Antibiotic Use In DentistryAntibiotic Use In Dentistry

Dr. Soukaina RyalatDr. Soukaina Ryalat

Writing PrescriptionsWriting Prescriptions

Rx: Drug Name (can be generic) Unit DoseRx: Drug Name (can be generic) Unit Dose(ex: Pen V-K 500 mg, Elixer, Sol’n)(ex: Pen V-K 500 mg, Elixer, Sol’n)

Disp: # of pills, milliliters (ml)Disp: # of pills, milliliters (ml)

Sig: Directions for use. q24h (daily), q12h, q8h, q6h, q4h, Sig: Directions for use. q24h (daily), q12h, q8h, q6h, q4h, prn pain, till goneprn pain, till gone

Refills__Refills__ SignatureSignature DEA #DEA #

Most antibiotics have 2 names, the trade or Most antibiotics have 2 names, the trade or brand name, created by the drug company brand name, created by the drug company that manufactures the drug, and a generic that manufactures the drug, and a generic name, based on the antibiotic's chemical name, based on the antibiotic's chemical structure or chemical classstructure or chemical class. . Trade names Trade names such as Keflex and Zithromax are such as Keflex and Zithromax are capitalizedcapitalized. . Generics such as Generics such as cephalexincephalexin and azithromycin are not capitalized.and azithromycin are not capitalized.

Barry Brainfart Dental Clinic 666 Bite Me LnCrossbyte Falls, MN Ph: 555-Y OU-HURTPt. Name: Address: DOB:

Rx: Date:

Disp:

Sig:

Refill____ Barry Brainfart, DDS

DEA:______________________

Antibiotics have 2 names : Generic name ; based on chemical constituents of

the drug & it is not capitalized . Trade name ; created by the drug company & it is

capitalized. Examples : generic name: cefalexin ( 1st generation

cephalosporin) Trade name: Sporidex produced by Ranbaxy

company & Keflex by Lilly company.

Antibiotic StrategiesAntibiotic Strategies

Cardinal Rules: 1) Use the right drug. Cardinal Rules: 1) Use the right drug. 2) Use the right dose. 3) Use the correct 2) Use the right dose. 3) Use the correct dosing schedule. 4) Correct duration.dosing schedule. 4) Correct duration.

Use a loading dose to rapidly achieve Use a loading dose to rapidly achieve therapeutic blood levels.therapeutic blood levels.

Avoid combinations of bacteriostatic and Avoid combinations of bacteriostatic and bacteriocidal drugs.bacteriocidal drugs.

Rules for prescribing antibiotics: Use the write drug Use the write dose Use the correct dose schedule & correct duration. Most odontogenic infections are caused by mixed

organisms . When we prescribe antibiotic we have to reach MIC ( Minimum

Inhibitory Concentration: is the smallest concentration of an antimicrobial needed to stop bacterial growth ).

Most of the drugs take their action within 2-3 days but we give an extra 2 days to make sure that the patient has taken the drug the right way & the desired effect has been achieved ( patient compliance).

ConsiderationsConsiderations

Gram Positive?Gram Positive? Gram Negative?Gram Negative? Mixed Infection?Mixed Infection? Anaerobes?Anaerobes?

Broad Spectrum AntibioticsBroad Spectrum Antibiotics

Affects both Gram + and Gram – bacteria, Affects both Gram + and Gram – bacteria, better for mixed infections. better for mixed infections.

Examples: Amoxicillin, AmpicillinExamples: Amoxicillin, Ampicillin

Common Pathogens

Necrotic pulp and apical abscesses

Obligate anaerobic bacteriaGram negative rods

Prevotella & porphyomonas spp.

Fusobacterium spp.

Campylobacter rectus

Gram positive rodsEubacterium spp.

Actinomycetes spp.

Gram positive cocci– Peptostreptococcus spp.

– Facultative anaerobic bacteria Gram positive cocci

– Strep and Entercoccus spp.

Common PathogensCommon Pathogens

Periodontal Diseases Periodontal Diseases GingivitisGingivitis

Fuso, strep, & actinomycetesFuso, strep, & actinomycetes

Bacteroides, porphyomonas, Bacteroides, porphyomonas, peptostreptococcus & prevotellapeptostreptococcus & prevotellaAcute necrotizing ulcerative gingivitisAcute necrotizing ulcerative gingivitisSpirochetes, prevotella, fusoSpirochetes, prevotella, fuso

Localized juvenile periodontitisLocalized juvenile periodontitisActinobacillusActinobacillus

Antibiotic Resistance

Three main types– Chromosome mediated

Spontaneous mutations Non-major form of drug resistance Rarely lead to complete resistance

– Plasmid mediated (conjugation) VERY important from clinical standpoint Mostly gram negs Mediate resistance to multiple drugs High transfer rate from cell to cell

– Transposon (transduction and transformation) Phage mediated Clinically important for Gram +

Antibiotic ChoicesAntibiotic Choices

ß-Lactams

Natural penicillins– Pen V and Pen G

MOA (mechanism of action): Inhibit cell wall synthesis

Dose: 250-500 mg qid x 7-10 days Contraindications:

– Allergies– Poor renal fxn

Adverse events: GI upset Drug interactions: oral contraceptives Pregnancy category B

ß-Lactams

Natural penicillins– Pen V and Pen G

Bactericidal Allergic reaction: rare (4 per 100,000) Spectrum:

– Strep, staph, enterococcus, neiseria, treponema, listeria

Resistance:– Mostly staph (>80%)

ß-Lactams

Amino-penicillins– Amoxicillin, ampicillin

MOA: Inhibit cell wall synthesis Dose: 250-500 mg q 8 h x 7-10 days Contraindications:

– Allergies– Poor renal fxn

Adverse events: GI upset Drug interactions: oral contraceptives Amoxicillin and clavulanic acid (Augmentin)

ß-Lactams

Amino-penicillins– Amoxicillin, ampicillin

Bactericidal “ampicillin” rash (4-10%) Spectrum:

– Strep, staph, enterococcus, neiseria, treponema, listeria, E. coli, proteus, H. Flu, shigella, salmonella

Resistance:– Entero, citro, serratia, proteus vulagris, provedincia,

morganella, pseudomonas aeriginosa, acinetobacter

Cephalosporins

Cephalexin (Keflex)– MOA: Inhibit cell wall synthesis– Dose: 250-1000mg q 6 h x 7-10 days– Contraindications:

Allergies Poor renal fxn

– Adverse events: mild GI– Drug interactions: probenecid– Pregnancy category B

Cephalosporins

Cephalexin (Keflex)– Bactericidal– Spectrum:

Gram +

– Resistance: Methicillin resistant gram +

– Low cross sensitivity with PCN

Cephalosporins, 1st generation Cefadroxil Cephalosporins, 1st generation Cefadroxil DURICEFDURICEFCefazolin Cefazolin ANCEFKEFZOLANCEFKEFZOLCephalexin Cephalexin KEFLEXKEFLEXMainly skin and soft-tissue infectionsMainly skin and soft-tissue infections

Gastrointestinal upset and diarrhea Gastrointestinal upset and diarrhea NauseaAllergic reactionsNauseaAllergic reactions

Cephalosporins, 2nd generation CefaclorCefoxitin Cephalosporins, 2nd generation CefaclorCefoxitin MEFOXINMEFOXINCefprozil Cefprozil CEFZILCEFZILCefuroxime Cefuroxime CEFTINZINACEFCEFTINZINACEFLoracarbefLoracarbef

Some respiratory infections and, for cefoxitin Some respiratory infections and, for cefoxitin MEFOXINMEFOXIN, abdominal infectionss, abdominal infectionss

Gastrointestinal upset and diarrheaNauseaAllergic Gastrointestinal upset and diarrheaNauseaAllergic reactionsreactions

Cephalosporins, 3rd generation Cefixime Cephalosporins, 3rd generation Cefixime SUPRAXSUPRAXCefdinir Cefdinir OMNICEFOMNICEFCefditoren Cefditoren SPECTRACEFSPECTRACEFCefoperazoneCefotaxime CefoperazoneCefotaxime CLAFORANCLAFORANCefpodoxime Cefpodoxime VANTINVANTIN

Ceftazidime Ceftazidime FORTAZTAZICEFFORTAZTAZICEFCeftibuten Ceftibuten CEDAXCEDAXCeftizoxime Ceftizoxime CEFIZOXCEFIZOXCeftriaxone Ceftriaxone ROCEPHINROCEPHIN

3d generation3d generation

Given by mouth: Broad coverage of Given by mouth: Broad coverage of many bacteria for people with mild-to-many bacteria for people with mild-to-moderate infections, including skin and moderate infections, including skin and soft-tissue infections.soft-tissue infections.

Given by injection: Serious infections Given by injection: Serious infections (such as meningitis or infections (such as meningitis or infections acquired in a hospital)acquired in a hospital)

Cephalosporins, 4th generation Cephalosporins, 4th generation Cefepime Cefepime MAXIPIMEMAXIPIMESerious infections (including Serious infections (including Pseudomonas infections), particularly in Pseudomonas infections), particularly in people with a weakened immune system people with a weakened immune system and infections due to susceptible and infections due to susceptible bacteria resistant to other antibioticsbacteria resistant to other antibiotics

Cephalosporins, 5th generation Cephalosporins, 5th generation CeftobiproleCeftobiprole

Complicated skin infections, including Complicated skin infections, including foot infections in people with diabetes, foot infections in people with diabetes, due to susceptible bacteria, such as due to susceptible bacteria, such as Escherichia coli, Pseudomonas Escherichia coli, Pseudomonas aeruginosa, and methicillin-resistant aeruginosa, and methicillin-resistant Staphylococcus aureus (MRSA)Staphylococcus aureus (MRSA)

LincosamidesLincosamides

Clindamycin (Cleocin)– MOA: binds to the 50S ribosomal subunit and inhibits

protein synthesis– Dose: 100-450mg q 6 h x 7-10 days– Precautions:

Poor hepatic fxn

– Adverse events: GI upset, pseudomembraneous colitis

– Drug interactions: neuromuscular blocking agents– Pregnancy category B

Lincosamides

Clindamycin– Bactericidal or static depending on

concentration– Spectrum:

Gram +, anaerobes, parasites

– Resistance Enteroccocus

*Clostridium diff. pseudomembranous colitis!!*Clostridium diff. pseudomembranous colitis!!

Macrolides

Azithromycin (Zithromax), clarithromycin (Biaxin)– MOA: bind to the 23S rRNA in the 50S subunit ribosome– Dose: 250-500 mg/day x 5-10 days– Precautions :

Poor hepatic fxn

– Adverse effects: GI– Drug interactions: Cytochrome P-450 – Pregnancy category B

Macrolides

Azithromycin, clarithromycin– Bactericidal– Spectrum:

Gram +, gram -, anaerobes

– Resistance: B. fragilis, and strep pneumo

Tetracyclines

Doxycycline (Vibramycin)– MOA: inhibit protein synthesis by preventing aminoacyl

transfer RNA from entering the acceptor sites on the ribosome

– Dose: 100mg qd-bid x 7-14 days– Contraindications:

Food pregnancy

– Adverse events: GI – Drug interactions: anti-epileptics– Pregnancy category D

Tetracyclines

Doxycycline– Bacteriostatic– Spectrum:

Broad, Gram +, -, anaerobes, aerobes, and spirochetes

– Resistance: Widespread, cross resistance

– PHOTO SENSITIVITY!!!

Nitroimidazoles

Metronidazole (Flagyl)– MOA: reduced intermediate interacts and

breaks the bacterial or parasitic DNA– Dose: 250-1000 mg q 6-8 h x 7-10 days– Precautions : poor hepatic fxn– Adverse events: GI upset.– Drug interactions: warfarin, Li+– Pregnancy category D

Nitroimidazoles

Metronidazole– Bactericidal– Spectrum:

Gram - anaerobes

– Resistance: Rare, H. Pylori?

– Unpleasant metallic taste

Fluoroquinolones

Ciprofloxacin (Cipro)– MOA: Inhibition of DNA gyrase, and Topo II– Dose: 250-500 mg qd x 7-10 days– Contraindications: <18 yrs old, pregnancy– Adverse events: spontaneous tendon rupture– Drug interactions: probenacid, warfarin– Pregnancy category C

Fluoroquinolones

Ciprofloxacin– Bactericidal– Spectrum:

Very broad except B. frag

– Resistance: MRSA, MRSE

Antifungals

Nystatin – MOA: inhibit cell wall synthesis– Dose: 5 ml swish and swallow q 4 h x 10-14 d– GI upset– Drug interactions: minor– Pregnancy category C

Antifungals

Clotrimazole (Mycelex), ketoconazole (Nizoral), fluconazole (Diflucan) – MOA: inhibit cell wall synthesis– Dose: 200-800 mg qd x up to 12 months– GI upset– Drug interactions: major p-450 enzyme inhibitor,

interactions with many drugs– Pregnancy category C

ADA RegulationsADA Regulations

Antibiotic prophylaxis is Antibiotic prophylaxis is NOTNOT recommended for dental patients recommended for dental patients with with plates, pins, or screws,plates, pins, or screws, nor is nor is

it routinely recommended for it routinely recommended for MOSTMOST dental patients with dental patients with TOTAL TOTAL

JOINT REPLACEMENTS.JOINT REPLACEMENTS.

Prophylaxis recommended – Total joint replacement within the last two years

AND: Compromised immune system OR Type 1 DM OR Previous prosthetic joint infections OR Malnourishment OR

Hemophilia

Prophylaxis antibiotic recommendations

– No specific regimen recommended– Keflex is often the first drug of choice

Legal ConsiderationsLegal Considerations

The dentist may not be aware of the The dentist may not be aware of the patient’s medical condition.patient’s medical condition.

Physician may not be aware of the advisory Physician may not be aware of the advisory statements or of the dental procedure to be statements or of the dental procedure to be performed.performed.

Documentation.Documentation.

Pharmaceutical pregnancy categories : Category A : Adequate & well controlled studies on both humans &

animals have failed to demonstrate risk to the fetus. Category B : Animal reproduction studies have failed to demonstrate a

risk to the fetus & there are no adequate & well controlled studies in pregnant women.

Category C : Animal reproduction studies have shown an adverse effect

on the fetus & there are no adequate & well controlled studies in humans, but potential benefits may warrant use of the drug in pregnant women despite potential risk.

In Summary….In Summary….

Principles of Antibiotic Therapy

Therapeutic effectiveness– Clinical indications

Pharmcodynamics, pharmacokinetics

– Age and extent of infection

Patient factors

Age, allergies, compliance, pregnancy risk Patient function

– Renal, hepatic, immunosuppresion, route applicability

Cost– Brand name, length of course, alternatives?

Cost

Drug Name Cost of Therapy $ (~10 Days) Generic if Available

Pen VK 6.81

Amoxicillin 8.41

Ampicillin 12.45

Cephalexin 15.65

Clindamycin 38.45

Azithromycin 41.52

Clarithromycin 74.45

Augmentin 76.82

Doxycycline 5.15

Metronidazole 9.65

Ciprofloxacin 76.65

Nystatin 9.86

Clotrimazole 97.05

Ketoconazole 30.69

Fluconazole 116.25

Dental Infection

Acute—Rapid growth< 3 days

Chronic > 3 days

Pen VK 500mg q6h orAmox 500mg q8h or

Cephalosporin

Allergic to PCN

Clindamycin 300mg q8h orCephalosporin (check allergic Rxn) or

Azith or Clarithromycin

Think AnaerobesAdd Metronidazole 250-500mg

To PCN, Amox, or Ceph

Clindamycin 300mg q8h