Optimizing topical combination therapy for the treatment of acne vulgaris

Given the multifactorial and complex contributors to acne development, combination therapy is standard of care. By addressing multiple pathogenic factors, combination therapy provides a quicker and more efficacious treatment outcome than monotherapy. Topical retinoids normalize follicular keratinocyte differentiation and are anti-inflammatory. Their use is limited by the potential for cutaneous irritation. Antimicrobials reduce Propionibacterium acnes colonization on the skin and reduce the bacteria's proinflammatory effects. Topical antibiotics and benzoyl peroxide (BPO) are commonly employed in fixed-dose combination products or two separate medications. BPO has the added benefit of being comedolytic and can minimize the risk for bacterial antibiotic resistance. Like topical retinoids, BPO may cause skin irritation, burning, erythema, and peeling. Managing cutaneous side effects when using multiple products that cause irritation can be a challenge. Careful product selection, dose titration, and patient-directed regimens can help to optimize outcomes. This review presents the latest data on two topical acne products that have demonstrated excellent efficacy and tolerability profiles. In addition, their in vitro profiles suggest the potential for combination use, affording greater dosing flexibility.     

Study results of benzoyl peroxide 5%/clindamycin 1% topical gel, adapalene 0.1% gel, and use in combination for acne vulgaris

Combination therapy is the standard of care in the management of acne vulgaris. It is essential to treat as many aspects of acne pathogenesis as possible. Due to increasing insensitivity of Propionibacterium acnes to antibiotics, the concomitant use of other topical agents that exhibit other modes of antibacterial and anti-inflammatory activity is integral to the successful treatment of acne. The combination of topical benzoyl peroxide and clindamycin gel has been shown to be more effective than either agent alone. The addition of a topical retinoid may further enhance therapeutic results. This 12-week study evaluated the safety and efficacy of initial topical benzoyl peroxide 5%/clindamycin 1% gel as monotherapy and in combination with adapalene gel versus adapalene gel monotherapy in the management of acne.     

The clinical impact of vehicle technology using a patented formulation of benzoyl peroxide 5%/clindamycin 1% gel: comparative assessments of skin tolerability and evaluation of combination use with a topical retinoid

A major challenge encountered in clinical practice in patients with acne vulgaris is irritation related to topical medications used for treatment. Advances in vehicle technology have improved formulations containing active ingredients known to produce irritation in some patients, such as benzoyl peroxide (BP) and topical retinoids. Clinical studies, including combination therapy studies have demonstrated that certain additives, such as silicates and specific humectants, reduce irritation by maintaining barrier integrity. A patented gel formulation of BP 5%/clindamycin phosphate 1% (clindamycin) containing dimethicone and glycerin has been studied both as a monotherapy and in combination with topical retinoid use. This article evaluates specific vehicle additives included in this gel formulation and explains their role in reducing irritation. Data from clinical trials utilizing this technology in acne management are also reviewed.     

Tazarotene: therapeutic strategies in the treatment of psoriasis, acne and photoaging

Tazarotene is a member of the new generation of receptor-selective, synthetic retinoids for the topical treatment of mild to moderate plaque psoriasis, acne vulgaris and photoaging. Though they are effective in monotherapy, clinical studies with a focus on novel combination treatments and a comparison of different agents for these skin disorders are accumulating. The concomitant use of tazarotene with a mid-potency or high-potency corticosteroid enhances the efficacy in psoriatic plaques and reduces the risk of steroid-induced skin atrophy. Combining phototherapy with adjunctive tazarotene accelerates the clinical response and reduces the cumulative UVB or PUVA exposure load. Tazarotene applied once daily is superior to adapalene monotherapy in acne vulgaris and is efficacious in the treatment of photodamage. Novel therapeutic regimens such as short-contact therapy have been developed for both acne and psoriasis in order to diminish the major adverse events like pruritus, burning, local skin irritation and erythema.     

Acne: comparing hormonal approaches to antibiotics and isotretinoin

Acne is a common and disfiguring disease affecting a significant proportion of the general population. In milder cases topical therapy is sufficient. However, in more severe cases where papulopustular or nodulocystic acne is present, there is a need of systemic treatment. The latter include antibiotics, anti-androgens and retinoids. A systematic review of the literature was performed of systemic monotherapy using these drugs. Because of the significant methodological variability of the studies examined, it was not possible to make a meta-analysis. Instead the overall effects were assessed by calculating mean weighted effects across different reported effect variables. Isotretinoin scored 85 +/- 10% improvement compared with the baseline, whereas tetracyclines and cyproterone acetate plus ethinyloestradiol were less effective (54 +/- 3% versus 65 +/- 4% improvement compared with baseline, respectively). Moreover, studies suggested that isotretinoin reduces the risk of acne relapse in the few studies that included a follow-up period. A number of restrictions limit the general use of these drugs as monotherapy, e.g., potential teratogenicity. There is a continued need for effective drugs for the therapy of acne, although judicious combined use of existing topical and systemic therapies offers great relief to many patients. In addition, methodological problems in previous studies prevent adequate synthesis of existing knowledge within the framework of evidence-based medicine. There is therefore a demand for future standardisation of further acne studies to enable direct comparison of different treatment efficacies.     

Acne: comparing hormonal approaches to antibiotics and isotretinoin

Acne is a common and disfiguring disease affecting a significant proportion of the general population. In milder cases topical therapy is sufficient. However, in more severe cases where papulopustular or nodulocystic acne is present, there is a need of systemic treatment. The latter include antibiotics, anti-androgens and retinoids. A systematic review of the literature was performed of systemic monotherapy using these drugs. Because of the significant methodological variability of the studies examined, it was not possible to make a meta-analysis. Instead the overall effects were assessed by calculating mean weighted effects across different reported effect variables. Isotretinoin scored 85 ± 10% improvement compared with the baseline, whereas tetracyclines and cyproterone acetate plus ethinyloestradiol were less effective (54 ± 3% versus 65 ± 4% improvement compared with baseline, respectively). Moreover, studies suggested that isotretinoin reduces the risk of acne relapse in the few studies that included a follow-up period. A number of restrictions limit the general use of these drugs as monotherapy, e.g., potential teratogenicity. There is a continued need for effective drugs for the therapy of acne, although judicious combined use of existing topical and systemic therapies offers great relief to many patients. In addition, methodological problems in previous studies prevent adequate synthesis of existing knowledge within the framework of evidence-based medicine. There is therefore a demand for future standardisation of further acne studies to enable direct comparison of different treatment efficacies.     

Topical antibacterial therapy for acne vulgaris

Topical antibiotics and benzoyl peroxide, are the two main topical antibacterial treatments indicated for mild-to-moderate acne vulgaris. Topical antibiotics act both as antibacterial agents suppressing Propionibacterium acnes in the sebaceous follicle and as anti-inflammatory agents. Benzoyl peroxide is a powerful antimicrobial agent that rapidly destroys both bacterial organisms and yeasts. Topical clindamycin and erythromycin have been proven to be effective against inflammatory acne vulgaris in concentrations of 1-4% with or without the addition of zinc. However, none of the antibacterials tested was more effective than benzoyl peroxide, which also has the advantage of not being associated with antimicrobial resistance.Topical antibacterial therapy should be discontinued once improvement is observed. If no improvement is observed within 6-8 weeks, the agent should be discontinued and a therapeutic switch considered. The primary limitation of benzoyl peroxide for some acne vulgaris patients is cutaneous irritation or dryness.Antibacterial therapy can be used in combination with other agents. Combining topical antibiotics and topical retinoids may enhance the efficacy, since the retinoid will improve the penetration of the antibiotic. Combining a topical antibiotic with benzoyl peroxide may increase the bactericidal effect of the antibiotic and reduce the potential for bacterial resistance. Topical and oral antibacterials should not be used in combination for the treatment of acne vulgaris, since this association may increase the risk of bacterial resistance.     

A comparative review of the efficacy and tolerability of retinoid-containing combination regimens for the treatment of acne vulgaris

Many physicians regularly prescribe combination therapy involving a retinoid for their acne patients. The most common retinoid-containing regimens include either oral antibiotics or topical benzoyl peroxide and antibiotic products. A fair number of studies have been conducted to evaluate the efficacy of these combination therapies, but there is a lack of comparative studies examining different regimens head-to-head. Also, many of the noncomparative studies have very similar trial designs. A review of these studies was conducted in order to organize the available data side by side from the different regimens. Although not derived from comparative studies, this presentation of data is expected to provide dermatologists with valuable information from which they can easily make their own comparisons among similarly designed trials.     

Topical delivery for the treatment of psoriasis

Importance of the field: Psoriasis is one of the most common human skin diseases. Topical therapy forms the cornerstone in the management of mild-to-moderate psoriasis. Topical therapies are also used as adjunctive to systemic therapy in moderate and severe forms of the disease.

Areas covered in this review: In this review, an overview of psoriasis pathogenesis, new topical medications for psoriasis, new targets and molecules, combination topical therapies and combination of topical and phototherapy is provided. Over the past decade several efficacious and acceptable treatment options have emerged from the age-old therapies. The development of sophisticated formulation options has led to an enhancement in the rate and extent of drug delivery across the skin, increasing therapeutic value and improving patient compliance.

What the reader will gain: Readers will learn about monotherapy and combination topical products as well as new topical drug delivery technology to achieve optimal clinical outcomes. This review will highlight the need to generate more dermal pharmacokinetic data for better understanding of the impact of formulation change on skin pharmacokinetics to help design improved topical drug delivery systems.

Take home message: New topical formulations have the potential to achieve better efficacy with improved safety profile.     

Adverse events related to topical drug treatments for acne vulgaris

ABSTRACT

Introduction: Acne vulgaris is a widespread skin disease. Topical therapy is a standard treatment for mild to moderate acne. Given the complex pathophysiology of acne, various agents with complementary action are nowadays frequently combined to increase the efficacy of therapy.

Area covered: This review focus on safety profile of topical agents used for the treatment of acne vulgaris, including topical retinoids, benzyl peroxide, azelaic acid, topical antibiotic, and combined agents. Data from clinical trials but also metanalyses, systematic reviews, and other secondary analyses are presented.

Expert opinion: In general, topical agents used for acne vulgaris have a favorable safety profile. The most commonly reported AEs were associated with local skin irritation, usually mild to moderate in intensity, intermittent, and rarely led to the cessation of therapy. Irritative potential seems to be highest for BPO and topical retinoids. Due to the possibility of development of Cutibacterium acnes resistance, topical antibiotics should not be used in monotherapy but as a part of combination therapy. In female adolescent and adults of childbearing potential, topical retinoids should be used with caution, because they are contraindicated in pregnant females (FDA Pregnancy category) C (adapalene, tretinoin) and X (tazarotene).     

Treatment considerations for inflammatory acne: clinical evidence for adapalene 0.1% in combination therapies

Acne vulgaris is an exceptionally common, chronic, and recurring disease. It involves multiple etiological factors including follicular hyperkeratinization, increased sebum production, Propionibacterium acnes proliferation, and inflammation. Presently, oral isotretinoin is the only single agent that is effective against all 4 major pathophysiologic features. However, this drug is also responsible for several serious side effects, including teratogenicity. Therefore, it should be used in only the most severe cases and alternative treatment approaches for inflammatory acne, such as initial combination therapy, should be considered first. Combination therapy in inflammatory acne simultaneously targets multiple pathogenic factors. Current guidelines recommend early initiation of combination therapy with a topical retinoid and antimicrobials for mild to moderate inflammatory acne and topical retinoids with oral antibiotics (with or without the use of benzoyl peroxide) for moderate to severe cases of acne, followed by maintenance therapy with topical retinoids. This review evaluates the rationale and clinical evidence for the use of adapalene in combination therapy for inflammatory acne.     

Benzoyl peroxide: a review of its current use in the treatment of acne vulgaris

Background: Owing to the use of topical and systemic antibiotics for acne vulgaris, the incidence of antibiotic-resistant Propionibacterium acnes is increasing worldwide. Topical benzoyl peroxide (BPO) is an alternative to antibiotics in the treatment of acne vulgaris. Objective: This review describes and evaluates recent clinical literature regarding the efficacy and tolerability of BPO. Methods: A PubMed literature search was conducted using the keywords benzoyl peroxide, acne, and combination therapy. Results: BPO is equally effective at concentrations of 2.5, 5.0 and 10%. However, a concentration-dependent irritant dermatitis can occur with higher concentrations. The efficacy of BPO can be enhanced when used in combination with topical retinoids, antibiotics and tertiary amines. BPO-containing combinations do not induce bacterial resistance and are important first-line treatments for mild to moderate acne vulgaris.     

The modern age of acne therapy: a review of current treatment options

This review of current acne treatments begins with the crucial discovery in 1979 of isotretinoin treatment for nodulocystic acne. This drug s approval in 1982 revolutionized therapy, since it was the first oral acne-specific drug, and it provided prolonged remissions. In addition, it may prevent the emergence of resistant bacteria, a problem linked to the traditional use of antibiotics for acne. Patients who are not candidates for isotretinoin therapy may benefit from one of the other drugs or drug combinations reviewed, including the third-generation topical retinoids adapalene and tazarotene, retinoic acid reformulated in new vehicles, azelaic acid, and topical antibiotics. Proper selection and education of patients are essential, since serious consequences may result from poorly monitored use of antibiotics and retinoid.     

Tazarotene foam, 0.1%, for the treatment of acne

Introduction: Acne is a common skin condition of the pilosebaceous units that affects the young and old, ranges from moderate to severe and can be treated with an array of options. Topical retinoids are the initial treatment for acne due to their ability to treat comedones, the starting point of acne.

Areas covered: Tazarotene is a topical retinoid available as a cream, gel and foam. Tazarotene 0.1% foam was FDA approved in 2012 for the treatment of acne in patients ages ≥12 and is the first foam topical retinoid on the market. Phase I and III trials support the efficacy and safety of tazarotene foam for acne.

Expert opinion: The foam vehicles may increase compliance and satisfaction in some patients and as retinoids are commonly first line acne treatments, this new topical retinoid foam may be a useful option for some acne patients.     

Brinzolamide plus brimonidine for the treatment of glaucoma: an update

Introduction: Glaucoma is a common sight-threatening condition that is primarily treated by lowering intraocular pressure (IOP). Today the mainstay of treatment is topical ocular hypotensive medications; many patients require more than one agent to achieve target IOP. For such patients, fixed combination formulations have several advantages including simplicity of treatment regimen, adherence to the treatment regimen, efficacy, improved ocular surface comfort and reduced cost. All currently available fixed combinations contain a β-blocker, which is contraindicated in some patients. Hence there is a clinical need for fixed-combination preparations without a β-blocker. This paper reviews the current literature on a new fixed-combination drug containing brinzolamide 1% and brimonidine 0.2% (BBFC).

Areas covered: A PubMed, Embase and ClinicalTrials.gov registry search was performed to identify all relevant studies. Four published clinical papers pertaining to three randomized controlled trials were identified for review. All studies demonstrated a significant reduction (p < 0.01) in mean IOP in patients administered with BBFC compared with its individual components, brinzolamide 1% or brimonidine 0.2%. Adverse effects from BBFC were no different from each of the individual components, the most common being blurred vision, eye irritation and dysgeusia (abnormal taste sensation). Although BBFC use was associated with more adverse effects compared with the individual components used as monotherapy (p < 0.001), the cumulative adverse effect profile from BBFC did not appear greater than one would expect from the simultaneous use of the two components.

Expert opinion: BBFC is a potential alternative to other fixed-combination medications and is especially useful when topical β-blockers are contraindicated. Longer-term experience will determine if additional adverse effects occur or if efficacy is maintained over longer periods.     

Tazarotene versus tazarotene plus clindamycin/benzoyl peroxide in the treatment of acne vulgaris: a multicenter, double-blind, randomized parallel-group trial

Topical retinoids offer highly effective treatment for both inflammatory and non-inflammatory acne, with tazarotene demonstrating greater efficacy than other topical retinoids. A multicenter, double-blind, randomized, parallel-group trial has been performed to evaluate whether the adjunctive use of clindamycin/benzoyl peroxide could enhance the efficacy of tazarotene still further. Patients with moderate to severe inflammatory acne applied tazarotene 0.1% cream each evening and were randomly assigned to morning applications of vehicle gel or a ready-to-dispense formulation of clindamycin 1%/benzoyl peroxide 5 % gel containing 2 emollients. Tazarotene/clindamycin/benzoyl peroxide achieved a significantly greater reduction in comedo count than tazarotene monotherapy and, among patients with a baseline papule plus pustule count of > or =25 (the median value), a significantly greater reduction in inflammatory lesion count. The combination therapy was also at least as well-tolerated as tazarotene monotherapy. The adjunctive use of clindamycin/benzoyl peroxide gel with tazarotene cream promotes greater efficacy and may also enhance tolerability. Any improvements in tolerability could be due to the emollients in the clindamycin/benzoyl peroxide gel formulation.     

Combined effect of anti-inflammatory dose doxycycline (40-mg doxycycline, usp monohydrate controlled-release capsules) and metronidazole topical gel 1% in the treatment of rosacea

Research into the pathophysiology of rosacea suggests a central role for inflammatory mediators such as nitric oxide (NO), reactive oxygen species (ROS), and matrix metalloproteinases (MMPs). Effective treatments for rosacea, including topical metronidazole and systemic antibiotics, have anti-inflammatory activity, which may be more important than their antimicrobial activity in this setting. Phase III studies have substantiated the efficacy of anti-inflammatory dose doxycycline (40-mg doxycycline monohydrate controlled-release capsules) administered once daily for the treatment of inflammatory lesions of rosacea. Results of a 16-week, randomized, double-blind, placebo-controlled study of anti-inflammatory dose doxycycline plus topical metronidazole gel 1% for mild to moderate rosacea are presented here. At week 12, metronidazole was discontinued and patients continued on either placebo or doxycycline. Combination therapy significantly reduced inflammatory lesion counts as early as week 4 and through week 12 compared to topical metronidazole 1% gel monotherapy. The combined therapy appeared effective and well-tolerated.     

Short-term combination therapy and long-term relapse prevention in the treatment of severe acne vulgaris

Few long-term treatment regimens for severe acne vulgaris have been investigated in clinical trials. Data were combined from two consecutive, randomized, double-blind, controlled studies to evaluate the efficacy, safety and subject satisfaction of four nine-month regimens in severe acne vulgaris treatment. Subjects were first randomized to receive doxycycline (DCN) and adapalene 0.1% - benzoyl peroxide 2.5% (A/BPO) or vehicle once daily for 12 weeks. Subjects who had at least 50% global improvement were subsequently randomized to receive A/BPO or its vehicle once daily for 24 weeks. Over nine months, there were four regimens: A/BPO and DCN followed by A/BPO, vehicle and DCN followed by A/BPO, A/BPO and DCN followed by vehicle, and vehicle and DCN followed by vehicle. Among the four regimens, A/BPO and DCN followed by A/BPO led to the highest percentage of subjects rated "clear" or "almost clear" (50.0% vs. 40.4%, 26.2% and 25.0%, respectively), biggest reduction in total lesion counts (76% vs. 70%, 51% and 47%, respectively) and greatest subject satisfaction (85.0% vs. 75.5%, 63.3% and 52.4%, respectively) at week 36. It provided a faster onset of action compared to groups started with vehicle and DCN (P<.05 at week 2). Subjects receiving A/BPO and DCN followed by vehicle experienced deterioration once the active treatment was discontinued. All regimens were safe and well-tolerated. In conclusion, efficacious initial therapy and long-term treatment are both important. An initial combination therapy with adapalene-BPO and DCN followed by longer-term adapalene-BPO treatment is an efficacious and satisfactory new regimen for severe acne subjects.