patho 1

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patho 1
2012-01-29 02:09:47

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  1. Antibiotic resistance
    occurs when the infectious organisms the antibiotics are designed to kill haveadapted to the drug, making the drug less effective
  2. prophylaxes
    • these agents are given to prevent infection rather than to treat an established infection.
  3. supra infection
    issimply a special example of the emergence of drug resistance. A suprainfection isdefined as a new infection that appears during the course of treatmentfor a primary infection.
  4. narrow spectrum
    are active against only a few species of organisms
  5. bacteriostatic
    can slow bacterial growth but do not cause cell death.
  6. bacteriocidal
    are directly lethal to bacteria at clinically achievable concentrations
  7. selective toxicity
    – is defined as the ability of a drug to injure a target cell or targetorganism without injuring other cells or organisms that are in intimate contact with the target.
  8. metronidazole adverse effects
    • Adverse
    • Effects: (class ppt)

    • CNS-headache,
    • dizziness, seizures, neuropathy

    • Metallic
    • taste, GI upset, diarrhea “Antabuse like” reaction ( sweating, flushing, nausea)
    • when taken with alcohol
  9. metronidazole nursing consideration
    • Assess for pregnancy & previous reaction to drug
    • Monitor CBC & assess for neurological problems or changesif given long term (more than 2 weeks)
    • Monitor for GI effects
    • Evaluate client response to therapy
  10. metronidazole client teaching
    • Take with meals to avoid nausea; may cause metallic taste
    • changes; chewing sugarless gum may help with taste change
    • Urine is expected to turn reddish brown during treatment;
    • warn patientAvoid alcohol while taking & for 48 hours after
    • completing drug therapy Report numbness & tingling in extremities, extremeweakness, fever/chills, mouth sores & call prescriber if symptoms of nfection do not improve

    • NOTES
    • metronidazole
    • (Flagyl, Protostat) is used for protozoal infection and infections caused by anaerobic bacteria.
  11. metronidazole mechanism of aciton
    • Metronidazole is active against many anaerobic bacterial infections of the CNS, abdominal organs, bones and joints, skin and stoft tissues, and genitourinary tract. Metronidazole is a drug of hoice for antibiotic associated colitis caused by C. Diff. In addition, the drug is used for Metronidazole
    • is lethal to obligate anaerobic organism ONLY. In order to produce effects, Metronidazole must be taken up by the cells and then converted to its active form (only converted by anaerobes). The active form interacts with DNA to cause the breakage of the helical structure, thus preventing nucleic acid synthesis and ultimately cell death.prophylaxis in
    • surgical procedures associated with a high risk of infection by anaerobes (such as colorectal surgery, abdominal surgery, vaginal surgery). Metronidazole is also used in combination with a tetracycline and bismuth subsalicylate to
    • eradicate Heliocobacter pyloi in people with peptic ulcer disease.
  12. metronidazole administration consideration
    • etronidazole is administered by IV infusion and under appropriate conditions,the patient may switch to oral.
    • Infusions must be done slowly over a one hour span. Therapy of anaerobic infections in adults isinitiated with a loading doase of 15mg/kg. After this, maintenance doses of 7.5 mg/kg are given every 6-8hours. Treatment duration is usually 1-2weeks. Patients with renal impairment
    • and those receiving prolonged treatment may need a reduced dosage to avoid toxicity from drug accumulation.
    • For oral preparations, Metronidazole is supplied in cap sules, standard tablets, andextended release tablets.
  13. fluoroquinolones client teaching adn adverse action
    • ·
    • Allergic reactions
    • GI -abdominal pain, nausea, diarrhea
    • CNS-dizziness,headache, drowsiness, confusion-especially in elderly clients
    • Achille’sTendonitis or tendon rupture
    • photosensitivity hypo orr hyperglycemia

    Phlebitiswith IV admin.—give slowly over at least 1 hour
  14. Penicillins summary overiew
    • Beta-lactam antibiotic derived from mold
    • Bacteriocidal (cell wall buster)
    • Most effective against Gram + aerobic bacteria
    • #1 drug for people to have an allergy to (mild to severe)
    • Short half life (dosing every 4 to 6 hours)
    • 4 groups based on spectrum and sensitivity to bacterial
    • penicillinase
    • ü Can cause GI upset, diarrhea, overgrowth of fungus or
    • resistant bacteria.
    • ü Teach: best on empty stomach, complete the course, call if not better in 48-72 hours
    • ü Sometimes used w/ Gentamycin (b/c that targets Gram-), but USE separate tubing
    • ü Monitor electrolytes:
    • potassium or sodium overloads w/ certain high dose IV penicillins
    • If Strep throat has you chillin’ then you need a
    • “cillin”
  15. penicillin
    Mechanism of action
    • ·
    • Mechanism of action
    • target enzymes to weaken bacterial cell
    • walls – cells swell & burst due to interior osmotic pressure (note: human cells have no cell wall, so penicillins have no direct effect on cells of host).
    • most effective against Gram+ aerobic
    • bacteria (lecture slide)
    • Mechanism of bacterial resistance: gram negative cell (outer membranedifficult to penetrate),
    • penicillinases (Beta-Lactamases) that render penicillins inactive,producing strains with low affinity for
    • penicillins - (MRSA)
  16. 1.
    –Spectrum: Penicillinase-sensitive
    • Penicillin G
    • only available IV (potassium penicillin)
    • (Procaine or benzathine “depot”
    • penicillin)—IM formulation
    • Used for infections with Gram + cocci,
    • e.g. Streptococcus pneumoniae & Gram + bacilli Clostridium & anthrax;
    • meningococcal meningitis; syphilis
    • Prescribed in Units; IM preparations
    • should be given into deep, large muscle mass

    • Penicillin V
    • oral formulation used for treating
    • Strep throat; 25-50 mg/Kg in children every 4-6 hours; 500 mg in adults
  17. Narrow-Spectrum:
    • Nafcillin
    • Oxacillin &
    • Dicloxacillin
  18. Broad-Spectrum:
    • Enhanced activity against G- species;
    • E.coli; Salmonella & Shigella; Proteus & H. flu.
    • Ampicillin

    • IV & PO; combined with beta lactam inhibitor
    • sulabactam as IV (Unasyn). IV diluted
    • with 0.9 %(Normal)Saline; doses > 500mg given over ~ 30 minutes. CNS toxicity & seizures can occur with too high a dose or with too rapid administration

    • Amoxicillin
    • Provides better blood levels and less
    • diarrhea with PO administration; combined with
    • clavulanic acid as (Augmentin) to reduce resistance.
  19. Extended-Spectrum:
    Antipseudomonal Penicillins
    • Ticarcillin
    • Piperacillin
    • *Beta lactamase inhibitors added to broadspectrum & extended spectrum penicillins to prevent bacterial inactivation
  20. penicillin administration consideration
    • right route & dosage [p. 990, Table83-2 ] patients with history of penicillin allergy – skin test to determine current allergic status, do not mix penicillins &aminoglycosides (Gentamycin) in same IV solution, separate tubing for IV and waiting between doses or else they inactivate.
    • avoid intra-arterial injection or injection into peripheral nerves (serious damage can occur).
    • never give procaine or benzathine in an
    • IV (causes seizures)
  21. penicilin client monitoring
    • allergic reactions, adverse effects include GI upset,diarrhea, CNS headaches, seizures, blood dyscrasias (rare) (lecture slide)
    • • signs of superinfection –Candida Clostridium (lecture slide)
    • • CBC and renal function
    • • therapeutic effects (↓fever, ↓pain, ↓inflammation, improved appetite)
    • • electrolytes potential sodium overload) & cardiac status for patients receiving high IV doses of ticarcillin,

    • electrolytes (potential potassium overload) & cardiac status for patients receiving high IV doses of potassium penicillin.
  22. cephalpsporin
    bacteriocidal antibiotics with low toxicity and wide therapeutic index, mainly renally excreted, four generations (we are responsible for knowing: 1st gen cefazolin/Ancef and 3rd gen Ceftriaxone/Rocephin)
  23. 1.
    1st gen Cefazolin/Ancef specific
    • a.Used primarily for gram positive infections and surgical prophylaxis
    • b. Readily avaiuven lable and inexpensive, alternative to penicillin for mild allergy
    • c. gIM/IV 500mg-2GM every 6-8hrs, children 80-160mg/kg/day divided doses
    • d. Watch for nausea and/or candidal overgrowth
  24. 1.
    3rd gen Ceftriaxone/Rocephin specific
    • a. Active against gram negative organisms,good CNS penetration, long half-life
    • b. Given IM/IV 250mg-2GM every 12-24hrs, children 50-100 mg/kg/daily
    • c. Fatal precipitates with calcium, cannot be given IV with IV calcium or IV solutions that contain calcium (Ringer’s or Ringer’s lactate)
  25. vancomycin
    • Give via slow IV infusion - over 60
    • minutes or more.
    • Levels may be insufficient to treat meningitis. Intrathecal (injection into spinal canal) admin may be required.
    • Vancomycin is eliminated unchanged by kidneys. Dosage must be reduced for renal patients.
  26. adverse effect of vancomysin
    • Most serious adverse effect:ototoxicity (damage to cochlea of auditory nerve) at plasma levels above 30mcg/mL . Risk increases with renal disease.·
    • Rapid infusion causes Red Neck:flushing, rash, pruritus (itching), urticaria (hives), tachycardia, and hypotension.
    • Thrombophlebitis (inflammation due to blood clot) - avoid by changing infusion site.
    • Rarely: loss of platelets and spontaneous bleeding.
  27. tetracycline
    Tetracyclines re broad spectrum antibiotics which inhibit ribosomal protein synthesis within bacterial cells. Bacteria transport systems allow Tetracyclines to enter bacterial cells but not human cells. Tetracyclines are widely distributed to most tissues and body fluids; however, penetration to cerebrospinal fluid (CSF) is poor, and therefore levels in the CSF are too low to treat menigeal infections. Tetracyclines readily cross the placenta and enter fetal circulation.
  28. Short-
    acting Tetracycline
    poorly lipid soluble; forms insoluble complexes with positive ions-- calcium, iron, magnesium, aluminum & zinc Eliminated by kidneys/renal & in bile
  29. Long
    acting teracycline: Doxycycline; Minocycline
    increased lipid solubility &excreted through bile; fewer problems with concurrent renal disease
  30. why use tetracycline
    • uses—Rickettsial diseases(Rocky Mt.Spotted Fever, Typhus)
    • Chlamydial infections
    • Cholera
    • Mycoplasma pneumonia,
    • Lyme disease,·
    • Anthrax
    • H.pylori treatment (causes gastric ulcers)
    • Topical--Treatment of acne & periodontal rinses