Lymecycline

Approved Indications:

• Acne Vulgaris:
  Indicated for the treatment of moderate to severe acne vulgaris, particularly inflammatory types involving papules, pustules, and nodules.
• Susceptible Bacterial Infections:
  When supported by culture and sensitivity testing, Lymecycline is used for:
• Respiratory tract infections (e.g., bronchitis, atypical pneumonia)
• Urogenital infections (e.g., Chlamydia trachomatis urethritis or cervicitis)
• Skin and soft tissue infections
• Rickettsial infections (e.g., Rocky Mountain spotted fever, typhus)
• Mycoplasma pneumonia
• Early Lyme disease (Borrelia burgdorferi)

Clinically Accepted Off-label Uses:

• Inflammatory rosacea
• Periodontitis (as an adjunct to mechanical therapy)
• Malaria prophylaxis (alternative to doxycycline in specific cases)

Adults:

• Acne vulgaris: 300–408 mg orally once daily for 8–12 weeks
• Bacterial infections: 300–408 mg orally once or twice daily, depending on the severity and site of infection

Adolescents (≥12 years):

• Same as adult dosage

Children (<12 years):

• Not recommended due to the risk of permanent teeth discoloration and enamel hypoplasia

Elderly:

• No routine dose adjustment needed; monitor renal function as appropriate

Renal Impairment:

• Use with caution in moderate to severe renal impairment
• Adjust dose or extend dosing interval if necessary

Hepatic Impairment:

• No dose adjustment generally required
• Monitor liver function tests during prolonged therapy

Route of Administration:

• Oral, with a full glass of water
• Preferably taken on an empty stomach, but may be taken with food to minimize gastrointestinal discomfort
• Avoid taking with milk, antacids, calcium, magnesium, iron, or zinc supplements within 2 hours of dosing

Treatment Duration:

• Acne: 8–12 weeks
• Infections: 7–14 days or as clinically indicated

Lymecycline is a broad-spectrum tetracycline-class antibiotic that acts as a prodrug of tetracycline. It inhibits bacterial protein synthesis by binding reversibly to the 30S ribosomal subunit, blocking the attachment of aminoacyl-tRNA to the mRNA-ribosome complex. This action prevents the addition of amino acids to the elongating peptide chain, resulting in inhibition of protein synthesis and a bacteriostatic effect. Additionally, in acne, Lymecycline helps reduce Propionibacterium acnes colonization and has anti-inflammatory effects on inflammatory lesions.

• Absorption: Rapidly and well absorbed orally; peak plasma levels in 2–4 hours
• Bioavailability: Approximately 100%
• Distribution: Widely distributed in body tissues, including skin and respiratory tract; crosses placenta
• Protein Binding: Approximately 25%
• Metabolism: Minimal hepatic metabolism
• Elimination:
• 50–70% excreted unchanged in urine
• Some fecal and biliary excretion
• Half-life: 8–10 hours

• Pregnancy:
• FDA Category D (historical classification): There is evidence of fetal risk.
• Use is contraindicated during pregnancy due to the risk of permanent tooth discoloration and inhibition of fetal bone growth.
• Lactation:
• Lymecycline is excreted in human milk.
• Contraindicated during breastfeeding due to potential adverse effects on bone growth and teeth development in infants.

• Primary Class: Antibiotic
• Subclass: Tetracycline-class (semisynthetic)
• Generation: Second-generation tetracycline derivative (tetracycline prodrug)

• Known hypersensitivity to Lymecycline, tetracyclines, or any component of the formulation
• Children under 12 years of age
• Pregnancy
• Breastfeeding
• Severe renal insufficiency (if not monitored closely)
• Concurrent use with oral retinoids (e.g., isotretinoin) due to risk of pseudotumor cerebri

• Photosensitivity: Risk of sunburn or phototoxic reactions; advise sun protection
• Intracranial Hypertension: Rare; increased risk if used with retinoids; monitor for persistent headache or vision changes
• Superinfections: May lead to overgrowth of non-susceptible organisms, including Candida or Clostridium difficile
• Hepatic Effects: Monitor liver function in long-term or high-dose use
• Tooth and Bone Development: Avoid use in children and pregnant women to prevent permanent staining of teeth and growth inhibition
• Renal Impairment: Caution advised; risk of accumulation if renal function is significantly impaired

Common Side Effects:

• Gastrointestinal: Nausea, abdominal pain, diarrhea, vomiting
• Dermatologic: Photosensitivity, rash
• Neurologic: Headache

Less Common or Rare Side Effects:

• Hepatic: Elevated transaminases, hepatotoxicity (rare)
• Renal: Worsening renal function in susceptible patients
• Hematologic: Eosinophilia, thrombocytopenia, neutropenia
• Immune: Hypersensitivity reactions including urticaria, angioedema, and rare anaphylaxis
• CNS: Benign intracranial hypertension (pseudotumor cerebri)

Dose-Related & Timing:

• Adverse effects are typically mild and reversible
• Phototoxicity may appear within hours of sun exposure

• Antacids & Divalent Cations (e.g., calcium, magnesium, iron): Decreased absorption of Lymecycline; separate dosing by at least 2 hours
• Oral Retinoids (e.g., isotretinoin): Risk of increased intracranial pressure; avoid concurrent use
• Oral Contraceptives: May reduce contraceptive efficacy; recommend additional contraception
• Penicillins: May antagonize bactericidal effect; avoid concurrent use
• Warfarin and Other Anticoagulants: May enhance anticoagulant effect; monitor INR closely

CYP Enzymes:

• Not a significant substrate or inhibitor of CYP450 enzymes

• Lymecycline remains a first-line oral antibiotic in European acne treatment guidelines for moderate to severe acne.
• EMA and national authorities continue to recommend short-term use (8–12 weeks) to reduce antibiotic resistance.
• No new FDA or EMA safety warnings as of the most recent updates.
• Antimicrobial stewardship efforts emphasize the avoidance of prolonged, repeated courses.

• Temperature: Store below 25°C (77°F)
• Humidity & Light: Protect from moisture and direct sunlight
• Handling Precautions:
• Keep in original packaging
• Keep out of reach of children
• Reconstitution/Refrigeration: Not applicable (oral capsules)