Zidoval

Treatment for bacterial vaginosis with metronidazole gel

Zidoval is a prescription-only vaginal gel containing metronidazole 7.5mg/g (0.75%), used in adults to treat bacterial vaginosis (BV). Unlike oral antibiotics, it's applied directly inside the vagina using a disposable applicator, delivering the active ingredient to the site of infection. Each pack contains a 40g tube of gel with five single-use applicators, providing a full five-day course.

Access Zidoval following an online medical consultation

Start the online consultation and complete the medical questionnaire. A UK-registered prescriber will review your answers and, where appropriate, issue a prescription for Zidoval. Your medication will be dispensed by a GPhC-registered pharmacy and delivered to your door.

What is bacterial vaginosis?

Bacterial vaginosis is the most common cause of abnormal vaginal discharge in women of reproductive age. It happens when the vagina's natural bacterial balance shifts, with a fall in protective lactobacilli and an overgrowth of other bacteria, such as Gardnerella vaginalis. BV is not a sexually transmitted infection, though it is more common in women who are sexually active.

Typical symptoms include a thin, greyish-white discharge and a fishy odour, often more noticeable after sex, usually without itching or soreness. This distinguishes BV from thrush, which tends to cause thick, white discharge with itching but little odour, and from STIs such as chlamydia, which can cause pain or bleeding. Because these conditions can be mistaken for one another, proper assessment, and testing where appropriate, is important before treatment. Around half of women with BV have no symptoms at all.

How does Zidoval gel work?

Zidoval contains metronidazole, an antibacterial active against the anaerobic bacteria associated with BV, helping the vagina's lactobacilli re-establish. Applied directly into the vagina, it acts largely at the site of infection.

Metronidazole is also taken orally, and both forms work the same way once they reach the affected tissue. The key difference is systemic exposure: a single applicator of Zidoval produces a peak blood concentration of around 2% of that seen after a standard 500mg oral dose, which is why the gel is sometimes preferred where systemic side effects or interactions are a concern. This doesn't mean it's free of them, though, and similar precautions still apply. Your prescriber can advise which formulation suits you.

How is Zidoval gel used?

Zidoval is used once daily at bedtime for five consecutive days, or as directed by your prescriber. Always follow the instructions on your dispensing label.

• Wash your hands, then pierce the tube seal with the point on the cap.
• Screw a fresh applicator onto the tube and squeeze gently to fill it.
• Lying down with knees bent, insert the applicator as far as it comfortably goes.
• Push the plunger fully down, then remove and discard the applicator immediately.
• Repeat with a new applicator each night until the course is finished.

If you forget a dose, apply it when you remember; but don't double up. Complete the full five-day course even if symptoms improve early, as stopping early makes recurrence more likely. If symptoms persist after finishing the course, contact your prescriber for reassessment.

What should I avoid while using Zidoval gel?

This reflects the current UK patient information leaflet:

• Avoid sexual intercourse during the infection and throughout treatment
• Use during menstruation isn't recommended; if your period starts mid-course, speak to your prescriber
• Avoid unnecessary or prolonged use beyond the prescribed course
• Tell your prescriber if you have, or suspect, thrush, as Zidoval can make symptoms more noticeable
• Mention you're using Zidoval if having blood tests, as it can affect certain results

The leaflet doesn't give specific guidance on tampons, douching, or condom compatibility; check with your prescriber or pharmacist if you're unsure.

Who is the treatment suitable for?

Tell your prescriber before starting if you:

• Are allergic to metronidazole, nitroimidazole antibacterials, or parabens (preservatives in the gel)
• Have, or have had, a blood disorder or liver disease
• Are pregnant, breastfeeding, or trying to conceive
• Have neurological problems, or take other medicines, including those bought over the counter

Zidoval is not recommended under 18, and its safety in elderly patients hasn't been established, so it's generally avoided in this group too. Metronidazole can increase the effects of warfarin and other coumarin anticoagulants, lithium, ciclosporin, and 5-fluorouracil, so a full medicines review at consultation matters.

What side effects can occur?

Common (up to 1 in 10 people):

• Vaginal irritation, itching, or burning
• Discharge
• Pelvic discomfort
• Thrush
• Headache and dizziness
• Nausea, vomiting, or stomach cramps
• An unusual or metallic taste
• Reduced appetite
• Localised skin dryness or irritation

Uncommon (up to 1 in 100 people):

• Diarrhoea
• Constipation
• Tiredness
• Low mood
• Sleep disturbance
• Tingling in fingers or toes
• Darkened urine
• Urinary tract infection symptoms
• Changes to your usual bleeding pattern

Seek urgent medical attention for facial, lip, tongue or throat swelling, difficulty breathing, a severe skin reaction, or neurological symptoms such as confusion. Speak to your prescriber if side effects are troublesome, or symptoms haven't improved after finishing the course.

Recurrence and alternative treatments

BV commonly recurs: many women experience a further episode within months of successful treatment, regardless of which treatment is used. This isn't a sign Zidoval hasn't worked; it reflects how easily the vaginal microbiome can be disrupted again.

Options for recurrence include repeating Zidoval, switching to oral metronidazole tablets, or trying clindamycin vaginal cream, which targets similar bacteria via a different antibacterial class. Frequent recurrences usually warrant closer review, including checking for contributing factors and confirming the diagnosis with further testing, rather than repeating the same treatment indefinitely.

How to get Zidoval gel through DoktorABC

• Complete your online consultation: answer a short, confidential health questionnaire covering your symptoms and medical history.
• Prescriber review: a UK-registered prescriber reviews your answers and, if Zidoval is appropriate, approves your prescription.
• Delivered to your door: your medication is dispensed by a GPhC-registered pharmacy and delivered in discreet packaging.