Drug Therapy

Question 1

Antimicrobial

Answer 1

any substance of natural, semi-natural, or synthetic origin that kills or inhibits the growth of microorganisms but causes little damage to the host

Question 2

Antibiotics/Antibacterials

Answer 2

Against bacteria

drugs for bacterial pneumonia

Question 3

Antibirals

Answer 3

Against viruses

Drugs for herpes and HIV

Question 4

Antiparasitic agents

Answer 4

against parasites

Drugs for malaria

Question 5

Antifungals

Answer 5

against fungi

drugs for yeast infections

Question 6

Antibiotic

Answer 6

a chemical substance produced by microorganisms that has the capacity in dilute solution to selectively inhibit the growth or kill other microorganisms

Produced by mainly soil dwelling microorganisms
Very old natural molecules
Communication between microorganisms
Inhibition of potential competitive microorganisms

Question 7

Antimicrobial use in animals

Answer 7

Treat: animals diagnosed with an illness
Control: spread of illness in a herd or flock
Prevent: illness in healthy animals when exposure is likely
Growth: balance good/bad bacteria for improved nutrition

Question 8

Therapeutic use

Answer 8

Treatment of diseased animals with the aim to cure infection

When the animal has symptoms

Question 9

Prophylactic use

Answer 9

Treatment of healthy herds or animals with the aim to prevent infection

Before the animal is infected

Question 10

Metaphylactic use

Answer 10

Treatment of diseased herds with the aim to cure infection in some individuals and prevent infection in others

Some animals have symptoms, some are infected no symptoms, some are not infected

Question 11

Growth promotion

Answer 11

Treatment of healthy animals with low (sub-therapeutic) concentrations in feed with the aim to improve growth rate, efficiency of feed utilization and improve reproduction

EU banned the use of antibiotic growth promotors since 2006
The elimination of AGPs was met with a rise in prescribed veterinary antimicrobials for preventive use in subsequent years
To address the preventive use of antibiotics, regulators introduced a yellow card system

Question 12

FDA

Answer 12

Promote judicious use of medically important antimicrobial drugs in food animals
Document to help phase out the use of antimicrobials for production purposes (enhance growth or improve feed efficiency)

Remove the use of antimicrobial drugs for production purposes
Add where appropriate, scientifically-supported disease treatment, control or prevention uses
Change marketing status from over-the-counter to veterinary feed directive for drugs administered through water

Question 13

Antimicrobial alternatives

Answer 13

Antimicrobial peptides
Hyperimmune IgY
Enzymes
Phytogenics (essential oils etc)
Organic acids
Prebiotics
Probiotics
Others (bacteriophages)

Question 14

Classification of antibacterial agents

Answer 14

Chemical structure
origin
spectrum
mode of action
antimicrobial effect

Question 15

Origin

Answer 15

Natural: produced by fungi and bacteria
Semi-synthetic: chemically altered natural compounds
Synthetic: chemically designed by us

Natural are less effective more toxic
Synthetic are more effective less toxic

Question 16

Broad-soectrum

Answer 16

antimicrobials active against both gram + and gram - microorganisms
tetracycline, chloramphenicol

Question 17

Narrow spectrum

Answer 17

antimicrobials with limited activity against a particular species of microorganisms
Penicillin, polymyxin

Question 18

Four quadrant coverage

Answer 18

Gram + Gram -
Aerobe Anaerobe
Intracellular Mycoplasma
Protozoa Fungi

Question 19

Cell wall synthesis inhibitors

Answer 19

B-lactam antibiotics such as penicillin, ampicillin
Promote autolysin activity –> cell lysis
Inhibit peptidoglycan synthesis by binding to penicillin-binding proteins (PBPs) that are involved in this synthesis

Question 20

Protein synthesis inhibitors

Answer 20

aminoglycosides, macrolides

Inhibit 50S or 30S of ribosomal chromosome

Question 21

Bactericidal drugs

Answer 21

kill microorganisms and reduce total number of viable bacteria

Question 22

Bacteriostatic drugs

Answer 22

Inhibit growth and multiplication of bacteria, thus allowing the host immune system to complete pathogen elimination

Question 23

Can be bacteriostatic or bactericidal

Answer 23

Depending on
Drug concentration
presence of other drugs
bacterial species

Question 24

Antiviral drugs

Answer 24

Interfere with the ability of a virus
-to infiltrate a target cell
-to target different stages of replication and synthesis of components
Synthesize antibodies or administration of natural antiserum

Question 25

Immune system stimulation

Answer 25

Interferons, class of proteins that has antiviral effects and modulate functions of immune system

Question 26

Antiviral (2 types)

Answer 26

Targeting cellular functions that the virus needs Targeting viral function - neuraminidases - Integrases - proteases - nuclei acid polymerases

Question 27

Vermicide

Answer 27

Anthelmintics that kill infesting helminths

Question 28

Vermifuge

Answer 28

Anthelmintics that expel infesting helminths

Question 29

Ideal anthelmintics

Answer 29

``` Orally effective Effective in single dose Inexpensive Wide safety of margin with highest toxicity to worms but not to host No or low tissue residue Benzimidazoles, Ivermectin ```

Question 30

Anthelminthics: animal

Answer 30

``` age Immune status Genetics Nutritional status Hypobiosis Pregnancy ```

Question 31

Anthelminthics: Environmental

Answer 31

``` Worm species Temperature Moisture Sunlight Pasture composition ```

Question 32

Anthelminthics: Farm management

Answer 32

``` Grazing Housing system Co-grazing Alternate grazing Drenching ```

Question 33

Factors affecting drug choice

Answer 33

``` Infection Antimicrobial action and effect Experience Cost Compliance Toxicity Host Pharmacokinetic drug properties ```

Question 34

Infection

Answer 34

Nature, location, severity, susceptibility of casual pathogen

Question 35

Antimicrobial action and effect

Answer 35

Variables influencing clinical response

Question 36

Toxicity

Answer 36

of drug; risk of adverse effects, withdrawal period (food-producing animals)

Question 37

Host

Answer 37

Species, health, status, age, value

Question 38

Pharmacokinetic drug properties

Answer 38

Formulation, preparation, route of administration, dosage

Question 39

Antibiotic selection

Answer 39

Population of bacteria with a subset of antibiotic resistant organisms In the presence of an antibiotic susceptible strains are killed; the resistant strain survives The resistant strain proliferates and may be capable of causing a new infection

Question 40

Co-resistance

Answer 40

The co-existence of multiple genes or mutations encoding resistance to different drugs within the same strain or genetic element

Question 41

Cross-resistance

Answer 41

Resistance against one compound gives automatically resistance against another compound Mainly within the same chemical group Macrolides, phenicols

Question 42

Co-selection

Answer 42

Selection of multiple resistance genes when one of these genes is selected

Question 43

Hotspots for antimicrobial selection

Answer 43

Municipal and industrial wastewater Land spreading of animal manure and sewage sludge Aquaculture Antibiotic pollution is generally couples with contamination by heavy metals and other chemicals --> promote development of resistance mechanisms (co-selection)