Brands, Medical Use, Clinical Data
Drug Category
- Antimalarials
- Anti-bacterial Agents
- Tetracyclines
Dosage Forms
- Tablet
- Capsule
- Gel
- Liquid
- Powder
- Powder for solution
Brands / Synonyms
Alti-Doxycycline; Apo-Doxy; Atridox; Doryx; DOXCYCLINE ANHYDROUS; Doxy 100; Doxy-Caps; Doxy-Lemmon; Doxychel; Doxychel Hyclate; Doxycin; Doxycycline; Doxycycline Hyclate; Doxycycline Monohydrate; Doxylin; Doxytec; Doxytetracycline; Jenacyclin; Monodox; Novo-Doxylin; Nu-Doxycycline; Oracea; Periostat; Supracyclin; Vibra-Tabs; Vibramycin; Vibramycin
Indications
For the treatment of the following infections:Rocky mountain spotted fever, typhus fever and the typhus group, Q fever, rickettsialpox, and tick fevers caused by Rickettsiae, Chancroid caused by Haemophilus ducreyi, Uncomplicated gonorrhea caused by Neisseria gonorrhoeae, Respiratory tract infections caused by Mycoplasma pneumoniae or Streptococcus pneumoniae. Lymphogranuloma ve
Pharmacology
Doxycycline, a long-acting tetracycline derived from oxytetracycline, is used to inhibit bacterial protein synthesis and treat non-gonococcal urethritis and cervicitis, exacerbations of bronchitis in patients with COPD, and adult periodontitis.
Mechanism of Action
Doxycycline, like minocycline, is lipophilic and can pass through the lipid bilayer of bacteria. Doxycycline reversibly binds to the 30 S ribosomal subunits and possibly the 50S ribosomal subunit(s), blocking the binding of aminoacyl tRNA to the mRNA and inhibiting bacterial protein synthesis.
Absorption
completely absorbed after oral administration
Toxicity
anorexia, nausea, diarrhoea, glossitis, dysphagia, enterocolitis and inflammatory lesions (with monilial overgrowth) in the anogenital region. skin reactions such as maculopapular and erythematous rashes, exfoliative dermatitis, photosensitivity, hypersensitivity reactions such as urticaria, angioneurotic oedema, anaphylaxis, anaphyl-actoid purpura, pericarditis, and exacerbation of systemic lupus erythematosus, benign intracranial hypertension in adults disappearing on discontinuation of the medicine, haematologic abnormalities such as haemolytic anaemia, thrombocytopenia, neutropenia, and eosinophilia. LD50=262 mg/kg(i.p. in rat)
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 tetracyclines in conjunction with penicillin.
Absorption of tetracyclines is impaired by antacids containing aluminum, calcium, or magnesium, and
iron-containing preparations.
Absorption of tetracycline is impaired by bismuth subsalicylate.
Barbiturates, carbamazepine, and phenytoin decrease the half-life of doxycycline.
The concurrent use of tetracycline and Penthrane (methoxyflurane) has been reported to result in fatal renal
toxicity.
Concurrent use of tetracycline may render oral contraceptives less effective.
Drug/Laboratory Test Interactions
False elevations of urinary catecholamine levels may occur due to interference with the fluorescence test.
|
