From the Guidelines
Metrogel (metronidazole) is the preferred treatment for rosacea due to its faster reduction of redness and inflammatory lesions, as demonstrated in a 9-week split-face study where metronidazole 0.75% produced a 65% decrease in inflammatory lesion counts compared with a 15% reduction for vehicle 1. When considering treatment options for rosacea, both Metrogel (metronidazole) and azelaic acid are effective, but they have different mechanisms of action and may be better suited for different patients.
Key Differences
- Metrogel is typically prescribed as a 0.75% or 1% gel applied once or twice daily, while azelaic acid is available as a 15% gel or 20% cream applied twice daily.
- Azelaic acid has the added benefit of helping with hyperpigmentation and may be better for patients who have both rosacea and acne.
- Side effects for Metrogel include skin irritation, dryness, and metallic taste if absorbed, while azelaic acid commonly causes temporary stinging, burning, and itching upon application.
Treatment Outcomes
- Treatment duration for both medications is typically 8-12 weeks before evaluating effectiveness, and many patients require ongoing maintenance therapy.
- For severe or resistant cases, combination therapy using both medications may be recommended.
- A head-to-head comparison of azelaic acid 20% and metronidazole 0.75% in a 15-week, double-blind, split-face study of 40 subjects with symmetric numbers of inflammatory lesions found that both treatments were effective, but metronidazole may have an edge in reducing inflammatory lesions 1.
Mechanism of Action
- Both medications work by reducing inflammation, though metronidazole has antimicrobial properties while azelaic acid also provides keratolytic effects that help with skin cell turnover.
- Azelaic acid improves rosacea by exerting anti-inflammatory activity on the cathelicidin pathway, which is upregulated in rosacea-affected skin 1.
From the Research
Comparison of Metrogel and Azelaic Acid for Rosacea
- Metrogel, which contains metronidazole, is a common treatment for rosacea, but the provided studies do not directly compare Metrogel to Azelaic Acid.
- Azelaic Acid 15% gel has been shown to be effective in reducing inflammatory lesions of rosacea, with studies demonstrating its efficacy and safety in patients with mild to moderate papulopustular rosacea 2, 3, 4.
- The mechanism of action of Azelaic Acid involves reducing reactive oxygen species and inhibiting the pathologic expression of cathelicidin, which contributes to the development of rosacea 4.
- Topical metronidazole, which is the active ingredient in Metrogel, has also been found to be effective in treating rosacea, although the provided studies do not compare its efficacy directly to Azelaic Acid 5, 6.
- Combination therapy, such as using Azelaic Acid or topical metronidazole with anti-inflammatory doxycycline, may have a synergistic effect in treating rosacea 5.
Efficacy and Safety of Azelaic Acid
- Azelaic Acid 15% gel has been shown to be effective in reducing inflammatory lesions and erythema in patients with mild to moderate papulopustular rosacea 2, 3, 4.
- The treatment is generally well-tolerated, with adverse effects being mostly mild and transient 2, 3.
- Azelaic Acid 15% gel is considered a suitable first-line topical therapy for the treatment of moderate facial rosacea 4.
Treatment Options for Rosacea
- Several topical and oral treatments are available for rosacea, including metronidazole, azelaic acid, and doxycycline 5, 6.
- The choice of treatment depends on the severity and subtype of rosacea, as well as the presence of triggers such as Helicobacter pylori infection and small intestinal bacterial overgrowth 6.