Antimicrobials Flashcards
Should all surgical cases get an antibiotic?
No, you should weigh the risks and benefits. Is it worth exposing the patient to an antibiotic? For example, thyroid surgeries tend to NOT get infected. So you might hold off in this case.
What are the 3 general rules for using antibiotics in the surgical setting?
- You want to inhibit microorganisms as a level that is tolerated by the host. 2. In the seriously ill or immunocompromised you should use bactericidal as opposed to bacterostatic 3. Use a narrow spectrum before a broad spectrum to target a specific organism to preserve the patients normal flora.
When choosing an antibiotic for a patient is cost a factor?
Yes, providers need to choose cost effective antibiotics.
When choosing an antibiotic that seems cost effective, what is one thing you should consider?
Most of the cheaper antibiotics are broad spectrum. You must consider the benefit/risk of exposing the patient to a broad spectrum.
When should a surgical prophylactic antibiotic be given?
No more than 1 hour before incision, but completed before incision.
Are surgical prophylactic antibiotics a single-dose deal?
No, they can be continued for 48 hours in some cases.
Will giving a patient a brief course of antibiotics prophylactically increase resistance in organisms?
There is no evidence that a short course increases resistance.
When choosing an antibiotic for active infection, is it essential to identify the a causative organism?
Yes, so in this case, if there is an infected site that needs a washout or drained out, you may want to hold off on that first dose of antibiotic until after the intial incision is made and after samples for culture can be obtained.
Efficacy of antibiotic will depend on it’s _________ to the site of infection
delivery. Consider transport across blood brain barrier, if you have to deliver antibiotic to brain. Also, antibiotics will more readily penetrate infected tissue after it has been debrided and infectious material removed.
True or False. Using multiple antibiotics is the preferred method of treatment of infection.
False. Usually you treat with a single drug.
Does the route of administration need to be considered?
Yes. If it is orally administered it might suffer first pass metabolism and the complete dose will not reach the target tissue.
Does the duration of treatment need to be considered when choosing an antimicrobial?
Yes, is the patient going to have to take this medication at home?
What are the 2 main types of reactions that occur with antibiotics?
- Hypersensitivity 2. Direct drug toxicity
Does the dose of the antibiotic have anything to do with a hypersensitivity reaction?
No. It doesn’t matter what dose you gave, hypersensitivity can occur at even the smallest doses.
Does the antibiotic dose have anything to do with direct drug toxicity?
Yes. If you give more than can be cleared, the drug will reach toxic levels in the bloodstream.
What should you consider when giving antibiotics to a pregnant mother?
- most antimicrobials cross the placenta and enter breast milk. (Moms should discard milk for 24 hours) 2. We should be concerned with teratogenecity with any drug.
What are 4 physiological changes in the elderly that we need to consider when giving them antibiotics?
- They may have renal or liver impairment 2. They have decreased plasma proteins 3. Reduced gastric acid and motility 4. Increased body fat.
What would a decrease in plasma protein have to do with antibiotics?
If there are less plasma proteins for the medication to bind to then there is a higher free fraction of the drug in the bloodstream.
What is the difference between bactericidal and bacteristatic?
Bacterocidal drugs kill bacteria by disrupting cell wall synthesis. Bacteristatic drugs inhibit bacterial protein synthesis.
Is penicillin bactericidal or bacteristatic?
bactericidal
What family is pencillin part of?
the beta lactams
Which 3 main organisms does penicillin target?
pneumococcal, meningococcal, streptococcal.
How is PCN excreted?
90% of it is renally excreted
Name 2 derivatives of penicillin that we commonly see?
Ampicillin and Amoxicillin