AntiinfectivesKey Points

N203ATI (Unit 2)

Antiinfectives -

Broad-spectrum vs. narrow-spectrum antibiotics

Antimicrobials treat bacterial, viral, and fungal infections

Culture and sensitivity specimens should be collected prior to initiation of therapy.

Adverse reactions include:

Hypersensitivity & anaphylaxis Superinfection

Organ toxicity (ototoxic, nephrotoxic)

warfarin activity

efficacy of oral contraceptives

Penicillins

N203ATI (Unit 2)

Antiinfectives -

Expected Action:β-lactam – destroys bacteria by weakening cell wall

Therapeutic Uses:Med of choice for G+ cocci (Strep pneumoniae, S. viridans, S. pyogenes)Med of choice for syphilis First choice for meningitisProphylaxis against bacterial endocarditis

Extended spectrum against Pseudomonas, Proteus, KlebsiellaAdverse Effects:

Anaphylaxis / Renal Impairment / Hyperkalemia (w doses)Contraindications:

Allergies to Penicillin, Cephalosporin, or Imipenem / Kidney DysfunctionInteractions:

Aminoglycosides / η Oral ContraceptivesEducation:

Take orals ĉ H2O, ŝ food (some may be taken ĉ food)

Cephalosporins

N203ATI (Unit 2)

Antiinfectives -

Expected Action:β-lactam – destroy bacteria by destroying cell wallFour generations, each is:η against G- and anaerobes –more resistant to

lactamase – more able to reach CSFTherapeutic Uses:

Broad spectrum with TI for postop infections, meningitis, pelvic infectionsAdverse Effects:

Anaphylaxis / Bleeding / Thrombophlebitis / Pain ĉ IM / cross allergies to penicillins / AA-pseudomembranous colitis

Contraindications:Allergies to Penicillin / Kidney DysfunctionCaution with anticoagulants, antiplatelets, and thrombolytics

Interactions:EtOH intolerance (disulfiram reaction) / Probenecid renal excretion

Education:Take ĉ food

Carbapenems

N203ATI (Unit 2)

Antiinfectives -

Expected Action:β-lactam – destroy bacteria by destroying cell wall

Therapeutic Uses:Broad spectrum effective for serious infections such as pneumonia, peritonitis, and

UTIs. P. aeruginosa develops resistance (use combo) – [broadest spectrum available]

Adverse Effects:Allergy / GI symptoms / Superinfection

Contraindications:Caution with renal impairment

Interactions:

Education:

Monobactams

N203ATI (Unit 2)

Antiinfectives -

Expected Action:β-lactam – destroy bacteria by destroying cell wall

Therapeutic Uses:MRSA / Antibiotic-associated pseudomembranous colitis by C. difficile

Adverse Effects:Ototoxicity / Infusion Rxn (red man syndrome) / Thrombophlebitis

Contraindications/Precautions:Caution with renal impairmentInfuse over 60 minutesVery low therapeutic index

Interactions:

Education:

Tetracyclines

N203ATI (Unit 2)

Antiinfectives -

Expected Action:Bacteriostatic by preventing protein synthesis

Therapeutic Uses:Acne / rickettsia / Chlamydia / Helicobacter pylori / periodontal disease / typhus

fever / Rocky Mountain spotted fever / Lyme disease / UTI & VIAdverse Effects:

GI symptoms / tooth discoloration / hepatotoxicity / photosensitivity / superinfection of bowel

Contraindications/Precautions:Renal disease (except doxycycline) / Use during pregnancy will stain deciduous

teeth but not permanent teethInteractions:

Milk / Ca2+, Fe3+ supplements / Mg2+ laxatives / antacids (chelates to η) η of oral contraceptives

Education:Give with water on an empty stomach (except doxycycline & minocycline)

Bacteriostatic Inhibitors(Macrolides / Ketolides)

N203ATI (Unit 2)

Antiinfectives -

Expected Action:Bacteriostatic by inhibiting protein synthesis – Bactericidal at high doses

Therapeutic Uses:Use for pts with penicillin allergies / pertussis / diphtheria / Legionnaires’Chlamydia, Mycoplasma pneumoniae, Streptococcus pyogenes

Adverse Effects:GI discomfort / thrombophlebitis

Contraindications/Precautions:Pre-existing liver disease

Interactions:Toxic with: antihistamines, theophylline (asthma med), carbamazepine

(anticonvulsant), warfarinEducation:

Administer on empty stomach with water – IV is rarely used

Aminoglycosides(Medication List)

N203ATI (Unit 2)

Antiinfectives -

gentamicin amikacin kanamycin

tobramycin sulfate neomycin paromomycin

streptomycin

Aminoglycosides

N203ATI (Unit 2)

Antiinfectives -

Expected Action: Kill bacteria by disrupting protein synthesis

Therapeutic Uses: Med of choice against aerobic G- bacilli (E. coli, K. pneumoniae, P. mirabilis, P.

aeruginosa) Oral paromomycin use for amebiasis and tapeworm

Adverse Effects: Ototoxicity ()/ nephrotoxicity / neuromuscular blockade / hypersensitivity Streptomycin: Neurologic disorders

Contraindications/Precautions: Renal impairment reduced doses

Interactions: Ethacrynic acid (oto-tox) / amphotericin, cephalosporins, vanco (neph-tox) /

tubocurarine / penicillins ( AG)Education:

Penicillins(Medication List)

N203ATI (Unit 2)

Antiinfectives -

Penicillin G

Augmentin (amoxicillin-clavulanate) - Broad spectrum

Nafcillin - Antistaphylococcal

Carbenicillin - Antipseudomonas

Cephalosporins(Medication List)

N203ATI (Unit 2)

Antiinfectives -

1º Cephalexin (Keflex) Cephapirin (Cefadyl)

2º Cefaclor (Ceclor) Cefotetan (Cefotan)

3º Cefatriaxone (Rocephin) Cefotaxime (Claforan)

4º Cefepime (Maxipime)

Carbapenems(Medication List)

N203ATI (Unit 2)

Antiinfectives -

Imipenem (Primaxin)

Meropenem (Merrem IV)

Monobactams(Medication List)

N203ATI (Unit 2)

Antiinfectives -

Vancomycin (Vancocin)

Aztreonam (Azactam)

Fosfomycin (Monurol)

Tetracyclines(Medication List)

N203ATI (Unit 2)

Antiinfectives -

Tetracycline hydrochloride (Sumycin)

Doxycycline (Vibramycin)

Minocycline

Macrolides / Ketolides(Medication List)

N203ATI (Unit 2)

Antiinfectives -

Azithromycin (Zithromax)

Clarithromycin (Biaxin)

Dirithromycin

Erythromycin

Clindamycin (Cleocin)

Sulfonamides & Trimethoprim(Medication List)

N203ATI (Unit 2)

Antiinfectives -

Sulfamethoxazole–Trimethoprim (TMP-SMZ, Bactrim)

Cotrim

Septra

Sulfadiazine

Sulfamethoxazole

Sulfisoxazole

Sulfonadmides-Trimethoprim

N203ATI (Unit 2)

Antiinfectives -

Expected Action: Bacteriostatic by inhibiting folate synthesis

Therapeutic Uses: Med of choice for UTI by E. coli and Pneumocystis carinii.

Adverse Effects: Hypersensitivity (sulfonamides, thiazide diuretics, tolbutamide, loop diuretics) Blood dyscrasias / crystalluria / kernicterus ( bilirubin) / photosensitivity

Contraindications/Precautions: Avoid in: folate deficiency / pregnancy / creatinine clearance < 15 mL/min Reduce dosages with renal dysfunction

Interactions: Warfarin / phenytoin / tolbutamide ( effects of these)

Education: Empty stomach with full glass of water

Urinary Tract Aseptics

N203ATI (Unit 2)

Antiinfectives -

Expected Action: Damages DNA Prototype: Nitrofurantoin Static a@ doses, Cidal @ doses

Therapeutic Uses: Acute UTIs / Prophylaxis for recurrent lower UTI

Adverse Effects: GI / hypersensitivity / blood dyscrasias / peripheral neuropathy

Contraindications/Precautions: Renal dysfunction ĉ creatinine clearance < 40

Interactions:

Education: Urine will be brown

Antimycobacterial

N203ATI (Unit 2)

Antiinfectives -

Expected Action:Prototypes: isoniazid (INH), streptomycin, ethambutol,

pyrazinamide

Prevents synthesis of mycolic acid

Therapeutic Uses: Active and latent tuberculosis

Adverse Effects: Peripheral neuropathy (administer 50-200 mg of vitamin B6 daily) Hepatotoxicity

Contraindications/Precautions: Liver disease

Interactions: Phenytoin (accumulates) INH with EtOH, rifampin, pyrazinamide hepatotoxicity

Education: Empty stomach but ĉ food if needed

Anti-Hansen’s Disease

N203ATI (Unit 2)

Antiinfectives -

Expected Action: Prototype: Dapsone Others: Clofazimine, Rifampin

Prevents synthesis of folate which inhibits M. leprae.

Therapeutic Uses: Used in combination therapy to treat leprosy

Adverse Effects: Rifampin: Discoloration of body fluids / Hepatotoxicity GI discomfort

Contraindications/Precautions: Use caution with liver dysfunction

Interactions: Rifampin η ĉ warfarin / OC / protease inhibitors / NNRTIs (HIV)

Education:

Antiviral

N203ATI (Unit 2)

Antiinfectives -

Expected Action:

Prototype: Acyclovir

Others: ganciclovir, interferon, ribavirin, amantadine

Prevents reproduction of viral DNA

Therapeutic Uses:

Adverse Effects: Acyclovir: Phlebitis, nephrotoxicity, nausea & headache Ganciclovir: Granulocytopenia / thrombocytopenia / reproductive toxicity /

teratogenic

Contraindications/Precautions: Pregnancy / neutrophil count (<500/cc)

Interactions:

Nursing Info: Acyclovir: Never give IV bolus, Infuse over 1 hour min.

Fluoroquinolones(Medication List)

N203ATI (Unit 2)

Antiinfectives -

Expected Action: Prototype: Ciprofloxacin Bactericidal by inhibition of enzyme needed for DNA

Therapeutic Uses: Broad spectrum / prevention of inhaled anthrax

Adverse Effects: GI discomfort / Achilles tendon rupture / superinfection

Contraindications/Precautions: Avoid use in children <18 d/t risk for tendon rupture

Interactions: Cations ( Cipro absorption) / Theophylline & warfarin ( med plasma levels)

Education: Infuse slowly over 60 minutes

Antiprotozoals

N203ATI (Unit 2)

Antiinfectives -

Expected Action:

Proto: AmphotericinOthers: flucytosine, miconazole, nystatin, griseofulvin, ketoconazole

permeability leakage of intracellular cations (static or cidal)

Therapeutic Uses: Systemic or cutaneous fungal infections

Adverse Effects: Amphotericin: Infusion rxn (1-3 hrs) / thrombophlebitis / nephrotoxicity /

hypokalemia / marrow suppression Ketoconazole: Hepatotoxicity / Sex hormone effects

Contraindications/Precautions: Renal dysfunction

Interactions: Aminoglycosides (streptomycin, cyclosporine) – additive nephrotoxicity Flucytosine – antifungal effects are potentiated with amphotericin

Education: Highly toxic, infuse slowly (2-4 hr) Renal damage limited by infusing 1 L NS on day of amphotericin infusion

Antiprotozoals

N203ATI (Unit 2)

Antiinfectives -

Expected Action: Proto: metronidazole (Flagyl)

Broad spectrum with anaerobic activity

Therapeutic Uses: Protozoal infections / Bacterial infections against obligate anaerobes Prophylaxis for surgical procedures at high risk for anaerobic infections (vaginal,

abdominal, colorectal) H. pylori with tetracycline and bismuth salicylate

Adverse Effects: GI discomfort / metallic taste / darkening of urine / CNS symptoms

Contraindications/Precautions: Caution with renal dysfunction / avoid during 1st trimester of pregnancy

Interactions: Disulfiram-like reaction ĉ EtOH Warfarin – Flagyl inhibits inactivation of warfarin

Education: