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
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)
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
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:
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:
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)
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
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:
Penicillin G
Augmentin (amoxicillin-clavulanate) - Broad spectrum
Nafcillin - Antistaphylococcal
Carbenicillin - Antipseudomonas
1º Cephalexin (Keflex) Cephapirin (Cefadyl)
2º Cefaclor (Ceclor) Cefotetan (Cefotan)
3º Cefatriaxone (Rocephin) Cefotaxime (Claforan)
4º Cefepime (Maxipime)
Sulfamethoxazole–Trimethoprim (TMP-SMZ, Bactrim)
Cotrim
Septra
Sulfadiazine
Sulfamethoxazole
Sulfisoxazole
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
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
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
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:
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.
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
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
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: