Antibiotic active substances in periodontal therapy

Besides periodontal pockets, systemically administered antibiotics also reach other bacterial niches in the oral cavity. Systemic antibiotic administration is therefore indicated in accordance with the German Society of Periodontology (DG PARO) recommendations in generalized periodontitis in particular.


Active ingridient group: β-lactams

Mechanism of action: Inhibition of the cross-linking of peptidoglycans in the bacterial cell wall. Bactericidal.

Contraindication: Absolute: In cases of proven penicillin hypersensitivity, caution with regard to possible cross-allergies with other ß-lactam antibiotics. Relative: In patients with infectious mononucleosis and in patients with lymphatic leukemia (elevated risk of eruption).

Interactions: Possible interactions with cardiac glycosides, gout medications and some anticoagulants. The activity of oral contraceptives may be weakened.

Side effects: Mild gastrointestinal disturbances, skin reactions (rash, urticaria), severe allergic reactions (drug fever, asthma, anaphylactic shock).

Use in the context of periodontal therapy: Amoxicillin covers all periodontitis-associated bacteria in principle. But because anaerobes frequently produce ß-lactamases, use of amoxicillin alone is unreliable.


Active ingredient group: Lincosamides

Mechanism of action: Clindamycin binds to the ribosome and blocks bacterial protein synthesis. Bacteriostatic.

Contraindication: Absolute: Hypersensitivity towards clindamycin and lincomycin, infants under 1 month (immature metabolism). Relative: Allergic diathesis (asthma), pregnancy, liver and kidney damage, impairment of neuromuscular transmission (myasthenia gravis, Parkinson’s disease) and history of gastrointestinal diseases (e.g. Crohn’s disease, ulcerative colitis).

Interactions: Possible interactions with muscle relaxants and oral contraceptives.

Side effects: Gastrointestinal disturbances (diarrhea, vomiting, nausea) Rare: eruption, raised transaminase levels, leukopenia, antibiotic-associated colitis caused by Clostridium difficile (= pseudomembranous colitis).

Use in the context of periodontal therapy: Alternative product to metronidazole. Agent of choice where Parvimonas micra has been identified.


Active ingredient group: Nitroimidazoles

Mechanism of action: Induces strand breaks in bacterial DNA, thereby inhibiting nucleic acid synthesis. Bactericidal.

Contraindication: CNS disorders, pregnancy, hypersensitivity, lactation, severe liver damage, children under 6 years of age.

Interactions: Possible interactions with oral anticoagulants such as warfarin, lithium preparations, disulfiram, barbiturates, phenytoin, cimetidine.

Side effects: Gastrointestinal disturbances, headache, peripheral neuropathy, metallic taste, central nervous system disturbances, reversible neutropenia, discolored urine, inability to tolerate alcohol.

Use in the context of periodontal therapy: Agent of choice where red, orange and orange-associated complex bacteria are identified


Active ingredient group: Macrolides

Mechanism of action: Blockade of protein synthesis through inhibition of translocation on the bacterial ribosome. Bacteriostatic.

Contraindication: Severe hepatic or renal impairment, hypersensitivity to clarithromycin, pregnancy and lactation.

Interactions: Possible interactions with terfenadine, digoxin or astemizole (arrhythmias), ergotamine, ciclosporin.

Side effects: Gastric emptying, diarrhea, rash, intrahepatic cholestasis, hepatic impairment, torsades de pointes arrhythmia, ototoxicity.

Use in the context of periodontal therapy: Agent of choice where orange-associated complex bacteria occur in isolation.


Active ingredient group: Fluoroquinolones

Mechanism of action: Interaction with bacterial topoisomerases and thus inhibition of DNA synthesis. Bactericidal.

Contraindication: Children and adolescents in the growth phase, pregnancy, nursing, epilepsy. Precautions: maintain adequate fluid intake.

Interactions: Possible interactions with tizanidine, probenecid, phenytoin, methotrexate, theophylline, macrolide antibiotics, oral anticoagulants. Absorption reduced by antacids and calcium-containing foods. The activity of oral contraceptives may be weakened.

Side effects: Gastrointestinal reactions, central nervous disorders (seizures, psychotic conditions, vigilance disorders, taste impairment), exanthema, circulatory disorders, phototoxicity, Achilles tendon rupture.

Use in the context of periodontal therapy: Alternative for penicillin-allergic patients


Active ingredient group: Tetracyclines

Mechanism of action: Blocking of protein synthesis by binding to the 30S ribosome. Bacteriostatic.

Contraindication: Pregnancy, nursing, children, myasthenia gravis (only applies for i.v. preparations, which contain magnesium), allergy.

Interactions: Doxycycline may potentiate the effects of sulfonylurea derivatives (oral antidiabetic agents) and dicoumarol-like anticoagulants. Doxycycline absorption may be reduced by di- or trivalent cations such as aluminum, calcium (milk, milk products, fruit juices). The activity of oral contraceptives may be weakened.

Side effects: Irreversible discoloration of the teeth, deposition in bones, phototoxicity, rarely gastrointestinal disturbances, increased intracranial pressure, arrhythmias (if i.v. administration is too fast), hepatoxicity.

Use in the context of periodontal therapy: Covers all relevant periodontopathogenic marker bacteria. Used primarily as an alternative product or as a topical antibiotic.

In order to guarantee the active ingredient concentrations in the gingival crevicular fluid that are needed for sustained bacterial reduction, an adequate dosage and duration of treatment are critical.

Please note: This overview is a summary. The information it contains should not be the only source for health-related decisions.