Antimicrobial therapy Flashcards
Define the term antibacterial
preventing the growth or spread of bacteria
Explain the difference between narrow and broad spectrum antibiotics.
Broad - drug has range of activity against gram-positive and gram-negative bacteria
Narrow - drug is active against a select group of bacteria
Define the two types of antibiotic therapy
Empiric therapy - tx of an infection beofre culture information has been reported or obtained
Prophylactic therapy - tx with antibiotics to prevent an infection.
Define superinfection
Infection occurding during AB therapy, AB’s destroy normal flora and overgrowth of micro-org become resistant to AB’s.
Differentiate between the terms bactericidal and bacteriostatic
Bactericidal - kills bacteria directly
Bacteriostatic - inhibits growth of susceptible bacteria. allows the hosts defenses to eventually cause bacterial death.
Describethe mechanisms of action forthe broad category of penicillins.
Inhibit bacterial cell wall synthesis by disrupting rigid cross link structure causing lysis and cell death. Also called ‘beta-lactam’, therefore it is bactericidal.
Describe benefits of Penicillin
Effective against wide variety of bacteria, both gram+/- bacteria. Tx of choice for gram +ve infection. E.g. amoxicillin, flucloxacillin.
What can bacteria do that is capable of destroying penicillin and how can this be overcomed?
Bacteria can produce enzymes called beta-lactamases capable of destroying penicillin. To overcome this form of resistance, beta-lactamase ihibitors were developed e.g. clavulanic acid. Amoxycillin + clavulanic acid = amoxycillin clavulanate.
Discuss theadverseeffects for penicillins.
- Nausea, vomiting, diarrhea, abdo pain, candidasis, alleric reactions
Some to be taken on an empty stomach but majority on full
Effectiveness of oral penicillins decreased when taken with caffeine, crtrus fruit, cola, fruit juices or tomato juice.
Discuss the nursing role in supporting the patient/client taking antibiotic therapy.
Ax other medication nicl herbal or OTC. Check specimen results and follow up as required. Infection control. Pt education - what is AB for, how and when to take, empty stomach or w food. Explain possible side effects, consider superinfection, Montir for change in symptoms, improvement and deterioration.
Why are viruses diffcult to kill?
Becuase they live inside teh cells, so any drug that kills a virus may also harm the human host cell
How are vaccines helpful?
Designed to induce immune response to eliminate the antigen and prevent spread of infection.
Define the term antibiotic resistance
when bacteria and fungi change so that antibiotics no longer work to tx infections
Identify strategies to prevent the incidence of antibiotic resistance.
immunization, safe food preperation, handwashing, using AB’s as directed
Define the term antiviral
effective against viruses.
Ways antibiotics work
- Interefere with bacterial cell wall structure (penicillin). Interfere with DNA replication. Interfere with protein synthesis (Macrolides, tetracyclines).
The class of antibacterial drugs that inhibit bacterial protein synthesis is the:
aminoglycosides
a major nursing implication for patients prescribed penecillin:
Careful monitoring for allergic reaction for at least 30 minutes following first administration.
Most penicillins are much more effective against Gram-negative than Gram-positive bacteria. T/F
False. This is because the outer wall of Gram-negative bacteria is difficult to penetrate by penicillins.
Vancomycin, penicillins and cephalosporins have one common mechanism of inhibiting bacterial cell wall synthesis.
False
A superinfection can best be described as:
Infection occurring during AB therapy AB’s destroy normal flora → overgrowth of micro-org resistant to AB’s
Failure of antimicrobial therapy is due to:
Dosing too small, AB’s not given over a long enough time frame. Poor pt compliance
If an antibiotic dose is missed what happens to the drug levels?
The trough level is decreased.
The trough level is
The trough level is the lowest concentration in the patient’s bloodstream, therefore, the specimen should be collected just prior to administration of the drug
The peak level is the
The peak level is the highest concentration of a drug in the patient’s bloodstream.
Mechanisms of antimicrobial drug resistance include
he anitmicrobial drug is unable to reach site of action.
microorganism produces an enzyme to reduce or eliminate toxic effect of the antibiotic on the cell wall.
target site for the drug has been altered
Antibiotics are
Antibiotics are natural substances derived from certain organisms that can suppress growth or destroy microorganisms.
Bacteriostatic agents do what
inhibit bacterial growth allowing host defence mechanisms additional time to remove the invading organism.
If a antibiotic dose is missed you should double the next dose.
False
Difference between vaccine and antiviral drug
vaccines prevent or mitigate infections. · Antivirals are drugs that can treat people who have already been infected by a virus.
Common sign and symptom of penicillin
Common signs and symptoms of penicillin allergy include hives, rash and itching.
List two antiviarl drugs used to treat influenza in NZ?
Tamiflu and Relenza - flu
