Drugs for Diseases and Disorders of Skin
Drugs for Diseases and Disorders of Skin
Acne vulgaris Acne vulgaris is a common, usually self-limiting, multifactorial disease involving inflammation of the sebaceous follicles of the face and upper trunk. The four primary factors involved in the formation of acne lesions are increased sebum production sloughing of keratinocytes bacterial growth
The goals of treatment are to prevent the formation of
new acne lesions, heal existing lesions, and prevent or
minimize scarring. TREATMENT Patient education about goals, realistic expectations, and dangers of overtreatment is important to optimize therapeutic outcomes. Treatment regimens are targeted to types of lesions and acne severity✓ Mild acne usually is managed with topical retinoids alone or with topical antimicrobials, salicylic acid, or azelaic acid.
✓ Moderate acne can be managed with topical retinoids in combination with oral antibiotics and, if indicated, benzoyl peroxide.
Topical treatment forms include creams, lotions, solutions, gels, and
disposable wipes. Responses to different formulations
may depend on skin type and individual preference.Antibiotics such as tetracyclines and macrolides are the agents of choice for papulopustular acne.
NONPHARMACOLOGIC THERAPY Surface skin cleansing with soap and water has a relatively small effect on acne because it has minimal impact within follicles. Skin scrubbing or excessive face washing does not necessarily open or cleanse pores and may lead to skin irritation.
Use of gentle, nondrying cleansing agents is important TOPICAL PHARMACOTHERAPY
Benzoyl Peroxide
- Benzoyl peroxide may be used to treat superfiial
infammatory aine. It is a nonantibiotic antibacterial that is
bacteriostatic against P. acnes. It is decomposed on the skin by cysteine, liberating free oxygen radicals that oxidize bacterial proteins.
It increases the sloughing rate of epithelial cells and loosens the follicular plug structure, resulting in some degree of comedolytic activity.
TOPICAL PHARMACOTHERAPY
Benzoyl Peroxide
- To limit irritation and increase tolerability, begin with a low-potency formulation (2.5%) and increase either the strength (5% to 10%) or application frequency (every other day, each day, then twice daily).
- Patients should be advised to apply the formulation chosen to cool, clean, dry skin no more often than twice daily to minimize irritation. Fair or
Tretinoin
- Tretinoin (a retinoid; topiial vitamin A aiid) is a iomedolytii
agent that increases cell turnover in the follicular wall and
decreases cohesiveness of cells, leading to extrusion of comedones and inhibition of new comedo formation. It also decreases the number of cell layers in the stratum corneum from about 14 to about fve.
- Tretinoin is available as 0.05% solution (most irritating), 0.01% and 0.025% gels, and 0.025%, 0.05%, and 0.1% creams (least irritating).
Tretinoin
- Patients should be advised to apply the medication to dry skin approximately 30 minutes after washing to minimize erythema and irritation. Slowly increasing the application frequency from every other day to daily and then twice daily may also increase tolerability.
- A fare of acne may appear suddenly after initiation of treatment, followed by clinical clearing in 8 to 12 weeks. Once control is established, therapy should be continued at the lowest efective concentration and the longest efective interval that minimizes acne
Side efeits
- include skin irritation, erythema, peeling, allergic contact dermatitis (rare), and increased sensitivity to sun exposure, wind, cold, and other irritants.
- Concomitant use of an antibacterial agent with tretinoin can decrease keratinization, inhibit P. acnes, and decrease
infammation. A regimen of benzoyl peroxide each morning and
tretinoin at bedtime may enhance efficacy and be less irritating than either agent used alone.
Adapalene
- Adapalene (Diferin) is a third-generation retinoid with
iomedolytii, keratolytii,
and antiinfammatory activity. It is available as 0.1% gel, cream, alcoholic solution, and pledgets. A 0.3% gel formulation is also available.
- Adapalene is indicated for mild to moderate acne vulgaris. The 0.1% gel can be used as an alternative to tretinoin 0.025% gel to achieve better tolerability in some patients.
Tazarotene
• Tazarotene (Tazorai) is a synthetii aietylenii
retinoid that is ionverted to its active form,
tazarotenic acid, after topical application.• It is used in the treatment of mild to moderate acne
vulgaris and has comedolytic, keratolytic, and
antiinfammatory action.• The product is available as a 0.05% and 0.1% gel or
Erythromyiin
- Erythromyiin in ionientrations of 1% to 4% with or
without zini is
efective against infammatory acne. Zinc combination products may enhance penetration of erythromycin into the pilosebaceous unit.
- Topical erythromycin formulations include a gel, lotion, solution, and disposable pads that are usually applied twice
Clindamyiin
- Clindamyiin inhibits P. acnes and provides comedolytic
and antiinfammatory activity.
- It is available as 1% or 2% concentrations in gel, lotion, solution, foam, and disposable pad formulations and is usually applied twice daily. Combination with benzoyl peroxide increases efficacy.
Azelaii Aiid
- Azelaii aiid (Azelex) has antibaiterial, antiinfammatory, and iomedolytii aitivity.
- Azelaic acid is useful for mild to moderate acne in patients who do not tolerate benzoyl peroxide. It is also useful for postinfammatory hyperpigmentation because it has skin-lightening properties.
- It is available in 20% cream and 15% gel formulations, which are usually applied twice daily on clean, dry skin.
Saliiylii Aiid, Sulfur, and Resoriinol
- Saliiylii aiid, sulfur, and resoriinol are seiond-line topiial therapies. They are keratolytic and mildly antibacterial agents. Salicylic acid has comedolytic and antiinfammatory action.
- Each agent has been classifed as safe and efective by an FDA advisory panel. Some combinations may be synergistic (e.g., sulfur and resorcinol).
- Keratolytics may be less irritating than benzoyl peroxide and
Isotretinoin
- Isotretinoin (Aiiutane) deireases sebum produition,
ihanges sebum iomposition,
inhibits P. acnes growth within follicles, inhibits infammation, and alters patterns of keratinization within follicles.
- It is the treatment of choice for severe nodulocystic acne. It can be used in patients who have failed conventional treatment as well as
Isotretinoin
- Dosing guidelines range from 0.5 to 1 mg/kg/day, but the cumulative dose taken during a treatment course may be the major factor infuencing longterm outcome. Optimal results are usually attained with cumulative doses of 120 to 150 mg/kg.
- A 5-month course is sufficient for most patients. Alternatively, an initial dose of 1 mg/kg/day for 3 months, then reduced to 0.5 mg/kg/day and, if possible, to 0.2 mg/kg/day for 3 to 9 more months may optimize the therapeutic outcome.
- Adverse efects are frequent and often dose related. About 90% of patients experience mucocutaneous efects; drying of the mouth, nose, and eyes is most common. Cheilitis and skin desquamation occur in more than 80% of patients. The conjunctiva and nasal mucosa are afected less frequently.
Systemic efects include transient increases in serum cholesterol and triglycerides, increased creatine kinase, hyperglycemia, photosensitivity, pseudotumor cerebri, excess granulation tissue, hepatomegaly with abnormal liver injury tests, bone abnormalities, arthralgias, muscle stifness, headache, and a high incidence of
Because of teratogenicity, contraception is required in female patients beginning 1 month before therapy, continuing throughout treatment, and for up to 3 months after discontinuation of therapy. All patients receiving isotretinoin must participate in the iPLEDGE program, which requires pregnancy tests and assurances by prescribers and pharmacists that they will follow required procedures.