Doxycyclin hydrochloride (0.1 g capsules)

Capsulae Doxycyclini hydrochloride 0.1


International not patented name



Pharmacotherapeutic group

Antibiotic from the tetracyclines group


Preparation composition

1 capsule contains 100 mg of doxycyclin hydrochloride.


Pharmaceutical action


Doxycylin hydrochloride possesses a wide spectrum of anti-microbial action. It inhibits the proteins synthesis in the microbial cell violating the transporting aminoacyl RNA connection with 30S subunit of the ribosomal membrane. It exerts a bacteriostatic effect.


The preparation is efficient against the majority of the Gram-positive and Gram-negative microorganisms including Mycoplasma, Chlamidia, Rickettsia, Yersinia, Brucella, vibrions, bacteroids, Clostridia, Fusobacteria, protozoa (plasmodium malariae, ameba, etc.). It penetrates into the cell suppressing the intracellular pathogenic agents reproduction.



Taken per os doxycylin hydrochloride is absorbed quickly; the bioavailability achieves 95%. The antibiotic effective concentrations being introduced per os preserve for 18 – 24 hours. It penetrates into most of the body tissues and fluids, into bile, exudations of the maxillary and frontal sinuses, into pleural, synovial, ascetic liquids. It accumulates in bones, teeth, liver, spleen, prostate. It provides therapeutic concentrations in the eye tissues. The preparation excretes mainly with bile (90%) and with urine. Being reinjected and incase the renal excretory function is changed it may accumulate.



Doxycylin is prescribed to adults and children over 8 years for diseases caused by microorganisms sensitive to its action. It is applied for rickettsiosis, borreliosis, brucellosis, yersiniosis, bacillary and amebic dysentery, tularemia, cholera, Lyme’s disease, malaria, granulocytic erlichiosis; for ORL organs and lower parts of respiratory tracts diseases (sinusitis, otitis, tonsillitis, bronchitis, pneumonia, pleuritis), infections of bile and urinary tracts, urogenital mycoplasmosis, gynecologic infectious diseases (endometriosis, endocervicitis), acute prostatitis, epididimitis, gonorrhea, purulent infection of skin and soft tissues (phlegmons, abscesses, furunculosis, acne, etc.), for infectious ulcerous keratitis, for surgical infections prevention after medical abortions, operations on the large intestine, for treating postoperative purulent complications; for managing complications after viral infections, for malaria preventing, etc. It is applied for treating syphilis as an alternative preparation in case of benzyl penicillin effect absence and in case of allergy to the preparations from the penicillin group.


Mode of appliance and dosing regime

The preparation is taken during or after meal. The 24 hour dose for adults on the first day of therapy is 0.2 g. It is taken as a single dose or 0.1 g with 12 hours interval. On the following days 0.1 g of preparation is taken daily. In case the infection is severe the 24 hour dose on the first day and on the following days of therapy is 0.2 g. Doxycylin hydrochloride is prescribed to children aged 8 – 12 years on the first day in dose 4 mg/kg (as a single dose or two equal doses taken with 12 hours interval), on the following days in dose of 2 mg/kg, in case of a severe infection in dose of 4 mg/kg daily. Preparation is prescribed in adult doses to children over 12 years.


The preparation is usually taken for 7 – 10 days.


For treating gonorrhea it is prescribed to patients with acute not complicated uretritis the course dose being 0.5 g (the first intake – 0.3 g, the next two intakes – 0.1 g with 6 hours interval); in case of complicated gonorrhea forms the antibiotic course dose (0.8 – 0.9 g) is divided into 6 – 7 injections (0.3 g as a first intake, 0.1 g as 5 – 6 next intakes with 6 hours intervals).


In case of acne the preparation is prescribed in dose 0.05 g a day for 6 – 12 weeks.


In case of a primary or a secondary syphilis 0.3 g of the preparation a day is taken fractionally during 10 days (at least).


Special warnings

For preventing esophagus ulceration it is necessary to take the preparation with a large quantity of liquid. During the therapy and in 4 – 5 days after it is has been completed direct sunlight and UV irradiation is contraindicated.


Side effects

Gastro-intestine disturbances, the mucous membranes irritation, allergic reactions, photosensitivity, worsening of the lupus erythematosus course, stable changing of the teeth enamel color, hemolytic anemia, thrombocytopenia, neutropenia, transitory increase of the blood contents of liver transaminases, alkaline phosphatase,bilirubin, residual nitrogen are possible; in case of a long time oral intake dysbacteriosis, yeast like  fungi hyperinfection may develop.



Doxycylin is contraindicated in case of an increased sensitivity to tetracyclines, of a severe renal failure, during pregnancy, lactation (during the therapy breast feeding should be stopped), to children younger 8 years (period of teeth development).


Safety measures

In case of hepatic and renal failure the preparation is used under the liver and kidneys functions control. In case the preparation is taken for a long time the peripheral blood cellular composition should be monitored periodically, hepatic functional tests should be performed, the blood serum nitrogen and urea should be determined.


Interaction with other medicines


Doxycylin should not be combined with the drugs containing metals ions (antacids, those containing alluminium, potassium and magnesium salts; preparations containing manganese, zinc ions, ferrous preparations) for not active chelates may form. The doxycylin absorption is suppressed by cholestiramine. Barbiturates, carbamazepin, phenitoin reduce the serum doxycylin concentration. Doxycylin reduces the penicillin, oral contraceptives efficiency; in case of being prescribed in combination with oral contraceptives the possibility of bleeding during the cycle increases. In case of receiving a simultaneous anticoagulants therapy the blood coagulation should be monitored carefully (on the background of tetracyclines intake the K vitamin synthesis reduces).


Dosage form

100 mg capsules. Ten capsules in contour cellular packs or 10 capsules in a pot.