PCN/Cephalosporins Flashcards
Amoxicillin brand name
Amoxil, Moxatag, Trimox
Amoxicillin susceptible pathogens
Gram-: H. influenzae, E. coli, P. mirabilis, N. gonorrhoea
Gram+: streptococci (including faecalis), nonpenicillinase-producing staphylococci and D. pneumoniae
Amoxicillin indications/dosage
adults infected with susceptible pathogens: 250-500mg q8h or 500-875mg q12h
children: 20-45mg/kg/day in divided doses. (125 and 250mg forms given q8h and 200 and 400mg forms given q12
gonorrhea and other infections due to N. gonorrhoeae
Adults: 3G as a single dose
prepubertal children >2y: 50mg/kg amoxicillin + 25mg/kg probenecid as single dose
Amoxicillin mechanism
inhibits bacterial cell wall synthesis via acylation of transpeptidase enzyme
Amoxicillin distribution
most body tissues excluding CSF, except when meninges are inflamed
Amoxicillin excretion
excreted unchanged in urine
20% protein bound
Amoxicillin drug interactions
changes GI flora, may disrupt absorption of oral contraceptives
renal excretion decreased with probenecid
theoretical: don’t use with bacteristatic antibiotics, bactericidal nature depends on rapid growth of bacteria to exert effects
Amoxicillin CI/precautions
CI with hypersensitivity to PCN/cephalosporins
estimated cross-sensitivity is 5-16%
caution in renal function impairment
report persistent or severe diarrhea to physician
Amoxicillin pregnancy category
B
Amoxicillin ADR’s
nausea, vomiting, DIARRHEA, hives, itching, RASH
Amoxicillin patient education
prefer to take on empty stomach (1h before or 2h after meals) with full glass of water
chewable: MUST be chewed before swallowing, or mixed with food
take at even intervals around the clock
complete full course of therapy
keep suspension refrigerated, discard after 14 days
Amoxicillin + ClavK brand name
Augmentin (XR)
Amoxicillin + ClavK Indications/organisms
sinusitis and otitis media due to beta-lactamase producing strains of H. influenzae and B. catarrhalis
lower respiratory tract infections due to beta-lactamas producing strains of H. influenzae
skin and skin structure infections due to beta-lactamase producing strains of Staph aureus, E coli, and Klebsiella species
urinary tract infections due to beta-lactamase producing strains of E. coli, Klebsiella species, and Enterobacter species
recurrent acute otitis media due to Strep pneumo, H. flu, and M. cat characterized by antibiotic exposure for AOM in past 3 months and either
Amoxicillin + ClavK dosing
sinusitis, AOM, LRTI, SSTI, UTI’s
Adult: ‘250’ q8h or ‘500’ q12h if less severe, ‘500’ q8h or ‘875’ q12h if more severe
children: 25-45mg/kg/day of amoxicillin, in equally divided doses BID
recurrent AOM: Augmentin ES 600 at 90mg/kg/day divided BID
Acute sinusitis or CAP: 2 augmentin XR q12h for 10 days (sinusitis) or 7-10 days (CAP) with meals
Amoxicillin + ClavK
Amoxicillin: bacteriocidal. Inhibits bacterial cell wall synthesis via acylation of transpeptidase enzyme
ClavK: binds competitively to active sites of B-lactamase enzymes, rotecting PCN’s from destruction
Amoxicillin + ClavK excretion
excreted unchanged in urine
20% protein bound
ClabK absorbed more readily when taken with food
Amoxicillin + ClavK drug interactions
may disrupt absorption of oral contraceptives
renal excretion decreased by probenicid
should not be given with -static ABX as -cidal ABX rely on rapid growth of bacteria to exert pharmacological effects
Amoxicillin + ClavK CI/Precautions
CI in hypersensitivity. Crossreactivity with cephalosporins 5-16%
caution: renal impairment
different tablets are not equal!! ClavK component does not translate
Amoxicillin + ClavK ADR’s
nausea, vomiting, DIARRHEA, hives, itching, RASH
Amoxicillin + ClavK patient education
prefer to be taken AT START of mealto enhance of absorption
take at even intervals around the clock
complete full course
follow chewables with full glass of water
keep suspension refrigerated, discard AFTER 10 DAYS
Cefdinir brand name
Omnicef
Cefdinir bacteria treated
S. aureus, S. pneumo, S. pyogenes, H. influenzae, H. parainfluenzae, . cat, S. epi, Strep. agalactiae, Citrobacter diversus, E. coli, K. pneumo, and P mirabilis
Cefdinir indications/dosage
CAP in adults, acute exacerbations of chronic bronchitis in adults, acute maxillary sinusitis, pharyngitis/tonsilitis, uncomplicated SSTI, AOM in children
all: 600mg/day in 1-2 doses
Cefdinir mechanism
3rd gen cephalosporin
inhibits cell wall synthesis via acylation of transpeptidase enzyme
Cefdinir drug interactions
aluminum or magnesium antacids and iron supplements decrease BA of drug
probenecid inhibits renal excretion, thus increasing plasma levels
Cefdinir CI/precautions
CI: hypersensitivity to PCN or cephs (~10% crossreactivity)
Caution: renal impairment
do not give within 2 hours of antacids or iron
C. diff has occurred with cephs, report persistent and severe diarrhea
Cefdinir pregnancy category
B
Cefdinir ADRs
diarrhea, vaginal moniliasis, nausea, headache, abdominal pain
Cefdinir patient education
shake suspension well
do not take antacids or iron within 2 hours of dose
discard unused suspension after 10 days
complete full course of therapy unless otherwise directed
Cefuroxime brand name
Ceftin
Cefuroxime bacteria treated
S. pyogenes, S. pneumo, H. flu, M. cat, S. aureus, E. coli, K. pneumo, and N. gonorrheae
Cefuroxime indications/dosages
pharyngitis and tonsilitis, otitis media, LRTI’s, impetigo, UTI’s, SSTI’s: 250-500mg BID for adults, or 125mg BID for children (250mg BID for AOM)
treatment of gonorrhea is a single 1g dose
Cefuroxime mechanism
2nd generation cephalosporin
inhibits cell wall synthesis via acylation or transpeptidase enzyme
Highly stable to bacterial beta-lactamases
Cefuroxime drug interactions
may alter absorption of estrogens
probenecid increases serum concentration
may cause false positive for nonspecific urine glucose test, some proteinuria tests, and direct Coombs’ test
falsely elevate urinary 17-ketosteroid values
false negative for blood gluse using ferricyanide test
Cefuroxime CI/precautions
CI: hypersensitivity to PCN or ceph (~10% corss-sensitivity)
caution: renal impairment
C. diff can occur, report persistent or severe diarrhea
Cefuroxime pregnancy category
B
Cefuroxime ADRs
DIARRHEA, HIVES, ITCHING, RASH, and nausea
Cefuroxime patient education
Tablets can be taken without regard to food
take suspension with food
take at even intervals
complete full course
suspension can be stored at room temp, discard after 10 days from reconstitution
Cefuroxime patient education
Tablets can be taken without regard to food
take suspension with food
take at even intervals
complete full course
suspension can be stored at room temp, discard after 10 days from reconstitution
Cephalexin brand name
Keflex
Cephalexin susceptibilities
Streptococci, staphylococci, E. coli, P. mirabilis, klebsiella species, H. flu, and M. cat
Cephalexin indications/dosages
infections due to susceptible strains: 250mg-1g q6h.
can do 500mg q12h for strep pharyngitis, SSTI’s, and uncomplicated cystitis in patients >15y
Cephalexin mechanism
1st gen cephalosporin
inhibits cell wall synthesis via acylation of transpeptidase enzyme
Cephalexin drug interactions
may alter absorption of estrogens
probenecid increases serum concentration
may cause false positive for nonspecific urine glucose tests, some proteinuria tests, and direct Coombs’ test, and may falsely elevate urinary 17-ketosteroid values
Cephalexin CI/precautions
CI: hypersensitivity to PCN or cephs
Caution: renal impairment
C. dif can occur with cephs, report persistent/severe diarrhea
Cephalexin ADRs
nausea, vomiting, DIARRHEA, HIVES, ITCHING, RASH
Cephalexin patient education
prefer to be taken on an empty stomach, with full glass of water
complete full course
keep suspension refrigerated, discard after 14 days
report persistent/severe diarrhea
