Antibiotics & Antifungals p1 Flashcards
Antimicrobial, what is it?
Chemical substance that has the ability to kill or inhibit the growth of microbes
Antimicrobial classifications (5)
- Antibiotics
- Antifungals
- Antivirals
- Antiprotozoals
- Antiparasitic
T/F: Antibiotics only work on bacteria
True!!
Narrow spectrum vs Broad spectrum antibiotics
- Narrow:
- Work only on either gram-positive or gram-negative bacteria (not both!) - Broad:
- Work on both gram-positive and gram-negative bacteria (but not necessarily all).
Antibiotic classifications definitions
1. Bactericidals
2. Bacteriostatics
- Kill the bacteria
- Inhibit the growth or replication of bacteria
Goal of antimicrobial therapy is to ___ or ___ pathogen without ___ the host
- Kill
- Disable
- Injuring
What are the three requirements for success with Antimicrobial therapy?
- Micro-organisms is susceptible to the drug.
- Drug must reach the site of infection at an effective concentration.
- Drug must not cause serious injury to the animal treated.
A variety of mechanisms cause antibiotics to work (6)
- Inhibition of cell wall synthesis
- Damage to the cell membrane
- Inhibition of protein synthesis
- Interference with metabolism
- Impairment of nucleic acids
- Interference with bacterial attachment
What is the difference between antimicrobial
and antibiotic?
1. Antibiotic kills/slows bacteria, antimicrobial
kills/slows a pathogen
2. Antibiotic kills/slows bacteria, antimicrobial
boosts host immune system
3. Antibiotic kills/slows pathogen, antimicrobial
damages host cells
4. There is no difference
- Antibiotic kills/slows bacteria, antimicrobial
kills/slows a pathogen
Why should we culture a patient to determine what antibiotic to give them?
- Some antibiotics target different bacterial groups. Such as gram + vs gram - and aerobe vs anaerobe.
- If we know the types of bacteria (via susceptibility testing), we can give an antiB that targets said group.
- Or if we know a certain history for that presentation & what types of infection are common from that, we can make an educated guess.
How would you describe this bacteria?
1. Gram + rod
2. Gram - rod
3. Gram + cocci
4. Gram - cocci
- Gram - rod
How would you describe this bacteria?
1. Gram + rod
2. Gram - rod
3. Gram + cocci, chains
4. Gram - cocci, chains
- Gram + cocci, chains
Which antibiotic is the bacteria most sensitive to?
1. A
2. B
3. It can’t be determined from this information
- It can’t be determined from this information.
- A chart must be available to determine the sensitivity.
Antibiotic susceptibility testing
1. Sensitive
2. Intermediate
3. Resistant
- The bacteria is sensitive to the antibiotic & will be killed or inhibited.
- The bacteria are damaged by the antibiotic, but some growth can occur.
- The bacteria resists the action of the antibiotic & is able to effectively multiply.
T/F: Antibiotic chosen does not need to be able to reach the site of infection & achieve therapeutic levels
False! It MUST reach the site of infection and achieve therapeutic levels.
What tissues are difficult to penetrate? (8)
Hint: KNOW! QUIZ!
- Keratin of skin
- Brain & spinal fluid
- Bone
- Inner ear
- Eye
- Prostate
- Uterus
- Any “pocket of pus!”
Antibiotics may ___ at certain sites to produce levels ___ at some sites than in serum.
- Accumulate
- Higher
What are sites antibiotics may accumulate and produce at higher levels? (3)
- Urine accumulation in urinary bladder
- GI & Liver
- First pass metabolism - Topical therapy
- Skin
- Uterus infusion
- Urinary bladder infusion
- Cornea (not absorbed)
- GI tract (not absorbed)
Antibiotic resistance means the bacteria ___ & continue to ___ after administration of the antibiotic.
Occurs when bacteria ___ in some way that reduces or eliminates the ___ of the agent used to cure or prevent the infection.
Can develop thru bacterial ___, bacteria acquiring ___ that code for resistance, or other means.
Can be ___ resistance due to the mechanism of action of the antibiotic (g- vs g+).
- Survive
- Multiply
- Change
- Effectiveness
- Mutation
- Genes
- Natural
T/F: Chronic exposure to low-dose antibiotics greatly increases the risk of antibiotic resistance
True
To prevent antibiotic resistance, you should avoid… (3)
- Sub-therapeutic doses of antibiotics
- Antibiotic contamination of water supply
- Antibiotic contamination of food products
Antibiotic residue is the presence of a ___ or its metabolites in animal tissue or ___ products.
These can cause ___ reactions in people or produce ___ bacteria that can be transferred to people who consume these products.
- Chemical
- Food
- Allergic
- Resistant
General cautions of antibiotic use (5)
- Antibiotics should be given at sufficient dosage to maintain therapeutic levels & clear infection.
- Inappetence is a common side effect, may lessen if drug given with food.
- Vomiting & diarrhea may also occur and would be reasons to change drugs.
- Toxicity of kidneys or liver or other systems are occasionally a concern.
- Allergic reactions occasionally occur.
