Uses of Doxycycline 100mg

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1. What does Doxycycline 100mg do?

Doxycycline 100mg is a line of antibiotics produced by Domesco Vietnam company. The drug is prepared in the form of hard capsules with a cap and a blue capsule body. The composition of the powder has a uniform yellow color. Doxycycline 100mg drug has the effect of killing parasites, anti-inflammatory or preventing the growth of viruses and fungi. Doxycycline 100mg belongs to the tetracycline group.
Contents of Doxycycline 100mg include:
Doxycycline calcium: 50 mg/5 ml oral solution. With Doxycycline hyclate: Capsules 50 mg, 100 mg. 100 mg slow-release capsule. 100 mg film coated tablet. Powder for intravenous infusion: 100 mg and 200 mg. Doxycycline monohydrate: Capsules 50 mg, 100 mg. Powder for oral solution 25 mg/5 ml.

2. Indications and contraindications to the use of Doxycycline 100mg

2.1. Indications Doxycycline 100mg antibiotic is indicated for use in the following cases:
Treatment of infections caused by susceptible strains of Gram-positive and Gram-negative bacteria, some other bacteria.
Respiratory tract infections: Pneumonia caused by Chlamydia pneumoniae, Mycoplasma pneumoniae, chronic bronchitis, sinusitis. In addition, there are lower respiratory tract infections caused by susceptible strains of Streptococcus pneumoniae, Klebsiella pneumoniae, Haemophilus influenzae and other bacteria. Urinary tract infections: Bacterial infections caused by strains of Klebsiella, Enterobacter Spp,...and other bacteria. Nonspecific urethritis caused by strains of Ureaplasma urealyticum. Sexual pathologies: Treatment of gonorrhea, syphilis, endometrial/anal infections, urethritis, uncomplicated urethral infections. Because Doxycycline 100mg oral drug is an antibiotic of the tetracycline group, it also helps to treat infections that respond to the tetracycline group, specifically:
Ophthalmic infections: treatment of trachoma caused by D susceptible strains of Gonococcus, Staphylococcus and Haemophilus influenzae. Treatment of Rocky Mountain spotted fever, typhus, Q fever and Coxiella and tick fever endocarditis. Treatment of parrot fever, cholera, melioidosis, leptospira infection, chloroquine-resistant falciparum malaria. Prophylaxis of malaria for people traveling short-term to areas where the parasite strain is present. Brucellosis; cholera , atypical pneumonia e; inguinal granuloma, chronic erythema multiforme, relapsing fever. Treatment of periodontitis Treatment of gonorrhea and syphilis Prevention and treatment of anthrax caused by Bacillus anthracis. 2.2. Pharmacodynamics Doxycycline 100mg is a bacteriostatic antibiotic. The main mechanism of action of the drug is protein synthesis. The drug passes through the lipid bilayer of the bacterial cell and into the inner cytoplasm by means of an energy-dependent active transport system.
Then, Doxycycline inhibits protein synthesis by binding to the 30S subunit of the bacterial ribosome. Prevents the addition of amino acids to the growth of the peptide chain. Doxycycline reduces protein synthesis in mammalian cells at high concentrations.
Doxycycline has a wide range of antibacterial activity against Gram-positive and Gram-negative aerobic and anaerobic bacteria, some bacteria that are resistant to drugs acting on cell walls such as Rickettsia, Mycoplasma pneumonia, Legionella spp., Ureaplasma,... Doxycycline 100mg has no clinical antifungal effect.
Doxycycline is less hepatotoxic causing local irritation, gastrointestinal irritation and dysbiosis in the gut). In addition, the drug is preferred over other tetracyclines, because it is better absorbed and has a longer half-life, allowing for less daily dosing. Doxycycline can be used in people with kidney failure. Currently, in Vietnam, many drug-resistant pneumococci are often encountered. Plasmodium falciparum is often resistant to many drugs such as chloroquine, sulfonamides and other antimalarials, but doxycycline can still be used for prophylaxis.
According to reports, antibiotics in general and Doxycycline in particular should be carefully consulted before use. Because in Vietnam, many strains of bacteria such as E.coli, Shigella flexneri, Enterobacter, Shigella flexneri,..., are resistant to Doxycycline. Therefore, the rate of resistance varies by region and time.
2.3. Pharmacokinetics Absorption: Oral doxycycline 100mg is absorbed 95% from the gastrointestinal tract, food and milk have little effect on absorption. Approximately 80-95% of Doxycycline in the blood is bound to plasma proteins. Doxycycline can be taken twice a day, the half-life is from 16h-18h. The maximum plasma concentration is 3 microgram/ml, 2 hours after the first dose of 200 mg Doxycycline and the plasma concentration is maintained above 1 microgram/ml for 8-12 hours. Doxycycline plasma concentrations when oral and injected are similar. Distribution: Doxycycline is distributed into tissues and secretions including urine and prostate gland in the body. The drug usually accumulates in the spleen, bone-marrow, reticuloendothelial cells of the liver, dentin, and undeveloped enamel. Doxycycline is more lipophilic than tetracycline. Elimination: Normally, the elimination half-life is 12-24 hours. Doxycycline is eliminated primarily in the feces (via the liver) and secondary in the urine (via the kidneys). Therefore, it is safest to treat infections in patients with renal failure. However, because Doxycycline is less excreted by the kidneys, it should be combined with high doses to treat urinary tract infections.

3. Dosage of Doxycycline 100Mg

You should use the medicine as prescribed by the doctor. Combine the pill with a full glass of water. Should be taken after meals or with milk for people with stomach pain. However, taking the drug with food may decrease its absorption.
Patients should take the medicine during or after a meal with plenty of water, in an upright or standing position. In adults: take 1 tablet twice a day for the first time. On the next day, take 1 dose once a day. If severe infection should take 1 tablet with 2 times / day Children over or 8 years old: the first day from 4-5mg/kg/day. Divide 2 times/day. On the next day, take 2-2.5mg/kg as a single dose of the day. If severe infection, take 2-2.5mg/kg twice a day. Severe infections: adults dose 2 tablets/time/day. 10 days of treatment for Streptococcus infections is recommended to prevent rheumatic fever or glomerulonephritis. Treatment of acute gonorrhea infection should use 2 tablets + 1 tablet in the evening on the first day, then 1 tablet x 2 times/day for 3 consecutive days. Treatment of urethral infections, infections of the inside of the cervix / vagina caused by Chlamydia trachomatis and Ureaplasma urealyticum: 1 tablet x 2 times / day for a minimum of 10 days. There is no need to reduce the dose in patients with renal impairment because Doxycycline is also eliminated by the hepatobiliary tract and gastrointestinal tract.

4. Drug interactions

Antacids containing aluminum, calcium, or magnesium will decrease the absorption of Doxycycline in the body. Iron salts and bismuth subsalicylate, which may reduce the bioavailability of Doxycycline. Doxycycline half-life is decreased due to increased metabolism by barbiturates, phenytoin, and carbamazepine. Calcium, iron, magnesium, zinc and amino acids. The anticoagulant warfarin. Carbamazepine Rifampicin Methoxyflurane Penicillin Acid retinoic

5. Notes when taking Doxycycline

In children under 8 years old, Doxycycline 100mg causes permanent tooth discoloration, enamel hypoplasia and slow growth of the skeleton. Therefore, do not use the drug for this age group. Limit the use of Doxycycline for a long time. This can cause fungal and bacterial superinfections. When taking Doxycycline, prolonged sun exposure should be avoided, as it may be photosensitive. Take the medicine with at least 1 full glass of water in a standing position. This avoids esophageal ulcers, reducing gastrointestinal irritation. In alcoholics there may be a sharp drop below therapeutic levels. The use of slow-release capsules can cause some microorganisms such as Candida to grow. List your doctor's history of taking birth control pills, planning to become pregnant, or are breast-feeding.

6. Objects of special attention

6.1. Pregnancy Tetracyclines are distributed mainly across the placenta. Do not use Doxycycline in the second half of pregnancy. Because it can cause permanent tooth discoloration, enamel hypoplasia, and bone structure disorders. In pregnant women, fatty liver may occur, especially when high doses are administered intravenously. 6.2. Lactation Doxycycline is excreted in breast milk, forming an unabsorbed complex with calcium in breast milk. Breastfeeding women should not take Doxycycline, if taking the drug should stop breastfeeding.

7. Side effects when using Doxycycline

When using antibiotic Doxycycline 100mg, patients will experience some unwanted side effects such as:
Hypersensitivity reactions: anaphylactic reactions and anaphylactic shock; dyspnoea, hypotension, tachycardia, urticaria, allergic purpura, pericarditis, angioedema, exacerbation of systemic lupus erythematosus, serum sickness, peripheral angioedema, Infection Bacterial and parasitic infections: Causes Clostridium difficile overgrowth and Candida overgrowth genital dermatitis. Blood and lymphatic system disorders: Hemolytic anemia, thrombocytopenia - neutrophils, eosinophilia, porphyria. Endocrine disorders: When taking the drug for a long time, it will produce a dark brown discoloration of thyroid tissue. Nervous system disorders: Causes headache, bulging fontanelle in neonates, benign intracranial hypertension. These symptoms disappear when the drug is stopped. However, diplopia, diplopia, and permanent vision loss have been reported. Ear disorders and tinnitus. Digestive system disorders: In the gastrointestinal tract, mild symptoms such as abdominal pain, anorexia, nausea, diarrhea, stomatitis, etc. esophagitis and esophageal ulcers have been reported. In addition, long-term use also causes tooth discoloration and enamel reduction. Liver and biliary disorders: hepatitis, liver failure, pancreatitis and jaundice. Skin and Subcutaneous Tissue Disorders: Rash including maculopapular and erythematous rash, exfoliative dermatitis, erythema multiforme, Stevens-Johnson syndrome and toxic epidermal necrolysis, exfoliative, photosensitivity . Musculoskeletal system disorders causing arthralgia and myalgia. Renal and urinary disorders: Increased urea in the blood. Disorders of the reproductive system, mammary glands cause vaginitis. Doxycycline 100mg drug belongs to the tetracycline group, has the effect of killing parasites, anti-inflammatory or preventing the growth of viruses and fungi. To ensure effective treatment and avoid unwanted side effects, patients need to strictly follow the instructions of the doctor, professional pharmacist.
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