Doxycycline: Uses, Side effects & contraindications!

Doxycycline is an antibiotic of the tetracycline class, it acts on both gram positive & gram negative bacteria.


  • Acne
  • Lyme disease
  • Cholera
  • Acute intestinal amebiasis
  • Rosacea
  • Rickettsia
  • Pelvic Inflammatory Disease (PID)
  • Chronic prostatitis
  • Chlamydia
  • Gonorrhea
  • Syphilis
  • Periodontitis
  • Rocky mountain spotted fever
  • Chancroid
  • Prevention of malaria
  • Reducing transmission of diseases like river blindness & elephantiasis.


Dosage forms available:

  • Immediate release tablets: 20 mg, 50 mg, 75 mg, 100 mg, 150 mg
  • Delayed release tablets: 50 mg, 60 mg, 75 mg, 100 mg, 125 mg, 150 mg, 200 mg
  • Capsules: 50 mg, 75 mg, 100 mg, 150 mg
  • Delayed release: 40 mg
  • Syrup: 50 mg/5 ml
  • Powder reconstituted for solution/injection: 100 mg/10 ml
  • Oral suspension: 25 mg/5 ml
  • Periodontal XR liquid: 10%
  • Doxycycline + benzoyl peroxide topical kit

Dosage guidelines:

  • Chlamydia: 100 mg tablet or capsule twice a day, or 200 mg once a day for 7 days.
  • Lyme disease: 100 mg tablet/capsule twice a day for 15-28 days depending on the complications of the disease.
  • Pelvic Inflammatory Disease: 100 mg oral dose or IV dose every 12 hours for 14 days.
  • Other doses depend on factors like the type & location of infection, bacteria, age, sex, presence of underlying diseases, immunity & doctor’s guidance.

Missed dose: Take the missed dose as soon as you remember. Skip the missed dose if it is almost time for your next scheduled dose, similarly not take extra medicine to make up the missed dose.

a) Administration of gastric lavage
b) Dialysis
c) Maintaining hydration & supplying intravenous therapy.


  • Difficulty swallowing
  • Drug rash
  • Esophageal ulcer
  • Headache
  • Lesions on the genitals
  • Low
  • Loss of appetite
  • Low blood sugar (hypoglycemia)
  • Skin hyperpigmentation
  • Skin peeling (exfoliative dermatitis)
  • Tongue swelling
  • Tooth discoloration
  • Upper abdominal pain.


  • Hypertension
  • Metabolic syndrome
  • Esophagitis
  • Hepatotoxicity
  • Severe skin reaction
  • Blurred vision & vision loss
  • Superinfection
  • Low WBC & platelet count
  • IBD
  • Lupus
  • Pancreatitis
  • Fast heart rate.


Doxycycline is contraindicated & precaution is advised in patients that have the following conditions;

  • Pregnancy
  • People who have history of intracranial hypertension
  • Patients with dysphagia
  • Renal impairment
  • Hepatic dysfunction
  • Heart & cardiovascular problems
  • Oral candidiasis
  • Existing treatment of other conditions with other drugs
  • Pediatric patients
  • Patients undergoing penicillin therapy
  • Compromised immune system.


Tetracyclines – Doxycycline when given with these drugs product the following effect:

  • Antacids: Decrease absorption of doxycycline
  • Barbiturates: Decrease serum concentration of doxycycline
  • Carbamazepine: Decrease the serum concentration of doxycycline
  • Cholera Vaccine effect is diminished in presence of tetracyclines.
  • Iron preparations absorption is decreased.
  • Lithium: Serum concentration is increased in presence of doxycycline.
  • Mecamylamine: Tetracyclines may enhance the neuromuscular-blocking effect of Mecamylamine.
  • Proton Pump Inhibitors: May decrease the bioavailability of Doxycycline.
  • Adverse effects of Retinoic acid derivatives is enhanced in the presence of tetracyclines.
  • Sucralfate: Decreases absorption of doxycycline.
  • Vitamin K Antagonists (eg, warfarin): Tetracyclines may enhance the anticoagulant effect of Vitamin K antagonists.


  • Pregnancy: Doxycycline is a pregnancy category D drug, therefore some studies have given evidence that it can cause harm to pregnant mother & fetus & is therefore contraindicated in pregnancy.
  • Breast Feeding: Not recommended in breast feeding mothers.
  • Children: In children upto 8 years doxycycline should not be given as it can cause tooth discoloration & hyperpigmentation.