metronidazole 400mg for treating trichomonas vaginalis (TV) or bacterial vaginosis (BV)

Trichomoniasis is actually the most common curable sexually transmitted infection, STI, in the world. However, it's thought that many cases are still not recognised and are not diagnosed.

Trichomoniasis is caused by a tiny parasite called Trichomonas vaginalis (TV).

In 2011 just over 6,000 cases were diagnosed in England. In contrast, more than 186,000 cases of Chlamydia were reported the same year. Over 90% of TV cases are diagnosed in women.

However, it's estimated that in the United States of America 7.4 million new cases of TV appear annually compared with 3 million cases of Chlamydia and 718,000 cases of gonorrhoea. Despite being a readily diagnosed and treatable sexually transmitted infection, TV is not a reportable infection and control of it has received relatively little emphasis from public health STI control programmes.

Symptoms of TV usually develop within a month of infection, although up to half of all infected men and women have no symptoms.

The symptoms of TV are similar to those of many other STI's so it can sometimes be difficult to diagnose.

In women, this parasite mainly infects the vagina and urethra (tube that carries urine out of the body). In men, the infection most commonly affects the urethra but the head of the penis or prostate gland (a gland near the bladder that helps produce semen) can become infected too.

TV is usually spread by having unprotected vaginal sex (sex without a condom) or insertion of fingers into the vagina. It could be spread by sharing sex toys, if you don't wash them or cover them with a new condom before use. It can't be caught from oral or anal sex, kissing, hugging, sharing cups, plates, cutlery or from toilet seats.

You don't have to have had many sexual partners to catch TV. Anyone who is sexually active can catch it and pass it on. 

An abnormal vaginal discharge that may be thick, thin or frothy and yellow-green in colour. It may also have  an unpleasant, strong fishy smell.  

Pain or discomfort when passing urine or having sex.

Soreness, inflammation(swelling) and itching around the vagina and sometimes the inner thighs become itchy too.

The genital inflammation caused by TV can increase a woman's suseptability to HIV infection if she is exposed to the virus. Having TV may increase the chance that an HIV infected woman passes HIV to her sex partner(s). 

Pain during urination or ejaculation or needing to urinate more frequently than usual.

Thin white discharge from the penis and/or soreness, swelling and redness around the head of the penis (balanitis) or foreskin (balanoposthitis). 

Bacterial vaginosis(BV), also known as gardnerella vaginalis, mainly affects sexually active women although it can be found in non-sexually active women who disturb the natural balance of bacteria in the vagina due to overuse of feminine hygiene products and heavily scented soaps. The infection is often symptomless but may cause an unpleasant smelling, greyish discharge in women. If left untreated there is a small risk that the infection can cause serious health complications such as miscarriage or pelvic inflammation.

A woman can pass it to another woman during sex but partners don't need treatment, unless female partners have symptoms.

Although men can test positive for BV as it can colonise in the urethra(the tube that leads from the bladder to the outside of the body) of men it doesn't produce any symptoms and there is no scientific evidence to show that men can pass it onto a partner. 

BV can be detected using our 7 in 1 test kit for men or women.

If you have been diagnosed with a sexually transmitted infection, STI, it's necessary to inform any sexual partners, from the last 6 months, that they may also be at risk. Then they can be screened and have treatment if necessary. Also, to prevent infecting or re-infecting your partner with a STI you should both avoid any sexual contact until you have both been treated.

If you suspect that you have a STI you can go to your GP or local genitourinary medicine, GUM, clinic; also referred to as sexual health clinics, where you can be tested and treated.

If you prefer to use our fast, discreet, confidential service at Webmed Pharmacy then you can order a test kit online to be used in the comfort of your own home. You only have to provide a urine sample for men or a simple vaginal swab for women. It's quick, easy and effective while avoiding any potential embarrassment.

The test kits are posted in discreet, plain unmarked packaging with no indication of their contents.

Complications of TV are rare, although some women with the infection may be at risk of further problems. If you're infected with it while pregnant, the infection may cause your baby to be either born prematurely (before the 37th week of pregnancy) or have a low birth weight.

Detecting TV

The NAAT test used by The Doctors Lab, TDL, has been approved for the detection of TV and is more sensitive than wet mount or culture used in some sexual health clinics.

Women use a swab test and men use a urine test. Men should not have passed urine for an hour and should use the first part of their urine as indicated on the instruction leaflet supplied with the test kit.

If you order a STI test kit from  Webmed Pharmacy by 4pm Monday to Friday, you will receive it the next working day by DPD tracked delivery for all mainland UK except the Scottish Highlands.* There is no additional cost for postage unless you want it to be delivered on a Saturday or Sunday.

You send your sample, in the pre-paid envelope, to The Doctors Laboratory, TDL, in Manchester.** You can post your sample in any Royal Mail post box. TDL are the largest independent providers of clinical laboratory diagnostic services in the UK. Once the lab has received your sample, your results will be available 2-3 days later. We will contact you by your chosen method of communication, email or SMS, to let you know that there is a message in your "in box" via your secure log in at Webmed Pharmacy. 

If your test is positive for Chlamydia, gonorrhoea or TV we ask you to complete a simple medical questionnaire for our doctor to assess your suitability for treatment.

If you or your partner have already tested positive for a STI then you may still complete our simple medical questionnaire and if approved by our doctor, be prescribed oral antibiotics to treat the infection(s). 

* For the Scottish Highlands we use Royal Mail Special Delivery, guaranteed by 1pm next working day for most postcodes. Full postal details are available on the "Delivery" tab.

** The Doctors Laboratory, TDL www.tdlpathology.com

TV is unlikely to go away without treatment but can be very effectively treated with an antibiotic called metronidazole. It's usually taken twice a day for 5 to 7 days or, alternatively, can be taken as a single dose.

It's important to complete the whole course of antibiotics and avoid having sex (even with a condom) until one week after both you and your partner have finished your treatment. Then you will be clear of infection and prevent re- infection.

Your current sexual partner and any other recent partners should be treated.

Metronidazole, generic name, is also known under the brand name Flagyl.

Metronidazole belongs to a class of antibiotics known as nitroimidazoles. It works by inhibiting bacterial DNA synthesis, preventing the replication of bacteria and protozoa and thereby stopping their growth. Then the body's own immune system can get rid of it.

There is a choice of 2 doses :-

Metronidazole, 2g orally, in a single dose or Metronidazole 400mg twice a day for 5 days. Both treatments are equally effective but while the single dose is more convenient you are more likely to suffer from side effects; the most common being diarrhoea, nausea and abdominal pain.

Preferably, you should take the tablet(s) during or after a meal and they should be swallowed whole, not chewed or broken, with water.

You are advised not to drink any alcohol while taking your antibiotics and for at least 48 hours after finishing treatment. This is because the alcohol may cause the antibiotics to give you a severe headache, make you feel sick or produce palpitations. However, the antibiotics would still work if you get this reaction.

More common side effects :-

Nausea, vomiting and diarrhoea

Taste disturbances

Loss of appetite

Furred tongue

Some of the very rare side effects :-

Jaundice

Drowsiness

Dizziness

Headache

Myalgia

Visual disturbances

Itching and skin rashes

Click here to download the patient information leaflet