Antibiotics Flashcards
What are common Gm- antibiotics?
Tetracyclines
Sulfonamides
3rd gen cephalosporins
What are common Gm+ antibiotics?
Penicillins
1st and 2nd gen Cephalosporins
Macrolides
What are 4 common beta-lacy am drug categories?
Penicillins
Cephalosporins
Mononactams
Carbapenems
Which antibiotics act by targeting cell walk?
PCNs
Cephalosporins
Carbapenems
Inhibit cell wall synthesis
Which abx act by inhibiting enzymes essential for bacterial growth and replication?
Sulfonamides
Which abx act by adversely affecting bacterial protein synthesis?
Tetracyclines
Macrolides
Amino glycosides
Which abx act by impairing bacterial DNA or RNA synthesis?
Fluoroquinolones
What’s the relationship between oral contraceptives and abx?
Rifampin impairs effectiveness.
Tetracycline and PCN may reveal decreased level of OC in some.
What are 4 ways in which bacteria can develop resistance to block otherwise damaging effects of antibiotics?
Develop ways to prevent/reduce drug receptor binding.
Develop ways to stop drug uptake process for abx that pass through cell wall to access receptor site.
Develop enzymes that break down abx.
Develop way to synthesize metabolites
How do super-infections develop?
When the “good” bacteria are decreased with abx therapy, other microbes use opportunity to multiply - opportunistic infections - take opportunity & multiply.
Common superinfection - yeasts
What characteristics describe 1st line antibiotics?
Greater efficacy Few adverse effects Narrow spectrum if activity for target organism Adequate access to site of infection Reasonable cost
Why choose 2nd or 3rd line antibiotic?
Allergy to 1st choice drug
Inability of 1st choice drug to reach infection site at effective concentration
Unusual toxic response to 1st choice drug
In the case of immunosuppression, should a bacteriostatic or bactericidal abx be used? Why?
In the case of immunosuppression, the body may not be able to mount a sufficient response if bacteriostatic drugs are used; therefore a bactericidal drug may be indicated.
Which diagnoses lead to inappropriate and unnecessary Rx?
Ear infections 30% Sore throat 50% Sinusitis 50% Bronchitis 75-80% Common cold 100%
When is it okay to combine abx?
Initial tx of severe infection, organism unknown
Infection of more than one organism
TB or other infection require combo therapy
Why the need for antibiotic prophylaxis?
For routine teeth cleaning and dental procedures. Those with prosthetics and/or with history of rheumatic heart disease are at greater risk of fam developing bacterial endocarditis. Because oral cavity has bacteria that can lead to systemic infection if enters systemic circulation.
What’s the danger of nonadherence?
When ppl feel better, S&S dissipate, they quit taking antibiotic without completing full course and being “cured.”
Side effects also contribute to premature termination of therapy. This has potential to continue or worsen infection and risk killing off weaker more vulnerable bacteria, allowing strong bacteria to survive, may make infection worse.
Which antibiotic is recommended as 1st line therapy for streptococcal pharyngitis?
Amoxicillin
If there is an allergy to amoxicillin, which antibiotic should be prescribed?
Erythromycin 1st line therapy for streptococcal pharyngitis when allergy to PCN.
When educating parents, why is it impt. To have them return to clinic if child is not improved in 2-3 days?
Strep throat associated with dangerous sequelae including glomerular nephritis and rheumatic fever, which can damage heart valves.
May also be failure to respond to treatment.
