Doxycycline

Medically Reviewed By University of Illinois Chicago Drug Information Group Alexandra Perez, PharmD, MBA, BCGP

Doxycycline at a glance

Key highlights to know about doxycycline include:

  • Doxycycline is an antibiotic that is used to treat infections caused by bacteria that are sensitive to doxycycline. It is also used for other reasons, including treating acne, treating the pimples or bumps caused by a condition called rosacea, and preventing malaria while traveling.
  • Doxycycline is administered once or twice per day, with or without food. Administering doxycycline with food or milk may reduce stomach upset.
  • Doxycycline is usually considered a low cost drug, which is defined in this article as costing less than $30 per month. Some forms may be more costly.
  • Some forms of doxycycline are available as generics, but others are only available as brand-name drugs, such as Oracea for rosacea.

Important safety warnings for doxycycline

People who use doxycycline should be aware of these safety warnings:

  • Pregnancy warning: This drug may harm a fetus. Stop administering doxycycline if you become pregnant during therapy.
  • Permanent teeth discoloration warning: This drug may permanently turn a baby’s or child’s teeth a yellow-gray-brown color. Do not administer doxycycline during tooth development (during the last half of pregnancy and from birth to age 8 years). Tooth discoloration has occurred with long-term use and after multiple short courses of treatment.
  • Intestine infection warning: Most antibiotics can cause an infection of the intestines called pseudomembranous colitis. Call your doctor if you have diarrhea or bloody stools.
  • Immune system reactions warning: This drug can cause immune system reactions, such as lupus-like syndrome, hepatitis (inflammation of the liver), and vasculitis (inflammation of the blood or lymph vessels). Stop taking or administering doxycycline if there is joint pain, fever, rash, or body weakness.
  • Discoloration warning: This drug may cause a darkening of the skin, scars, teeth, gums, nails, or whites of the eyes. Some people have experienced darkening right away, or it can happen after long-term use.
  • Benign intracranial hypertension warning: This drug can cause high pressure in the fluid around the brain, which is also called pseudotumor cerebri. Vision changes or permanent vision loss can occur. Stop administering doxycycline and call your doctor if there are any vision changes or unusual headaches.

Talk with your doctor about these warnings in the context of your individual treatment plan and medical history.

What doxycycline treats

This medication is used to:

  • treat various infections caused by bacteria, including infections of the lung, genital system, urinary tract, eye, and gastrointestinal system
    • Doxycycline is sometimes used to treat infections in people who are allergic to another antibiotic called penicillin.
  • treat anthrax infections in the lung after exposure to anthrax particles in the air
  • treat severe acne
  • prevent malaria in some people who travel for less than 4 months to areas where other medications are not effective
  • treat inflammatory lesions (pimples and bumps) of rosacea in adults
    • It does not treat the skin redness associated with rosacea.

Doctors sometimes prescribe medications for different uses. Ask your doctor or pharmacist for information about other uses for this medication.

How it works

Doxycycline is a prescription drug that belongs to a class of antibiotics called tetracyclines. It works by stopping bacteria from making proteins that they need to grow and survive. Doxycycline works against many types of bacteria.

Doxycycline comes in many forms that are administered by mouth, including capsules, tablets, delayed-release tablets, and oral liquid. Some forms of doxycycline are available as generics, but others are only available as brand-name drugs. Some brand names of doxycycline include Vibramycin, Oraxyl, Oracea, Doryx, and Acticlate.

Side effects of doxycycline

Doxycycline side effects are possible and may go away with continued use. Serious side effects are rare.

Common side effects

The more common side effects that occur with doxycycline include:

  • sore throat
  • sinus infection
  • fungal infection
  • flu-like symptoms
  • diarrhea
  • stomach pain or bloating
  • high blood pressure
  • changes in certain blood tests

Serious side effects

Call your doctor right away if you have serious side effects. Seek emergency care (call 911) if you experience life threatening symptoms, such as:

Serious side effects and their symptoms can include the following:

  • Intestine infection. Symptoms can include:
    • diarrhea
    • bloody stools
  • Immune system reactions. Symptoms can include:
  • Benign intracranial hypertension. Symptoms can include:
  • Severe skin reactions. Symptoms can include:
  • Drug-resistant bacteria. Bacteria can become resistant to antibiotics such as doxycycline. If this happens, the bacteria may not be treatable by other antibiotics in the future. Resistance is more likely if doxycycline is not taken exactly as directed by a doctor.
  • Secondary infections. Administering antibiotics can lead to an overgrowth of other infection-causing organisms, including fungi. This can lead to vaginal infections (yeast infections) or other types of secondary infections.
  • Blood cell changes. Symptoms can include:

Other side effects are possible. Talk with your doctor or pharmacist if you have any side effects that bother you or that do not go away.

Costs of doxycycline

Without insurance, doxycycline is typically a low cost drug, which is defined in this article as costing less than $30 per month. However, some forms of doxycycline are only available as brand-name products that may be high cost drugs, which are defined in this article as costing more than $100 per month. You can check the out-of-pocket cash pay price for doxycycline on prescription drug discount websites.

With insurance, prices can vary considerably. Individual health plans may have preferred drugs with better pricing. If the price of doxycycline on your health plan is too expensive, ask your doctor or pharmacist if there is an equivalent drug you can substitute.  

How doxycycline may interact with other medications

Doxycycline may interact with other medications you may be taking, including prescription or over-the-counter drugs, vitamins, and herbal supplements. Either doxycycline or the other medication can be affected and cause serious side effects. 

To help avoid harmful interactions, your doctor should manage all of your medications carefully. Be sure to tell your doctor about all medications, vitamins, or herbal supplements you are taking. To find out how this drug might interact with something else you are taking, talk with your doctor or pharmacist.

This is not a complete list of drugs that may interact with doxycycline. However, examples of drugs that may interact with doxycycline include the following.

Birth control pills

Doxycycline can reduce the effectiveness of birth control pills. This may increase the chance of pregnancy. While taking doxycycline, you may want to use an additional form of birth control, such as a condom.

Blood thinner medications

Bleeding may be more likely when doxycycline is used with blood thinner medications. Lowering the dose of the blood thinner may be necessary. Examples of blood thinner medications include warfarin (Coumadin).

Antiseizure medications

Some antiseizure drugs can decrease levels of doxycycline in the body. Examples of antiseizure medications include:

  • carbamazepine (Carbatrol, Epitol, Equetro, Tegretol, Tegretol-XR, Teril)
  • phenobarbital (Solfoton, Luminal)
  • phenytoin (Dilantin, Phenytek)

Certain antacid medications

Doxycycline may be less effective when used with proton pump inhibitors (PPIs) or antacids that contain aluminum, calcium, or magnesium. Examples of PPIs include:

  • dexlansoprazole (Dexilant)
  • esomeprazole (Nexium, Nexium 24 HR)
  • lansoprazole (Prevacid, Prevacid 24 HR)
  • omeprazole (Prilosec, Prilosec OTC)
  • omeprazole/sodium bicarbonate (Zegerid, Zegerid OTC)
  • pantoprazole (Protonix)
  • rabeprazole (Aciphex)

Examples of antacids that contain aluminum, calcium, or magnesium include:

  • Alka-Seltzer
  • calcium carbonate chewable tablet
  • milk of magnesia
  • Tums

Penicillin-class antibiotics

Doxycycline can reduce the effectiveness of antibiotics in the penicillin class. Avoid administering these medications together. Examples of penicillin-class antibiotics include:

  • amoxicillin (Moxatag)
  • amoxicillin/clavulanate (Augmentin, Augmentin XR)
  • dicloxacillin (Dycill, Dynapen)
  • penicillin V
  • penicillin VK

Iron or bismuth subsalicylate

Doxycycline may be less effective when used with drugs that contain iron or bismuth subsalicylate. Examples of these medications include:

  • bismuth subsalicylate (Pepto-Bismol)
  • ferric citrate (Auryxia)
  • ferrous fumarate (Femiron, Hemocyte)
  • ferrous gluconate (Ferate, Fergon, Simron)
  • ferrous sulfate (Feosol, Slow Release Iron)

Retinoids

Medications called retinoids that are taken by mouth can have the same effect as doxycycline on increasing the pressure of the fluid around the brain, or pseudotumor cerebri. Avoid using these medications together. Examples of retinoids taken by mouth include isotretinoin (Absorica, Zenatane, Myorisan) and acitretin (Soriatane, Soriatane CK).

Disclaimer: Since drugs interact differently in each person, this information is not guaranteed to include all possible interactions. This information is not a substitute for medical advice. Always speak with your healthcare professional about possible interactions with all prescription drugs, vitamins, herbal supplements, and over-the-counter drugs you are taking.

Other doxycycline alerts

This drug comes with several alerts and warnings.

Allergy warning

This drug can cause a severe allergic reaction. Symptoms include:

Call your doctor right away if you have serious side effects. Seek emergency care (call 911) if you experience life threatening symptoms, such as:

  • difficulty breathing
  • chest pain
  • a loss of consciousness
  • sudden vision changes
  • swelling of the face, mouth, tongue, or throat

Do not take this drug again if you have ever had an allergic reaction to it or to other tetracycline antibiotics. Taking it again could cause death.

Diarrhea warning

Antibiotics can commonly cause diarrhea that ends when the antibiotics are stopped. Diarrhea that occurs later, as late as 2 months after stopping the antibiotic, may indicate an intestinal infection. Call your doctor if you have watery or bloody stools, stomach cramps, or fever.

Warnings for other groups

This drug should not be used in infants or children younger than 8 years of age because it can cause stained teeth in children whose teeth are developing.

For pregnant and breastfeeding people

Doxycycline may harm the fetus. Tell your doctor if you are pregnant or plan to become pregnant. Doxycycline can pass into breast milk. You and your doctor can decide if you will take doxycycline or breastfeed, as you should not do both.

Can I take doxycycline when pregnant?

Doxycycline may harm a fetus, especially if taken for longer periods of time. Short-term use (such as for an infection) may be less likely to cause harm, but doxycycline administered during pregnancy has caused serious effects on the growth of bone and teeth. Stop taking doxycycline and contact your doctor if you become pregnant while taking doxycycline.

If you are a male taking doxycycline for rosacea, do not take doxycycline if you are with a female sexual partner who plans to become pregnant.

Can I take doxycycline when breastfeeding?

Doxycycline can pass into breast milk, which may harm your baby. Talk with your doctor about the best way to feed your baby if you are taking doxycycline. You may need to decide whether to stop breastfeeding or stop administering this medication. Breastfeeding is not recommended during treatment and for 5 days after stopping treatment.

How and when to take doxycycline

This drug is administered by mouth. Administer doxycycline with enough fluid to completely swallow the capsule. This will lower your risk of irritation and the development of ulcers in your esophagus (the tube that connects your mouth to your stomach).

Administration with food or milk may reduce stomach upset. Doxycycline is not affected by administration with food or milk.

The oral liquid form of doxycycline contains sodium metabisulfite, which can cause allergic reactions in some people. People who have asthma may be more likely to react. Allergic reactions can be mild, causing symptoms such as difficulty breathing, or severe, causing life threatening reactions.

Oral liquid forms must be shaken well before administration.

Some tablet forms of doxycycline can be broken at the scored lines to provide smaller doses. Other tablet forms should not be crushed or chewed. Capsule forms of doxycycline should be swallowed whole. Do not break, open, crush, dissolve, or chew the capsules.

Doryx tablets can be broken and the contents sprinkled on a spoonful of cool (not hot) applesauce. Do not chew or crush the tablets. The entire applesauce mixture must be swallowed immediately without chewing and followed with a glass of water.

Even if you start to feel better when taking doxycycline for an infection, continue taking doxycycline for the full number of days prescribed by your doctor. Skipping doses or not finishing the full treatment course can make doxycycline less effective for your infection or lead to bacteria that are not treatable by antibiotics in the future.

All possible dosages and forms of doxycycline may not be included here. Your dose, your form, and how often you take doxycycline will depend on:

  • your age
  • the condition being treated
  • the severity of your condition
  • other medical conditions you have
  • how you react to the first dose

Drug forms and strengths

The sections below look at different forms and strengths of doxycycline.

Doxycycline monohydrate

  • Form: capsule
  • Strengths:
    • 50 milligrams (mg)
    • 75 mg
    • 100 mg
    • 150 mg
  • Form: capsule (for rosacea)
  • Strengths:
    • 40 mg
  • Form: tablet
  • Strengths:
    • 50 mg
    • 75 mg
    • 100 mg
    • 150 mg
  • Form: oral suspension
  • Strengths:
    • 25 mg per milliliter (ml)

Doxycycline hyclate

  • Form: capsule
  • Strengths:
    • 50 mg
    • 75 mg
    • 100 mg
  • Form: tablet
  • Strengths:
    • 20 mg
    • 50 mg
    • 75 mg
    • 100 mg
    • 150 mg
  • Form: delayed-release tablet
  • Strengths:
    • 50 mg
    • 75 mg
    • 80 mg
    • 100 mg
    • 120 mg
    • 150 mg
    • 200 mg

Doxycycline calcium

  • Form: oral suspension
  • Strengths:
    • 50 mg/5 ml

Dosage for infection

  • For adults ages 18 years and above:
    • The typical dosage is 100 mg every 12 hours for the first day, followed by 100 mg once or twice per day for 7–14 days.
    • For more severe infections, 100 mg every 12 hours may be needed for the entire treatment course.
  • For children who weigh under 45 kilograms (kg):
    • Initial and subsequent doses are based on body weight.

Dosage for rosacea

  • For adults ages 18 years and above:
    • The typical dosage is 40 mg once daily in the morning on an empty stomach. Administer doxycycline at least 1 hour before or 2 hours after a meal.
    • It is not known if doxycycline is effective for use longer than 16 weeks or safe for use longer than 9 months.

Dosage for preventing malaria

  • For adults ages 18 years and above:
    • The typical dosage is 100 mg daily.
    • If you are taking doxycycline to prevent malaria while traveling, administer starting 1–2 days before travel. Continue administering daily while in the area and for 4 weeks after leaving the area.
    • Do not take doxycycline to prevent malaria for longer than 4 months.
  • For children dosage ages 8 years and above:
    • Initial and subsequent doses are based on body weight.
    • If you are taking doxycycline to prevent malaria while traveling, administer starting 1–2 days before travel. Continue administering daily while in the area and for 4 weeks after leaving the area.
    • Do not take doxycycline to prevent malaria for longer than 4 months.

Dosage for preventing anthrax after exposure to particles in the air

  • For adults ages 18 years and above:
    • The typical dosage is 100 mg twice daily for 60 days.
  • For children who weigh under 45 kg:
    • Initial and subsequent doses are based on body weight.

If you miss a dose of doxycycline

Your doctor will tell you what to do if you miss a dose of this medication. Different people may handle missed doses in different ways based on why they are taking the drug.

If you take too much doxycycline

If you take too much doxycycline, you have a higher risk of having side effects caused by this drug. If you think you have taken too much of this drug, call your doctor or local poison control center at 800-222-1222.

Seek emergency care (call 911) if you experience life threatening symptoms, such as:

  • difficulty breathing
  • chest pain
  • a loss of consciousness
  • sudden vision changes
  • swelling of the face, mouth, tongue, or throat

Helpful tips when taking doxycycline

Keep these considerations in mind if your doctor prescribes doxycycline for you.

General

  • Doxycycline can make you more sensitive to sunlight and cause severe sunburn. Avoid sunlight, tanning booths, sunlamps, and UVA/B treatment while administering doxycycline. Use sunscreen or clothes that cover your skin if you must be out in the sunlight.

Storage

  • Store this drug at room temperature between 59ºF and 86°F (15°C and 30°C).
  • Store this drug in a tightly closed container.
  • Keep this drug away from light.
  • Do not store this medication in moist or damp areas, such as bathrooms.
  • Do not use doxycycline that is out of date or has not been stored properly.
  • Unused portions of doxycycline oral liquid forms should be discarded after 2 weeks.

Alcohol

There are no known interactions between doxycycline and alcohol. If you are concerned about taking doxycycline while drinking alcohol, talk with your doctor.

Refills

Your doctor will write the number of authorized refills on your prescription. Talk with your pharmacist if you have questions about refills.

If you are taking doxycycline for an infection, you may only need a single course of treatment. In this case, you will not need any refills.

Travel

When planning to travel, keep these tips in mind for packing your medication.

  • Bring enough medication for the full number of days of your trip, plus at least 2 days to be safe.
  • When flying, keep your medication with you. Do not put it into a checked bag in case you are separated from your luggage.
  • Liquid, gel, cream, and aerosol medications are exempt from the 3-1-1 liquid rule for flying.
  • Keep your medications in their original containers, if possible, to reduce delays during airport or security screening. Keep all your medications together to quicken the process.
  • Avoid leaving your medication in a parked car for extended periods to protect it from extreme temperatures.

Clinical monitoring

  • Your doctor may order blood tests to check for side effects of doxycycline.
  • Doxycycline may interfere with some urine tests. Before you have a urine test, tell your doctor if you are taking doxycycline.
  • Doxycycline can increase levels of a marker of kidney function called blood urea nitrogen. This may be more likely with higher doses. This usually happens in people without kidney problems.

Availability

Not every pharmacy stocks every form of doxycycline. When filling your prescription, be sure to call ahead to make sure your pharmacy carries the form your doctor prescribes.

Prior authorization

Some insurance companies may require a prior authorization for this drug. This means that your doctor will need to get approval from your insurance company before your insurance company will pay for the prescription.

Medications similar to doxycycline

Doxycycline is an antibiotic from the tetracycline class. Other tetracycline antibiotics include demeclocycline, tetracycline (Achromycin V), and minocycline (Dynacin, Minocin).

Discontinuing use of doxycycline

Do not stop taking this drug unless instructed by your doctor.

Healthgrades disclaimer

This information is for educational purposes only. It should not be interpreted as medical advice, diagnosis, or treatment. Healthgrades takes every effort to ensure this information is accurate and up to date. This content is not intended to cover all possible uses, side effects, warnings, precautions, allergic reactions, or drug interactions. Do not assume that the absence of such information means the medication is safe for your personal use. Always consult your doctor, pharmacist, or healthcare professional before taking or discontinuing any medication.

Medical Reviewers: University of Illinois Chicago Drug Information Group Alexandra Perez, PharmD, MBA, BCGP
Last Review Date: 2021 Jul 13
THIS TOOL DOES NOT PROVIDE MEDICAL ADVICE. It is intended for informational purposes only. It is not a substitute for professional medical advice, diagnosis or treatment. Never ignore professional medical advice in seeking treatment because of something you have read on the site. If you think you may have a medical emergency, immediately call your doctor or dial 911.