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86 CPD ACTIVITY ADAPALENE FOR ACNE Table 1. Summary of the interim decision of the ACMS to reschedule adapalene to S3 (March 2020, confirmed August 2020).1 Dr Brett MacFarlane Brett is the Chief Pharmacist at the Australasian College of Pharmacy. He also contributes to the college’s development activities and its educational products. Dr MacFarlane is also a visiting fellow in the School of Clinical Sciences, Faculty of Health at the Queensland University of Technology. He graduated with honours from the School of Pharmacy at the University of Queensland and has worked for the Therapeutics Research Group at the Princess Alexandra Hospital Southern Clinical School in Brisbane where he gained a PhD in skin science. Inquiries: brett.macfarlane@acp.edu.au Consideration Reasons Risks Benefits Toxicity Product Misuse Acne • • • • • • • • Adapalene can cause local skin irritation, photosensitivity reactions and is a potential teratogen. Data on photocarcinogenicity in humans is unclear but animal data suggests an increased risk. Extensive history of broad use for comedo, papular and pustular acne on the face, chest and back. Low systemic toxicity when applied topically. Highoraldosesinanimalsandhightopicaldosesinhumansshownoteratogeniceffects. Adapalene 0.1% is low concentration – a poor response to 0.1% adapalene will trigger a doctor referral for reassessment. Potential for label advice to limit adverse effects with warnings about pregnancy and breast feeding, skin sensitivity and the importance of concomitant use of sunscreen. S3 adapalene is restricted to acne only, not for cosmetic/anti-ageing use. LEARNING OBJECTIVES After completing this CPD activity, pharmacists should be able to: • Describe the cause and classification of acne vulgaris • Discuss the safe and effective use of S3 topical adapalene 0.1% for the treatment of acne vulgaris 2016 Competency Standards: 1.3, 2.2, 2.3, 3.1, 3.2, 3.5. Accreditation Number: A2011RP3 (Exp. 31/10/2022). In August 2020, the Therapeutic Goods Administration Advisory Committee on Medicines Scheduling (ACMS) announced a change to the Poison Standard to include topical preparations of adapalene containing 0.1% or less in Schedule 3 (S3), enabling recommendation and supply by pharmacists for the treatment of acne vulgaris in adults and children over 12 years of age. The announced change will be implemented on 1 June 2021.1 This is a perfect opportunity for pharmacists to upskill in this area, as adapalene 0.1% will be the first ‘potent’ topical vitamin A derivative available in Australia to treat acne without prescription. The ACMS decision The final decision of the ACMS in August 2020 was to confirm the March 2020 interim decision to reschedule topical adapalene 0.1% from prescription only (S4) to S3. A summary of the interim decision is presented in Table 1. The reason for the decision to change the scheduling of adapalene 0.1% to S3 was based on the confidence of the ACMS that pharmacists are suitably qualified to limit the risks of adapalene to patients and ensure its safe and efficacious use.2 To understand where topical adapalene fits into the treatment of acne, it’s imperative to understand how acne develops and how it’s classified. Acne vulgaris is common. It primarily affects adolescents due to increase in circulating androgens but can occur in a small percentage of people as late as the sixth and seventh decades of life. Males often experience more severe acne than females during adolescence, which then resolves, while females tend to continue to have acne into adulthood. Acne is a chronic inflammatory skin condition affecting the pilosebaceous unit (hair follicle, erector pili muscle and sebaceous gland). Sebum is produced by the gland under the influence of circulating androgens. Acne primarily affects areas of the skin highest in sebaceous glands (face, chest and upper back). A common mistake is to think of acne as having an infective origin (involving Cutibacterium acnes, formerly known as Propionibacterium acnes). While C. acnes plays a role, it’s important to think of the development of acne as a cascade, whereby C. acnes infection is just one component. The cascade of acne development is presented in Table 2. Acne is classified based on severity (mild- moderate-severe), which is determined by the number and type of acne lesions present, the presence of inflammatory lesions, and the surface area of skin affected. Acne classification can be somewhat subjective and therefore there is crossover between the classifications of severity, which follows on to the way acne is treated. The effect of acne on the patient’s emotional state and quality of life should also be considered when determining severity and treatment. However, such a consideration is outside the scope of this article. Acne is a combination of the different types of lesions listed below. The presence of pustules without comedones indicates it isn’t acne and another cause should be investigated. Acne lesions3 Comedones: Pores blocked by corneocyte plugs causing small non-inflammatory ‘spotty’ lesions. Comedones can either be open at the skin surface (blackheads) or closed (whiteheads). Papules and pustules (papulopustules): As inflammation develops within the pore, raised red lesions (papules) develop. If pus is evident within the lesion, they’re called pustules. Nodules and cysts: As inflammation spreads outside of the pore, larger nodules (hard, sore lumps under the skin) or cysts (large, deep, pus filled lesions) develop. Nodules and cysts are more likely to result in scarring. Acne severity2 Mild: a few comedones and papulopustules (eg, <30 in total), no scarring, often limited to the forehead, nose, cheeks and chin (T-zone). Moderate: numerous comedones and papulopustules (eg, up to 125 in total), some nodules, no scarring, extensive coverage of face and sometimes trunk. Severe: nodules and cysts (nodulocystic) (eg, >5) and scars over the face and sometimes trunk. Treatment of mild-moderate acne The primary care role of pharmacists extends across all severities of acne from advice on lifestyle and recommendation of over-the-counter treatments for mild acne to counselling about the safe and effective RETAIL PHARMACY • NOV/DEC 2020 2 CPD CREDITS