Antibiotics in Dentistry

Iyad Abou Rabii DDS, OMFS, MRes, PhD

QASSIM UNIVERSITY

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Antibiotics in Dentistry

Iyad Abou Rabii DDS, OMFS, MRes, PhD

Antibiotic is a a chemical substance derivable from a mold or bacterium that can kill

microorganisms and cure bacterial infections

Best use of Antibiotics

Cardinal Rules:

1. Use the right drug. 2. Use the right dose. 3. Use the correct dosing schedule. 4. Correct duration. 5. Use a loading dose to rapidly achieve therapeutic blood levels. 6. Avoid combinations of bacteriostatic and bacteriocidal drugs.

Chose well

1. Narrow Spectrum? 2. Extended/Broad Spectrum? 3. Designer Antibiotics? 4. Anaerobes? Consider if the infection is present > 3days or if no improvement

Know your enemy (bateria)

1. Gram Positive? 2. Gram Negative? 3. Mixed Infection? 4. Anaerobes?

Identify your weapon

1. Specific for the pathogen. 2. Fewer disturbances of non-pathogenic bacteria. 3. Fewer side effects. 4. Rapid response for sensitive organisms. Ex: Pen VK, Pen G, Erythromycin 5. Affects both Gram + and Gram - bacteria, better for mixed infections. 6. May give up some effectiveness for Gram + to gain effectiveness for Gram

Examples: Amoxicillin, Ampicillin

Identify you patients

1. Age, allergies, compliance, pregnancy risk 2. Patient function 3. Renal, hepatic, immunosuppresion, route applicability 4. Cost Brand name, length of course, alternatives?

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Prophylactic antibiotic

The goal of antibiotic prophylaxis in Odontology is to prevent the onset of infections through the entrance way provided by the therapeutic action, therefore it is indicated provided there is a considerable risk of infection, either because of the characteristics of the operation itself or the patient’s local or general condition. The physician’s criterion for choosing antibiotic prophylaxis or not must be based on the benefit and the cost of the risk. In the last instance, the prophylaxis decision is the choice of the physician, who will use the equation: risk = degree of damage x probability of experiencing it. To that aim, patients could be classified as:

a)healthy patients, b) patients with local or systemic infection risk factors, and c) patients with post-bacteraemia focal infection risk factors.

In healthy subjects, prophylaxis is based exclusively on the risk of the procedure.

Topical Antibiotics

Pharmaceutical Forms

Some topical antibiotics are available without a prescription and are sold in many forms, including creams, ointments, powders, and sprays. Some widely used topical antibiotics are bacitracin, neomycin, mupirocin, and polymyxin B. Among the products that contain one or more of these ingredients are Bactroban (a prescription item), Neosporin, Polysporin, and Triple Antibiotic Ointment or Cream. Antibiotic mouthwash can be prepared by the patient by dissolving the contents of 250 mg tetracycline capsule in 10 ml of water to give a 2% solution. It may be more effective to add glycerol to the solution as a demulcent, this must be done by pharmacist.

Advantages

The value of topical antibiotics overweighs such risks in some cases. Tetracycline is a useful topical antibiotics. As at 2% solution it’s often effective in reducing secondary infection (and thus the discomfort) in cases of aphtous stomaitis, primary herpetic stomaitis, and all oral ulcerative conditions. Use of topical antibiotics is also seen to be helpful in acute chronic gingivitis treatment.

Disadvantages

There are inherent disadvantages associated with the use of topical antibiotics because of the possibilities of selection for resistant strains and inducing hypersensitivity reaction at the patient.

Use of Topical Antibitics

Indication

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Topical antibiotics help prevent infections caused by bacteria that get into minor cuts, scrapes, and burns. Treating minor wounds with antibiotics allows quicker healing. They are always used to prevent secondary infection (ulcers)

Duration

The use of topical antibiotics cannot normally be practiced as long- term treatment, it is better to be reserved for acute episodes. Otherwise, there will be the risk of overgrowth of resistant organisms, although a candidal infection may occur. However, in some rare cases a prolonged topical antibiotic treatment is justified (Patients with severe and persistent oral lesions), in that case a tetracycline with triamcinolone combination is preferred

Topical antifungal treatment

Antifungal drugs

The polyene antifungal agents, nystatin and amphotericin B, are well established and relatively free from side-effects when used locally. They are available in various forms, such as lozenges, pastilles, creams, and suspensions. Unfortunately, patient compliance is often poor with these preparations, which may take a while to dissolve in the mouth (for example, pastilles and lozenges) and have a a distinctive4taste. The newer azoles have very useful properties, although resistance is rather more

commonly met and may be problematic in the future, particularly in the

immunocompromised patient. (C. krusei and and C. glabrata are usually resistant

to fluconazole.) The locally active agent, miconazole is available as an oral gel or

cream.

Pharmaceutical Forms

Conventional In order to assure topic application of antifungal agents, conventional lozenge, mouthwash, or gel would be the simplest dosage forms for the delivery of drugs in the buccal cavity, but these conventional dosage forms had the disadvantage of an initial burst of salivary concentration followed by a rapid decrease. A lozenge produced effective salivary drug levels for more than one hour but repeated administration was restricted due to systemic toxicity coming from the large quantity of ingested drug. The action of mouthwashes was even more transient than that of lozenges, and gels/pastes were difficult to retain in the mouth . Sustained Release forms In case of oral fungal infections, a prolonged therapy with antifungal agent was required, and some papers documented prolonged release of antifungal agent from buccal devices in the form of an adhesive tablets. I.Abou Rabii et al (2004, France) has developped a Miconazole musoadhesive tablette which has been given higher concentration of Miconazole in Saliva (Over the IMC for more than 9h).

Topical antifungal therapy

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Pseudomembranous, erythematous hyperplastic candidosis

Amphotericin lozenges (10 mg) Nystatin pastilles (100 000 units) Dissolve slowly in mouth, after meals; use 4 times daily;

Candida-associated denture stomatitis

Amphotericin or nystatin (as above) and remove dentures Miconazole gel applied to palatal surface of denture 4 times daily for 1 to 4 weeks Chlorhexidine 0.2% rinse, 4 times daily (do not use with nystatin)

Candida-associated angular cheilitis

Nystatin cream; apply to corners of mouth 3 to 4 times daily, until resolution Miconazole cream (or gel); apply 3 to 4 times daily to angles