EPT Trichomoniasis

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What Is Trichomoniasis?

Trichomoniasis (trick oh moh NY ah siss) is one of the most common sexually transmitted infections (STI). It is caused by a parasite called Trichomonas vaginalis. The infection can happen to both men and women.



Some males have a slight mucus-like discharge from the penis.  Some have pain or burning when they urinate. Most males have no symptoms. Men can carry the germs and can pass them to their partners during sexual contact.


Females may have:

  • Doamy, greenish-yellow discharge from the vagina
  • Itching, redness and irritation in the genital area
  • Pain or burning when they urinate

Some women have no symptoms, even though they carry the germs that cause Trichomoniasis.

Testing for Trichomoniasis


A urine sample is taken to test for Trichomoniasis.


If no symptoms are present, a urine sample or vaginal sample may be taken to test for Trichomoniasis.

If you do have symptoms, the doctor or nurse practitioner will examine your vaginal area. They will take a sample of your discharge and test it for Trichomoniasis.

Preventing Future Infection

  • Respect yourself and your partner.
  • Limit the number of sexual partners. Know your partner and his or her sexual history.
  • ALWAYS USE A LATEX CONDOM. Use it correctly.  Use it every time you have sex, the whole time you have sex. 
  • Be prepared.  Have another condom available in case the one you are using breaks.
  • All sexually active teens should be tested for STIs at least once a year even if there are no symptoms.

Treatment: Metronidazole

You received a prescription for a medicine to treat this infection.  It is called metronidazole. This medicine is an antibiotic.  It treats Trichomoniasis by killing the organism that causes the infection. This prescription can be filled at any pharmacy. Even though you are being given this medicine, you should see a doctor as soon as possible. 

People can have more than one infection at the same time.  Metronidazole will not cure other infections. You need to get tested for other sexually transmitted infections. Having an infection like Trichomoniasis can increase your risk of getting HIV, so make sure to also get an HIV test.

How to Take Metronidazole

  • You have been prescribed metronidazole 2 g to take as a single dose.
  • Read the label carefully.  This is a one-time dose. That means that all the medicine should be taken at the same time.
  • This medicine should be taken 1 hour before or 2 hours after eating. But, if it upsets your stomach, it can be taken with food.
  • If you vomit the medicine within 1 hour after taking it, call the doctor who wrote the prescription. You may need another dose.

This medicine is very safe. However, DO NOT TAKE IT if any of the following are true:

  • You are female and have lower belly pain, pain during sex, vomiting, or fever. You should see a health care provider if you have any of these symptoms.
  • You think you might be pregnant or you are breastfeeding. You should talk to your doctor before taking this medicine.
  • You have a serious long-term illness, such as kidney, heart, or liver disease. 
  • You are allergic to metronidazole or tinidazole. Tell your doctor about the allergy and your symptoms. These may be:
    • Rash
    • Hives
    • Itching
    • Ahortness of breath, wheezing or cough
    • Awelling of face, lips, tongue or throat
    • If you have any of these, or if you are not sure, do not take the medicine.  Instead, talk to your doctor as soon as possible.  Your doctor will find the best treatment for you.

Other Warnings

Do not drink alcohol within 2 days of taking this medicine. Combining this medicine with alcohol can be dangerous. Some cold medicines, cough syrups and mouthwashes contain alcohol.  Check with your doctor or pharmacist before taking over-the-counter medicines. Using alcohol with this medicine can cause:

This medicine should not be taken with these medicines:

  • Disulfiram, within two weeks (causes the same reactions as if taken with alcohol)
  • Rifampin
  • Phenobarbital
  • Phenytoin (Dilantin®)
  • Lithium
  • Warfarin (Coumadin®)

If you take any other medicines, check with your doctor or pharmacist before taking metronidazole.

Side Effects Warning

Common side effects include:

  • Taste of metal in the mouth
  • Urine that appears to be brown
  • Nausea or vomiting
  • Dry mouth
  • Sensitivity to sunlight (easy to sunburn)

When to Call the Doctor

Call your doctor right awayif you have either of these serious side effects:

  • Rash
  • Numbness or tingling in fingers or toes

When to call for Emergency Help

Call for emergency help (911) if you have any of these signs of an allergic reaction:

  • Trouble breathing
  • Swelling of the tongue, lips or throat
  • Swelling of hands, feet or ankles

Following Treatment of Trichomoniasis

  • Do not have sex for the next seven days. During those first seven days, you can pass on the infection to your sex partner.
  • If you have sex without a condom or if a condom breaks, you can also get re-infected.
  • If you have any other sex partners, tell them you are being treated for Trichomoniasis. They need to get treatment too.
  • Schedule a follow-up appointment to be re-tested in 3 months.  It is important to get re-tested. People who are infected with Trichomoniasis once are more likely to get it again.

More Information

EPT: Trichomoniasis (PDF)

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