What is the purpose of Azelaic RU (azelaic acid) serum for treating rosacea in adults?

Purpose of Azelaic Acid Serum for Rosacea

Azelaic acid serum is a first-line topical treatment for mild to moderate inflammatory rosacea that reduces papules, pustules, and perilesional erythema through anti-inflammatory, antimicrobial, and antikeratinizing mechanisms. 1, 2

Primary Therapeutic Actions

Azelaic acid works through multiple complementary mechanisms to treat rosacea:

• Anti-inflammatory activity: Reduces reactive oxygen species and downregulates the cathelicidin pathway, which is upregulated in rosacea-affected skin 3, 4
• Antimicrobial effects: Inhibits microbial cellular protein synthesis against Propionibacterium acnes and Staphylococcus epidermidis 5
• Antikeratinizing properties: Normalizes keratinization, reduces stratum corneum thickness, and decreases microcomedo formation 5, 6

Clinical Efficacy and Expected Outcomes

The 15% gel formulation achieves a 51% success rate (marked improvement or complete remission) after 12 weeks of twice-daily application. 3, 1

Timeline for Improvement

• Initial response: Early improvement begins within 3-4 weeks of starting therapy 7
• Optimal results: By 12 weeks, inflammatory lesion counts decrease from baseline averages of 17.5-17.8 to 6.8-8.9 3, 7
• Peak efficacy: At 9 weeks with the 20% cream formulation, 78.2% of patients achieved complete remission or marked improvement versus 31.2% with placebo 3, 7

Specific Benefits

• Inflammatory lesions: Significant continuous reduction in papules and pustules throughout 12-15 weeks of treatment 1, 4, 8
• Erythema: Effective for perilesional erythema (redness around lesions), though it does not improve telangiectasia or fixed vascular changes 1, 2, 8
• Sustained improvement: Unlike metronidazole which plateaus after 8 weeks, azelaic acid shows continuous improvement throughout the treatment period 8

Application Instructions

Apply a thin film twice daily (morning and evening) gently massaged into affected facial areas after cleansing. 7, 2

• Approximately 3-5% of the applied dose penetrates the stratum corneum, with up to 10% reaching the epidermis and dermis 5
• Only 4% is systemically absorbed, making it safe with negligible systemic effects 5

Treatment Duration and Maintenance

Continue therapy for at least 12 weeks to adequately assess efficacy, followed by long-term maintenance to prevent relapse. 1, 7

• Without maintenance therapy, up to two-thirds of patients will relapse when treatment is discontinued 1, 7, 2
• The minimum treatment necessary to maintain control should be used indefinitely 1

Managing Initial Side Effects

Local irritation (burning, stinging, tingling) is most pronounced during the first 3 weeks but typically resolves with continued use. 3, 7

• These adverse effects are predominantly transient and mild-to-moderate in intensity 8, 9
• Counsel patients to persist through this initial period rather than discontinuing prematurely 7
• The irritation does not usually necessitate discontinuation of therapy 4

When to Escalate Treatment

For moderate rosacea requiring more rapid control, combine azelaic acid 15% gel with oral doxycycline 40 mg daily, which shows significant improvement by 3 weeks. 1, 7, 2

• This combination addresses both the inflammatory component and provides more aggressive control than monotherapy 1
• For persistent facial erythema not responding to azelaic acid alone, add brimonidine 0.33% gel or oxymetazoline 1% cream, as azelaic acid does not treat fixed vascular changes 1, 2

Critical Pitfalls to Avoid

• Discontinuing before 6-12 weeks: This prevents adequate assessment of efficacy, as full therapeutic benefit requires this duration 1, 7
• Stopping due to early irritation: The burning and stinging typically resolve after the first 3 weeks 7
• Failing to use maintenance therapy: Leads to relapse in the majority of patients 1, 7, 2
• Expecting improvement in telangiectasia: Azelaic acid does not improve visible blood vessels, only inflammatory lesions and perilesional erythema 8

Formulation Considerations

The 15% gel and foam formulations are FDA-approved and equally effective for inflammatory lesions and perilesional erythema. 1, 2 The gel formulation has been most extensively studied in clinical trials, demonstrating superior efficacy to metronidazole 0.75% gel with continuous improvement rather than the plateau effect seen with metronidazole. 8