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Doxycycline-TK 100 mg, 10 capsules





One capsule contains

  • Active ingredient – doxycycline (in the form of doxycycline hyclate) – 100 mg
  • Excipients: lactose monohydrate, magnesium stearate
  • Capsule composition: cap – crimson red (E 124), titanium dioxide (E 171), gelatin; body – crimson red (E 124), titanium dioxide (E 171), gelatin.


Pharmacological properties


Doxycycline is rapidly absorbed from the gastrointestinal tract in proportion to the dose taken. The absorption process can be slowed down by food contents, especially dairy products and preparations containing metal ions. After ingestion of 200 mg of the drug, the maximum plasma concentration of 2.6 μg / ml of doxycycline reaches 2 hours later.

Approximately 50% of doxycycline is metabolized in the liver. Doxycycline is 80-90% bound to serum proteins.

The biological half-life of the drug is from 18 to 22 hours and is extended to approximately 25 hours in patients with renal insufficiency. Due to the long half-life, the drug can be taken once a day.

Doxycycline is highly soluble in fats. Easily penetrates into most biological fluids and tissues of the body. The drug reaches high concentrations in the aqueous humor of the eye, in the prostate gland, ovaries, uterus, bladder, bile, liver, muscles, rudiments of teeth and bones, in the discharge of the bronchial tree, lungs, lymph nodes, paranasal sinuses, palatine tonsils. Passes through the placenta. Penetrates into mother’s milk.

In patients with preserved renal function, approximately 40% of the drug is excreted unchanged in the urine, and the rest of the drug is excreted in the feces, mainly in the form of metabolites.

Doxycycline does not undergo significant accumulation in the body of patients with renal insufficiency. The biological half-life and AUC value of doxycycline do not change. In patients with renal insufficiency, dosage adjustment is not required, due to the fact that in such patients the concentration of doxycycline in the bile increases, resulting in an increase in its excretion with feces.

Hemodialysis does not affect the biological half-life of the drug from serum.


Doxycycline-TK is an antibiotic belonging to the group of tetracyclines. It has a wide spectrum of action against gram-negative and gram-positive bacteria, as well as protozoa. The bacteriostatic mechanism of action of the drug is to inhibit protein synthesis at the ribosomal level.

Antibacterial activity.

Doxycycline in vitro has antibacterial action against:

– Gram-negative bacteria

Neisseria gonorrhoeae Campylobacter granulomatis Haemophilus ducreyi Haemophilus influenzae Pasteurella pestis Pasteurella tularensis Vibrio cholerae Bartonella bacilliformis Brucella spp .; show variable sensitivity: Escherichia coli Klebsiella spp ., Enterobacter aerogenes Shigella spp ., Mima spp ., Herella spp ., Bacteroides spp .

– Gram-positive bacteria

Streptococcus pyogenes Streptococcus pneumoniae Streptococcus faecalis Streptococcus faecium Staphylococcus aureus , α-hemolytic streptococci of the viridans group

– Other microorganisms

Rickettsia Chlamydia psittaci Chlamydia trachomatis Mycoplasma pneumoniae Ureaplasma urealyticum Borrelia recurrentis Treponema pallidum Clostridium spp ., Fusobacterium fusiforme Actinomyces spp Bacillus anthracis Propinibacterium acnes Entamoeba coliant coli Plasmodium falciparum . Doxycycline resistance has been observed among many strains, especially Gram-positive bacteria. This phenomenon is characterized by heterogeneity, because there are often large differences in bacterial resistance in different regions of the world. The mechanism of resistance to doxycycline is associated with a decrease in the ability of the drug to penetrate into the bacterial cell. This resistance is due to the presence of transferable R-plasmids in the cell.

Streptococcus pneumoniae strains  that are resistant to doxycycline also show resistance to other tetracyclines, and often to penicillins and macrolides (cross-resistance). There is a synergism of action between doxycycline and macrolides.


Indications for use

Doxycycline is used to treat various infections caused by susceptible strains of gram-positive and gram-negative bacteria and some other microorganisms.

– Respiratory tract infections : pneumonia and other infections of the lower respiratory tract caused by susceptible strains of Streptococcus pneumoniae , Haemophilus influenzae ,  Klebsiella pneumoniae and other organisms, mycoplasma pneumonia, chronic bronchitis, sinusitis.

– Infections of the genitourinary system : infections caused by susceptible strains of Klebsiella species Enterobacter species  Escherichia coli, Streptococcus faecalis and other organisms; including sexually transmitted infections: infections caused by Chlamydia trachomatis  including uncomplicated urethral, ​​endocervical or rectal infections. Non-gonococcal urethritis caused by Ureaplasma urealyticum (T-mycoplasma), chancre, inguinal granuloma, and lymphogranuloma venereum.

Doxycycline is an alternative drug in the treatment of gonorrhea and syphilis.

– Skin infections: severe forms of acne (as part of combination therapy).

– Other diseases:   yaws, legionellosis, chlamydia of various localization (including prostatitis and proctitis), rickettsiosis, Q fever, Rocky Mountain spotted fever, typhus (including typhus, tick-borne relapsing), Lyme disease (I stage – erythema migrans), tularemia, plague, actinomycosis, malaria; infectious eye diseases, as part of combination therapy – trachoma; leptospirosis, psittacosis, ornithosis, anthrax (including pulmonary form), bartonellosis, granulocytic ehrlichiosis; whooping cough, brucellosis, osteomyelitis; sepsis, subacute septic endocarditis, peritonitis;

– prevention of postoperative purulent complications;

– malaria caused by Plasmodium falciparum during short-term travel (less than 4 months) in areas where strains resistant to chloroquine and / or pyrimethamine-sulfadoxine are common.


Dosage and administration

Use strictly as prescribed by the doctor to avoid complications. Doxycycline is prescribed only if there is an absolute indication.

Capsules should be taken with plenty of liquid. It is recommended to take the drug while lying down or standing before going to bed at night to reduce the likelihood of esophageal irritation and ulceration.

If stomach irritation occurs, it is recommended that Doxycycline be taken with food or with milk. Studies have shown that food or milk intake does not significantly affect the absorption of doxycycline.

Adults: On the first day of treatment, doxycycline is usually prescribed 200 mg in 1 dose or divided into 2 doses – 100 mg every 12 hours, and then switched to a maintenance dose of 100 mg per day.

In severe infections during the entire period of treatment, doxycycline 200 mg per day is prescribed.

Course of treatment: when taking the drug orally, depending on the characteristics of the course and severity of the disease, the course of treatment is 7-10 days.

Exceeding the recommended dose may increase the frequency of side effects.


Side effects

The following adverse reactions have been observed in patients receiving tetracyclines, including doxycycline:

Infections and infestations

Superinfection: As with other antibiotics, overgrowth of nonsusceptible organisms can lead to candidiasis, glossitis, staphylococcal enterocolitis, pseudomembranous colitis (may cause Clostridia overgrowth ), and inflammatory lesions (urogenital candidiasis) of the genitourinary system.

From the blood and lymphatic system

Hemolytic anemia, thrombocytopenia, neutropenia, porphyria and eosinophilia.

From the side of the immune system

Allergic reactions, including anaphylactic shock, anaphylactoid reactions, anaphylactic purpura, hypotension, pericarditis, angioedema, urticaria, exacerbation of systemic lupus erythematosus, shortness of breath, serum sickness, peripheral edema, tachycardia.

Endocrine Disorders

With prolonged use of tetracyclines, a brown-black staining of the thyroid tissue was observed, which was detected by microscopic examination. Thyroid dysfunction was not found.

From the side of the nervous system

Headache, dizziness, benign intracranial hypertension, which may manifest as blurred vision, scotomas, diplopia.

On the part of the hearing and vestibular apparatus : tinnitus.

From the digestive tract

Gastrointestinal symptoms are usually mild and rarely require discontinuation of treatment. These include: abdominal pain, stomatitis, anorexia, nausea, vomiting, diarrhea, dyspepsia, and rarely dysphagia. Esophagitis and esophageal ulceration have been reported. Tetracyclines can cause discoloration of teeth or hypoplasia of tooth enamel, which is usually observed with long-term use of the drug.

From the digestive system : a transient increase in the level of hepatic transaminases, impaired liver function, hepatitis, jaundice and pancreatitis. Isolated cases of hepatotoxicity, liver failure were observed.

Skin: maculopapular and erythematous rash, skin photosensitivity, photoonycholysis, erythema multiforme, exfoliative dermatitis, Stevens-Johnson syndrome, toxic epidermal necrolysis.

From the bones and joints: arthralgia, myalgia.

Violation of the function of the kidneys and urinary tract: increased levels of residual urea nitrogen.

Miscellaneous: candidiasis.



– hypersensitivity to doxycycline, other tetracyclines or to any substance that is part of the drug

– severe liver and kidney failure

– children’s age up to 18 years

– pregnancy and lactation

– hereditary intolerance to lactose, galactose, lactase deficiency


Drug Interactions

The simultaneous use of iron preparations, preparations containing aluminum, calcium, magnesium, zinc or bismuth disrupts the absorption of doxycycline. It is recommended to avoid the simultaneous use of these drugs.

Ergotamine and methysergide

There is an increased risk of ergotism when doxycycline is co-administered with ergotamine and methysergide.


Doxycycline increases the risk of methotrexate toxicity. It should be used with caution in patients treated with methotrexate.

Kaolin and sucralfate may reduce the absorption of doxycycline.

Quinapril contains magnesium carbonate and may reduce the absorption of doxycycline.

It is desirable to avoid the simultaneous use of doxycycline in combination with penicillin due to a decrease in the absorption of doxycycline.

The use of doxycycline and warfarin causes prolongation of prothrombin time. Tetracyclines inhibit plasma prothrombin activity, and therefore the dose of concomitant anticoagulants should be reduced.

The simultaneous use of barbiturates, carbamazepine, phenytoin or primidone causes a reduction in the half-life of doxycycline. In such cases, consideration should be given to increasing the daily dose of doxycycline.

Alcohol may decrease the half-life of doxycycline.

Doxycycline reduces the effectiveness of oral contraception and increases the frequency of “breakthrough” bleeding when taking estrogen-containing oral contraceptives.

Doxycycline may increase the plasma concentration of ciclosporin . Joint administration of these drugs should be carried out only under the supervision of a physician.

Hepatic enzyme-inducing drugs, such as rifampicin , may accelerate the elimination of doxycycline, thereby reducing its half-life, which may result in subtherapeutic blood concentrations of doxycycline. In such cases, medical supervision is recommended and, if necessary, consider increasing the dose of doxycycline.

The simultaneous use of doxycycline with retinoids should be avoided due to an increased risk of developing benign intracranial hypertension.

The simultaneous use of tetracyclines and methoxyflurane increases the risk of nephrotoxicity with a possible fatal outcome.

Oral typhoid vaccination should be avoided during doxycycline treatment due to antibiotic inactivation.

When conducting a fluorescent test, a false increase in the level of catecholamines in the urine can be observed.


Special instructions

Patients with impaired liver function.

Doxycycline should be used with caution in patients with hepatic insufficiency, as well as in those receiving potentially hepatotoxic drugs.

Liver dysfunction associated with oral or parenteral administration of tetracyclines, including doxycycline, has been observed rarely.

Patients with impaired renal function.

Excretion of doxycycline through the kidneys is approximately 40% in 72 hours in individuals with preserved renal function. This range may drop to 1-5% over 72 hours in individuals with severe renal insufficiency (creatinine clearance below 10 ml/min).

Studies have not revealed a significant difference in the half-life of doxycycline from serum in individuals with preserved and impaired renal function. Hemodialysis does not affect the half-life of the drug from the blood serum.

The anti-anabolic effect of tetracyclines can lead to an increase in the level of urea in the blood. The antianabolic effect was absent when doxycycline was used in patients with impaired renal function.


Some patients taking tetracyclines, including doxycycline, experience photosensitivity reactions. During treatment with doxycycline, as well as after the end of therapy for 4-5 days, it is recommended to protect exposed areas of the body from direct sunlight and artificial UV radiation. Treatment with tetracyclines, including doxycycline, should be stopped immediately at the first manifestations of erythema on the skin.

Growth of resistant microflora.

To prevent the development of candidiasis, it is recommended to use antifungal drugs simultaneously with Doxycycline.

Pseudomembranous colitis

There have been reports of the development of pseudomembranous colitis with the use of almost all antibacterial substances, including doxycycline. The severity of complications ranged from mild to life-threatening. A decision should be made regarding discontinuation of doxycycline therapy, and, if necessary, appropriate treatment (administration of specific antibiotics and chemotherapeutic agents).

Treatment with antibacterial drugs alters the normal flora of the large intestine, leading to overgrowth of non-susceptible organisms, including Clostridium difficile. Cases of diarrhea caused by Clostridium difficile have been reported with almost all antibacterial drugs. Patients treated with antibacterial drugs should be closely monitored due to the risk of diarrhea caused by Clostridium difficile within two months after the end of therapy.


Cases of esophagitis and esophageal ulcers have been reported in patients using encapsulated or tablet forms of the tetracycline class of drugs, including doxycycline. Most of these patients took the drug just before bedtime or with insufficient fluids.

Mild intracranial hypertension has been reported in individuals receiving the drug at the maximum therapeutic dose. It quickly disappeared after discontinuation of the drug.


Rare cases of porphyria have been observed in patients taking tetracycline.

Treatment of venereal diseases

Appropriate diagnostic procedures, including dark-field microscopy and other tests, should be used in the treatment of sexually transmitted diseases with suspected concomitant syphilis. In such cases, monthly serological tests should be performed for at least four months.

Beta-hemolytic streptococcus

The course of treatment in patients with infections caused by group A beta-hemolytic streptococci should be at least 10 days.

Myasthenia gravis

Drugs of the tetracycline group can cause neuromuscular blockade, so care must be taken when using doxycycline in patients with myasthenia gravis.

Systemic lupus erythematosus

 Tetracyclines can exacerbate systemic lupus erythematosus.


Caution should be exercised while using methoxyflurane with tetracyclines due to increased nephrotoxicity.

The ability to influence the reaction rate when driving vehicles and working with mechanisms.

Until the patient’s individual response to the drug is clarified, one should refrain from driving vehicles or other mechanisms, given that during treatment with doxycycline, loss of vision, blurred vision, dizziness may occur.



Symptoms of an overdose of doxycycline are fever, facial flushing, dizziness, and sometimes collapse may develop.

Treatment : withdrawal of the drug, gastric lavage, control of basic vital functions (pulse, respiration) and, if necessary, symptomatic treatment.

The use of hemodialysis to eliminate the drug from the blood is ineffective.


Storage conditions

In a dry, dark place, at a temperature not exceeding 25°C.

Keep out of the reach of children! 

Shelf life – 3 years

Do not use after the expiration date.

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