Doxycycline

 Doxycycline

Doxycycline is a broad-spectrum tetracycline antibiotic used to treat a wide range of bacterial infections. It works by inhibiting bacterial protein synthesis, preventing bacteria from growing and multiplying.

Uses

Doxycycline is commonly prescribed for:

Respiratory tract infections (e.g., pneumonia)

Acne vulgaris

Skin and soft tissue infections

Urinary tract infections (in selected cases)

Sexually transmitted infections, including chlamydia

Lyme disease

Cholera

Rickettsial infections (e.g., Rocky Mountain spotted fever)

Malaria prevention and treatment (in certain situations)

Note: Doxycycline is effective against bacterial infections but does not treat viral infections such as the common cold or influenza.

Adult dosage

The dose depends on the condition being treated. Common regimens include:

100 mg every 12 hours on the first day, followed by 100 mg once daily or 100 mg twice daily, depending on the infection.

Always take it exactly as prescribed by your healthcare provider.

How to take doxycycline

Take with a full glass of water.

Remain upright (sitting or standing) for at least 30 minutes after taking it to reduce the risk of irritation of the esophagus.

It may be taken with food if it causes stomach upset, but avoid taking it at the same time as dairy products, antacids, or iron/calcium supplements, as these can reduce absorption.

Common side effects

Nausea or vomiting

Diarrhea

Stomach upset

Loss of appetite

Increased sensitivity to sunlight (photosensitivity)

Serious side effects

Seek medical attention if you experience:

Severe allergic reactions (rash, swelling, difficulty breathing)

Severe or persistent diarrhea

Difficulty swallowing or severe chest pain after taking the medicine

Severe headache or vision changes

Signs of liver problems, such as yellowing of the skin or eyes

Who should avoid doxycycline?

People with a known allergy to tetracycline antibiotics.

Children under 8 years of age, except when the benefits outweigh the risks, because it can affect developing teeth and bones.

Pregnant women, unless specifically prescribed by a healthcare professional, as it may affect fetal bone and tooth development.

Drug interactions

Doxycycline may interact with:

Antacids containing aluminum, magnesium, or calcium

Iron supplements

Calcium supplements

Some anti-seizure medications

Warfarin (may increase bleeding risk)

Tips

Complete the entire prescribed course, even if you feel better.

Use sunscreen and protective clothing when outdoors because doxycycline can make your skin more sensitive to sunlight.

Do not share antibiotics with others or use leftover antibiotics without medical advice.