What is doxycycline used for?

Doxycycline is an antibiotic used to treat infections and prevent malaria. This page explains what doxycycline is used for, how it works and its risks.

To get doxycycline, you have to have a prescription written for you by a doctor.

Your doctor may prescribe doxycycline to:

• treat respiratory tract infections like pneumonia or bronchitis
• treat other infections such as prostatitis and chlamydia
• control acne
• prevent malaria for people travelling in high-risk areas 

Your doctor may have prescribed doxycycline for another reason. If you are unsure why you are taking doxycycline, ask your doctor.

It is important to always finish the course of doxycycline as prescribed by your doctor, even if you feel better.

How does doxycycline work?

Doxycycline works by stopping bacteria from multiplying. In acne, it reduces the number of bacteria on the skin surface and it has an anti-inflammatory action.

Doxycycline also works against malaria-causing parasites.

What forms of doxycycline are available?

Doxycycline is the name of the active ingredient. It is available in many different brands, which have different:

• names
• appearances (size, shape or colour)
• forms (tablets and capsules)
• packaging

No matter which brand you are prescribed, doxycycline works in the same way to fight the infection.

What are the possible side effects of doxycycline?

All medicines have benefits, and they also have the risk of side effects.

The more common side effects of doxycycline include:

• stomach upset or vomiting
• oral or vaginal thrush
• rash or itching
• nail changes
• mild irritation of the oesophagus (food pipe)
• taste loss
• ringing or other persistent noise in the ears

Serious side effects of doxycycline, which may need urgent medical attention, include:

• increased pressure in the brain (headache, blurred vision, vomiting)
• severe blisters and bleeding in the lips, eyes, mouth, nose and genitals
• severe skin reactions
• difficulty or pain in swallowing
• dizziness
• fast heart rate

Doxycycline can also make your skin more sensitive to sunlight, increasing your risk of sunburn and causing pain. So make sure you protect exposed skin with at least SPF30+ sunscreen, clothing and a hat.

Doxycycline can stain teeth and affect how teeth enamel forms, so it should not be given to children under the age of 8 or women who are more than 16 weeks pregnant (when the baby’s teeth are developing).

Although it is rarer, some people can have an allergic reaction to doxycycline. The reaction can include hives (raised, red and itchy rash), breathing problems and swollen lips, tongue or face. If you’ve ever had allergies to any antibiotics in the past, be sure to tell your doctor. And if you’ve taken doxycycline and are having any difficulties breathing, have someone get you to a hospital emergency department immediately or call triple zero (000) for an ambulance.

This is not a full list of side effects. For more information about the side effects of doxycycline, read Consumer Medicine Information (CMI) for the brand of doxycycline prescribed, or speak to your doctor or pharmacist.

When should I speak to my doctor?

Speak to your doctor if you:

• experience side effects that trouble you
• have signs of an allergic reaction
• have a health condition or are taking medication that may affect how your body reacts to doxycycline
• become pregnant or start breastfeeding

See the CMI for full details about when to speak with your doctor before or after you have started taking doxycycline.

More information

Asking about your treatment or medication is important to help you understand your options. Read our guide to important questions to ask your pharmacist or doctor before taking a medicine.

You can also visit healthdirect's list of medicines that contain doxycycline to read the CMI for the brand of doxycycline prescribed.