Doxycline

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Doxycline uses

• Pharmacological action
• Pharmacokinetics
• Why is Doxycline prescribed?
• Dosage and administration
• Doxycline side effects, adverse reactions
• Doxycline contraindications
• Using during pregnancy and breastfeeding
• Special instructions
• Doxycline drug interactions
• Doxycline in case of emergency / overdose
• Doxycline reviews

Pharmacological action

Doxycline is an semisynthetic tetracycline group's antibiotic of broad-spectrum. This medication has bacteriostatic action due to suppression of protein synthesis of pathogens. It active against aerobic gram-positive bacteria: Staphylococcus spp., Streptococcus spp. (including Streptococcus pneumoniae), Bacillus anthracis, Listeria monocytogenes; anaerobic bacteria: Clostridium spp.

Doxycline is also active against aerobic gram-negative bacteria: Neisseria gonorrhoeae, Escherichia coli, Shigella spp., Salmonella spp., Enterobacter spp., Klebsiella spp., Bordetella pertussis, as well as against Rickettsia spp., Treponema spp., Mycoplasma spp. and Chlamydia spp.

Pseudomonas aeruginosa, Proteus spp., Serratia spp., most strains of Bacteroides fragilis are resistant to Doxycline.

Pharmacokinetics

After oral administration Doxycline is quickly and almost completely absorbed from the gastrointestinal tract. Ingestion has very little effect on the absorption of Doxycline. This medication is widely distributed in tissues and body fluids. Plasma protein binding is 80-95%. T_1/2 is 12-22 h. Doxycline excreted in the urine as unchanged (40%) but the main part of the dose excreted unchanged in the feces through bile secretion.

Why is Doxycline prescribed?

Infectious-inflammatory diseases caused by microorganisms sensitive to Doxycline including infections of the respiratory and ENT organs; gastrointestinal tract infections; purulent infections of skin and soft tissues ; infection of the genitourinary system (including gonorrhea, primary and secondary syphilis); typhus, brucellosis, rickettsiosis, osteomyelitis, trachoma, chlamydia.

Dosage and administration

Doxycline is indicated for adults orally or IV (infusions) in 200 mg / day dosess on the first day of treatment, in the coming days at 100-200 mg / day. Multiplicity of admission (or IV infusion) is 1-2 times / day. For children older than 8 years of age and weighing over 50 kg the daily Doxycline dose for oral administration or IV (infusion) in the first day of treatment is 4 mg / kg. In next days ir is 2-4 mg / kg depending on the severity of the clinical course of disease. Multiplicity of admission (or intravenous infusion) is 1-2 times / day. The recommended minimum time for IV infusion 100 mg of Doxycline (a concentration of infusion solution is 0.5 mg / ml) is 1 hour.

Maximum doses: for adults for oral administration is 300 mg / day or 600 mg / day (depending on the etiology of the agent); for iv injection it is 300 mg / day.

Doxycline side effects, adverse reactions

Digestive system: nausea, vomiting, anorexia, abdominal pain, diarrhea, constipation, dysphagia, glossitis, esophagitis, transient increase in the blood of hepatic transaminases, alkaline phosphatase, bilirubin.

Hematopoietic system: neutropenia, thrombocytopenia, hemolytic anemia.

Allergic reactions: skin rash, itching, eosinophilia, rarely - angioedema, photosensitivity.

Other: increased residual nitrogen, candidiasis, intestinal dysbiosis, discoloration of teeth in children.

Doxycline contraindications

Pregnancy, children age up to 8 years, hypersensitivity to tetracyclines, porphyria, severe liver insufficiency, leukopenia, lactation period, myasthenia (for IV administration).

Using during pregnancy and breastfeeding

Doxycline is contraindicated during pregnancy and lactation. Doxycline crosses the placental barrier. This medication may cause long-term discoloration of the teeth, enamel hypoplasia, inhibition of growth of bones of the fetus and also the development of fatty liver.

If necessary using during lactation patients should stop breastfeeding.

Special instructions

With careful use of Doxycline with impaired liver function. If a patient has renal impairment the dose adjustment is not required.

To prevent local irritating action Doxycline should be taken during the day with plenty of fluids, food or milk. Due to possible development of photosensitivity it is necessary the restriction of insolation during treatment and for 4-5 days thereafter.

Doxycline is not used in children younger than 8 years because tetracyclines (including Doxycline) are causing long-term discoloration of the teeth, enamel hypoplasia and retardation of longitudinal growth of bones in these patients.

Doxycline solution for IV administration should be used no later than 72 hours after its preparation.

Doxycline drug interactions

Medications containing metal ions (antacids, products containing iron, magnesium, calcium) form inactive chelates with Doxycline, in connection with what it is necessary to avoid their simultaneous use.

It needed to avoid combination with penicillins, cephalosporins, bactericidal action and is an antagonist of bacteriostatic antibiotics (including Doxycline).

Absorption of Doxycline is reduced by cholestyramine and colestipol (observe the interval between the reception of at least 3 h).

Due to suppression of intestinal microflora Doxycline reduces prothrombin index which requires dose adjustment of indirect anticoagulants.

Doxycline reduces the reliability of contraception and increases the frequency of breakthrough bleeding while taking estrogen-containing oral contraceptives.

Simultaneous administration of Doxycline with: