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Last reviewed on RxList: 3/14/2017
Doryx Side Effects Center

Medical Editor: John P. Cunha, DO, FACOEP

Last reviewed on RxList 03/14/2017

Doryx (doxycycline hyclate) is a tetracycline antibiotic used to treat or prevent infections with bacteria either proven or strongly suspected to be susceptible to this drug. Doryx is used to treat many types of infections such as acne, plague, cholera, relapsing fever, anthrax, syphilis, and many others. Doryx is available in generic form. Common side effects of Doryx include:

  • nausea,
  • vomiting,
  • upset stomach,
  • diarrhea,
  • skin rash or itching,
  • vaginal itching or discharge, and
  • dizziness.

Contact your doctor if you have serious side effects of Doryx including:

  • fever,
  • bloody or watery diarrhea,
  • fast heart rate,
  • jaundice (yellowing of skin or eyes),
  • severe skin reaction or rash,
  • swelling of the throat/face/tongue,
  • GI overgrowth by Clostridium difficile,
  • fever,
  • headache, and
  • renal problems.

Doryx is available in 75 and 100 mg strength tablets. The usual dose is 100 mg twice daily in adults on day one, then 100 mg daily. Doses in children (age 8 and above) is based on weight. Drugs in the tetracycline class may cause permanent discoloration of teeth (yellow-brown) if used in the last half of pregnancy, infancy to the age of eight years. There are no adequate and well-controlled studies on the use of doxycycline in pregnant women. Doryx passes into breast milk and may affect bone and tooth development in a nursing baby. Breastfeeding while taking Doryx is not recommended.

Our Doryx Side Effects Drug Center provides a comprehensive view of available drug information on the potential side effects when taking this medication.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Doryx Consumer Information

Get emergency medical help if you have any of these signs of an allergic reaction: hives; difficulty breathing; swelling of your face, lips, tongue, or throat.

Call your doctor at once if you have a serious side effect such as:

  • severe headache, dizziness, blurred vision;
  • fever, chills, body aches, flu symptoms, swollen glands, rash or itching, joint pain, or general ill feeling;
  • urinating less than usual or not at all;
  • diarrhea that is watery or bloody
  • pale or yellowed skin, dark colored urine, fever, confusion or weakness;
  • severe pain in your upper stomach spreading to your back, nausea and vomiting, fast heart rate;
  • loss of appetite, jaundice (yellowing of the skin or eyes); or
  • severe skin reaction -- fever, sore throat, swelling in your face or tongue, burning in your eyes, skin pain, followed by a red or purple skin rash that spreads (especially in the face or upper body) and causes blistering and peeling.

Less serious side effects may include:

  • mild nausea, mild diarrhea;
  • upset stomach;
  • mild skin rash or itching; or
  • vaginal itching or discharge.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Read the entire detailed patient monograph for Doryx (Doxycycline Hyclate)

Doryx Professional Information


Due to oral doxycycline's virtually complete absorption, side effects to the lower bowel, particularly diarrhea, have been infrequent. The following adverse reactions have been observed in patients receiving tetracyclines:

Gastrointestinal: Anorexia, nausea, vomiting, diarrhea, glossitis, dysphagia, enterocolitis, and inflammatory lesions (with monilial overgrowth) in the anogenital region. Hepatotoxicity has been reported. These reactions have been caused by both the oral and parenteral administration of tetracyclines. Rare instances of esophagitis and esophageal ulcerations have been reported in patients receiving capsule and tablet forms of drugs in the tetracycline-class. Most of these patients took medications immediately before going to bed (see DOSAGE AND ADMINISTRATION).

Skin: Maculopapular and erythematous rashes, Stevens-Johnson syndrome, toxic epidermal necrolysis, and erythema multiforme have been reported. Exfoliative dermatitis has been reported but is uncommon. Photosensitivity is discussed above (see WARNINGS).

Renal toxicity: Rise in BUN has been reported and is apparently dose-related (see WARNINGS).

Hypersensitivity reactions: Urticaria, angioneurotic edema, anaphylaxis, anaphylactoid purpura, serum sickness, pericarditis, and exacerbation of systemic lupus erythematosus.

Blood: Hemolytic anemia, thrombocytopenia, neutropenia, and eosinophilia have been reported.

Intracranial Hypertension: Intracranial hypertension (IH, pseudotumor cerebr) has been associated with the use of tetracyclines (see WARNINGS).

When given over prolonged periods, tetracyclines have been reported to produce brown-black microscopic discoloration of thyroid glands. No abnormalities of thyroid function are known to occur.

Read the entire FDA prescribing information for Doryx (Doxycycline Hyclate)

Related Resources for Doryx

Read the Doryx User Reviews »

© Doryx Patient Information is supplied by Cerner Multum, Inc. and Doryx Consumer information is supplied by First Databank, Inc., used under license and subject to their respective copyrights.

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