Minocycline (Oral)

Generic name:

Minocycline

Drug class:

Tetracycline antibiotic

Dosage form:

Oral tablet, extended-release tablet, capsule, oral suspension

Root of administration:

Oral

Dose:

200 mg initial dose followed by 100 mg every 12 hours; acne vulgaris: 50–100 mg once or twice daily; others: 100–200 mg/day depending on indication and renal/hepatic function

Mechanism of action:

Minocycline binds to the 30S ribosomal subunit of susceptible bacteria, inhibiting protein synthesis and exhibiting bacteriostatic activity.

Drug usage cases:

• Acne vulgaris
• Chlamydia trachomatis infections (urethritis, cervicitis)
• Rickettsial infections (Rocky Mountain spotted fever, typhus)
• Respiratory tract infections (community-acquired pneumonia, bronchitis)
• Urinary tract infections
• Syphilis and gonorrhea
• Brucellosis
• Anthrax prophylaxis
• Plague
• Malaria prophylaxis
• Periodontitis
• Off-label: rheumatoid arthritis, rosacea, granuloma annulare

Drug contra indications:

• Hypersensitivity to minocycline, tetracyclines, or formulation components
• Children under 8 years of age (risk of permanent tooth discoloration and bone growth inhibition)
• Pregnancy (second and third trimesters)
• Severe hepatic impairment
• History of intracranial hypertension

Side effects:

• Nausea, vomiting, diarrhea
• Dyspepsia, esophagitis, esophageal ulceration
• Photosensitivity reactions
• Dizziness, vertigo
• Skin hyperpigmentation (blue-gray pigmentation)
• Hypersensitivity reactions (rash, urticaria, anaphylaxis)
• Intracranial hypertension (pseudotumor cerebri)
• Hepatotoxicity
• Lupus-like syndrome
• Tooth discoloration and enamel hypoplasia in children
• Superinfection (Clostridioides difficile-associated diarrhea, fungal infections)
• Blood dyscrasias (rare)

Warnings:

• Photosensitivity: avoid excessive sunlight exposure
• Oral tablet lodging: take with plenty of water and remain upright for 30 minutes
• Monitor liver function in hepatic impairment
• May increase intracranial pressure; monitor for headache, visual changes
• Avoid use in children and pregnancy due to tooth and bone effects
• May cause vestibular disturbances; caution when driving
• Risk of antibiotic resistance; use only for indicated infections

Use during pregnancy or breastfeeding:

Minocycline crosses the placenta and is excreted in breast milk. Use during pregnancy (especially second and third trimesters) can cause permanent fetal tooth discoloration and inhibit bone growth. Breastfeeding mothers should avoid minocycline due to potential effects on infant bone and teeth development. Only use if the potential benefit justifies the risk; consult medical guidance.