Doxycycline: A look at this commonly prescribed, broad-spectrum antibiotic

Doxycycline is a commonly used antibiotic known for being effective against a broad range of bacterial infections. Whether you're dealing with a sinus infection, acne, or even Lyme disease, doxycycline might be prescribed to help you get better.

What is doxycycline?

Doxycycline is an antibiotic that belongs to the tetracycline class of drugs. It was first approved for medical use in the 1960s and has since become one of the most prescribed antibiotics worldwide.

Doxycycline is broad-spectrum, meaning it can target and kill a wide variety of bacteria. This makes it useful when a condition such as pneumonia might be caused by one of several types of bacteria. Tetracyclines, including doxycycline, can also manage inflammation in certain diseases.

Common uses of doxycycline

Doxycycline is very versatile because of its antibacterial and anti-inflammatory properties. This makes it useful in treating various infections as well as inflammatory conditions.

Some of the most common reasons your doctor might prescribe doxycycline include:

• Respiratory infections: Doxycycline is often prescribed for sinus infections, pneumonia, and bacterial bronchitis.
• Skin conditions: It is a popular treatment for many inflammatory skin conditions including acne, rosacea, perioral dermatitis, and hidradenitis suppurativa. Doxycycline may also be used to treat skin infections (cellulitis).
• Sexually transmitted infections (STIs): Doxycycline can be used to treat infections like chlamydia.
• Tick-borne illnesses: This antibiotic is the treatment of choice for certain diseases caused by a tick bite, such as Lyme disease and Rocky Mountain spotted fever.
• Malaria prevention: In some parts of the world, doxycycline is prescribed to travelers as a preventive measure against malaria.
• Other infections: Doxycycline can also be used to treat dental infections (periodontitis), ear infections (otitis media), and to prevent infection after a dog bite.

How doxycycline works

Doxycycline works by stopping bacteria from making proteins that are essential for their growth. Without these proteins, the bacteria can't multiply and eventually die off, which helps your body overcome the infection. Because it targets the bacteria specifically, doxycycline doesn't harm human cells, which is why it's generally safe when used as directed.

Doxycycline also helps reduce inflammation by interfering with the production of nitric oxide, which is involved in the inflammation process.

Who should not take doxycycline?

While doxycycline is effective for many people, it's not suitable for everyone. Certain groups should avoid this medication or use it with caution:

• Pregnant and breastfeeding women: Doxycycline can affect the development of the fetus, particularly the teeth and bones, so it's usually not recommended during pregnancy. While prolonged and repeated use of doxycycline is not recommended while breastfeeding, it's generally considered safe for short-term use. If you are pregnant or breastfeeding, talk to your doctor about the risks and benefits of doxycycline before taking this medication.
• Children under 8 years old: In young children, doxycycline can cause permanent discoloration of the teeth and affect bone growth, which is why it's generally avoided unless absolutely necessary.
• People with allergies to tetracyclines: If you have a known allergy to doxycycline or other tetracycline antibiotics, you should not take this medication.
• Other special groups: If you have a history of myasthenia gravis, an autoimmune disease that can cause muscle weakness, you should not take doxycycline because it could worsen your symptoms. People with a history of lupus should discuss the use of doxycycline with their doctor because it may exacerbate the symptoms.

Doxycycline can interact with certain foods and medications, including antacids and iron and calcium supplements. Tell your doctor about any medications or supplements you are taking prior to starting a course of doxycycline.

Potential side effects of doxycycline

Doxycycline is usually well tolerated, but it can cause side effects in some people. The most common side effects are digestive issues such as upset stomach, nausea, vomiting, and diarrhea. Other common side effects include:

• Sun sensitivity. Doxycycline can make your skin more sensitive to sunlight, increasing the risk of sunburn. Use sunscreen and wear protective clothing when outdoors.
• Yeast infections. Antibiotics can disrupt the natural balance of bacteria in the body, allowing overgrowth of yeast in the mouth (thrush) or a woman's vagina (yeast vaginitis).
• Pill esophagitis. Doxycycline can irritate the lining of the esophagus, causing esophagitis.

Though rare, some individuals may experience an allergic reaction to doxycycline that could include rash, itching, or swelling.

Other rare adverse effects include:

• skin hyperpigmentation
• liver injury
• Stevens-Johnson syndrome, a potentially life-threatening blistering skin condition.

What else to know if you are taking doxycycline

If you are prescribed doxycycline, there are a few other important things to keep in mind:

• Take it with plenty of water. This helps prevent irritation in your throat and esophagus. Doctors recommend taking the medication with at least 8 ounces of water.
• Avoid lying down immediately after taking it. Staying upright for at least 30 minutes can help prevent stomach upset and irritation.
• Store it properly. Keep doxycycline in a cool, dry place, and out of direct sunlight. Do not use the medication if it has expired, as it can become toxic.