Antibiotics Flashcards
who should receive antibiotic prophylaxis?
certain surgical patients (cardiac, peripheral vascular, ortho, GI, hysterectomy), severely neutropenic patients, the patient at risk for bacterial endocarditis, the patient with recurrent UTIs, severe rheumatic endocarditis
PCN: Narrow- spectrum penicillinase sensitive
Pen G, Pen V- Useful for strep spa, Neisseria spa, many anaerobes, spirochete
PCN: Narrow- spectrum penicillinase resistant
Nafcillin, oxacillin, cloxacilin, dicoxacillin- useful for staph aureus
PCN: Broad- spectrum
Ampicillin, amoxillin, bicampicillin- Useful for H. influenzae, E.Coli, P.mirabilis, N. gonorrhoeae, entercocci
PCN- Extended- Spectrum pencillins
carbenicillin indanyl, ticarcillci, mezlocillin, piperacillin- useful for H. Influenzae, E.Coli, P.Mirabilis, N. Gonorrhoeae, entercocci, plus, Pseudomonas, enterobacter spp., bacterioides fragilis, many klebsiella
PCN- Side effects and toxicities
Pain at IM inn site, rare neurotoxicity, reactions to procaine and potassium, allergy in 2-30min is immediate, accelerated is 1-72 hours, late is days to weeks, anaphylactic retains more common than other drugs
Cephalosporins
are beta-lactam antibiotics that bind to PBPs, resistance to cephalosporins occurs due to beta-lactamases which cleave open the drugs. Groups into generations which take into account spectrum of activity, susceptibility, to beta-lactamases, and increasing ability to penetrate the CSF
First generation cephalosporins
Good gram positive coverage
second generation cephalosporins
gram positive coverage and some gram negative coverage
third generation cephalosporins
gram negative aerobes, ceftazidime is effective against pseudomonas
fourth generation cephalosporin
cefipime- broadesr spectrum, good penetration
Side effects and toxicities of cephalosporins
allergy- micropapular rash after several days is the most common manifestation
Increased bleeding tendencies (cefmetazole, cefoperazone, cefotetan), alcohol intolerance
Carbapenems
broad spectrum beta-lactam anx. Include imipenem (most broad), meropenem, ertapenem
Vancomycin
reserved for serious infections- AAPMC (second choice to metronidazole) MRSA, serious infections in the PCN allergic patients. Binds to cell wall synthesis but is not a beta lactam, ototoxicilty at high levels. Other rxn include rashes, thrombophlebilits, no cross- reactivity in the PCN allergic patient
Tetracyclines
tertracycline, oxytetracyline, demeclocycline, methacycline, doxycycline, and minocycline
Therapeutic uses of tetracycline
infection diseases: rickettsia, chlamydia trachomitis, brucellosis, cholera, mycoplasma pneumonia, lyme disease, anthrax, H Pylori. TX of acne- topical and PO. PUD, periodontal disease
Side effects and toxicities of tetracyclines
GI irritation; NVD, esophageal ulceration, Staining of teeth- avoid during pregnancy, avoid form ages 4mos to 8yrs, supra infection; AAPMC, candida, hepatoxicity, renal toxicity, photosensitivity
Macrolides
Erythromycin, clarithromyscin, azithromycin and dirithromycin
erythromycin- Activity, SE, drug interactions
macrolide. has activity against most gram + and some gram -, drug of choice for the PCN allergic for whooping cough and legionnaires disease.
SE: NVD, cholestatic hepatitis (10-20 days after, reversed with d/c of drug) and supra infection
Drug interaction- Cyp450 inhibitor; theophylline, carbamezepine, warfarin- monitor closely. Do not combine with clinda or chloramphenicol
clarithromycin
for soft tissue and skin infections, H pylorim respiratory tract infections in PCN allergic patients
azithromycin
for skin and soft tissue infections, H pylori, respiratory tract infections, and drug of choice for chlamydia trachoma tis
sulfonamides uses and side effects
UTIs, nocardiosis, burns, superficial eye infections. Hypersensitivity reactions: rash, drug fever, photosensitivity, stevens-johnson syndrome. Hemolytc anemia- seen in patients with G6PD deficiency. Kernicterus- do not give in preggo, breastfeeding, or infants, 2 months. Renal damage from cystalluria
Trimethoprim uses and side effects
rarely used alone for uncomplicated UTIs
Fluoroquinolones uses and side effects
borad spectrum antibiotics used for bone and soft tissue infections, UTIs, respiratory tract infections, GI infections and prevention of anthrax. Mild GI side effects, CNS s/e include dizziness, headache, restlessness, seizures rare. TENDON RUPTURE (usually achilles tendon) rare but d/c at first sign of tendon pain, do not use in children ,18yo, may elevate warfarin and theophylline
metronidazole uses
used to treat anaerobic bacterial infections of CNS , abdominal organs, skin, joints, soft tissues, and GU and protozoal infections. Also prophylactic antibiotic for colorectal surgery, abdominal surgery, vaginal surgery. May be used in combo for H pylori.
metronidazole side effects
GI: nausea, dry mouth, metallic taste, urine may turn darker color, avoid using in first trimester pregnancy, causes disulfiram-like reaction with alcohol, lower doses of warfarin when used with metronidazole
What do you use to treat empirically for PCN resistant strep for pneumococcal disease?
ceftriaxone/ cefotaxime or quinolones (levo or moxifloxin)
General antibiotic classes
BETA-LACTAMS- Penicillins= ampicillin, amoxicillin, nafcillin, diclocillin, piperacillin, ticarcillin. Cephalosporins= Cefazolin, cephalexin, cefoxitin, cefotetan,ceftriaxone, ceftazidime, cefepime) Monobactam (aztreonam) Carbapenem (imppenem, meropenem)
COMBINATIONS- Amoxicillin/clavulanate, ampicilin/sulbactam, piperacillin/tazobactam
GLYCOPEPTIDES- vancomycin, teicoplanin
MACROLIDES- erythromycin, clarithromycin, azithromycin
LINCOSAMIDES- clindamycin
AMINOGLYCOSIDES- gentamycin, tobramycin
QUINOLONES- norfloxacin, ciprofloxacin, oflaxacin, levofloxacin, gemifloxacin, moxifloxacin
SULFONAMIDES- trimethoprim + sulfamethoxazole
TETRACYCLINE- tetracycline, doxycyline, minocyline
NITROIMIDAXZOLE- metronidazole
ANTIBIOTIC SIDE EFFECTS: PCN, CEPHALOSPORINS, CARBAPENEMS, VANCOMYCIN
PCN: Allergic reactions (1-5%), anaphylaxis (rare), cross reactions (3-7% with ceph), prolonged high dose- granulocytopenia, interstitial nephritis
CEPHALOSPORINS- Allergic reactions (1-3%), cerfotetan- disulfiram-like reaction and hemostasis (hypoprothrombinemia)
CARBAPENEMS (allergic reactions with PCN, SZ in high doses)
VANCOMYCIN- red man syndrome, nephrotoxicity when used with amino glycosides
ANTIOBIOTIC SIDE EFFECTS: MACROLIDES, AMINOGLYCOSIDES, QUINOLONES, SULFONAMIDES, TETRACYLCINES, METRONIDAZOLE
Macrolides- GI COMPLAINTS, Cramping, diarrhea, drug interactions
Aminoglycosides- nephrotoxicity, ototoxicity,
QUINOLONES- GI and CNS complaints, SZ with high doses
SULFONAMIDES- Allergic reactions, stevens johnson
TETRACYCLINES- photosensitity
METRONIDAZOLE- Disulfiram-like reactions with ETOH, CNS( SZ) and neuropathy
Treatment of skin and soft tissue infections (not bite wounds)
staph aureus, strep pyogenas (impetigo, erysipelas, lymphangitis, cellulitis, surgical wound infections, pyomyositis, necrotizing fasciitis).
Cefazolin, cephalexin, nafcillin, dicloxacillin, clindamycin, vancomycin, amox/ clav. ampicillin/ sulbactam. DURATION; 10 days
Treatment of skin and soft tissue infection: Bite wounds
staph and strep (including microaerophilic), Eikenella (animal bites: pasturella), bactericides, prevotella, fusobacterium, peptostreptococcus. Treatment: clean, deride and tetanus shot. Amox/clavulanate, ampicillin, sulbactam
Upper Respiratory Tract infections: Pharangitis, otitis media, sinusitis/ bronchitis
Pharangitis: Group A strep, PCN x10days
Otitis media: Pneumococcus, H influenze, moraxella catarrhalis- amocillin (augmentin) Macrolides, Cephalosporins
Sinusitis/ bronchitis: Pneumococcus, Hinfluenze, Klebsiella, moraxella, staph aureus, anaerobes. TMP/SMX. Second choice amoxicillin, augmentin, macrolides, cephalosporins, quinolones
Community acquired pneumonia: Typical
Acute once, symptoms ,1week, productive cough, SOB, Chest X-ray shows lobar infiltrates. bugs: Streptococcus pneumoniae, H. influenzae, Moraxella catarhalis, klebsiella pneumoniae, staph aureus, aspiration or naerobic lung abscess. empiric treatment with ceftriaxone or cefotaxime; alternatives are vanco, clindamycin, or quinolone (levo, gemi, moxi)
Community acquired pneumonia: Atypical/walking
insidious onset, symptoms >1week (2-3 weeks usually), nonproductive cough, dyspnea on exertion (then SOB), chest X-ray shows interstitial infiltrates. Bugs: mycoplasma pneumonia, chlamydia pneumoniae, legionella pneumophila, influenza A 7B (parainfluenze, adenovirus) TB, miliary, fungal, pneumocystis carinii. Treatment with erythromycin (clarithromycin, azithromycin). Alternative is quinolones
UTI: bugs, DX, and TX
Ecoli, enterococcus, s.saprophyticus, proteus klebsiella, pseudomonas. DX: Clean catch. Pyuria, leuocyte esterase, hemturia, >100,000 bacterial colonies. TX: Empiric TMP/SMX, quinolone for 5-7 days. Pyelonephritis: 14 days
GI bugs and treatments
GASTEROENTERITIS: Shigella, salmonella, enterotoxic E coli, campylobacter- Hydration, TMP/SMX, quinolones.
C DIFF COLITIS- Metronidazole, Vanco
HEPATOBILIARY- enteric gram neg, enterococcis, anaerobes- Ceftriaxone, ampicillin/ sulbactam, cefoxiten
CATASTROPHIC GI- polymicrobial- cefoxiten, amp/sulbactam, amp+gent+metronidazole
Urethritis/ Cervicits, nongonnococcal urethritis (NGU), bugs and tx
Chlamydia trachomatis, ureaplasm urealyticum, mycoplasma genitalium, HSV and trichomonas vaginalis. Tx Doxycyline 100mg BID x7days or Azithromycin 1 gram single dose. Other alternatives are erythromycin 500mg QIDx7dys, ofloxacin 300mg BID x7days, refractory metronidazole 2 gram in single dose
Urethritis/cervicitis: Gonoccal urethritis bugs and tx
Mucopurulent, n gonorrhoeae, cefixime 400mg or cirpfloxin 500mg or ofloxacin 400mg orally in single dose or ceftriaxone 125mg IM in a single dose PLUS doxycyline 100mg BID x 7days or azithromycin 1 gram unless using ofloxacin BD x7day regime. GC pharyngitis is same but cefixime is not effective. Disseminated GC needs IV
Vaginal discharge: Bacterial Vaginosis. S/SX, DX, and TX
White, noninflammatory discharge, clue cells, Ph.4.5, fishy odor, (+/- KOH 10%). Metronidazole 500mg BID x7days. Alternative Clindamycin cream 2% or metronidazole gel 0.75% intravaginally QHS x7days
Vaginal discharge: Trichomoniasis. S/SX and TX
Malodorous, yellow-green with irritation, trichomonad vaginalis protozoan. Metronidazole 2 grams orally in single dose or 500mg BID x 7days
Vaginal discahrge: Vulvovaginal candidiasis
White discharge with parities +/- or burning. Candida albicans or others. Topical azole antifungals 3-14 days or fluconazole 150mg orally in a single dose
PID- S/Sx, bugs and tx
upper genital tract: endometriosis, salpingitis, tubo-ovarian abscess, pelvic peritonitis. Lower abdominal pain, adenexal, cervial motion tenderness +/- temp, discharge, ESR, CRP pr histopath/ US/ Laparoscopic N. gonorrhoeae, C. Trach, anaerobes, G. Vaginalis, Hinfluenze. oral regimen: ofloxacin BIDx14days plus metronidazole 500mg BID x14days
Syphilis
Primary and Secondary- Benzathine Penicillin G 2.4Mill IM x1 week. If PCN allergy: Doxycyline 100mg PO BID x2 weeks
Latent syphilis-> tertiary syphilis- Benzathine PCN G 7.2 million IM weekly x3 days. Neuro syphilis needs IV
Chancroid
multiple painful ulcers, no syphilis, adenopathy, H ducreyi
TX: Azithromycin 1 gram x1 or ceftriaxone 250 IM or ciprofloxacin 500mg BIDx3 days or erythromycin 500mg QID x7days
Herpes Simplex
Painful ulcers, positive culture for HSV. Acyclovir 400mg TID or famciclocie 250mg TID or Valacyclovir 1 gram BID for 7-10days
Tips for COMMON INFECTION: OTITIS MEDIA
1/3 cases are viral, antibiotics can be deferred for 48h in mild cases, Amoxicillin, TMP/SULFA are most appropriate,. If no clinical improvement in 48-72 hours, change ANX
Tips for COMMON INFECTION: ACUTE BRONCHITIS
most are self-limiting and viral. Consider ANX for COPD, suggestive of PNA, or symptoms lasting longer than 10days
tips for common infection: PHARYNGITIS
MOst are self limiting, only 12% caused by group a strep. Determine that strep is the causative agentPCN drug of choice
Tips for the common infection: COLD AND ACUTE SINUSITIS
most are viral. Green or yellow discharge is not indicative of bacterial infection. Defer tx unless temp is >39C, facial pain or swelling, or cough with purulent rhinorrhea for .7-10 days
Guidelines for prevention of spread of antibiotic resistance
Do not use broad spectrum as freebies, use local epidemiological data, educate patient about taking full course of and, shorter courses when possible
