Use the search bar to find a specific medication or choose the first letter in the sidebar on the right.


Generic Name

doxycycline (dox ee SI kleen)


Trade Name

Vibra-Tabs(50 mg, 100 mg)
Vibramycin is also available as an Oral Suspension or a Syrup. This drug is available in a generic form.


What is doxycycline?

This drug is an antibiotic which kills bacteria and clears up infection within the body.


What is it used for?

Doxycycline is used for many different bacterial infections. In gastroenterology it is often used to prevent or treat travelers diarrhea which is caused by an E. Coli bacterial strain.


How do I take it?

Follow your physician’s instructions carefully. Take doxycycline with a full glass of water or other liquid to avoid irritating your esophagus (food pipe). Doxycycline can be taken with or without food. If it upsets your stomach, you may want to take it with a glass of milk or after you have eaten. Take dosages at approximately the same time each day. As with all antibiotics, be sure to take the full prescribed dose. Doxycycline should be stored at room temperature away from light and excessive heat. Keep all medications away from children. Never share your medications with anyone else.


What do I do for a missed dose?

If you miss a dose, take it as soon as you remember. If it is almost time for the next dose and you take just one dose a day, take the missed dose and take the next one 10 to 12 hours later. If you take 2 doses a day, take the missed one and then take the next one 5 to 6 hours after the missed dose. If you are taking 3 doses a day, take the missed one and then take the next one 2 to 4 hours after the missed dose and then return to your regular schedule.


Are there interactions with food or beverages?

Avoid meats, iron-fortified cereals and iron supplements for 2 hours before and after taking this drug. There are no interactions with alcohol, but combining doxycycline and alcohol should be avoided if you have active liver disease.


Are there interactions with other drugs?

An interaction generally means that one drug may increase or decrease the effect of another drug. Also, the more medications a person takes, the more likely there will be a drug interaction.

Interactions with this drug may occur with the following:

  • blood thinners (Coumadin)
  • digoxin (Lanoxin)
  • lithium (Eskalith)
  • carbamazepine (Tegretol)
  • phenytoin (Dilantin)
  • cimetidine (Tagamet)
  • barbiturates (phenobarbital)
  • birth control pills
  • antacids
  • penicillins
  • iron, mineral or calcium supplements


Is there a problem if I have another disorder or disease?

At times, a drug may have a different or enhanced effect when other diseases are present. At other times, the drug may worsen or effect another disease.

With this drug, the following disorders may be a problem:

  • severe chronic liver disease (cirrhosis)
  • systemic lupus erythematosus
  • Steven’s-Johnson Syndrome


What about allergies?

People who have known allergies or asthma may be at an increased risk for a reaction from any new medication. The physician should always know a patient’s allergy history. Signs of an allergic reaction are skin rash, hives and itching. Of course, a person should not take doxycycline if there has been a previous reaction to this or a similar drug such as tetracycline.


What if I’m pregnant, considering pregnancy or breast-feeding?

Most females now know that, if possible, no drug, including alcohol, should be taken during pregnancy or lactation. The potential danger, of course, is an injury to the baby. However, some drugs are much safer than others in this regard. So, the FDA has a grading system for each drug which reflects what is known medically. It ranks drugs from A, where medical studies show no evidence for danger to the fetus or mother, to B, C, D and X, where the medical evidence indicates that the risk to the fetus outweighs any benefit to the mother. Doxycycline is ranked D. Always consult your physician before taking any drug during or when planning pregnancy.


What are the effects on sexual function?

Birth control pills may not be as effective while you are taking doxycycline. A supplemental form of birth control is recommended during antibiotic therapy.


Are there other precautions?

  • Doxycycline is not recommended in children under 8 or pregnant women because it can cause a permanent discoloration of the teeth (yellow-gray-brown).
  • Doxycycline may cause photosensitivity making you more prone to a sunburn.
  • Never take outdated doxycycline because it may be toxic to the kidneys.
  • Troublesome and persistent diarrhea can develop in some individuals. If diarrhea develops and persists for more than 24 hours, discontinue the medication and contact your physician.
  • Prolonged or repeated use of antibiotics may result in fungal infection. These are usually due to yeast organisms and occur in the mouth, intestinal tract and vagina.


How long is it safe to take doxycycline?

This drug, as well as other antibiotics, should be taken for the full prescribed dose. Long-term use for months or years, while generally safe, requires periodic evaluation by a physician.


How about side effects?

Adverse reactions can occur with any drug, even over-the-counter medications. Some of these are mild such as a stomach upset, which may be avoided by taking the medication with food. Minor reactions may go away on their own but if they persist, contact the physician. For major reactions, the patient should contact the physician immediately.

For doxycycline, the following are the observed side effects:


  • discoloration and soreness of tongue
  • nausea
  • stomach irritation
  • vomiting
  • diarrhea
  • itching of genital or rectal area


  • yellow color to skin or eyes
  • swollen joints or lymph nodes


A physician’s comment…

Most antibiotics taken by mouth are fairly safe. However, resistance to these drugs does occur when they are used too often. Therefore, they should only be used for specific purposes and for the length of time decided by the physician.