Antibiotics: Penicillin, Cephalosporins, And Tetracyclines (Cram)

What is the meaning of the suffix "–cidal"?

Kills microorganisms

What is the meaning of the suffix "–static"?

Inhibits the growth of microorganisms

Note: This is not neccessarily a disadvantage if the immune system is functioning properly

Term for when a drug is being used in ANY way that is not approved on the label or drug information

Extra–label (or off–label)

Example: Non–approved species, different route of administration, different dose, different disease, etc.

True or false: Extra–label drug use is illegal and a veterinarian could have their license revoked for extra–label drug use

False. It is legal, but a veterinarian must be able to back up the discission (needs research papers, case studies, etc.). The drug also must be prescription

Term for a drug that covers a variety of different situations

Broad spectrum

Example: Antibiotic that kills both gram positive and gram negative bacteria

Term for a drug that only covers very specific situations

Narrow spectrum

Time from last or final dose of any medication until the food products are safe for human consumption

Withdrawl time

Note: This applies to milk, meat, and eggs

What are the six types of anti–infective drugs?

1. Antibiotic
2. Anti–bacterial
3. Anti–fungal
4. Anti–viral
5. Antiseptic (ie. disinfectants)
6. Anti–parasitic

Drug that has the ability to kill or inhibit the growth of bacteria

Antibiotic

Note: These are natural products (ie. cultured from mold or dirt samples), not purely man–made like antibacterials

Antibiotic that kills bacteria

Bacteriocidal antibiotic

Antibiotic that inhibits the growth or reproduction of bacteria

Bacteriostatic antibiotic

True or false: All antibiotcs are broad spectrum

True

Which catagory of antibiotics was first produced from mold in the 1920's?

Penicillin

Fill in the blank: Some penicillins can work against bacteria that produce an enzyme called ____-_______. This makes bacteria more resistant.

beta, lactamase

Penicillin is generally very safe, but what is its most dangerous complication?

Allergic reaction

Note: This is true of humans as well. Penicillin drugs are the most common drug allergy

Penicillin G may be administered ___ or ___ (routes). It is often combined with ______ to decrease pain of injection, and with ______ or ______ to make it long–acting.

IM, SQ, procaine, benzathine, benzyl (called benzylpenicillin)

Fill in the blank: Crystalline forms of penicillin (penicillin sodium or potassium) may be administered ___ or ___ (routes), or ___ (in water source) for herd/flock treatment.

IM, IV, PO

Which penicillin is used frequently in the oral form in small animals for dermatitis, otitis, UTI, and respiratory tract infections?

Amoxicillin

What is added to amoxicillin to make it more effective against beta–lactamase producing bacteria?

Clavulanic acid

Which penicillin is similar to amoxicillin but is available in oral and injectable forms?

Ampicillin

Which penicillin is used mainly to treat mastitis as an intramammary infusion, but is also in tablet and oral suspension formats for small animals?

Cloxacillin

Which catagory of antibiotics are broad spectrum, and are classified according to their generation, with each succeeding generation more broad spectrum and more resistant to beta–lactamase?

Cephalosporins

Are cephalosporins used for dogs or cats more?

Mostly dogs. For some cephalosporins use in cats is extralabel

What is a first generation cephalosporin that can be used in dogs or cats to treat skin and soft tissue infections and UTI's?

Cefadroxil

The advantage of cefadroxil in cats is that it only needs to be given once a day. What is the disadvantage?

It can cause vomiting

What is a first generation cephalosporin that is not frequently used in veterinary medicine?

Cephalothin

What is a first generation cephalosporin that is used for small animals orally or injectable? Available PO as a paste or a chewable tablet

Cephalexin

Note: This is one of the most commonly used cephalosporins

What is a first generation cephalosporin that is used IM or IV?

Cefazolin

What is a cephalosporin used IV, IM, or SQ that is specifically for Pseudomonas infections?

Ceftazidime

What is a cephalosporin mostly seen in mastitis preparations?

Cephapirin

What is a cephalosporin that can be used SQ and offers 14 days of therapeutic drug levels for the treatment of skin infections and UTI?

Cefovecin

What is a third generation cephalosporin that can be used treat almost any bacterial infection, especially respiratory tract infections. It has short or no withdrawl time in food producing animals

Ceftiofur

What is the major advantage and disadvantage of ceftiofur in food producing animals?

Advantage: It has little to no withdrawl time
Disadvantage: Once rehydrated it must be used within 7 days (if refridgerated), or 8 weeks (if frozen)

Excede® is brand name for ceftiofur for bovine respiratory disease. Where MUST it be injected?

SQ in the ear. It will cause DEATH if it goes IV!

What does RTU stand for?

Ready to use

Example: Excenel RTU® (ceftiofur injection)

What is a cephalosporin that comes in a tablet for SID dosage in dogs. It is metabolized into its active form in the liver

Cefpodoxime proxetil

Note: Metabolized into cefpodoxime in the liver

What catagory of antibiotics is known to cause bone growth problems and kill much of the normal flora in the GIT?

Tetracyclines

Fill in the blank: Tetracyclines have the ability to bind strongly to ______-charged ions (Ca++, Mg++, Fe++, and Cu++). This causes problems when tetracyclines bind to _____ products in the GIT, or _______ in bone (including in a fetus), and accumulate in milk.

positively, dairy, calcium

What kind of circulation do tetracyclines undergo?

Enterohepatic, meaning most tetracyclines are eliminated unchanged by excretion through the kidneys

Tetracyclines interact with what other category of antibiotic?

Penicillin

Note: If given together, they would become ineffective

What are tetracyclines used to treat in young calves and foals? It has nothing to do with its antibiotic ability

Contracted tendons, this is because tetracyclines can bind to calcium

Which tetracycline is a common OTC antibiotic used in cattle?

Oxytetracycline

Which two forms of oxytetracycline are available for use in small animals?

1. Oral
2. Ophthalmic

What does the LA mean in the oxytetracycline Oxymycine® LA?

Long acting

What does the LP mean in the oxytetracycline Oxyvet® LP?

Low pain

What condition does oxytetracycline in the opthalmic form treat in small animals?

Chlamydial conjunctivitis

Which tetracycline is used mainly as a feed additive or in uterine boluses?

Chlortetracycline

Which tetracycline is available as a gel which is applied directly to the gingiva of dogs with periodontal disease, or as tablets/capsules?

Doxycycline

Which tetracycline is mostly used in human medicine?

Minocycline