Drugs for acne vulgaris

Acne vulgaris is a self-limited disorder primarily of teenagers and young adults. It occurs due to increase in sebum production by sebaceous glands after puberty. Small cysts, called comedones , form in hair follicles due to blockage of the follicular orifice by retention of keratinous material and sebum. The activity of bacteria (Proprionobacterium acnes) within the comedones releases free fatty acids from sebum, causes inflammation within the cyst.
The drugs can be given by either topical route or by systemic route
Topical therapy includes Benzyl benzoate, retinoic acid, Adapalene, topical antibiotics & azelaic acid
Benzyl benzoate:
It gradually liberate oxygen which kills bacteria
Keratolytic
Comedolytic
Induce mild desquamation
Adverse effects: Burning & stinging sensation, dryness of skin, scaling, erythema etc
Avoid contact with eyes, lips & mucous membranes
It is used in the form of cream, gel or lotion
Retinoic acid:
Comedolytic
Keratolytic
epidermal cell turn over is stimulated resulted in peeling
response is delayed
Adverse effects are warmth, stinging, redness, crusting & edema
used in form of cream or gel
It is teratogenic, so should be avoided during pregnancy
retinoic acid & benzoyl peroxide should not be applied together because benzyl peroxide promote degradation of retinoic acid

Adapalene: It is newer synthetic tretinoin like drug
It act by binding to nuclear retinoic acid receptor
Comedolytic
Keratolytic
Antiinflammatory
less irritating as compared to tretinoin
can be combined along with benzyl peroxide

Topical Antibiotics: Clindamycin, erythromycin & tetracyclines can be used topically in the form of cream, gel or lotion. Nadifloxacin is a newer topical quinolone broad spectrum antibiotic which can be used in inflammed acne & folliculitis
Azelaic acid:
Natural product from Pityorosporum ovale
Many Aerobic, anaerobic organism & P. acnes are inhibited
reduces bacterial density
reduces free fatty acid content of skin
reduces proliferation of keratinocytes
used in the form of cream
response is delayed
also used in melasma

Systemic therapy:
Indicated in severe cases with cyst & pustules
Antibiotics: Tetracycline, doxycyclines, Minocyclines & erythromycin are used
Isotretinoin or cis retinoic acid:
It is an orally administered retinoid
decrease production of sebum
correct abnormal keratinization
Adverse effects are dryness of skin, eyes, nose , mouth, chelitis, epistaxis, pruritus, rise in serum lipids & intracranial tension.
It is highly teratogenic, strictly contraindicated during pregnancy & one month after