Quality Resource Guide –

Antibiotic Use in Dentistry 2nd Edition

www.metdental.com

Page 3

Most regimens involve a single, preoperative

dose of a bactericidal agent with activity

against

Streptococcus

viridans.

There is no

documentation showing that a second dose

will enhance outcomes.

There is also limited

evidence that antibiotic prophylaxis reduces

complications following implant placement and no

evidence supporting use to prevent complications

of third-molar surgery.

14,15

Antibiotic prophylaxis

prior to dental treatment in patients with total

joint arthroplasty (artificial joint) is controversial,

and professional guidance now emphasizes good

oral hygiene to prevent infective complications in

these patients.

At this time, there is insufficient

scientific evidence on which to base the practice.

However, when in doubt, the dentist is obligated

to consult with the patient’s physician(s) to

determine the need for antibiotic prophylaxis and

the appropriateness of the recommended regimen.

complication.

The development of any sign or

symptom of an allergic reaction (rash, itching

and/or hives) requires that the antibiotic agent

be discontinued immediately and the patient be

evaluated medically.

Drug Interactions

Antibiotics are capable of adversely interacting

with other dental and medical drugs, both

through pharmacodynamic and pharmacokinetic

mechanisms.

The most significant adverse

pharmacodynamic

interaction

for

commonly

prescribed antibiotics is the mutual antagonism

that occurs when a bactericidal agent (penicillins,

cephalosporins)

co-administered

with

bacteriostatic agent (tetracycline).

The recent

scientific evidence does not support an adverse

interaction between oral contraceptives and

antibiotics used in dentistry.

Adverse Effects

Antibiotics, as prescribed in dentistry, are

generally well tolerated.

With the exception of

allergy, most adverse effects from antibiotics are

related to their effects on the gastrointestinal

tract. They may irritate the stomach or stimulate

contractions of gastrointestinal smooth muscle,

resulting in nausea, vomiting and cramping. They

may also disrupt the normal flora, resulting in

diarrhea or lead to antibiotic-associated colitis,

and a potentially life-threatening overgrowth of

difficile.

Symptoms

with

most

cases

antibiotic-

associated diarrhea dissipate when the antibiotic

is discontinued. It is imperative that patients be

cautioned against the use of antidiarrheal drugs

and/or probiotics in place of medical diagnosis

and management of this rare, but serious,

Table 1 - Classification and Characteristics of Common Dental Antibiotics for Oral Administration

Antibiotic

Class

Mechanism

of Action

Common Adult

Oral Dosage*

Special Considerations

Penicillin VK

Beta lactam penicillin

Bactericidal

500 mg q 6h

Absorption impaired by food

Amoxicillin

Aminopenicillin

Bactericidal

500 mg q 8h

Absorption not impaired by food,

available with beta lactamase inhibitor

Cephalexin

Cephalosporin

Bactericidal

2 g 30 min-1 h

before procedure

Risk of cross-allergy with penicillins is low;

alternative agent for prophylaxis

Clindamycin

Lincosamide

Bactericidal

300 mg q 6h

Excellent alternative in cases of penicillin allergy

Azithromycin

Macrolide

Bacteriostatic

500 mg day 1,

then 250 mg 1 q d

Once daily dosing;

alternative agent for prophylaxis

Clarithromycin

Macrolide

Bacteriostatic

500 mg q 12h

Alternative agent for prophylaxis

Metronidazole

Nitroimidazole

Bactericidal

500 mg q 8h

Disulfiram-like reactions with alcohol;

effective against anaerobes only

Doxycline

Tetracycline

Bacteriostatic

20 mg q 12h prior

to meals

Adjunct for periodontal therapy;

available in local delivery forms

See reference 4 for information regarding pediatric dosages