Comparative evaluation of clindamycin phosphate 1% and clindamycin phosphate 1% with nicotinamide gel 4% in the treatment of acne vulgaris

Introduction

The role of Propionibacterium acnes (P.acnes) in the comedogenic phase of acne vulgaris remains controversial but its role in inflammatory acne is almost universally accepted.[1] Systemic antibiotics have been used for several years to reduce the population of P acnes. During the last decade topical antibiotics have become more acceptable for treating inflammatory acne vulgaris because they have fewer side effects and interactions than oral antibiotics.

But the fight against acne is becoming more difficult as the chief enemy P.acnes, discovers new ways to overpower its foes. According to three acne experts Alam Shalita, James J Leyden and William J. Cunliffe, speaking at the Clinical Derm 2000 meeting in Vancouver, widespread bacterial resistance to both systemic and topical antibiotics is just around the corner. But a new combination of antibiotic and bactericide may help in the next battle.

Topical antibiotics include tetracycline, erythromycin and clindamycin but erythromycin and clindamycin preparation are the most popular. Combination therapies are also used in the treatment of acne vulgaris, these include erythromycin with zinc or with benzoyl peroxide.[2] Topical clindamycin has been found to be as effective as systemic tetracycline, topical erythromycin and topical benzoyl peroxide. Clindamycin is bactericidal to Propionibacterium, acnes. Due to the inhibition of Pacnes the free fatty acid levels (break down product of sebum by Pacnes) on the skin surface also decrease. Clindamycin phosphate applied topically penetrates to a very great extent in to open comedonesand thus produces a high percentage of sterile comedones.

Topical nicotinamide has got a marked anti-inflammatory properties, the amide derivative of vitamine B3 (niacin) have been used to treat acne vulgaris. It is not yet certain by what mechanism the preparation exerts its anti-inflammatory effect.[3]

Due to the emergence of resistant strains of P acnes,staphylococci and the known anti-inflammatory effects of nicotinamide, topically applied clindamycin phosphate 1 % alone was compared with clindamycin phosphate gel I% and nicotinamide gel 4% in combination in the treatment of moderate acne vulgaris.

Materials and Methods

A 6-week study was conducted to evaluate the efficacy of 1 % clindamycin phosphate alone as compared to 1 % clindamycin phosphate and 4% nicotinamide gel in combination in moderate acne vulgaris. The study population was made up of eighty (80) patients aged 14-25 years with moderate acne vulgaris. Moderate acne was defined as the presence, on the face of the subject, of comedones, papules and few pustules .[4]

None of the patients had received any anti-acne therapy within the previous 30 days and none of the married female patients received any oral contraceptive or were pregnant.

Forty patients were treated with 1 % clindamycin phosphate (1) alone, and the other 40, patients with 1 % clindamycin phosphate and 4% nicotinamide gel (II) in combination twice daily for 6 weeks.

The efficacy of the drug was evaluated at two weekly intervals by counting the acne lesions. The criterion for effectiveness of the treatment was the reduction in the number of lesions, at the end of 6 weeks. The improvement was graded as follows: 1) excellent, when there was more than 75% reduction in the lesion count, 2) good, when there was 50-75% reduction in the lesion, 3) fair, when there was 25-50% reduction in the lesion count.

Few side effects such as mild burning, dryness, erythema, itching and peeling of the skin were observed in a very small percentage of patients in both the groups. None of these side effects were severe enough to necessitate withdraw) of therapy.

[Table - 1]: Response of Moderate acne vulgaris ( gradell) lesions to therapy with 1% topical clindamycin phosphate group I and 1% topical clindamycin phosphate and 4% nicotinamide gel (group II) after 6 weeks.

Results

A total of 80 (27 males and 23 females) patients were taken up for the study. Eighty patients (40 using 1 % clindamycin phosphate alone and 40 using 1 % clindamycin phosphate and 4% nicotinamide gel in combination) could be followed-up for the stipulated 6 weeks. Fishers exact test showed no significant difference in response between the two groups. The clinical response of the inflammatory lesions (IL) of acne vulgaris to both the topical preparations are depicted in [Table - 1].

40 patients in group I who were treated with 1 % topical clindamycin phosphate for 6 weeks showed excellent response in 16 or 40% of patients, good in 20 or 50% of patients, and fair in 4 or 10% of patients. Similarly 40 patients in group II who were treated with 1 % topical clindamycin phosphate and 4% nicotinamide gel for 6 weeks showed excellent response in 20 or 50% patients, good in 18 or 45% of patients and fair in 2 or 5% of patients.

Discussion

Clindamycin phosphate 1 % and nicotinamide gel 4% are equally and highly effective in the treatment of moderate acne either alone or in combination.Clindamycin is bactericidal to P acnes whereas nicotinamide has got a marked anti-inflammatory properties.

A double-blind study was done by Shalita et al with topical nicotinamide gel and topical clindamycin in the treatment of moderate acne. Seventy-six patients were randomly assigned to apply either nicotinamide gel 4% or clindamycin phosphate 1 % twice daily for 8 weeks. Both treatments produced a statistically similar reduction in the number of acne lesions and their Severity.[5]

Khanna[1] in a study with clindamycin 1 % alone obtained good to excellent result in more than 75% cases. The present study did not show any added advantage of clindamycin phosphate 1 % in combination with nicotinamide gel 4% over clindamycin phoshate 1% in alone.