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Generic Name

tetracycline (tet trah SI kleen)


What is tetracycline?

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


What is it used for?

Tetracycline is used for many different bacterial infections. When used with other antibiotics it can cure the stomach infection called Helicobacter pylori gastritis.


How do I take it?

Follow your physician’s instructions carefully. For best absorption take on an empty stomach at least 1 hour before or 2 hours after meals. To prevent stomach upset, you may take it with food. Take it at the same time each day with a full glass of water. The tablets may be crushed or the capsule may be opened and the medication sprinkled on soft food to make it easier to swallow. As with all antibiotics, be sure to take the full prescribed dose. Store capsules in a tightly sealed container away from light at room temperature. Liquid must be refrigerated but not frozen. Keep all medications away from children. Never share your medications with anyone else.


What do I do for a missed dose?

Tetracycline, like all antibiotics, works best when there is a steady blood level. Therefore, it is necessary to take this medication at even intervals and avoid missing doses. If you should miss a dose, take it as soon as you remember. If it is almost time for your next dose and you take the medication once a day, take the missed dose and then take the next dose 10 to 12 hours later. If you are to take this medication twice a day, take the missed dose and then take the next one 5 to 6 hours later. If you are prescribed 3 or more doses per day, take the one you missed and then take the next one 2 to 4 hours later, then return to your regular schedule.


Are there interactions with food or beverages?

Tetracycline should be taken on an empty stomach. Avoid cheese, yogurt, milk, ice cream, iron-fortified cereals and supplements, and meats for 2 hours before or after taking this drug. There is no interaction with alcohol.


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:

  • insulin
  • blood thinners (Coumadin)
  • digoxin (Lanoxin)
  • lithium (Eskalith)
  • furosemide (Lasix)
  • theophylline (Theo-Dur)
  • cholestyramine (Questran)
  • sucralfate (Carafate)
  • cimetidine (Tagamet)
  • irth control pills
  • penicillins
  • antacids
  • calcium or iron 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. Since the drug is metabolized by the kidney, patients with severe chronic kidney disease or on dialysis should discuss its use with the physician. If the kidneys are not working properly, even the usual dose of tetracycline may damage the liver.


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 tetracycline if there has been a previous reaction to this or a similar drug such as doxycycline or minocycline.


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. Tetracycline is ranked D. Always consult your physician before taking any drug during or when planning pregnancy.


What are the effects on sexual function?

Tetracycline can decrease the effectiveness of birth control pills. Additional contraceptive protection may be necessary while taking this medication.


Are there other precautions?

  • The use of tetracycline is not recommended in children under 8 or pregnant women because it can cause permanent discoloration of the teeth.
  • Some tetracyclines may cause photosensitivity, making you more prone to a sunburn.
  • Never take outdated tetracycline as it is very damaging to the kidneys.
  • The use of antibiotics, especially prolonged or repeated courses may result in fungal infection. These are usually due to yeast organisms and occur in the mouth, intestinal tract, rectum or vagina.
  • Troublesome and persistent diarrhea can develop in sensitive individuals. If diarrhea persists for more than 24 hours, discontinue the medication and contact your physician.


How long is it safe to take tetracycline?

Tetracycline, as well as other antibiotics, should be taken for the full prescribed dose. Long-term use for months to years, while generally safe, requires periodic physician evaluation.


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 tetracycline, the following are the observed side effects:


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


  • yellow color to skin or eyes
  • swollen joints or lymph glands
  • severe diarrhea


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.