Differin®: composition and pharmaceutical form
Differin® is an external preparation for acne. One gram of cream contains 1 mg of adapalene, which means the concentration of the active substance is 0.1%.
Among the excipients are propylene glycol and methyl parahydroxybenzoate, so the medicine can cause allergic reactions, including of the delayed type. The cream is intended solely for application to the skin: it is not taken by mouth and is not applied to the mucous membranes. The leaflet describes two external forms with the same adapalene content — a cream and a gel — and the rules of use for them are the same.
How Differin® works
Adapalene is a derivative of naphthalenecarboxylic acid. It does not react with oxygen and is not broken down by the action of light. In its effect adapalene is close to the retinoids: entering the cell, it binds to the nuclear retinoic acid receptors (RAR), changes gene expression and sets off the synthesis of new mRNA. Unlike the retinoids, it does not bind to the cytoplasmic receptors.
Applied to the skin, adapalene normalises the processes of keratinisation and differentiation of the epidermis. It is assumed that it puts the differentiation of the epithelium of the hair follicles in order, and this reduces the formation of comedones. Its anti-inflammatory action is more marked than that of the retinoids: it suppresses the chemotactic and chemokinetic reaction of the polymorphonuclear leucocytes and the peroxidation of arachidonic acid, limiting the formation of cellular mediators of inflammation. As a result the medicine both prevents the appearance of open and closed comedones and reduces the inflammatory elements — papules and pustules.
Indications
Differin® is used in acne vulgaris of mild and moderate severity.
This concerns two forms of the disease: comedonal acne, in which blackheads and closed comedones predominate, and papulopustular acne with inflammatory elements — papules and pustules. In severe forms of acne and when a large surface of skin is affected the medicine is not used: such cases call for different treatment, which is chosen by a doctor. An external preparation works where the process is limited and is not accompanied by deep nodules.
Method of use and dosage
The cream is applied once a day, better in the evening. Treatment begins with a small amount of the product, spread over the skin 10–15 minutes after washing and drying with a towel. The area around the eyes and lips, and also the nasolabial folds, are avoided. After applying the cream the hands must be washed thoroughly.
The result is assessed no earlier than after three months: if no improvement has come in that time, the decision on continuing treatment is taken by the doctor. Children under 12 are not prescribed the medicine. Applying the cream more often or in a larger amount is pointless — neither the speed nor the quality of the result grows from it, while the irritation of the skin does increase.
Contraindications
Differin® is not used in the following cases:
- hypersensitivity to adapalene or to any excipient of the medicine;
- severe forms of acne vulgaris;
- acne covering a large surface of the skin;
- damaged skin;
- skin with a suntan;
- eczema and other eruptions of non-acne origin in the area of application;
- pregnancy.
Special warnings and precautions
The medicine is intended for external use only. The lips, the eyes and the mucous membranes must be protected from contact with the product; if the cream does reach them, the place is rinsed with plenty of water. Soon after treatment begins, redness, irritation and dryness may appear on the face. In that case treatment is interrupted for several days, until these phenomena pass, and only then is the previous regimen resumed.
The sun and skincare during treatment
Adapalene reduces the thickness of the horny layer, so the skin becomes more sensitive both to ultraviolet light and to the medicines and cosmetics applied to it. During treatment excessive sun and ultraviolet exposure should be avoided, and a hat and sun protection filters used. Cosmetics for the care of problem skin and products with an astringent action are better set aside for the duration of the course. The excipients deserve a separate mention: propylene glycol and methyl parahydroxybenzoate are capable of causing allergic reactions, sometimes delayed in time. Children under 12 are not prescribed the cream. On the ability to drive a car and to operate machinery the medicine has no influence or only a negligible one.
Drug interactions
The cream should not be used at the same time as medicines with a similar mechanism of action or as other external preparations containing retinoids. Nor is it advisable to apply to the same skin products capable of irritating it: exfoliating and astringent preparations, scrubs and cleansers with an abrasive, and products containing alcohol.
Differin® can be combined with other acne preparations by separating them in time. Erythromycin 4%, clindamycin phosphate 1% and benzoyl peroxide 10% are applied in the morning, and the cream with adapalene in the evening.
Pregnancy and breastfeeding
In animal studies adapalene showed a toxic effect when taken by mouth in large doses. Clinical data on external use in pregnant women are few, and the information available does not point to a harmful influence on the course of the pregnancy or on the health of the foetus in the early stages. Nevertheless, because the volume of data is limited, the medicine is not used during pregnancy, and if a pregnancy occurs, treatment is stopped.
No studies of the passage of adapalene into the milk of animals or of women with external use have been carried out. No influence on the child is expected: applied to the skin, the effect of the medicine on the body of a breastfeeding woman is negligibly small, so the product is permitted during breastfeeding. To rule out contact of the child with the medicine, the cream is not applied to the breast area.
Adverse effects
The undesirable reactions are confined to the skin at the site of application and to the eyelids.
- common — dryness of the skin, irritation of the skin, a feeling of burning, redness;
- uncommon — contact dermatitis, eczema from irritation, a feeling of skin discomfort;
- uncommon — sunburn, itching, flaking of the skin, a flare of the acne;
- frequency not known — pain in the skin, swelling of the skin, allergic contact dermatitis;
- frequency not known — irritation of the eyelids, redness of the eyelids, itching of the eyelids, swelling of the eyelids.
The reactions of unknown frequency were identified only after the medicine came onto the market. Redness and flaking in the first weeks are an expected phenomenon: the skin is getting used to the action of adapalene. But if the irritation is marked or does not pass after a break of several days, one should see a doctor. The reactions of the eyelids deserve separate attention — they arise when the product accidentally reaches that area, so the cream must not be applied close to the eyes.
Overdose
Applying the medicine in an excessive amount does not speed up recovery and does not improve the result of treatment, but it can be the cause of noticeable redness, flaking and other signs of skin irritation.
In mice and rats toxic phenomena arose after oral doses above 10 g per kilogram of body weight. If the medicine has been swallowed accidentally, gastric lavage should be considered and a doctor consulted. If the irritation has arisen from applying it too often, treatment is interrupted for several days and then the usual regimen is resumed — one application a day.
How to get a prescription for Differin® online
Preparations containing adapalene are dispensed on prescription: a doctor must assess the form and severity of the acne and be satisfied that external treatment is enough.
During the online consultation the doctor will go through the state of the skin and the previous treatment, will explain the rules of application and of sun protection and will also ask which skincare products and other acne medicines you use. If there are no contraindications, they will issue an electronic prescription — the medicine can be collected from a pharmacy using its code.
