• Tetracycline group of drug.
  • Least Nephrotoxic
    • Used in renal failure without dose adjustment.


  • Inhibits bacterial protein synthesis by binding to 30S ribosomal subunit. 
  • Has bacteriostatic activity against broad range of Gram-positive & Gram-negative bacteria.


  • Indicated for treatment of
    • Rocky Mountain spotted fever, typhus fever, Q fever, rickettsial pox, & tick fevers caused by Rickettsia
    • Respiratory tract infections caused by Mycoplasma pneumoniae.
    • Lymphogranuloma venereum, trachoma, inclusion conjunctivitis, & uncomplicated urethral, endocervical, or rectal infections in adults caused by Chlamydia trachomatis.
    • Drug of choice for scrub typhus – Doxycycline (100 mg bd orally for 7-15 days)
    • Psittacosis (ornithosis) caused by Chlamydia psittaci.
    • Englishman visiting regions of chloroquine & mefloquine-resistant malaria.
    • Nongonococcal urethritis caused by Ureaplasma urealyticum
    • Relapsing fever due to Borrelia recurrentis
    • Chancroid caused by Haemophilus ducreyi
    • Plague due to Yersinia pestis.
    • Tularemia due to Francisella tularensis.
    • Cholera caused by Vibrio cholerae (single dose).
    • Campylobacter fetus infections.
    • Brucellosis caused by Brucella species (Combined with streptomycin)
    • Bartonellosis caused by Bartonella bacilliformis
    • Granuloma inguinale caused by Calymmatobacterium granulomatis
    • Lyme disease caused by Borrelia burgdorferi
    • Inflammatory acne with comedones.


Common side effects:

  • Diarrhoea
  • Itching of the rectum or vagina
  • Sore mouth
Serious side effects:
  • Maximum propensity for photodermatitis.
  • Severe headache
  • Blurry vision
  • Rash or hives
  • Trouble breathing or swallowing
  • Sunburn
  • Yellowing of the skin or eyes
  • Dark-coloured urine
  • Light-coloured bowel movements
  • Loss of appetite
  • Nausea or vomiting
  • Stomach pain
  • Extreme tiredness or weakness
  • Confusion
  • Less frequent urination

Exam Important

  • Doxycycline can be used in renal failure without dose adjustment.
  • Doxycycline is least Nephrotoxic.
  • Antibiotic treatment of choice for treating cholera in an adult is a single dose of Doxycycline.
  • Doxycycline drug of choice for Non-Gonococcal Urethritis.
  • Doxycycline is the drug of choice in Mycoplasma infection.
  • Doxycycline is the drug of choice in typhus fever.
  • Drug of choice for scrub typhus – Doxycycline (100 mg bd orally for 7-15 days)
  • Doxycycline is the drug of choice in Brucellosis.
  • Doxycycline acts by inhibiting protein synthesis.
  • Doxycycline has the maximum propensity for photodermatitis.
  • Chemoprophylaxis in an Englishman visiting chloroquine and mefloquine-resistant malaria region is done with Doxycycline.
  • A 19-year old male presents with several comedones, papules and pustules on face and trunk
    • The drug of choice for the patient would be Topical retinoic acid + Oral doxycycline.


Don’t Forget to Solve all the previous Year Question asked on DOXYCYCLINE

Module Below Start Quiz

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