Intro to Antibiotics Flashcards
type of anti-infective:
antibacterial
antibiotics
type of anti-infective:
viruses
antiviral
type of anti-infective:
fungus and yeast
antifungal
drugs that are directly lethal to bacteria at clinically achievable concentrations
bacteriocidal
drugs that can slow bacterial growth but do not cause cell death
bacteriostatic (the immune system actually kills the bug)
principle: antibiotics are harmful to the microbe but harmless to the human host
selective toxicity
Special populations which may require prophylactic antibiotics
pre-surgery or during surgery: heart valves, rheumatic fever, immunosuppressed
Example of drug given prophylactically in particular population
Bactrim to prevent PCP pneumonia in AIDS patients below a certain CD4 level
principle: treatment based on identification of most likely causative organism
empiric therapy (e.g. treating e coli for UTI since it’s the most common)
Three primary classifications of bacterial identification
gram +/-
shape: bacilli, cocci, spirilla
aerobic vs. anaerobic
Should culture and sensitivity specimen be taken before or after starting anti-infectives?
After
PCR
polymerase chain reaction, used in limited cases for quicker result
are anaerobic bacteria harder or easier to treat?
harder
[broad, narrow] spectrum antibiotics are used after the culture/sensitivity results come back
narrow
MIC
minimum inhibitory concentration: lowest concentration needed to be bacteriostatic/cidal
host consideration for
infants
high risk of toxicity
host consideration for
children/adolescents
certain drugs should not be used
host consideration for
pregnancy/lactating
risk to gestating parent and fetus
top three groups of drugs with allergies
penicillins, cephelosporins, sulfa drugs
host consideration for
older adults
heightened drug sensitivity
when to assess ability of antibiotics to penetrate the site?
meningitis (blood brain barrier), abscess (walled off)
Should a patient with foreign hardware receive bacteriocidal or bacteriostatic antibiotics
bacteriocidal – phagocytes used to attack the hardware, not just the bug.
G6PD deficiency is related to the use of which drug class?
sulfa drugs
Three ways we know antibiotics are working
reduction in s/s
reduction in WBC
peak and trough
Do we typically recheck cultures to assess whether a drug is working?
Nope, clinical presentation is usually enough. And cultures take a long time.
How does antibiotic resistants spread through the food supply?
Animals receive antibiotics prophylactically, and resistant bacteria spread to humans through ingestion and animal waste
Can a host have resistance to antibiotics?
Yes, through resistance in your normal flora
Can antibiotic resistance to a particular antibiotics spread within a host?
Yes, a resistant gene can be passed between bacteria
should antibiotics be used for sore throats?
only in presence of bacteria – typically strep
MDRO
multi drug resistant organism
MRSA
methicillin resistant staph aureus
VRE
vancomycin resistant enterococcus
ESBL
extended spectrum beta lactamase producers (an enzyme that makes it harder to treat)
killing of host flora allows remaining microorganism to grow and new infection occurs
superinfection (or suprainfection) – most common are c. diff and yeast.
what side effects are caused by almost all antibiotics
GI distress (nausea, vomiting, diarrhea)
Is GI distress a sign of an allergic reaction?
No – rash, hives, difficulty breathing
Are allergies dose dependent
no – can have a big reaction from a small dose
