Doxycycline, Avidoxy

Introduction

Written by Patricia Weiser, PharmD
Medically reviewed by Brittany A. Duke, PharmD, RPh
Updated on August 25, 2023

Doxycycline (doks i SYE kleen) is a generic medication prescribed for treating acne and certain bacterial infections in adults and some children. It’s also prescribed to help prevent malaria. Doxycycline belongs to a group of drugs called tetracycline antibiotics.

These approved uses differ based on the form of doxycycline your doctor prescribes.

This article doesn’t provide coupons for all forms of doxycycline. To find coupons for doxycycline oral capsule, see this article. For coupons for doxycycline delayed-release oral tablet, see this article.

Common questions about doxycycline

Below you’ll find answers to a few commonly asked questions about doxycycline.

What is the difference between doxycycline hyclate and doxycycline monohydrate?

There are no major differences between doxycycline hyclate and doxycycline monohydrate. Both drugs are used to treat the same conditions. They also contain the same active ingredient: doxycycline. (An active ingredient is what makes a drug work.)

“Hyclate” and “monohydrate” are inactive salts. At the chemical level, active ingredients often must be attached to an inactive salt in order for your body to use them. But inactive salts do not affect how well the active ingredient works.

If you’d like to know more about this, talk with your pharmacist.

How does doxycycline work? And how long does it take to start working?

Doxycycline is a type of antibiotic. Doctors prescribe it to treat certain bacterial infections and to help prevent malaria. It works by stopping bacteria from growing. It does this by binding to proteins that bacteria depend on to grow.

Doctors also prescribe doxycycline to treat acne. It works by stopping the growth of bacteria that can be a factor in acne symptoms. Doxycycline also has anti-inflammatory effects that help reduce acne symptoms.

How long doxycycline takes to start working depends on the condition it’s being prescribed to treat or prevent.

How long doxycycline takes to treat bacterial infections depends on the type and severity of your infection. Be sure to follow your doctor’s instructions carefully. Even if you feel better, finish the full course of medication. Stopping the drug too early may make the bacteria resistant to doxycycline or other antibiotics. This can make the infection come back even worse and be more difficult to treat.

To help treat acne, it may take a couple of weeks of doxycycline treatment before you notice a difference in your symptoms.

To help prevent malaria, the drug starts working within 1–2 days. You’ll need to continue taking it while traveling and for several weeks after leaving the area where malaria is common. Be sure to follow your doctor’s instructions.

If you’d like to know more about this, talk with your doctor or pharmacist.

Side effects of doxycycline

Doxycycline may cause mild or serious side effects. More common mild side effects of doxycycline and its serious side effects are listed below. This article doesn’t include all possible side effects of the drug. Side effects can vary based on your age, overall health, and any other medications you take.

To learn more about doxycycline’s side effects, see this article or ask your doctor or pharmacist. You can also refer to the prescribing information for doxycycline listed in the “Resources” section.

Mild side effects

More common mild side effects reported with some forms of doxycycline are listed below. These side effects may differ based on the form of doxycycline you take.

This article doesn’t include all possible mild side effects of the drug. To learn more about doxycycline’s side effects based on the form, refer to the prescribing information for doxycycline listed in the “Resources” section.

With many drugs, mild side effects may go away within a few days or a couple of weeks. If the side effects bother you, tell your doctor or pharmacist. They may be able to suggest ways to manage them.

Mild side effects of doxycycline, including doxycycline oral capsule, include:

• nausea
• vomiting
• skin sensitivity to sunlight
• tooth discoloration*
• mild allergic reaction†

* This side effect may be permanent in children whose teeth are still developing. In adult teeth, this discoloration is usually temporary or can be removed with a professional dental cleaning.
† For details about this side effect, see the “Interactions and warnings for doxycycline” section.

Serious side effects

Serious side effects of doxycycline are listed below. These side effects may differ based on the form of doxycycline you take.

This article doesn’t include all possible serious side effects of the drug. To learn more about doxycycline’s side effects based on the form, refer to the prescribing information for doxycycline listed in the “Resources” section.

With many drugs, serious side effects are possible but not common. If you have serious side effects from this drug, call your doctor right away. If you’re having severe symptoms or a medical emergency, call 911 or a local emergency number.

In general, doxycycline’s serious side effects include:

• severe diarrhea due to Clostridioides difficile bacteria
• high blood pressure in the skull, which may cause vision problems or vision loss
• pancreatitis
• liver problems
• blood disorders, such as anemia
• severe allergic reaction*

For doxycycline oral capsule or tablet, the following serious side effects also may occur:

• irritation or ulcers in your esophagus (the tube between your mouth and stomach), especially if you swallow a dose right before going to bed

* For details about this side effect, see the “Interactions and warnings for doxycycline” section.

Uses of doxycycline

The Food and Drug Administration (FDA) approves prescription drugs such as doxycycline for certain conditions. Approved uses for doxycycline are described below. These uses differ based on the form of doxycycline prescribed.

Use for certain bacterial infections

Doctors may prescribe doxycycline for treating certain bacterial infections. It’s used for this purpose in children ages 8 years and older and adults. It’s usually prescribed as a short-term treatment.

For this purpose, doctors may prescribe doxycycline oral tablets, oral capsules, or oral suspension (a type of liquid mixture). In some cases, such as if you’re receiving treatment in a hospital, they may give you doxycycline injection as an intravenous (IV) infusion (an injection given into your vein over time).

Bacterial infections can range from mild to severe. The symptoms depend on the type of infection. Examples of bacterial infections that doxycycline may be used to treat include:

• infections of the gums, urinary tract, respiratory tract, digestive tract, skin, and eyes that are caused by certain types of bacteria
• certain sexually transmitted infections (STIs), such as gonorrhea, chlamydia, and syphilis
• Rocky Mountain spotted fever
• anthrax infection

To determine whether doxycycline is the right choice to treat your specific infection, your doctor may order culture and sensitivity tests. These tests involve taking a tissue or fluid sample, growing the bacteria in a lab, and testing different antibiotics against the bacteria.

Use for acne

Doctors may prescribe doxycycline oral tablets, oral capsules, or oral suspension (a type of liquid mixture) for treating severe acne. It’s used for this purpose in children ages 8 years and older and adults. It’s usually prescribed as a long-term treatment.

With severe acne, you have pimples and nodules on your skin. These are bumps that appear red, discolored, or inflamed. Acne occurs when bacteria, oil, and dead skin cells clog your pores. Acne commonly affects the face, neck, back, and chest.

Doxycycline is usually prescribed together with other medications for treating acne. Examples include tretinoin topical cream (Retin-A) and clindamycin topical gel (Cleocin T). (A topical medication is applied directly to the affected area of your skin.)

Use for malaria prevention

Doctors may prescribe doxycycline oral tablets, oral capsules, or oral suspension (a type of liquid mixture) to help prevent malaria. It’s used for this purpose in children ages 8 years and older and adults. It’s usually prescribed as a short-term treatment.

Malaria is a disease caused by a germ called Plasmodium falciparum. It’s transmitted through the bites of mosquitoes that are infected with this germ. Malaria is more common in certain areas of the world, such as tropical regions.

Doctors may prescribe doxycycline for people traveling to at-risk areas. Specifically, this drug is used when malaria in that area is known to be resistant to certain other drugs. (When an infection is resistant, it means that certain drugs don’t work to treat or help prevent it.)

Interactions and warnings for doxycycline

Below, you’ll find information about doxycycline’s possible interactions and warnings.

Interactions of doxycycline

Certain things may affect how a drug works. These include getting vaccines, consuming alcohol or certain foods, or taking the drug with other medications. This effect is called a drug interaction.

Before you start doxycycline, ask your doctor to check for possible interactions. Be sure to tell them about any of the following you take or use:

• prescription or over-the-counter drugs
• vitamins, herbs, or supplements

To learn about drug-condition interactions, see the “Warnings for doxycycline” section below.

Warnings for doxycycline

Some people should not take doxycycline, and others should use it cautiously.

Doxycycline could cause harm to people with certain health conditions. This effect is called a drug-condition interaction. Other factors can also affect whether doxycycline is a safe option for you. These warnings may differ based on the form of doxycycline you take or use.

Ask your doctor about specific warnings for doxycycline, and be sure to tell your doctor about your:

• current health, including any allergies to medications
• past health conditions or surgeries

Allergic reaction

Doxycycline can cause an allergic reaction in some people. Severe allergic reactions are rare but possible.

If you’ve had an allergic reaction to doxycycline or any of its ingredients, your doctor will likely not prescribe doxycycline. They can tell you about medications that are safer options for you.

A mild allergic reaction may cause the following symptoms:

• skin rash
• itchiness
• flushing (temporary warmth, redness, or deepening of skin color)

A severe allergic reaction may cause the following symptoms:

• swelling under your skin, usually in your hands, feet, eyelids, or lips
• swelling of your mouth, throat, or tongue, which can cause breathing problems

If you have an allergic reaction to doxycycline, call your doctor right away. If you have severe symptoms, call 911 or a local emergency number.

Overdose of doxycycline

If you take doxycycline by mouth, you should not take more than your doctor prescribes. For some drugs, doing so may lead to harmful effects or overdose.

If you think you’ve taken too much doxycycline, call your doctor or pharmacist right away. Or you could call 800-222-1222 to speak with someone at America’s Poison Centers. You can also use its online resource. If you have concerning symptoms, call 911 or a local emergency number immediately. You can also go to the closest emergency room.

Pregnancy or breastfeeding and doxycycline

Information about doxycycline and pregnancy and breastfeeding is described below.

Doxycycline and pregnancy

It’s not known whether doxycycline should be taken during pregnancy. There are risks to taking doxycycline during pregnancy. For instance, doxycycline may result in tooth discoloration (yellow, gray, or brown) in a child. This side effect can be permanent. If you’re planning a pregnancy or can become pregnant, talk with your doctor before taking this medication.

Doxycycline and breastfeeding

There may be risks to taking doxycycline while breastfeeding. But there are also risks with having untreated infections during this time. (Keep in mind that doxycycline is used for treating certain bacterial infections.)

For instance, doxycycline may cause tooth discoloration (yellow, gray, or brown) in a breastfed child. This side effect can be permanent in teeth that are still developing.

If you’re planning to breastfeed, talk with your doctor about treatment options for your specific infection. Together, you can discuss the risks and benefits of your treatment options and decide whether or not you should take doxycycline. Your doctor may recommend other healthy ways to feed your child during doxycycline treatment.

What to ask your doctor

Let your doctor know if you have questions about doxycycline or would like more details about it.

Here’s a list of some possible questions you may want to ask your doctor:

• How long will I need to take doxycycline?
• Should I take a probiotic during doxycycline treatment?
• Does doxycycline interact with any other medications or supplements I’m taking?

Resources

• Doxycycline- doxycycline capsule. (2022). https://nctr-crs.fda.gov/fdalabel/services/spl/set-ids/fa1da527-7a0f-8ed6-e053-6394a90a1b62/spl-doc
• Doxycycline for oral suspension. (2022). https://nctr-crs.fda.gov/fdalabel/services/spl/set-ids/3e7cf78f-3b48-4614-9fa4-c6d1e0c05a35/spl-doc
• Doxycycline hyclate capsules. (2023). https://nctr-crs.fda.gov/fdalabel/services/spl/set-ids/f33ae6f5-bdb6-4c15-9e62-6180433bb1fb/spl-doc
• Doxycycline hyclate delayed-release tablets, for oral use. (2023). https://nctr-crs.fda.gov/fdalabel/services/spl/set-ids/3ae4ca12-be39-46b9-bc4c-f8356776c175/spl-doc
• Doxycycline hyclate tablet, film coated. (2020). https://nctr-crs.fda.gov/fdalabel/services/spl/set-ids/3af9348c-a98b-4059-a5ef-4229e2b33af0/spl-doc
• Doxycycline injection, powder, lyophilized, for solution. (2021). https://nctr-crs.fda.gov/fdalabel/services/spl/set-ids/6a5780a9-4548-427c-972a-ef49fdcbc84d/spl-doc
• Doxycycline monohydrate tablet, film coated. (2020). https://nctr-crs.fda.gov/fdalabel/services/spl/set-ids/f91373f2-c57b-f1f1-e053-6294a90a7bdd/spl-doc
• Food and Drug Administration. (2023). Orange Book: Approved drug products with therapeutic equivalence evaluations. https://www.accessdata.fda.gov/scripts/cder/ob/index.cfm

Disclaimer: Optum Perks has made every effort to make certain that all information is factually correct, comprehensive, and up to date. However, this article should not be used as a substitute for the knowledge and expertise of a licensed healthcare professional. You should always consult your doctor or another healthcare professional before taking any medication. The drug information contained herein is subject to change and is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. The absence of warnings or other information for a given drug does not indicate that the drug or drug combination is safe, effective, or appropriate for all patients or all specific uses.