillins bactericidal or bacteriostatic?

Bactericidal.

How do penicillins work?

They interfere with cell wall production and cell division.

What is the main spectrum of penicillins?

Mainly gram-positive, with newer drugs having some gram-negative activity.

What are common adverse effects of penicillins?

Skin rash, nausea, vomiting, diarrhea, and destruction of normal flora.

What are the 2 forms of Penicillin G?

Penicillin G potassium and Penicillin G procaine.

What is a concern with Penicillin G potassium?

Hyperkalemia.

What is a concern if Penicillin G procaine is given IV?

Adverse CNS effects.

explain penicillian V

narrow spectrum, acid resistant, active against streptococci, not used much in Vet med

Name 3 broad-spectrum penicillins.

Ampicillin, amoxicillin, and ticarcillin.

What is Clavamox?

Amoxicillin + clavulanic acid.

What does clavulanic acid do?

Helps overcome beta-lactamase resistance.

What is beta-lactamase?

An enzyme that causes resistance to beta-lactam antibiotics.

How does beta-lactamase cause resistance?

It breaks the β-lactam ring, deactivating the antibiotic.

Are cephalosporins bactericidal or bacteriostatic?

Bactericidal.

How are cephalosporins classified?

By generations.

How many generations of cephalosporins are listed?

5 generations.

Name 3 first-generation cephalosporins.

Cefadroxil, cefazolin, and cephalexin.

What is the main coverage of first-generation cephalosporins?

Gram-positive cocci.

What is special about second-generation cephalosporins?

They are beta-lactamase resistant.

Name 2 third-generation cephalosporins.whst bacter dose it cover

Ceftiofur and cefpodoxime. gram pos, some neg and some anerobic coverage

what are 3rd gen examples, what dose it cover

Ceftiofur, Cefpodoxime, in creased gram neg covergae

4th gen example what dose it cover

Cefepime, gram pos and gram neg and some anaerobic coverage

What is special about fifth-generation cephalosporins?

Enhanced gram-positive coverage and activity against MRSA.

Name 4 aminoglycosides.

Gentamicin, amikacin, neomycin, and streptomycin.

What are the 2 major toxicities of aminoglycosides?

Nephrotoxicity and ototoxicity.

What bacteria do aminoglycosides mainly target?

Gram-negative bacteria.

Are aminoglycosides well absorbed through the gut?

No.

What is an important interaction with aminoglycosides?

They have synergistic activity with penicillins, but should not be mixed in the same syringe with penicillins or cephalosporins.

Name 4 veterinary quinolones.

Enrofloxacin, difloxacin, marbofloxacin, and orbifloxacin.

Are quinolones broad or narrow spectrum?

Broad spectrum.

What bacteria do veterinary quinolones mainly target?

Gram-negative bacteria.

what are the 4 generations of quinolones

1st: Nalidixic acid
2nd: Enrofloxacin, difloxacin, marbofloxacin, ciprofloxacin
3rd: Orbifloxacin
4th: Pradofloxacin

explain Difloxacin

good chocie for renal patients

CANNOT USE IN CATS

good for liver/gallbladder infections good for osteomelitis

Explain Enrofloxacin (Baytril)

good for UTI, Prostatitis, hepatitis, Pneumonia, osteomyelitis

explain Marbofloxacin ( zeniquin) and Orbifloxacin ( orbax)

goof for UTI and pyoderma

explain Pradofloxacin ( veraflox)

wound infections, superficial/ deep pyoderm, UTI, Ginival/periodontal infections, acute upper respiratory infections, enhanced gram pos activity

What are major adverse effects of quinolones?

GI upset, cartilage/joint growth disorders in young animals, and retinal degeneration in cats.

Why should quinolones not be used in young growing animals?

They can cause cartilage and joint growth disorders.

What serious adverse effect can quinolones cause in cats?

Acute diffuse retinal degeneration.

What should quinolones NOT be given with?

Antacids or sucralfate.

What minerals can bind to quinolones and reduce absorption?

Calcium and magnesium.

Are sulfonamides alone bacteriostatic or bactericidal?

Bacteriostatic.

What are the 2 drugs commonly combined with sulfonamides?

Trimethoprim and ormetoprim.

What happens when sulfonamides are combined with trimethoprim or ormetoprim?

They become bactericidal due to the potentiated/synergistic effect.