Metronidazole, a local treatment for papulopustular rosacea.

Metronidazole is a antibiotic from the imidazole family, often prescribed to soothe cases of papulopustular rosacea. It helps to reduce skin inflammations such as papules and pustules, and the redness associated with rosacea. Metronidazole may also have a beneficial effect by reducing the presence of certain bacteria on the skin, which could contribute to the improvement of symptoms, although the involvement of bacteria in rosacea has not been proven.

Finally, metronidazole could potentially improve the quality of life for patients suffering from rosacea. Indeed, this disease affects the appearance of individuals, and consequently their self-confidence. Alleviating the physical symptoms can therefore reduce the psychological impact of rosacea such as stress and anxiety.

To date, the precise mechanisms by which the drug acts against rosacea are unknown. However, it has been suggested that metronidazole may reduce tissue lesions by inhibiting inflammatory mediators such as reactive oxygen species (ROS), for example. It also exhibits anti-bacterial activity, possibly by inhibiting the synthesis of bacterial DNA, thus preventing the replication of bacteria that can exacerbate the symptoms of rosacea.

In the form of a gel or cream, metronidazole is applied locally to areas affected by papulopustular rosacea. Its dosage will depend on the concentration of metronidazole contained in the treatment. Generally, it is the metronidazole 0.75% that is prescribed for rosacea.

It is recommended to apply this antibiotic twice a day, morning and evening, for three to four months. It is then possible to continue at a low dose to reduce the risk of relapse. Apply by gently massaging a thin layer onto the affected areas after they have been previously cleaned. Its use should not be discontinued before the prescribed treatment duration, except on the advice of a doctor.

When applied topically, metronidazole can cause skin reactions. These may include burning sensations in the affected areas, skin irritations, and itching. These reactions may be related to allergies to the medication.

If you notice one or more of these adverse effects, refrain from using the medication and consult your doctor.

When applying metronidazole, avoid contact with the eyes and mouth. In the event of accidental contact with the eyes, rinse thoroughly. After use, it is necessary to wash your hands to prevent accidentally touching these sensitive areas. The application should be gentle and non-aggressive, otherwise, the symptoms of rosacea may worsen. It is also important to not expose the treated areas to the sun or ultraviolet rays. Finally, store the medication at room temperature.

Metronidazole should not be used in case of allergy to imidazoles or other components of the drug. Although the effect of this medication during pregnancy or breastfeeding, or on children is poorly understood, it is advised to discuss it with your doctor before using it in your case.

The risk of drug interactions with metronidazole is low, if not non-existent, due to its low likelihood of entering the bloodstream. However, as a precaution, it would be wise to inform your doctor if you are taking an oral anticoagulant.

• MCCLELLAN K. J. & al. Topical metronidazole. American Journal of Clinical Dermatology (2000).

• Gamme de médicaments ROZEX. VIDAL (2017).