Antibiotics Flashcards
respiratory fluoroquinolones
levofloxacin (Levaquin), moxifloxacin (Avelox), Gemifloxacin (Factive)
which drugs warrant not using any drug from fluoroquinolone class
class 1 & 3 antiarrhythmics including amiodarone, disopyramide, quinidine, bepridil, sotalol, all drugs prolonging QT interval (CV risk, arrhythmia, even fatal). glucocorticoids (increased tendon rupture risk)
which drugs warrant not using levofloxacin
NSAIDS (increased CNS stim, seizures)
use of respiratory fluoroquinolones in pneumonia (levo, moxiflo, gemiflo -xacin)
first line for comorbidities/risks (diabetes, chronic heart/liver/lung disease, alcoholism, malignancies, asplenia, immunosuppressed, DRSP risks). give 7-14 days
when are respiratory fluoroquinolones used in chronic bronchitis exacerbations?
moderate exacerbations that may require hospitalizations or patients who dont respond to first line therapy
when are respiratory fluoroquinolones used in UTI?
for patients who are not able to tolerate first line therapy TPM/SMX, Bactrim, Septra). can ONLY use levofloxacin from this subcategory (still 24% resistance)
what groups cannot have fluoroquinolones or should avoid them if possible?
pregnant women. breast feeding. children (joint, cartilage ADRs). except cipro (non resp-fluro) for 2nd line complicated UTI or pyelonephritis in kids. treated diabetics. patients with prolonged QTc interval or taking drugs that prolong it. seizure prone patients (severe cerebral atherosclerosis, epilepsy, alcohol abuse, theophylline use, antipsychotic use). dont use for myasthenia gravis (black box). dont use if taking corticosteroids (black box tendon rupture higher risk) (those who are dialysis, elderly, heart/kidney/lung transplant also higher risk of this). they can be used cautiously in renal failure, but need to adjust dose (except moxifloxacin no dose adjust).
can the fluoroquinolones be used for chlamydia or gonorrhea?
no longer use in gonorrhea d/t resistance. levofloxacin and ofloxacin (non resp-fluoro) 2nd line for chlamydia (these can also be used in epidiymitis from enteric bacteria, if gonorrhea negative)
can fluoroquinolones be used for skin/tissue infections?
although approved, avoid because of resistance concerns. beta lactams usually work if not exposed to fresh water
can fluoroquinolones be used for diarrhea?
yes, the NON-respiratory ones are first line for travelers diarrhea and severe diarrhea not caused by antibiotics (6+ stools/day and/or temp 38.8+, tenesmus, blood, or fecal leukocytes)
can fluoroquinolones be used for sinusitis?
levo, moxiflo can be used for adults allergic to beta lactams (ISDA cautions against use d/t cost, resistance). levo should only be used in children with type 1 allergy to beta lactams (off label) after clindamycin/cefixime combo tried first (AAP caution against use d/t cost, toxicity, resistance)
considerations if fluoroquinolone is right or not
cost (brand name ones very costly, cipro and levo have generic), avoiding resistance (cipro & levo only PO abx available not resitant to p. aeruginosa, resp-fluros enhanced gram + activity not resistant to highly-penicillin resistant strains of s. pneumoniae which are also resistant to 4 other abx classes; gemiflo and moxiflo much higher AUC:MUC ratios so good for URI), ADRs, drug interactions, treated diabetics (avoid if possible), patients with prolonged QT interval/drugs that prolong it, children, pregnant women
what labs are needed for fluoroquinolones?
renal/hepatic/hematopoietic function if on prolonged therapy. baseline renal fxn labs before starting a drug in this class. baseline EKG before starting moxifloxacin (if syncope, repeat and withhold drug until view, could be lethal torsade de points). if on warfarin, closely monitor INR. if on theophylline or cyclosporine, get blood levels plasma concentrations of these drugs (metabolized by CYP3A4, which is inhibited by fluruouqunolones)
patient education for fluoroquinolones related to timing, food, drink
cipro take 2 hours after a meal and dont take with dairy. norfloxacin dont take with dairy. take all with full glass water to avoid dehydration -> crystallurea. 2-4/6 hour gap with drugs that can chelate them, including antacids, bismuth subsalycate, calcium, mag, iron, sucralfate, sevalamer, zinc
patient education for fluoroquinolones related to ADRs that warrant telling provider and/or discontinuing
d/c at any sign of hypersensitivity (hives, dyspnea, itching), as anaphylaxis and Stephen johnsons can even happen at first exposure. if diabetic, monitor BG carefully, report hypos immediately. if tender/inflamed tendon/s, immediately d/c and tell doc, rest, no exercise of effected joint. withhold drug and report any blister, rash, or itching (can cause photosensitivity or phototoxicity); recovery prolonged and recurs if exposed again to sunlight before recovering. d/c at first sign of jaundice (hepatitis, hepatonecrosis, liver failure). tell doc if diarrhea with blood/pus/mucus (c diff possible). rare CNS stimulation (sleep disorder, vertigo, nervous, sleeplessness, tired, bad dreams, restless, confusion, hallucination, toxic psychosis, seizure, increased ICP), but dose dependent and typically resolve with continued use (slight mag deficient amplify effects; higher risk in elderly, dialysis).
patient education for fluoroquinolones related to general cautions/precautions
can cause dizziness/light-headedness, dont drive/hazardous activities until know effects. adequate fluid to have UO of 1500 ml/d to avoid crystallurea. minimize urinary alkalizers like citrus drinks. avoid baking soda, antacids. avoid direct sun/tanning/sun lights from first dose till several days after last dose (photosensitivity, phototoxicity). common adverse effects: abdominal pain, nausea, altered taste, diarrhea.
bactericidal drugs
kill target organisms. include aminoglycocydes, cephalosporins, penicillins, quinolones
bacterostatic drugs
inhibit or delay bacterial growth, replication. include tetracclines, sulfonamides, macrolides
bactericidal and bacterostatic drugs
can be either depending on dose, duration of exposure, state of invading bacteria. includes aminoglycocides, flouroquinolones, metronidazole (they have concentration-dependent killing; their rate of killing increases as drug concentrations increase)
causes of drug resistance
recurrent abx use, overuse of broad spectrum; <2y or >65y, daycare, exposed to young children; multiple medical comorbidities; immunosupression
antimicrobial drug resistance
every class has resistant organisms; local resistance patterns can be IDd by monitoring antibiogram of local lab; vaccination with pneumococcal vaccine has decreased resistance
how do beta lactams work
inhibit synthesis of peptoglidican bacterial cell wall
beta lactams combined with what beta-lactamase inhibitors to broaden spctrum
clavulanate, slbactam, tazobactam
natural penicillins are sensitive agsints (effective for) which organisms
streptococcus, some enterococcus, some non-penicillinase producsing staph
aminopenicillin activitypa
more activity against gram negative bacteria due to enhanced ability to penetrate outer membrane organisms. gram negative urinary and GI pathogens e coli, proteus mirabalis, salmonella, some shigella, enterococcus faecalis. active against common gram negative respiratory pathogens moraxella catarrhalis and h. influenzae type B
penicillin PK
well absorbed from GI tract, but many less stable in acid (dicoxacillin, amoxicillin better than ampicilin) ; bound to proteins with good distribution to most tissues; small amount met, most excreted as unchanged drug in urine ; probenecid prolongs half life and increases risk for toxicity
penicillin ADRs
serious immediate allergic reaction 2-30min after admin, pts may be given desensitization therapy; maculopapular rash 9% not allergic origin, starts 7-10 days into treatment; diarrhea, n/v (add clavulinate makes diarrhea worse risk), fungal overgrowth, cdiff; most prego cat B
penicillins clinical use and dosing
commonly used for PCP infections. amoxicillin first line for AOM and sinusitis. amoxicillin-clavulinate first line for bites. PCN for streptococcal pharyngitis
cephalosporins (beta lactam) action
similar to penicllins. inhibit mucopeptide synthesis in bacterial wall
1st + 2nd gen cephalosporin active against
skin, soft tissue infections; primarily against gram positive bacteria, s. aureus, s. epidermidis; second gen also active against klebsiella, proteus, e coli
3rd gen cephalosporins active against
broader indications, more active against gram negative
4th gen cephalosporins active against
resistant to beta-lactamase, primarily active against gram positive
cephalosporins ADRs
allergies, skin rashes, arthralgia, coagulation abnormalities, anemia, neutropenia, leukopenia, thrombocytosis, fever, seizures, renal/hepatic failure
cephalosporins PK
PO absorbed from GI tract, widely distributed to most tissues, some highly bound to proteins, some met to less active compounds, most excreted by kidneys in various degree as unchanged drug
cephalosporin monitoring
mtr for c diff; renal fxn if l/t rx
cephalosporin clinical use and dosing
therapeutic failure in AOM. 1st gen: strep pharyngitis, skin infections. UTI second line: cephalexin, cefpodoxime, cefixime. ceftriaxone, cefixime for chlamydia/GC. CAP: cefopoxidime, cefuroxime, or parenteral ceftriaxone followed by oral cefpodoxime
flouroquinolines method of action
interfere with bacterial enzymes required for synthesis of bacterial DNA. noted for extensive gram negative activity. dont use kids <18. increased resistance d/t overrx, cant use for GC, resistant TB
flouroqunolones absorption
well absorbed, best if on empty stomach
flouroquinolones ADRs
black box: tendonitis, tendon rupture (elderly higher risk; can have delayed onset 120 days to months after admin) ; pseudomembraneous colitis, CNS (sleep disorder, dizzy, acidosis); renal/hepatic failure; CV (angina, flutter); avoid in prego, kids <18
flouroquinolones pt ed
food delays absorption, many drug interactions, take with full glass water, may cause dizzy, if tendon tender, stop immediately and tell doc
flouroquinolone monitoring
watched for prolonged use, ECG with at risk patgients before rx moxifloxacin, alcohol use, tendonitis/rupture
lincosamides (clindamycin/Cleocin) monitoring
stop med if sig diarrhea occurs
lincosamides (clindamycin/Cleocin) ADRs
box warning for severe colitis, dermotologic (rash, burning, itching, redness), transient eosinophilia, neutropenia, thrombocytopenia, diarrhea
lincosamides (clindamycin/Cleocin) use
inhibits protein synthesis. NO gram neg activity. gram + activity for cornebacterium acnes, gardnrella vaginalis, some MRSA. first line for MRSA in some areas, infection in PCN allergies, DSRP, dental infections. considered second line therapy, narrow aerobic activity spectrum. 1st line in special pops (prego, child)
lincosamides (clindamycin/Cleocin) absorption
completely absorbed, not affected by acid gastric
macrolides (eyrhthromycin) action
inhibits RNA dependent protein synthesis; activity increases in alkaline media; atypical and intracellular organisms commonly resistant to beta-lactam abx; cross resistance seen in all in class
macrolides (erythromycin) PK
well absorbed form duodenum, potent inhibitor of CYP 450 3A4; combo with statins may increase risk for myopathy; exhibit enterohepatic recycling => biildunp in systme n/v, tissue levels higher than serum levels
macrolydes (erthyromicyin) precautions, ADRs, interactions
most safe prego, kids. dose related GI (n/v, abd pain, cramp, diarrhea). skin: urticaria, bullous eruptions, excema, stephen johsnosn ; inhibitors of CYP 450 3A4
macrolydes (erthyromicyin) clinical use and dosign
drug of choice for CAP (mycoplasma); chlamydia; pertussis; H pylori (clarithromycin); chronic bronchitis; often as alternative for PCN allergies; increasing resistance; NOT OK for OM or sinusitis
macrolydes (erthyromicyin) monitoring
altered response to concurrent meds met by CYP 450 3A4 or 2C9; hepatic/renal impairment; hearing loss
sulfonamides, trimethoprim, nitrofurantoin clinical use and dosing
most commonly used w/UTIs, MRSA in some areas; low cost alternative in kids >2mos and PCN allergies
sulfonamides, trimethoprim, nitrofurantoin monitoring
C/S if treating UTI, CBC in l/t use, CXR if dev cough on nitrofurantoin
sulfonamides, trimethoprim, nitrofurantoin ADRS
avoid in G6PD deficiency. anorexia, n/v, diarrhea, stomatitis. rashes, increased hypersensitivty reactions, photosensitivity. HA, dizzy, drug interactions (CNS)
sulfonamides, trimethoprim, nitrofurantoin action
block folic acid synthesis (sulfonamides), inhibit DNA synthesis (trimethoprim), inhibit acytl coenzymes (nitrofurantoin). gram + and -. E coli, S. pyogenus, s. pseudomonae, h. influenzaie, some protozoa. resistance an issue
oxalodinones (Linezoid) ALL
inhibits bacterial ribosomal protein synth, most efefctive aerobic gram +. resistrance emerging. well absorbed orrally, not using CYP. Diarrhea, HA, nausea. myelosupression resolves w/d/c. used for pneumonia, complicated skin infections. costly 1>1k so use less expensive first.
tetracyclines (doxycycline, tetracycline) use
bind reversibly to 30S subunit of bacterial ribisome. first line for c. trachomatis and ureaplasma urealyticum (doxycycline). tetracycline and monocycline used to treat p. acnus. some H. pylori regimens
tetracyclines (doxycycline, tetracycline) admin and ADRs and precautions
food decreases absorption (doxycycline and minocycline can be taken with food). milk, Ca decreases absorption of tetracycline. dont use prego, lacto, or child <8. many drug interactions. avoid prego ed, admin
Vancomycin, telavancin/Vibativ, dalbavancin/Zeven (lipoglycopeptides) ALL
used for serious gram + infections with resistance eg MRSA (inhibits cell wall synthesis). only given IV (poor oral absorp). ototoxicity (transient or perm), nephrotoxicity, red man syndrome if given too fast. monitor hearing and renal fxn.
antimicobaterials (isoniazid, rifampin, ethambutol, streptomycin, capreomycin, ethionamide) all
ADRs: peripheral neuropathy, liver tox, optic neuritis, neutro/thrombo cytopenia, ototoxicity. many drug interactions, rifampin CYP450 inducer. resistance dev rapidly to monotherapy. cross resitance with isonazide and ethionamide. ed: adrs, importance of taking daily, resistance. monitoring: direclty observed therapy. active TB requires 4 drug rx. preventative rx with isoniazid
nucleoside analogs (acyclovir, valcyclovir, famcyclovir, gancyclovir) all
famcyclovir against herpes related + HBV. gancyclovir only CMV. acyclovir, valcyclover few ADRs if oral. valcyclovir in immunocompromised: thrombocytopenia purpura, hemolytic uremic syndrome. famcyclovir HA. gangcylovir may cause CA, blood anemai isues . monitor BUN/cr in ihgh risk pts. ed: start first sign infection, good hydration, s/s of renal failure, encaphalopathic changs, blood dyscrasias
flu antivirals (oseltamivir/Tamiflu oral, peravimir/Rapivab IV, zanamivir/Relenza inhaled) for flu A and B
bronchitis, SOB for inhaled Relenza poss. IV is for acute flu 18y or higher. oral and inhaled prophylaxis too. monitor renal fxn in elderly, debilitated. elderly: eval for confusion, hallucination, cog impair. ed: complete, yearly flu shot, ADRs
antifungals (amphotericin B, nystatin, allymines naftifine and terbinafine, flucosystein, griseofulvin, azoles like fluconazole ketoconazole etc) all
all azoles and terbinifine associated with liver tox. multiple interactions d/t CYP 34a inhibition. fluconazole fewest drug interactions. many enhanced absorption with food. patient should take with food, no alcohol, know signs of liver tox. monitor in ketoconazole: AST, ALT, alk phos, bilirubne beore and every 3-4mos
metronidazole all
treat parasite and bacteria. trichomonas, h pylori, clostridium, c diff. ADRs: anorexia, nausea, abd pain, dizzy, HA, metallic taste. avoid it in first trimester. dont take alcohol so no antebuse reaction. partner treatment if STI. monitor for signs of leukopenia
causes of abx resistance
use in animal feed, animals, fish, plants; overuse of abx (no indication like for virus, extended course, combo with redundant coverage), use of extended spectrum abx, improper use by HCPs and pts, kichen and bathroom prevalenc of antibacterial products, sicker ppl on more broad spectrum abx
how abx work and how bacteria react
abx: cell wall destruction, increased cell wall permeabillity, protein synthesis inhibition, DNA/RNA disruption, antimetabolites. bugs react: produce inactivating enzumes, change the target site, decrease uptake into their cells, sythesize antagonizing compounds
main types of resistance
decreased permeability (abx cant get in cell through channels), drug efflux (pump pushes abx back out of cell), drug inactivation (bacteria enzymes make abx in cell not work e.g. beta lactamase), altered target (the abx’s target receptor on bacteria is altered)
