ANTIBIOTICSA brief overview for DMAT PA-1

DEFINITIONS

*Antibiotic- agents derived from natural sources (bacteria or molds) used to treat infection by suppressing or destroying the causative microorganism

*Antimicrobial- those anti-infective agents which are derived from synthetic substances

* these two terms are now used interchangeably

Antiseptic- an agent used to inhibit bacterial growth

Bacteria- microscopic single-celled organisms containing DNA and cell walls

Bactericidal- kills the bacteria

Bacteriostatic- inhibits the growth of the bacteria

Disinfectant- an agent used to kill bacteria

Normal flora-non-pathogenic bacteria that live on human skin and mucous membranes

Pathogen-bacteria that cause disease

Spectrum of activity- a product’s range of antimicrobial activity

CLASSIFICATION OF BACTERIA

I. Shape Spherical (cocci) single cells (micrococci) pairs (diplococci) clusters (staphylococci) chains (streptococci) cubical groups (sarcinae) Rod-like (bacilli) oval shapes (coccobacilli) chains (streptobacilli) Spiral (spirochetes) rigid (spirilla) flexible (spirochetes) curved (vibrios)

II. Stain (gram-stain) gram-positive (stains blue) * gram-negative (stains pink) * have a unique outer membrane that prevents many drugs from penetrating them—making them more resistant

to antibiotics

III. Use of oxygen aerobic—require oxygen to live anaerobic---live in the absence of oxygen thrive in areas of the body with low levels of oxygen (intestines, decaying tissue, deep and dirty wounds—they

tend to invade skin and muscle tissue that has been damaged) facultative---can live and grow in the presence or absence of oxygen

COMMON EXAMPLESGram-positive aerobes streptococcus pneumoniae *pericarditis,pneumonia,acute sinusitis, meningitis, otitis media, septicemia enterococcus faecalis *burn wound sepsis, infective endocarditis staphylococcus aureus *pneumonia, cellulitis, boils, toxic shock, postoperstive bone and joint infections, peritonitis, styes, suppurative conjunctivitis, staphylococcus epidermis *human bites,burns,IV line infections, postoperative bone and joint infections bacillus anthracis *anthrax corynebacterium diphtheriae *pharyngitis, tonsilitis, diphtheria streptococcus agalactiae (group B streptococcus) *bacterial sepsis and meningitis in newborns, endometritis and fever in postpartum streptococcus pyogenes (group A streptococcus) *diabetic foot ulcers, pharyngitis, tonsilitis, burns, cellulitis, decubitus ulcers, impetigo, toxic shock, necrotizing fasciitis, scarlet fever,

rheumatic fever

Gram-positive anaerobes clostridium difficile *pseudomembraneous colitis clostridium botulinum *botulism clostridium tetani *tetanus clostridium perfringens

*gas gangrene

Gram-negative aerobes neisseria meningitidis

*meningitis escherichia coli *urinary tract infections, pyelonephritis, septicemia, gastroenteritis, peritonitis neisseria gonorrhoeae *gonorrhea, pelvic inflammatory disease pseudomonas aeruginosa *puncture wounds, complicated urinary tract infections (catheter related), burns, pneumonia (ventilator related) haemophilus influenzae *pneumonia, meningitis, otitis media, acute sinusitis moraxella catarrhalis *pneumonia klebsiella pneumoniae * wounds, otitis media, aspiration pneumonia legionella sp. * Legionnaires’ disease shigella sp. *severe diarrhea, gastroenteritis salmonella sp. *severe diarrhea, gastroenteritis, salmonella bacteremia campylobacter jejuni *diarrhea

Gram-negative anaerobes bacteroides fragilisclo *sepsis

CLASSIFICATION OF ANTIBACTERIAL AGENTS

AminoglycosidesB-lactams *Penicillins *Cephalosporins *CarbapenemsMacrolidesQuinolonesSulfonamidesTetracyclinesMiscellaneous Agents *Vancomycin *Clindamycin *Metronidazole *Fluconazole *Terconazole *Miconazole *Nystatin *Rifaximin *Nitrofurantoin *Mebendazole *Bacitracin *Triple antibiotic ointment *Neomycin/polymyxin B/hydrocortisone otic suspension

AMINOGLYCOSIDESMiscellaneous facts: bactericidal *”concentration-dependent killing”—the bactericidal effect increases as the antibiotic concentration increases *”post-antibiotic effect” – continues to inhibit bacterial growth for several hours after aminoglycoside concentrations are no longer detectable higher doses at longer intervals often used in combination with B-lactam antibiotics to achieve antibacterial synergy to treat serious pneumococcal and enterococcal

endocarditis no oral absorption – must give IV/IM rapid renal excretion poor CNS penetration clinical differences among the agents are subtle

Spectrum:gram-negative enterobacteria no activity against anaerobes

Therapeutic uses: suspected sepsis, pneumonia, meningitis, complicated urinary tract infections, osteomyelitis, bacteremia, peritonitis

Drawbacks: very limited by their toxic potential ototoxic (irreversible) and nephrotoxic

nephrotoxicity: more common than ototoxicity, often reversible, most common in the elderly and those concurrently receiving amphotericin B, cephalosporins, or vancomycin

accumulate in the proximal tubule of the kidney –mild renal dysfunction occurs in 25% of patients on these drugs for several days or more once daily dosing has been reported to be effective and less nephrotoxic caution in patients with decreased renal function caution with other ototoxic and nephrotoxic drugs neuromuscular blockade can occur with high doses, rapid IV administration, in addition to neuromuscular blocking agents or anaesthetics,

hypocalcemia, myasthenia gravis, and with blood transfusions Pregnancy category D Monitoring parameters:blood draws—peaks & troughs, BUN, serum creatinine levels

BLACK BOX WARNING nephrotoxicity & ototoxicity

Gentamicin(Garamycin)IV/IMMore active than tobramycin against serratia organisms (septicemia)Activity against mycobacterium and e.coliUsed in combination with other antibiotics to treat staph. aureus and certain species of streptococcusSerum concentrations are unpredictable after IM administration—IV is the preferred route

Gentamicin ophth soln (Garamycin)Potential ocular irritation and burning

Tobramycin (Nebcin)IV/IMBetter activity than gentamicin against pseudomonas aeruginosa (puncture wounds,urinary tract infections,burns,

pneumonia)Some studies suggest it is less nephrotoxic than gentamicin—not firmly establishedUsed in combination with other antibiotics to treat staph. aureus and certain species of streptococcusIV is the preferred route of administration

AmikacinKanamycinNeomycinNetilmicinStreptomycinParomomycin

B-LACTAMS

Miscellaneous facts: contain a unique 4 member ring that is essential for antibacterial activity certain bacteria produce and enzyme (B-lactamase) that breaks the ring and inactivates the

antibiotic B-lactamase producing bacteris: staph. Aureus h. influenzae bacteroides sp. pseudomonas sp. legionella sp.

drug interaction with probenecid—probenecid inhibits renal excretion of the antibiotics causing

higher, prolonged serum levels anaphylactic reactions are common (urticaria, laryngeal edema,bronchospasm) *Penicillins *Cephalosporins *Carbapenems

PENICILLINS

Miscellaneous facts:bactericidal

Four Subdivisions *Natural Penicillins *Aminopenicillins *Penicillinase-Resistant Penicillins *Extended-Spectrum Penicillins

Spectrum:broad spectrum

gram-positive and gram-negative

Therapeutic uses:oropharyngeal infections, sexually transmitted diseases, pharyngitis, otitis media, sinusitis, bacteremia, anthrax, skin and soft tissue infections, mild respiratory infections, uncomplicated urinary tract infections

Drawbacks: resistance

hypersensitivity reactions (occur in up to 10% of people receiving penicillins) bone marrow depression gastrointestinal distress potential to cause seizures when given in high doses to patients with renal dysfunction ticarcillin and carbenicillin can cause platelet dysfunction

NATURAL PENICILLINS

Miscellaneous facts:

highly active against gram-positive cocci and gram-negative cocci

most common use is for streptococcus sp.

Penicillin G Sodium (Pfizerpen) IV/IM

Penicillin VK (Veetids) oral

Penicillin G procaine

repository form IM use only

Penicillin G benzathine

repository form IM use only

AMINOPENICILLINSMiscellaneous facts: broad-spectrum penicillins their spectrum is similar to but broader than that of the natural and penicillinase-resistant penicillins ineffective against most staphylococcal organisms commonly used for upper respiratory infections, uncomplicated urinary tract infections and otitis media

Amoxicillin oral capsules & suspension semisynthetic agent better absorption and less frequent dosing than ampicillin better bioavailability than penicillin—more stable to gastric acid Amoxicillin/clavulanic acid (Augmentin)oral chewables, tablets and suspension clavulanic acid—no antibacterial activity, it inhibits B-lactamase by binding to it and inactivating it-therefore

increasing the spectrum of activity of amoxicillin clavulanic acid causes a high incidence of gastrointestinal effects more effective than amoxicillin against staph. aureus, klebsiells sp., and bacteroides fragilis

Ampicillin sodium IV/IMmore effective than amoxicillin against shigellosis sp.Ampicillin sulbactam (Unasyn) IV

PENICILLINASE-RESISTANT PENICILLINS

Miscellaneous facts: active against gram-positive aerobes limited activity against gram-negative and anaerobic bacteria are not inactivated by B-lactamase less potent than natural penicillins against organisms susceptible to natural penicillins– cannot substitute for natural penicillins complete cross-resistance exists among the group all are identical except for their route of administration commonly used for bacteremia, skin and soft tissue infections, respiratory tract infections, bone and joint infections, urinary tract

infections ineffective against MRSA/MRSE

Dicloxacillin(Dynapen)oral capsule food decreases oral bioavailibility—administer on an empty stomach

Nafcillin(Nallpen)IM/IV semisynthetic metabolized by liver – useful in patients with renal impairment associated with neutropenia in 10 to 20% of patients multiple drug interactions (warfarin,etc.)

CloxacillinMethicillinOxacillin

EXTENDED-SPECTRUM PENICILLINS

Miscellaneous facts:

also known as antipseudomonal penicillins

have broadest spectrum of all penicillins

used to treat serious infections caused by gram-negative aerobes

ineffective against staphylococci sp.

hypersensitivity reactions are more common in this subdivision

all inhibit platelet aggregation– result in bleeding

Piperacillin

Piperacillin/tazobactam (Zosyn)IV

tazobactam—no antibacterial activity, inhibits B-lactamase therefore enhancing the intrinsic activity of piperacillin—increased gastrointestinal side effects

most potent extended-spectrum penicillin against pseudomonas sp.

effective in treatment of nosocomial pneumonia

Ticarcillan

Ticarcillin/clavulanic acid

CEPHALOSPORINSMiscellaneous facts: B-lactam antibiotics bactericidal 4 generations classified according to their spectrum of activity each generation increases its gram-negative activity but, loses activity against gram-

positive organisms popular due to their low toxicity and activity against serious infectionsSpectrum: gram-positive and gram-negative no activity against MRSATherapeutic uses:perioperative prophylaxis, urinary tract infections, acute otitis media,

sinusitis, etc Drawbacks: most are eliminated via renal excretion—adjust dosages in renal insufficiency

hypersensitivity reactions (fever, maculopapular rash, anaphylaxis, & hemolytic anemia) gastointestinal effects hypoprothrombinemia

potential for nephrotoxicity cross-sensitivity with penicillins in up to 10% of patients receiving cephalosporins

1st GENERATION CEPHALOSPORINS

Miscellaneous facts: oldest cephalosporins gram-positive activity & basic gram-negative activity (except

enterococci) widely used for perioperative prophylaxis used to treat klebsiella sp., skin and soft tissue infections,

respiratory tract infections, otitis mediaCefazolin(Ancef)IM/IV compared to other 1st generation cephalosporins it achieves higher blood

levels after administration, has greater gram-positive coverage and requires less frequent dosing

Cephalexin(Keflex) oral capsules ,oral suspension primarily used for otitis media and respiratory tract infections

CephadroxilCephradine

2nd GENERATION CEPHALOSPORINS

Miscellaneous facts: less gram-positive coverage & more gram-negative coverage than 1ST generation cephalosporins

also active against B-lactamase producing strains of haemophilius influenzae

Cefaclor

Cefoxitin

Cefprozil

Cefuroxime

Cefotetan

3rd GENERATION CEPHALOSPORINS

Miscellaneous facts: increased gram-negative coverage & decreased gram-positive coverage over 2nd generation cephalopsorins best CNS penetration of all cephalosporins—very valuable in treatment of meningitis caused by meningococci,

pneumococci, haemophilus influenzae, and enteric gram-negative bacilli especially useful for gram-negative upper respiratory tract infections, otitis media, urinary tract infections and skin

infection empiric therapy for life-threatening infections in which resistant organisms are the most likely cause treatment of sepsis of unknown origin in immunosuppressed patients initial therapy in mixed bacterial infections

Cefotaxime(Claforan)IM/IV commonly used to treat empiric gram-negative meningitis, serious bacteremias, pneumonia, and community-acquired infections

Ceftriaxone(Rocephin)IM/IV longest half-life of all cephalosporins allowing for once daily dosing DOC=neisseria gonorrhoeaeCefdinirCefiximeCefoperazoneCefopodoxime proxetilCeftazidimeCeftibutenCeftizoximeCefditoren

4th Generation Cephalosporins

Miscellaneous facts:

newest cephalosporins same coverage as 3rd generation cephalosporins with additional coverage against pseudomonas sp

high degree of resistance to B-lactamase producing organisms

good activity against organisms that are resistant to 3rd generation cephalosporins

commonly used for febrile neutropenic patients

Cefepime (Maxipime)

CARBAPENEMS

• Miscellaneous facts:• B-lactam antibiotics

• bactericidal

• Spectrum:gram-positive cocci, gram-negative rods, and anaerobes

• broader spectrum than most B-lactams• Therapeutic uses:urinary tract infections, lower respiratory tract infections,

gangrene, sepsis, pneumonia,intra-abdominal infections, gynecological infections, etc.

• Drawbacks: anaphylactic reactions, seizures, confusion, dizziness, gastrointestinal issues

• Imipenem/cilastatin

• Ertapenem

• Meropenem

MACROLIDESMiscellaneous facts: mostly bacteriostatic—can be bactericidal newer macrolides-better absorption and less gastrointestinal effectsSpectrum: gram-positive cocci and bacilli & some gram-negative cocci mycoplasma pneumoniae, chlamydia trachomatis, legionella sp., corynebacterium

diphtheriae, campylobacter sp., treponema pallidum, propionibacterium acnes, & borrelia burgdorferi

DOC=group A streptococcal and pneumococcal infections when penicillin cannot be used

Therapeutic uses: Legionnaires disease, dental prophylaxis , chlamydial infections, ance, diphtheria, pertussis, ocular infections

Drawbacks: numerous drug interactions – erythromycin inhibits the hepatic metabolism of other

drugs (theophylline, digoxin, corticosteroids, carbamazepine, cyclosporin, lovastatin, etc.)

cardiac issues—causes QT prolongation and torsade de pointes gastrointestinal disturbances (dose-related),skin rashes, eosinophilia, tinnitus,

dizziness, reversible hearing loss

Erythromycin base (ERYTAB) oral tablet enteric coated, delayed-release tabs (do not crush)

DOC=Legionnaire’s disease, mycoplasma pneumonia and chlamydial infections drug interactions with terfenadine, astemizole, pimozide, etc.

dose must be decreased with decreased liver function pregnancy category B

Erythromycin ethylsuccinate(EES) oral suspensionErythromycin ophth oint. superficial ocular infections prophylaxis of neonatal ophthalmia due to neisseria gonorrhoeae or chlamydia trachomatisAzithromycin(Zithromax, Z-Pak) oral suspension,oral tabletssemisynthetic macrolideless active than erythromycin against gram-positive organismsmore active than erythromycin against haemophilus influenzae and other gram-negative organismsconcentrates in cells– tissue levels are higher than serum levels—increased efficacy and duration of action-less tendency to cause drug interactions once daily dosing

less gastrointestinal issues than with other macrolides very useful in nongonococcal urethritis caused by chlamydia, lower respiratory tract infections, mycobacterium avium complex infection, pharyngitis,

pelvic inflammatory disease, nongonococcal urethritis caused by chlamydia, Legionnaire’s disease pregnancy category B Clarithromycin(Biaxin) XL oral tablets, oral suspension semisynthetic macrolidesame spectrum as erythromycin –more potentenhanced activity against haemophilus influenzae and mycobacterium avium complex also active against toxoplasma gondii, and cryptosporidium sp. metalic aftertaste pregnancy category C

Erythromycin estolateErythromycin stearateDirithromycin

QUINOLONESMiscellaneous facts: bactericidal (concentration dependent) 4 generations – each generation adds coverage for a new group of pathogens different mechanism of action -- thus, no cross resistance with other classes of antibiotics produce a false-positive urine screening result for opiates when using a commercially available immunoassay kit

Spectrum: highly active against gram-negative aerobes & gram-positive activity no activity for most anaerobes

Therapeutic uses: urinary tract infections, lower respiratory tract infections, sinusitis, otitis media, infectious diarrhea, prostatitis, empiric use in febrile

neutropenic patients

Drawbacks: relatively free of side effects and toxicity phototoxicity not recommended in children under 18 years of age (cartilage malformations were found in studies in immature

animals),tendon rupture, cardiac QT prolongation( associated with 2nd and 3rd generations), CNS stimulation, hypoglycemia, seizures, anaphylactic reactions, pseudomembraneous colitis, can cause exacerbation of myasthenia gravis multiple drug interactions – theophylline, antacids, iron, multivitamins, warfarin, NSAIDs (potential to increase risk of seizure), antiarrhythmic drugs

pregnancy category C

1st GENERATION QUINOLONES

Miscellaneous facts:

bactericidal

gram-negative coverage (excluding pseudomonas) limited use due to the development of bacterial resistance

poor oral availability limits its systemic use

common uses include urinary tract infections

Nalidixic acid

2nd GENERATION QUINOLONES(FLUOROQUINOLONES)

Miscellaneous facts: bactericidal increased gram-negative coverage (including pseudomonas),

gram-positive cocci, and mycobacteria addition of fluorine ion to the quinolone structure

=fluoroquinolones QT prolongation and torsade de pointesCiprofloxacin (cipro)oral tablets/IV good penetration into bone—useful in osteomyelitis urinary tract infections, lower respiratory tract infections, sinusitis,

empiric use in febrile neutropenia, typhoid fever, infectious diarrhea, prostatitis, bacterial conjunctivitis, corneal ulcers, nosocomial pneumonia

indicated for use in mycobacterium avium complex in patients with AIDS

2nd GENERATION QUINOLONES(FLUOROQUINOLONES)

used in combination with other drugs to treat multi-drug-resistant tuberculosis

most potent flouruquinolone against pseudomonas aeruginosa no longer drug of choice for neisseria gonorrhoeae (becoming resistant) absolute contraindication: tendon pain, tendon rupture, tendonitis

oral dosage equivalent IV dosage 250mg q12h 200mg IV q12h 500mg q12h 400mg IV q12h 750mg q12h 400mg IV q8h

Ofloxacin (Floxin,Ocuflox) oral/ophth/otic use less potent than ciprofloxacn against most gram-negative bacteria most active 2nd generation against chlamydia trachomatisNorfloxacin (Noroxin, Chibroxin)

3rd GENERATION QUINOLONES(FLUOROQUINOLONES)

Miscellaneous facts: QT prolongation bactericidal

extended gram-positive coverage (particularly against penicillin-sensitive and penicillin-resistant streptococcus pneumoniae, mycoplasma pneumoniae & chlamydia pneumoniae)

gram-negative coverage (including pseudomonas sp.) decrease dosage in renal impairment treatment of community-acquired pneumonia, acute sinusitis, acute exacerbations of chronic

bronchitis, bacterial conjunctivitis

Gatifloxacin ophthalmic, bacterial conjunctivitisLevofloxacin oral, IV, ophthalmic less QT prolongation than with other fluoroquinolonesMoxifloxacin oral,IV, ophthalmic not used for urinary tract infections approved for treatment of complicated intra-abdominal infections

4th GENERATION QUINOLONES(FLUOROQUINOLONES)

Miscellaneous facts:

bactericidal

gram-positive & gram-negative

significant coverage against anaerobes

Trovafloxacin (Trovan)

restricted by FDA to serious life-or-limb-threatening infections due to serious drug induced hepatic adverse effects

BLACK BOX WARNING:

treatment restriction limitations—hospitals and long term care facilities

liver injury leading to liver transplantation and or death

SULFONAMIDESMiscellaneous facts:

bacteriostaticSpectrum: mostly gram-positive, some gram-negatives also activity against certain strains of chlamydia trachomatis, nocarida, actinomyces, & bacillus anthracisTherapeutic uses: animal and human bites, urinary tract infections, otitis media, chronic bronchitis, travelers’ diarrhea,

sexually transmitted bacterial infections, ocular infections and burnsDrawbacks:photosensitivity, can cause Stevens-Johnson syndrome, hypersensitivity reactions, blood dyscrasias,

caution in patients with G6PD deficiency (can cause acute hemolysis), crystalluria, hematuria drug interactions with phenytoin, oral anticoagulants, & sulfonylureas cross-allerginicity between the individual sulfonamides discontinue at first sign of skin rash or other reactionSMZ/TMP(Bactrim,BactrimDS)(sulfamethoxazole/trimethoprim)->synergistic combinationbacteriostatic-in combination with trimethoprim=bactericidal DOC=treatment and prophylaxis of pneumocystis cariniiuseful in acute gonococcal urethritis, acute exacerbation of chronic bronchitis Sodium Sulfacetamide 10% ophth solnUsed to treat conjunctivitis or superficial bacterial eye infections,corneal ulcers can cause a delay in corneal wound healing local irritation, burning, stingingSilver sulfadiazine1% cream(Silvadene)bactericidalgram-positive & gram-negative --- some effectiveness against yeastadjunct for prevention and treatment of wound sepsis in patients with 2nd & 3rd degree burns

TETRACYCLINESMiscellaneous uses: bacteriostatic cross-resistance with the group is extensive

Spectrum: gram-negative & gram-positive broad spectrum agents—coverage includes spirochetes, rickettsia, mycoplasma

pneumonia, chlamydia sp., & certain protozoa speciesTherapeutic uses:

DOC=rickettsial (Rocky Mountain Spotted Fever), chlamydial, mycoplasmal infections, anthrax frequently used for acne and periodontitis

useful alternative to penicillin in treatment of anthrax, syphilis, gonorrhea, Lyme disease, and h. influenzae respiratory infections

Drawbacks: photosensitivity gastrointestinal distress, hypersensitivity reactions, hepatoxic (especially in pregnant women), pregnancy category D, tooth discoloration (binds to calcium in teeth & bones-enamel hypoplasia can also occur), not recommended in children<8 years old, cannot give with antacids or milk, cannot use tetracycline after expiration date(causes renal tubular dysfunction which can lead to renal failure), take with fluids to avoid esophageal irritation

Doxycycline (Vibramycin) oral tablets excreted mainly in feces –very useful in patients with poor renal functionMinocyclineTetracycline

MISCELLANEOUS AGENTSVancomycin (Vancocin)IV peaks:20-40mcg/ml

Miscellaneous facts: bactericidal troughs:5-15mcg/ml very useful in patients allergic to penicillins or cepphalosporinsSpectrum: gram-positive organisms including MRSA/MRSE and enterococciTherapeutic uses:serious infections—endocarditis, osteomyelitis, staphylococcal pneumonia, treatment of pseudomembranous colitis caused by c.difficile or

s.aureus enterocolitis oral form used only for c. difficileDrawbacks: ototoxicit y

increased ototoxicity & nephrotoxicity when given with other ototoxic and nephrotoxic drugs monitor blood levels

hypersensitivity reactions facial flushing and hypotension with too rapid infusion of the drug (red man syndrome)

Clindamycin (Cleocin)oral/IV/IMMiscellaneous facts: bacteriostatic

cross resistance with macrolides is common reserve for serious infections in patients with penicillin allergies does not diffuse into cerebrospinal fluid—do not use for meningitisSpectrum:most gram-positive & many anaerobic organisms bacteroides fragilisTherapeutic uses: skin, respiratory tract, and soft tissue infections caused by staphylococci, pneumococci, and streptococci, dental infections, acne, bone &

joint infections, bacterial vaginosisDrawbacks: limited by its toxicities

gastrointestinal issues, blood dyscrasias, Stevens-Johnson syndrome dose must be decreased with impaired hepatic function potentiates the effects of neuromuscular blocking agents

BLACK BOX WARNING first antibiotic to be associated with pseudomembraneous colitis c. difficile associated diarrhea (pesudomembranous colitis) alters the colon flora which leads to c.difficile overgrowth c.difficile produces toxins A and B which contribtes to c.difficile associated diarrhea

Metronidazole(Flagyl) oral/IVMiscellaneous facts:antibacterial and antiprotozoal agent amebicide—amebicidal and trichomonacidalSpectrum:anaerobic gram-positive and anaerobic gram-negative certain protozoan parasites (trichomonas vaginalis, entamoeba histolyticass, giardia lamblia,etc.)

DOC=c.difficile, bacterial vaginosis (gardnerella vaginalis), c. tetaniTherapeutic uses:amebic dysentery, giardiasis, trichomoniasis, intra-abdominal, pelvic, soft tissue, periodontal, and odontogenic infections,

lung abscess, acne, meningitis, bacterial septicemia, lower respiratory tract infections, endocarditisDrawbacks: hepatic metabolism-dosage adjustment in patients with liver dysfunction gastrointestinal distress, headache, dark coloration of urine, leukopenia, dizziness, ataxia disulfiram-like reaction with ethanol

inhibits warfarin metabolism-increased bleeding metallic taste

use cautiously in pregnancy (avoid in first trimester) drug interactions: warfarin, phenytoin, phenobarbital, cimetidine, lithium, etc. absolute contraindication in breast feeding

use with caution in patients with evidence of or history of hematological disease

Fluconazole(Diflucan) oral tabletMiscellaneous facts: azole antifungal agent

fungistaticSpectrum:active against many fungi, including yeasts, dermatophytes, actinomycegtes, and some phycomycetes, cryptococcus, candida, aspergillis Therapeutic uses:vaginal candidiasis, oropharyngeal and esophageal candidiasis, systemic candida infections and cryptococcal meningitis DOC=cryptococcal meningitisDrawbacks:gastrointestinal disturbances, skin rashes, hepatic necrosis, Stevens-Johnson syndrome, anaphylaxis, alopecia

multiple drug interactions: phenytoin, cyclosporine, warfarin,sulfonylureas, etc pregnancy category C

Terconazole cream (vaginal)Miscellaneous facts: fungicidalSpectrum:candida albicansactive against dermatophytes, yeasts, and at high concentrations gram-positive & gram-negative bacteriaTherapeutic uses: complicated and uncomplicated vulvovaginal candidiasisDrawbacks: pruritis, irritation-vulvovaginal burning, headache, body pain

pregnancy category C (not recommended during first trimester)

Miconazole cream 2% Miscellaneous facts: imidazole antifungal agent fungistatic topical or intravaginal use

Spectrum:broad spectrum blastomyces dermatitidis, candida sp., cryptococcus neoformans, coccidioides immitis, histoplasma capsulatum, paracoccidioides brasiliensis, sporothrix schenckii

Therapeutic uses: for topical and vaginal fungal infections (vaginal candidiasis, tinea infections, cutaneous candidiasis)

Drawbacks: pregnancy category C

Nystatin creamMiscellaneous facts: antifungal agentfungicidal and fungistaticSpectrum: primary activity against candida sp.

ineffective against bacteria, protozoa, trichomonads, and viruses

Therapeutic uses: treatment of oropharyngeal, cutaneous, mucocutaneous and vulvovaginal candidiasis poor oral absorption, good local activity—great choice for oral and esophageal candida infections Drawbacks: oral form causes gastrointestinal distress contact dermatitis, Stevens-Johnson syndrome not administered systemically due to potential toxicity

Rifaximin(Xifaxan) oral tablets Miscellaneous facts: rifamycin antibiotic non-systemically absorbed-no significant drug interactions Spectrum: gram-positive, gram-negative, aerobes, anaerobesTherapeutic uses: Traveler’s diarrhea caused by non-invasive strains of e.coli Drawbacks: do not administer to patients with diarrhea complicated by fever or blood in the stools flatulence, headache, abdominal pain, nausea, constipation, pyrexia caution in patients allergic to any of the rifamycin antimicrobial agents not for use in children under 12 years of age pregnancy category C—if necessary—only in 2nd and 3rd trimesters poor GI absorption-no systemic bioavailability-no drug interactions

200mg tid for 3 days

Loperamide(Imodium) oral capsulesMiscellaneous facts: synthetic antidiarrheal for oral use

prolongs transit time of the intestinal contents (decreases peristalsis), reduces daily fecal volume, increases viscosity and bulk density---diminished loss of fluids and electrolytes

Spectrum:Therapeutic uses: control and symptomatic relief of acute nonspecific diarrhea and of chronic diarrhea associated with inflammatory bowel disease—also

used for reducing the volume of discharge from ileostomiesDrawbacks: dry mouth, flatulence, abdominal cramps and colic not recommended in infants under 24 months of age

2 capsules initially then, 1 capsule after each loose stool max 8 capsules (16mg) capsules per 24 hour

make sure patient receives appropriate fluid and electrolyte replacement tolerance to the antidiarrheal effect has not been observed

NitrofurantoinMiscellaneous facts: bacteriostatic-can be bactericidal in high concentrations

urinary tract antiseptic/bladder antiseptic concentrates in the renal tubules and bladder – doesn’t achieve blood levels high enough to treat systemic infections Spectrum:gram-positive and gram-negativeTherapeutic uses:prevention and treatment of uncomplicated urinary tract infections caused by escherichia coli or staphylococcus

saprophyticusDrawbacks:gastrointestinal issues fairly common

hypersensitivity reactions, headache, vertigo, dizziness polyneuropathy ---with high doses or patients with renal impairment

monitoring parameters BUN, CrCl, LFT’s

Mebendazole (vermox) oral tabletMiscellaneous facts: anthelmintic

death of the worm is slow—complete gastrointestinal clearance up to 3 days after therapy retreatment necessary if patient not cured in 3 weeksSpectrum: ancylostoma duodenale (hookworm) ascaris lumbricoides (roundworm) enterobius vermicularis (pinworm) necator americanus (American hookworm) trichuris trichiura (whipworm) Therapeutic uses: DOC= GI hematodesDrawbacks: drug interactions : carbamazepine and phenytoin abdominal pain, nausea, diarrhea

myelosuppression can occur with high doses

Bacitracin ointmentMiscellaneous facts: bacteriostatic– potential to be bactericidalSpectrum: gram-positive bacteriaTherapeutic uses: topical use to prevent superficial skin infections following minor

injuries on small areas of the bodyDrawbacks: caution in patients with neomycin hypersensitivity maximum duration of use = 7 days incidence of contact dermatitis is about 2 %

Triple antibiotic ointmentMiscellaneous facts: (neomycin/polymyxin B/bacitracin)Spectrum: gram-positive and gram-negative

(neomycin & polymyxin B both have gram-negative coverage)Therapeutic uses: superficial skin infectionsDrawbacks: can cause allergic dermatitis

neomycin containing products can cause allergic reactions in about 1 in 20 people

Neomycin/polymyxin/hc otic susp

Miscellaneous facts: antibacterial & anti-inflammatory

Spectrum:gram-negative aerobes

MRSA coverage

Therapeutic uses: superficial bacterial infections of the external auditory canal

maximum use = 10 days

Drawbacks: caution in patients with tympanic membrane perforation or chronic otitis media – risk of ototoxicity

allergic skin reactions

pregnancy category c

QUIZ

1.Which antibiotic is associated with “red man syndrome”? A.) clindamycin B.) vancomycin C.) penicillin D.) ciprofloxacin2.Which injectable cephalosporin is the drug of choice for neisseria gonorrhea? A.) Ancef B.) Rocephin C.) Claforan D.) Mefoxin3. Why should you not use tetracycline after the expiration date? A.) renal failure B.) hepatic failure C.) QT prolongation D.) diarrhea4.Which antibiotic is not included in the DMAT cache? A.) Rocephin B.) Amoxicillin C.) Levaquin D.) Cephalexin5. How many generations of quinolones are there? A.) 1 B.) 2 C.) 3 D.) 4

References

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