Doxycline

Mechanism of Action:

The tetracyclines are primarily bacteriostatic and are thought to exert their antimicrobial effect by the inhibition of protein synthesis. The tetracyclines, including doxycycline, have a similar antimicrobial spectrum of activity against a wide range of gram-positive and gram-negative organisms.

Drug Label Information | Brands:

Brands of Doxycline in Kenya

Alldox® , Medox Pharmaceuticals Ltd
Asdoxin®, Astra Lifecare
Biodox®, Biodeal Laboratories Ltd
Caredoxy® , Careplus ltd
Dawadoxyn®, Dawa Limited
Doxefil®, Fourrts (India) Laboratories Pvt. Limited
Doxy® , Laboratory & Allied Ltd
Doxy-100® , Universal Corporation Limited
Doxycycline , Elys Chemical Industries Ltd
Doxycycline ,Crown Healthcare
Doxylag®, Lagap SA
Doxyline®, Cosmos Limited
Doxyzim® ,Zim Laboratories Ltd
Pharmadoxy® , Shanghai Agen International Trade Co.ltd,
Unidoxy® , Medisel Kenya Ltd

INDICATIONS:

Doxycycline is indicated for the treatment of the following infections:

  • Rocky Mountain spotted fever, typhus fever and the typhus group, Q fever, rickettsialpox, and tick fevers caused by Rickettsiae.
  • Respiratory tract infections caused by Mycoplasma pneumoniae.
  • Lymphogranuloma venereum caused by Chlamydia trachomatis.
  • Psittacosis (ornithosis) caused by Chlamydia psittaci.
  • Trachoma caused by Chlamydia trachomatis, although the infectious agent is not always eliminated as judged by immunofluorescence.
  • Inclusion conjunctivitis caused by Chlamydia trachomatis.
  • Uncomplicated urethral, endocervical or rectal infections in adults caused by Chlamydia trachomatis.
  • Nongonococcal urethritis caused by Ureaplasma urealyticum.
  • Relapsing fever due to Borrelia recurrentis.

Doxycycline is also indicated for the treatment of infections caused by the following gram-negative microorganisms:

  • Chancroid caused by Haemophilus ducreyi.
  • Plague due to Yersinia pestis (formerly Pasteurella pestis).
  • Tularemia due to Francisella tularensis (formerly Pasteurella tularensis).
  • Cholera caused by Vibrio cholerae (formerly Vibrio comma).
  • Campylobacter fetus infections caused by Campylobacter fetus (formerly Vibrio fetus).
  • Brucellosis due to Brucella species (in conjunction with streptomycin).
  • Bartonellosis due to Bartonella bacilliformis.
  • Granuloma inguinale caused by Calymmatobacterium granulomatis.

Doxycycline is indicated for treatment of infections caused by the following gram-negative microorganisms, when bacteriological testing indicates appropriate susceptibility to the drug:

  • Escherichia coli
  • Enterobacter aerogenes (formerly Aerobacter aerogenes)
  • Shigella species
  • Acinetobacter species (formerly Mima species and Herellea species)
  • Respiratory tract infections caused by Haemophilis influenzae
  • Respiratory tract and urinary tract infections caused by Klebsiella species

Doxycycline is indicated for treatment of infections caused by the following gram-positive microorganisms when bacteriological testing indicates appropriate susceptibility to the drug:

  • Upper respiratory infections caused by Streptococcus pneumoniae (formerly Diplococcus pneumonia)
  • Anthrax due to Bacillus anthracis, including inhalation anthrax (post-exposure): to reduce the incidence or progression of disease following exposure to aerosolized Bacillus anthracis.

When penicillin is contraindicated, doxycycline is an alternative drug in the treatment of infections due to:

  • Uncomplicated gonorrhea caused by Neisseria gonorrhoeae
  • Syphillis caused by Treponema pallidum
  • Yaws caused by Treponema pertenue
  • Listeriosis due to Listeria monocytogenes
  • Vincent’s infection caused by Fusobacterium fusiforme
  • Actinomycosis caused by Actinomyces israelli
  • Infections caused by Clostridium species
  • In acute intestinal amebiasis doxycycline may be a useful adjunct to amebicides.
  • In severe acne doxycycline may be useful adjunctive therapy.
  • Prophylaxis:
  • Doxycycline is indicated for the prophylaxis of malaria due to Plasmodium falciparum in short-term travelers (<4 months) to areas with chloroquine and/or pyrimethamine-sulfadoxine resistant strains.

DOSAGE AND ADMINISTRATION

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. The maintenance dose may be administered as a single dose or 50 mg every 12 hours. In 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 1 mg/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 pounds, 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

Uncomplicated gonococcal infections in adults (except anorectal infections in men): 100 mg, by mouth, twiceaday for 7 days. As an alternate single visit dose, administer 300 mg stat followed in one hour by a second 300 mg dose. The dose may be administered with food, including milk or carbonated beverage, as required.

Uncomplicated urethral, endocervical, or rectal infection in adults caused by Chlamydia trachomatis: 100 mg by mouth, twice a day for 7 days.

Nongonococcal urethritis (NGU) caused by C. trachomatis and U. urealyticum: 100 mg, by mouth, twice a day for 7 days.

Syphilis – early: Patients who are allergic to penicillin should be treated with doxycycline 100 mg by mouth twice a day for 2 weeks.

Syphilis of more than one year’s duration: Patients who are allergic to penicillin should be treated with doxycycline 100 mg by mouth twice a day for 4 weeks.

Acute epididymo-orchitis caused by N. gonorrhoeae: 100 mg, by mouth, twice a day for at least 10 days.

Acute epididymo-orchitis caused by C. trachomatis: 100 mg, by mouth, twice a day for at least 10 days.

For prophylaxis of malaria: For adults, the recommended dose is 100 mg daily. For children over 8 years of age, the recommended dose is 2 mg/kg given once daily up to the adult dose. Prophylaxis should begin 1-2 days before travel to the malarious area. Prophylaxis should be continued daily during travel in the malarious area and for 4 weeks after the traveller leaves the malarious area.

Inhalation anthrax (post-exposure):

ADULTS: 100 mg of doxycycline, by mouth twice a day for 60 days.

CHILDREN: weighing less than 100 lb (45 kg); 1 mg/lb (2.2 mg/kg) of body weight, by mouth, twiceaday for 60 days. Children weighing 100 lb or more should receive the adult dose.

CONTRAINDICATIONS

The drug is contraindicated in persons who have shown hypersensitivity to any of the tetracyclines.

ADVERSE DRUG REACTIONS

Gastrointestinal: Anorexia, nausea, vomiting, diarrhoea, glossitis, dysphagia, enterocolitis, and inflammatory lesions (with monilial overgrowth) in the anogenital region. Hepatotoxicity has been reported rarely. These reactions have been caused by both the oral and parenteral administration of tetracyclines

Skin: Maculopapular and erythematous rashes. Exfoliative dermatitis has been reported but is uncommon. Photosensitivity has been reported.

Renal toxicity: Rise in BUN has been reported and is apparently dose related.

Hypersensitivity reactions: Urticaria, angioneurotic edema, anaphylaxis, anaphylactoid purpura, serum sickness, pericarditis, and exacerbation of systemic lupus erythematosus.

Blood: Hemolytic anemia, thrombocytopenia, neutropenia and eosinophilia have been reported.

Other: Bulging fontanels in infants and benign intracranial hypertension in adults

When given over prolonged periods, tetracyclines have been reported to produce brown-black microscopic discolouration of thyroid glands. No abnormalities of thyroid functions are known to occur.

DRUG INTERACTIONS

  • Since bacteriostatic drugs may interfere with the bactericidal action of penicillin, it is advisable to avoid giving tetracycline in conjunction with penicillin or other bactericidal antibacterials.
  • Because the tetracyclines have been shown to depress plasma prothrombin activity, patients who are on anticoagulant therapy may require downward adjustment of their anticoagulant dosage.
  • The concurrent use of tetracycline and methoxyflurane has been reported to result in fatal renal toxicity.
  • Absorption of tetracyclines is impaired by antacids containing aluminum, calcium or magnesium and preparations containing iron, zinc, or sodium bicarbonate.
  • Concurrent use of tetracycline may render oral contraceptives less effective.