Minocycline is a second-generation, semi-synthetic tetracycline-class antibiotic. The 65mg strength is a commonly available modified-release formulation in India, designed for once-daily dosing. It exhibits broad-spectrum bacteriostatic activity against a wide range of Gram-positive, Gram-negative, atypical, and anaerobic organisms. It is particularly valued for its superior tissue penetration, including the central nervous system, skin, and prostate, and its anti-inflammatory properties, which extend its use beyond traditional infections.
Adult: For Acne & most infections: 65mg to 100mg once daily or in divided doses (e.g., 50mg twice daily). The 65mg MR tablet is typically taken as ONE tablet once daily. For severe infections: Initial dose of 200mg, followed by 100mg every 12 hours or 65-100mg once daily.
Note: Swallow the 65mg modified-release tablet whole with a full glass of water. Can be taken with or without food, but taking it with food may reduce the risk of gastrointestinal upset. Do NOT take with dairy products, calcium-fortified juices, antacids, or iron supplements; maintain a 2-3 hour gap. Maintain adequate fluid intake to reduce risk of esophageal irritation and ulceration.
Minocycline inhibits bacterial protein synthesis by reversibly binding to the 30S ribosomal subunit. This prevents the attachment of aminoacyl-tRNA to the acceptor site on the mRNA-ribosome complex, thereby inhibiting the elongation of the peptide chain.
Pregnancy: CATEGORY D. Contraindicated. Tetracyclines cross the placenta and can cause permanent tooth discoloration (yellow-gray-brown) in the fetus if used during the second or third trimester. They can also retard fetal skeletal development. Risk increases with prolonged use or repeated courses.
Driving: May cause dizziness, vertigo, lightheadedness, and blurred vision. Patients should be cautioned about operating vehicles or machinery until they know how minocycline affects them.
| Warfarin/Acenocoumarol | Minocycline may potentiate anticoagulant effect by altering gut flora and reducing vitamin K production; increased INR/risk of bleeding. | Major |
| Oral Contraceptives (Estrogen-containing) | May reduce contraceptive efficacy, leading to breakthrough bleeding or unintended pregnancy. Use additional barrier method. | Major |
| Retinoids (Isotretinoin, Acitretin) | Concomitant use increases risk of benign intracranial hypertension (pseudotumor cerebri). Avoid combination. | Contraindicated |
| Antacids (Al, Mg, Ca), Iron, Zinc, Bismuth subsalicylate | Cationic compounds chelate minocycline, significantly reducing its absorption and serum levels. Separate doses by 2-3 hours. | Major |
| Methoxyflurane | Concurrent use with tetracyclines can cause fatal nephrotoxicity. Avoid. | Contraindicated |
| Penicillins (e.g., Amoxicillin) | Bacteriostatic (minocycline) may interfere with bactericidal activity of penicillins. Generally avoid concurrent use. | Moderate |