Doxycycline Capsules and Tablets 100 mg 

Doxycycline is a prescription antibiotic used for the treatment and prevention of certain types of infections. Though it is classified as a Tetracycline, it can also be used as a miscellaneous antimalarial. Acticlate, Adoxa, and Alodox are common examples of brand names for this drug. It comes in two different salt forms: doxycycline hyclate and doxycycline monohydrate which have distinct degrees of solubility in water.

Uses of Doxycycline

Doctors use Doxycycline for the treatment of the following:

  •     Acne
  •     Eye infections
  •     Urinary tract infection
  •     Gum disease
  •     Diseases caused by bugs, ticks, or lice
  •     Sexually transmitted infections (gonorrhea, syphilis, chlamydia)
  •     Respiratory tract infections (bacterial pneumonia or bronchitis)
  •     Chronic prostatitis
  •     Lyme disease
  •     Inflammation in osteoarthritis
  •     Pelvic inflammatory disease

Doxycycline can also be used to prevent malaria. Your Doctor may also prescribe it for other purposes not listed here.

How Does Doxycycline Work?

Doxycycline, like other Tetracyclines, is bacteriostatic. It works by inhibiting protein synthesis; it allosterically binds to some ribosomal units during protein synthesis. This suppresses the growth of bacterial cells or keeps them in the stationary growth phase (that is, limits their spread/decreases the progression of the infection). As an anti-inflammatory agent, Doxycycline inhibits inflammatory mediators like lymphocyte proliferation and nitric synthase.


Children below 8 years of age should not use this medicine except in life-threatening situations. It can cause irreversible teeth discoloration in children.

To be certain that this drug is safe for you, inform your doctor if you have any of the following:

  1. History of liver impairment
  2. Asthma or sulfite allergies
  3. Currently taking isotretinoin or blood thinners
  4. Kidney impairment
  5. Increased intracranial pressure

Do not take Doxycycline if you are pregnant as it can affect bone and teeth development in the unborn baby.

This drug can pass through the breast milk and harm a nursing baby; avoid breastfeeding while using this medication.

Doxycycline can make hormonal birth control pills to be less effective.

How to Use Doxycycline

Take this medicine as directed by your doctor. Even if your symptoms become better, do not take it less or more than prescribed as it could make the drug less effective the next time you take it.

Doxycycline can be taken with food or without food. While most brands can be taken with food or milk to reduce stomach upset, some brands should be taken 1 hour before or 2 hours after a meal.

Swallow the delayed-release tablets or capsules whole with a reasonable amount of water. Do not crush or chew them.

Sometimes your doctor may instruct you to split a regular tablet to get the correct dose. Ensure you remain in an upright position for at least 30 minutes after taking the medicine to reduce the chances of esophageal irritation.

Doxycycline Dosing Information

The dose to take is dependent on your weight/age as well as the severity of the infection. Dosage modifications exist for those with impaired kidney function. The instructions given here are just a guide.

  •     For mild to moderate bacterial infection: the initial dose is 100 mg every 12 hours on day one followed by 100 mg daily for the remaining days. Pelvic infections will require 100 mg twice daily for 7 days.
  •     Even though the maximum daily dose is 300 mg, acute gonorrhea can be treated with 600 mg daily for 5 days.
  •     For use as an anti-inflammatory agent, 40 mg daily is sufficient to exert anti-inflammatory effects while also maintaining the body's microbiome.
  •     For malaria prophylaxis, take 100 mg once daily beginning 1 to 2 days before traveling to malaria-endemic areas. The therapy should continue even till 4 weeks after returning.

N/B: Doxycycline should be used in conjunction with chloroquine.

Side Effects of Doxycycline

The common side effects of Doxycycline are usually mild and include:

  •     Loss of sense of taste
  •     Nausea
  •     Vomiting
  •     Diarrhea
  •     Vaginal or oral thrush
  •     Mild esophageal irritation
  •     Changes in the appearance of fingers or toenails
  •     Itchy skin or rashes
  •     Stomach upset
  •     Vaginal discharge
  •     Darkening of skin color

Serious side effects that need medical attention may include:

  •     Difficulty in breathing
  •     Pain or difficulty in swallowing
  •     Dizziness
  •     Hives
  •     Swelling in your eyes, face, or neck
  •     Fever
  •     Severe skin discoloration/reaction
  •     Severe weakness
  •     Flu-like symptoms
  •     Fast heart rate
  •     Increased pressure in the brain (accompanied by headache, blurred vision, and vomiting)
  •     Very little or no urination
  •     Severe abdominal pain
  •     Low white blood cell count


The major Doxycycline drug interactions are with the following:

  •     Cholera vaccine live
  •     Aminolevulinic acid
  •     BCG
  •     Digoxin
  •     Acitretin
  •     Digitoxin
  •     Fecal microbiota spores live
  •     Ketoconazole
  •     Etretinate
  •     Levoketoconazole
  •     Methoxyflurane
  •     Isotretinoin
  •     Mycophenolate mofetil
  •     Lomitapide
  •     Mycophenolic acid
  •     Pexidartinib
  •     Typhoid vaccine live
  •     Mipomersen
  •     Palovarotene
  •     Tretinoin
  •     Vitamin A
  •     Bexarotene

Missed Dose and Overdose

Take missed doses as soon as you can remember them if your next dosing time is not near. Otherwise, skip the missed dose. If you suspect an overdose, call the poison control center in your area immediately.


Doxycycline should be stored at room temperature away from moisture direct sunlight and heat. Reconstituted suspensions should be refrigerated and stored as per manufacturer's instructions.