Minocycline
Mechanism :
The tetracyclines are primarily bacteriostatic and are thought to exert their antimicrobial effect by the inhibition of protein synthesis. The tetracyclines, including minocycline, have similar antimicrobial spectra of activity against a wide range of gram-positive and gram-negative organisms. Cross-resistance of these organisms to tetracyclines is common
Indication :
- Acne vulgaris
- Chlamydia trachomatis
- Leprosy
- Bacterial infections
Contraindications :
This drug is contraindicated in persons who have shown hypersensitivity to any of the tetracyclines, in children <12 years. Avoid in complete renal failure. Use with caution in patients with hepatic dysfunction.
Dosing :
Acne Vulgaris:
>12 years: 1 mg/kg/dose orally twice a day for 12 weeks. Max: 400 mg/day.
Leprosy:
>15 years: 100 mg PO OD for 12 weeks. To give for 24 months in patients who cannot take
rifampicin.
Chlamydia trachomatis or Ureaplasma urealyticum:
100 mg orally, every 12 hours for 7 days.
Bacterial Infections:
>8 years: 4 mg/kg PO/IV initially; max 200 mg, then 2 mg/kg PO/IV every 12 hours; Max: 400 mg/day; for 5-10 days.
Adverse Effect :
Fever, discoloration of secretion, alopecia, erythema nodosum, hyperpigmentation of nails, pruritus, toxic epidermal necrolysis, vasculitis, maculopapular and erythematous rashes, urticaria, angioneurotic edema, polyarthralgia, anaphylaxis/anaphylactoid reaction, anaphylactoid purpura, myocarditis, pericarditis, exacerbation of systemic lupus erythematosus, pulmonary infiltrates with eosinophilia, anorexia, nausea, vomiting, diarrhea, dyspepsia, stomatitis, glossitis, dysphagia, enamel hypoplasia, enterocolitis, pseudomembranous colitis, pancreatitis, inflammatory lesions, hyperbilirubinemia, increases in liver enzymes, cough, dyspnea, bronchospasm, exacerbation of asthma, and pneumonitis, interstitial nephritis, arthralgia, arthritis, bone discoloration, myalgia, joint stiffness, joint swelling, agranulocytosis, hemolytic anemia, thrombocytopenia, leukopenia, neutropenia, pancytopenia, and eosinophilia.
Other: When given over prolonged periods, tetracyclines have been reported to produce brown-black microscopic discoloration of the thyroid gland. Tooth discoloration in children less than 8 years of age and in adults has been reported.
Interaction :
Anticoagulant therapy: May require downward adjustment of their anticoagulant dosage.
Penicillin: penicillin bacteriostatic drugs may interfere with the bactericidal action of penicillin, it is advisable to avoid giving tetracycline-class drugs in conjunction with penicillin.
Tetracyclines: Absorption of it is impaired by antacids containing aluminium, calcium, or magnesium, and iron-containing preparations.
Oral Contraceptives: Concurrent use of tetracyclines with oral contraceptives may render oral contraceptives less effective.
Administration of isotretinoin should be avoided shortly before, during, and shortly after minocycline therapy.
Renal Dose :
Dose in Renal Impairment GFR (mL/min)
20-50 | Dose as in normal renal function |
10-20 | Dose as in normal renal function |
<10 | Dose as in normal renal function |
Dose in Patients undergoing Renal Replacement Therapies
CAPD | Not dialysed. Dose as in normal renal function |
HD | Not dialysed. Dose as in normal renal function |
HDF/High flux | Unknown dialysability. Dose as in normal renal function |
CAV/VVHD | Unlikely to be dialysed. Dose as in normal renal function |
Hepatic Dose :
Minocycline should be used with caution in patients with hepatic dysfunction.