Brands, Medical Use, Clinical Data
Drug Category
- Anti-bacterial Agents
- Tetracyclines
Dosage Forms
- Capsules
- Subgingival (sustained-release)
- IV injection
Brands / Synonyms
Alti-Minocycline; Apo-Minocycline; Arestin; Dynacin; Gen-Minocycline; Klinomycin; Minociclina [Inn-Spanish]; Minocin; Minocyclin; Minocycline; Minocycline HCl; Minocyclinum [Inn-Latin]; Minocyn; Minomycin; Novo-Minocycline; Solodyn; Vectrin
Indications
For the treatment of infections caused by susceptible strains of microorganisms, such as Rocky Mountain spotted fever, typhus fever and the typhus group, Q fever, rickettsial pox and tick fevers caused by Rickettsiae, upper respiratory tract infections caused by Streptococcus pneumoniae and for the treatment of asymptomatic carriers of Neisseria meningitidis.
Pharmacology
Minocycline, the most lipid soluble and most active tetracycline antibiotic, is, like doxycycline, a long-acting tetracycline. Minocycline's effects are related to the inhibition of protein synthesis. Although minocycline's broader spectrum of activity, compared to other members of the group, includes activity against Neisseria meningitidis, its use as a prophylaxis is no longer recomended because of side effects (dizziness and vertigo). Current research is examining the possible neuroprotective effects of minocycline against progression of Huntington's Disease, an inherited neurodegenerative disorder. The neuroprotective action of minocycline may include its inhibitory effect on 5-lipoxygenase, an inflammatory enzyme associated with brain aging.
Mechanism of Action
Minocycline passes directly through the lipid bilayer or passively diffuses through porin channels in the bacterial membrane. Tetracyclines like minocycline bind to the 30S ribosomal subunit, preventing the binding of tRNA to the mRNA-ribosome complex and interfering with protein synthesis.
Absorption
Rapidly absorbed from the gastrointestinal tract and absorption is not significantly impaired by ingestion of food or milk. Oral bioavailability is 100%.
Toxicity
Minocycline has been observed to cause a dark discoloration of the thyroid in experimental animals (rats, minipigs, dogs and monkeys). In the rat, chronic treatment with minocycline has resulted in goiter accompanied by elevated radioactive iodine uptake and evidence of thyroid tumor production. Minocycline has also been found to produce thyroid hyperplasia in rats and dogs. LD50=2380 mg/kg (rat, oral), LD50=3600 mg/kg (mouse, oral)
Biotrnasformation / Drug Metabolism
Hepatic.
Contraindications
This drug is contraindicated in persons who have shown hypersensitivity to any of the tetracyclines.
Drug Interactions
Because tetracyclines have been shown to depress plasma prothrombin activity, patients who are on anticoagulant
therapy may require downward adjustment of their anticoagulant dosage.
Since bacteriostatic drugs may interfere with the bactericidal action of penicillin, it is advisable to avoid
giving tetracycline-class drugs in conjunction with penicillin.
Absorption of tetracyclines is impaired by antacids containing aluminum, calcium or magnesium, and iron-containing
preparations.
The concurrent use of tetracycline and methoxyflurane has been reported to result in fatal renal toxicity.
Concurrent use of tetracyclines with oral contraceptives may render oral contraceptives less effective.
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