Minocycline

Oral Antibiotics

Drug class: Tetracycline Antibiotic

Minocycline (MINOCIN)（中文：米諾環素）

Common Strengths

• 50 mg (tablets)
• 100 mg (capsules)

Drug Trade Names

Minocin

Drug Usage

Minocycline is a broad-spectrum antibiotic belonging to the tetracycline class. It is primarily used to treat various bacterial infections and has additional applications in dermatology and other fields.

• Bacterial Infections: including respiratory, urinary tract, skin, and soft tissue infections.
• Acne Treatment: Commonly prescribed for moderate to severe acne vulgaris
• Specific Infections such as:
  • Gonorrhea
  • Syphilis
  • Meningococcal carrier state
  • Mycobacterium marinum infections
• Topical Applications: Minocycline can also be used in topical forms for conditions like periodontitis.

Mechanism of Action

Minocycline works by inhibiting bacterial protein synthesis, thereby preventing the growth and reproduction of bacteria.

Route of Administration

Minocycline is administered orally in the form of capsules or tablets.

Dosages

• Normal Adults: Initial dose of 200 mg, followed by 100 mg every 12 hours.
• Diabetic Kidney Disease: Renal dosing should be based on eGFR. Generally, if eGFR <30 mL/min, reduce the dose or consider alternative therapies.

Side Effects

Frequency	Adverse reactions
Common Side Effects	Nausea
	Dizziness
	Skin discoloration (yellow-gray-brown)
Serious Side Effects	Intracranial hypertension: This condition can lead to severe headaches, blurred vision, and potential vision loss.
	Liver damage: Signs include yellowing of the skin or eyes (jaundice), dark urine, loss of appetite, and abdominal pain.
	Kidney problems: Indicated by changes in urination patterns, swelling in extremities, or fatigue.
	C. difficile infection: This serious intestinal condition can cause severe diarrhea that may be bloody.
	Drug-induced lupus or hypersensitivity syndrome: Symptoms may include fever, rash, joint pain, and other systemic symptoms that can be life-threatening if not addressed promptly.
	Severe skin reactions (e.g., Stevens-Johnson syndrome)

Pharmacokinetics

The onset of action typically occurs within 2–3 days, with a duration of action lasting up to 12 hours for standard doses.

Drug Precautions

Pregnancy

Minocycline can harm the fetus; it is generally not recommended during pregnancy.

Breastfeeding

Minocycline can pass into breast milk; caution is advised.

Children and Elderly

Not typically recommended for children under 8 years due to potential effects on teeth and bone development. Elderly patients may be more sensitive to side effects.

Drug Monitoring Items

Regular monitoring of liver function tests and renal function tests is advisable during treatment.

Drug Interactions

Minocycline can interact with:

• Anticoagulants: Such as warfarin, where minocycline may enhance anticoagulant effects, increasing bleeding risk.
• Birth Control Pills: Minocycline can reduce the effectiveness of hormonal contraceptives, potentially leading to unintended pregnancies
• Antacids and Supplements: Products containing aluminum, calcium, iron, or magnesium can bind to minocycline, reducing its absorption. It is recommended to take these products at least 2 hours apart from minocycline.

FAQ

How Should I Take the Tablet?

Take minocycline with a full glass of water, either with or without food.

What Should I Avoid while Taking?

Avoid taking antacids or iron supplements within two hours of minocycline as they can impair absorption. Also, limit sun exposure due to increased sensitivity.

What Happens if I Miss a Dose?

Take the missed dose as soon as you remember unless it is close to your next scheduled dose. Do not double up on doses.