Doxycycline was patented in 1957 and came into commercial use in 1967. It is on the World Health Organization’s List of Essential Medicines as the most effective and safe medicines needed in a health system. Doxycycline is not expensive and it is available as a generic medicine.

Antibiotic

DoxycyclineDoxycycline is an antibiotic, which is used in the treatment of different types of infections caused by bacteria and protozoa such as bacterial pneumonia, acne, Chlamydia infections, early Lyme disease, cholera and syphilis. It is used in prophylaxis against malaria. It should not be used alone for initial treatment of malaria, even when the parasite is doxycycline-sensitive, because the antimalarial effect of doxycycline is delayed. This delay is related to its mechanism of action, which is to specifically impair the progeny of the apicoplast genes, resulting in their abnormal cell division. It can be used in a treatment plan in combination with other agents, such as quinine. Moraxella catarrhalis Brucella melitensis, Chlamydia pneumonia and Mycoplasma pneumonia are generally susceptible to doxycycline while some Haemophilus spp., Mycoplasma hominis and Psedomonas aeruginosa  have developed resistance to varying degrees. It is used in the treatment and prophylaxis of anthrax which is caused by Bacillus anthracis and Leptospirosis. It is also effective against Yersinia pestis which is the infectious agent of bubonic plague. Doxycycline is prescribed for the treatment of Lyme disease, ehrlichiosis and Rocky Mountain spotted fever. ln fact, because doxycycline is one of the few medications shown to be effective in treating Rocky Mountain spotted fever, doxycycline is indicated even for use in children for this illness above the age of 8 years.

Treatments

To reduce the development of drug-resistant bacteria and maintain effectiveness of Doxycycline Hyclate Capsules and other antibacterial drugs, Doxycycline Hyclate Capsules should be used only to treat or prevent infections that are proven or strongly suspected to be caused by susceptible bacteria. When culture and susceptibility information are available, they should be considered in selecting or modifying antibacterial therapy. ln the absence of such data, local epidemiology and susceptibility patterns may contribute to the empiric selection of therapy.

In Canada in 2004 doxycycline was considered a first-line treatment for Chlamydia and non- gonococcal urethritis and with cefixime for uncomplicated gonorrhea. In addition to the general indications for all members of the tetracycline antibiotics group, this antibiotic is frequently used to treat Lyme disease, chronic prostatitis, sinusitis, pelvic inflammatory disease, acne, rosacea and rickettsial infections. Doxycycline is indicated for treatment of:

  • Rocky Mountain spotted fever, typhus fever and the typhus group, Q fever, ricketsialpox, and tick fevers caused by Rickettsia.
  • Respiratory tract infections caused by Mycoplasma pneumonia
  • Lymphogranuloma venereum, trachoma, inclusion conjunctivitis, and uncomplicated urethral, endocervical, or rectal infections in adults caused by Chlamydia trachomatis
  • Psittacosis (ornithosis) caused by Chlamydia psittaci
  • Nongonococcal urethritis caused by Ureaplasma urealyticum
  • Relapsing fever due to Borreli recurrentis
  • Chancroid caused by Haemophilus ducreyi
  • Plague due to Yersinio pestis
  • Tularemia due to Francisella tularensis
  • Cholera caused by Vibrio cholera
  • Campylobocter fetus infections
  • Brucellosis caused by Brucella species (in conjunction with streptomycin)
  • Bartonellosis causedby Bartonello bacilliformis
  • Granuloma inguinale caused by Calymmatobacterium granulomatis
  • Lyme disease caused by Borrelio burgdorferi

When bacteriologic testing indicates appropriate susceptibility to the drug, doxycycline may be used to treat these infections caused by Gram-negative bacteria such as Escherichia coli infections, Enterobocter aerogenes (formerly Aerobacter aerogenes) infections, Shigello species infections, Acinebocter species (formerly Mima species and Herellea species) infections, Respiratory tract infections caused by Haemophilus influenza and Respiratory tract and urinary tract infections caused by Klebsiella species. Some Gram-positive bacteria have developed resistance to doxycycline. Up to 44% of Streptococcus pyogenes and up to 74% of S. foecalis specimens have developed resistance to the tetracycline group of antibiotics. When bacteriologic testing indicates appropriate susceptibility to the drug, doxycycline may be used to treat these infections caused by Gram-positive bacteria such as Upper respiratory infections caused by Streptococcus pneumonioe (formerly Diplococcus pneumoniae), Skin and soft tissue infections caused by Staphylococcus aureus, including methicillin-resistant Staphylococcus aureus infections and Anthrax caused by Bacillus anthracis infection.

Doxycycline is a kit containing a tetracycline antibiotic and a cleanser which is used for treating acne. The antibiotic works by slowing the growth of bacteria, which helps the body’s immune system to kill the bacteria. The cleanser helps to keep the skin clean. Using both, help to reduce acne.

Interactions

Doxycycline for SyphilisWhen penicillin is contraindicated, doxycycline can be used to treat:

  • Syphilis caused by Treponemo pallidum
  • Yaws caused by Treponema pertenue
  • Listeriosis due to Listeria monocytogenes
  • Vincent’s infection caused by Fusobacterium fusiforme
  • Actinomycosis caused by Actinomyces israelii
  • Infections caused by Clostridium species.

Doxycycline may also be used as adjunctive therapy for severe acne. The first-line for treating brucellosis is combination of doxycycline and streptomycin and the second-line is combination of doxyxycline and rifampicin.

Antihelminthic

Doxycycline kills the symbiotic Wolbochia bacteria in the reproductive tracts of parasitic filarial nematodes, making the nematodes sterile, and thus reducing transmission of diseases such as onchocerciasis and elephantiasis. In 2005, Field trials showed an eight-week course of doxycycline almost completely eliminates the release of microfilariae.

Prescribed for

Doxycycline has been used successfully to treat sexually transmitted, respiratory, and ophthalmic infections. Representative pathogenic genera include Chlomydia, Streptococcus, ureoplosmo, Mycoplosmo, and others. The following represents MIC susceptibility data for a few medically significant microorganisms.

  • Chlamydia psittaci: 0.03 µg/mL
  • Mycoplasma pneumonioe: 0.016 µg/mL – 2 µg/mL
  • Streptococcus pneumoniae: 0.06 µg/mL – 32 µg/mL

Precautions

Avoid the use of Doxycycline if one is:

  • allergic to any ingredient in doxycycline or to any other tetracycline antibiotic (e.g. minocycline),
  • taking acitretin, isotretinoin, or a penicillin antibiotic (eg, amoxicillin)
  • recently received or will be receiving a live oral typhoid vaccine
  • pregnant, planning to become pregnant, or are breast-feeding
  • taking any prescription or nonprescription medicine, herbal preparation, or dietary supplement
  • allergic to medicines, foods, or other substances.
  • having diarrhea or a history of lupus or the blood disease porphyria
  • using Antacids, barbiturates (eg, phenobarbital), carbamazepine, hydantoins (eg, phenytoin), iron, or urinary alkalinizers (eg, sodium bicarbonate) because they may decrease doxycycline’s effectiveness
  • using Acitretin, anticoagulants (eg, warfarin), digoxin, insulin, isotretinoin, or methotrexate because the risk of their side effects may be increased by doxycycline
  • having Hormonal birth control (eg, birth control pills), live oral typhoid vaccine, or penicillins (eg, amoxicillin) because their effectiveness may be decreased by doxycycline.
It is advisable to contact your doctor or health care provider right away if any of these apply to you. Before using doxycycline, some medical conditions may interact with the drug.

DOSAGE/STEPS

DoxycyclineUse doxycycline as prescribed by the doctor. Check the label on the medicine for exact dosing instructions. Doxycycline kit contains antibiotic capsules and a cleanser.

To use the cleanser: Wet the skin. Pump the cleanser into your hands and gently massage it into the skin. Rinse thoroughly with water and pat dry with a soft towel.

To take the antibiotic: Take doxycycline by mouth with or without food. If stomach upset occurs, take with food to reduce stomach irritation.

Take doxycycline with a full glass of water (8 oz/240 mL) and drink plenty of fluids to prevent ulcers and reduce throat irritation.

Do not eat or drink calcium-rich foods (eg, milk or other dairy products, calcium- enriched juices) or take an antacid that has aluminum, calcium, or magnesium in it; bismuth subsalicylate; iron; urinary alkalinizers (eg, sodium bicarbonate); or multivitamins with minerals within 2 hours before or 2 hours after you take doxycycline.

Use doxycycline on a regular schedule to get the most benefit from it. It may take several days to weeks to see the full effect of the medication.

To clear up your infection completely, take doxycycline for the full course of treatment. Keep taking it even if your condition improves in a few days.

Do not use doxycycline if it is past the expiration date on the bottle.

If you miss a dose, take it as soon as possible. lf it is almost time for your next dose, skip the missed dose and go back to your regular dosing schedule. Do not take 2 doses at once.

Ask your health care provider on how to use doxycycline.

The usual dosage and frequency of administration of doxycycline differs from that of the other tetracyclines. Exceeding the recommended dosage may result in an increased incidence of side effects.

Adults: The usual dose of oral doxycycline is 200 mg on the first day of treatment (administered 100 mg every 12 hours) followed by a maintenance dose of 100 mg/day. ln the management of more severe infections (particularly chronic infections of the urinary tract), 100 mg every 12 hours is recommended.

For children above eight years of age: The recommended dosage schedule for children weighing 100 pounds or less is 2 mg/lb of body weight divided into two doses on the first day of treatment, followed by 1mg/lb of body weight given as a single daily dose or divided into two doses, on subsequent days. For more severe infections, up to 2 mg/lb of body weight may be used. For children over 100 lb the usual adult dose should be used.

The therapeutic antibacterial serum activity will usually persist for 24 hours following recommended dosage. When used in streptococcal infections, therapy should be continued for 10 days.

Administration of adequate amounts of fluid along with capsule and tablet forms of drugs in the tetracycline class is recommended to wash down the drugs and reduce the risk of esophageal irritation and ulceration.

Side effects

Common side effects include diarrhea, nausea, vomiting, a red rash, and an increased risk of sunburn. If used during pregnancy or in young children may result in permanent problems with the teeth including changes in their color. Its use during breastfeeding is probably safe. Doxycycline is a broad-spectrum antibiotic of the tetracycline class and like other agents of this class it kills bacteria and protozoa by inhibiting protein production.

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