A synthetic broad-spectrum antibiotic derived from tetracycline. The tetracyclines, including doxycycline, have a similar antimicrobial spectrum of activity against a wide range of gram-positive and gram-negative organisms. Doxycycline has been demonstrated to be active against most strains of the following microorganisms: Haemophilus ducreyi, Haemophilus influenzae, Yersinia pestis, Francisella tularensis, Vibrio cholerae, Bartonella bacilliformis, Brucella species, Escherichia coli, Klebsiella species,Enterobacter aerogenes, Shigella species, Acinetobacter species, Bacteroides species, Streptococcus pneumoniae.
When penicillin is contraindicated, doxycycline is an alternative drug in the treatment of the infections caused by the following microorganisms: Treponema pallidum, Treponema pertenue, Clostridium species, Fusobacterium fusiforme, Actinomyces species, Bacillus anthracis. In acute intestinal amebiasis, doxycycline may be a useful adjunct.
- Contraindications and cautions:
The drug is contraindicated in persons who have shown hypersensitivity to any of the tetracyclines, and to children under 12 years old.
Antibiotic with a broad spectrum effect. Active in such diseases provoked by microorganisms such as: Rickettsia spp. Mycoplasma, Haemophilus influenza, Stretococus spp, etc.
It is the main antibiotic for the treatment of diseases as: pneumonia, dysentery, chlamydia.
Not recommended pregnant women and children.
Because tetracyclines have been shown to depress plasma prothrombin activity, patients who are on anticoagulant therapy may require downward adjustment of their anticoagulant dosage. Barbiturates, carbamazepine, and phenytoin decrease the half-life of doxycycline. Doxycycline decreases the efficiency of oral contraceptives.
- Method of application:
The usual dosage and frequency of administration of doxycycline differs from that of the other tetracyclines.
- Adults: 100mg twice daily or 50mg twice daily. For severe infections: 200mg/day.
- In syphilis: 300mg/day in divided doses for 10 days.
- In gonorrhea: 100mg twice daily for 2-4 days or 200 mg.
- In typhus: 100-200mg. Children over 12 years old that weighing 50kg or more should receive the adult dose. Children under 50kg body weight should receive 4mg/kg/day divided in 2 doses for the first day, then 2mg/kg/day, in severe infections cases: 4mg/kg/day.
- Special precautions:
The use of Doxycycline in the period of teeth formation can change their color irreversibly.
- Side effects:
The following adverse reactions have been observed in patients receiving Doxycycline: Anorexia, nausea, vomiting, diarrhea, glossitis, dysphagia, Hemolytic anemia, thrombocytopenia, neutropenia, vaginitis and eosinophilia.