Hydroquinone
Class: Depigmenting Agents
ATC Class: D11AX11
VA Class: DE900
Chemical Name: 1,4 p-dihydroxybenzene
Molecular Formula: C6H6O2
CAS Number: 123-31-9
Brands: Aclaro PD, Eldopaque Forte, Eldoquin Forte, EpiQuin Micro, Lustra, Lustra-Ultra, Melpaque HP, Melquin
Introduction
Depigmenting agent; structurally related to monobenzone.
Uses for Hydroquinone
Hyperpigmentation
Used to reduce hyperpigmentation in conditions such as freckling (ephelides), inactive chloasma, melasma, generalized and senile lentigo, and other unwanted areas of melanin hyperpigmentation.
Used for gradual treatment of ultraviolet-induced dyschromia and skin discoloration resulting from the use of oral contraceptives, pregnancy, hormone replacement therapy, or skin trauma.
Most clinicians consider hydroquinone to be useful in some patients with hyperpigmentation in which a large excess of melanin is not being produced.
Has been used to reduce hyperpigmentation caused by photosensitization associated with inflammation or with the use of certain perfumes.
Used in combination with fluocinolone and tretinoin for short-term and intermittent long-term treatment of moderate to severe melasma.
Hydroquinone Dosage and Administration
General
Depigmentation varies among patients in completeness, time of onset, and duration; rarely completely reduces hyperpigmentation and some patients exhibit no response to the drug.
May require 1–4 months for depigmentation effects to occur. Following discontinuance of hydroquinone, depigmentation effects usually persist for 2–6 months.
Avoid unnecessary exposure to sunlight during and after therapy.
Prior to initiating therapy, assess the risk of irritation or allergic reactions by applying a small amount of hydroquinone preparation to an area of unbroken skin. After 24 hours, examine test site; discontinue treatment if itching, vesicle formation, or excessive inflammation occurs; however, minor redness is not a contraindication for further treatment.
Administration
Topical Administration
Apply topically to the skin as a cream, gel, emulsion, or solution. (See Sensitivity Reactions under Cautions.)
Limit application to an area equal to that of the face and neck or hands and arms.
For dermatologic use only; avoid contact with eyes. If such contact occurs, flush the affected eye(s) with copious amounts of water and contact a clinician.
Not for oral administration.
Apply hydroquinone cream, gel, emulsion, or solution (with or without sunscreens) uniformly to pigmented area and rub into skin. Do not rub cream containing opaque sunblocking agents (e.g., talc) into the skin.
If hydroquinone preparations without sunscreen agents are applied during the daytime, use sunscreen agents and/or protective clothing to minimize exposure and prevent repigmentation of treated areas; alternatively, apply these preparations only at nig...
