What antibiotic should be used pre-procedure for a dental extraction scheduled to take place later?

Antibiotic Prophylaxis for Delayed Dental Extraction

For patients requiring antibiotic prophylaxis before a scheduled dental extraction, administer amoxicillin 2 grams orally as a single dose 30-60 minutes before the procedure. 1, 2, 3

Patient Risk Stratification

Before prescribing prophylaxis, determine if the patient meets high-risk criteria requiring antibiotic coverage:

High-Risk Cardiac Conditions (Prophylaxis Required)

• Prosthetic cardiac valves or prosthetic material used for cardiac valve repair 1, 3
• Previous history of infective endocarditis 1, 3
• Specific congenital heart diseases: unrepaired cyanotic CHD, completely repaired CHD with prosthetic material during first 6 months post-procedure, or repaired CHD with residual defects at prosthetic patch/device site 1
• Cardiac transplant recipients with cardiac valvulopathy 1

Patients NOT Requiring Prophylaxis

• Mitral valve prolapse 2, 3
• Rheumatic heart disease without prosthetic valves 3
• Healthy individuals without cardiac risk factors 2
• Most patients with prosthetic joints (unless meeting specific high-risk criteria such as immunocompromised status or inflammatory arthropathies) 1

Standard Prophylaxis Regimen

For Patients Without Penicillin Allergy

• Amoxicillin 2 grams orally, single dose, 30-60 minutes before the extraction 1, 2, 3
• This timing ensures adequate tissue concentration at the time of the procedure 4
• Peak concentrations occur approximately 1 hour after oral administration 4

For Patients Allergic to Penicillin

• Clindamycin 600 mg orally, single dose, 30-60 minutes before the procedure 1, 2, 3
• Alternative options include azithromycin or clarithromycin 500 mg orally 3
• Do not use cephalosporins (such as cephalexin 2g) if the patient has a history of anaphylaxis, angioedema, or urticaria with penicillin 1, 3

For Patients Unable to Take Oral Medications

• Ampicillin 2 grams IM or IV within 30 minutes before the procedure 2, 3
• For penicillin-allergic patients unable to take oral medications, use vancomycin 1 gram IV over 1-2 hours 5

Special Clinical Situations

Patients Already on Chronic Antibiotic Therapy

• Select an antibiotic from a different class rather than increasing the current antibiotic dose 1, 2, 3
• For patients on long-term penicillin therapy, use clindamycin, azithromycin, or clarithromycin instead 2
• Avoid cephalosporins due to possible cross-resistance 2

Patients on Anticoagulation

• Use oral regimens and avoid intramuscular injections entirely 1, 2, 3
• The oral amoxicillin 2g dose is preferred over IM/IV routes 3

Patients on Hemodialysis

• The standard 2 grams amoxicillin dose remains appropriate if not allergic to penicillin 1, 3, 6
• Despite renal impairment, dose adjustment is not necessary for single-dose prophylaxis 6
• Most Australian and New Zealand nephrology units follow this approach 6

Critical Timing and Duration Considerations

• Only a single pre-procedure dose is indicated—post-procedure antibiotics are NOT recommended for prophylaxis 1, 2
• Research demonstrates that a single 2g dose of amoxicillin achieves concentrations in dental tissues (0.502 μg/g in roots, 0.171 μg/g in crowns) that exceed the minimal inhibition concentration for oral bacteria 7
• Studies comparing short prophylactic therapy versus extended postoperative regimens found no benefit to continuing antibiotics for 4 days after extraction 8
• Prolonged antibiotic courses only increase adverse event risk without additional benefit 3

Common Pitfalls to Avoid

• Do not prescribe prophylaxis for all dental patients—restrict to the highest-risk cardiac conditions only 3
• Do not prescribe prolonged courses—a single preoperative dose is sufficient 3
• Do not use cephalosporins in patients with immediate-type penicillin hypersensitivity 3
• Do not use IM injections in anticoagulated patients 3
• Do not increase the dosage of a patient's current antibiotic—switch to a different class 1, 2

Evidence Quality Note

The 2007 American Heart Association guidelines represent a paradigm shift, acknowledging that most cases of infective endocarditis result from randomly occurring bacteremias from routine daily activities rather than from dental procedures 3. However, for the highest-risk patients undergoing procedures that manipulate gingival tissue, perforate oral mucosa, or involve the periapical region of teeth, prophylaxis remains indicated 1, 3. A systematic review of randomized controlled trials demonstrated that a single oral dose of 2g amoxicillin before lower third molar extraction significantly decreased the incidence of surgical site infection (OR = 0.22; 95% CI, 0.08 to 0.59; P = 0.002) 9.