Products
Hydroquinone is commercially available in many countries as a drug product as a cream (combination preparation). Monopreparations are also available in some countries.
Structure and properties
Hydroquinone (C6H6O2, Mr = 110.1 g/mol) or 1,4-dihydroxybenzene exists as a white crystalline powder that is very soluble in water. It belongs to the diphenols or dihydroxybenzenes.
Effects
Hydroquinone (ATC D11AX11) causes reversible depigmentation of the skin. The effects are due to inhibition of enzymatic oxidation of tyrosine to 3,4-dihydroxyphenylalanine (DOPA) and other metabolic processes in melanocytes. Sunlight can lead to repigmentation.
Indications
For symptomatic treatment of melanin-related hyperpigmentation of the skin.
Dosage
According to the SmPC. Treated skin sites should not be exposed to intense sunlight. The duration of treatment should be kept short. According to the professional information, it is seven weeks on average.
Contraindications
- Hypersensitivity
- Non-melanin pigmentation
- Vitiligo
- Melanoma and suspected melanoma
- Acute inflammation and eczema of the skin
- Application on wounds, damaged skin or on mucous membranes
- Children under 12 years
- Large area application
- Pregnancy and lactation
Full precautions can be found in the drug label.
Adverse effects
Possible adverse effects include skin reactions such as dry skin, redness, stinging, burning, and allergic reactions, including allergic contact dermatitis. Hydroquinone may cause a blue to black discoloration of the skin (ochronosis). Hydroquinone is controversial because it has shown mutagenic and clastogenic properties in cell cultures and in animal studies. It is also nephrotoxic. Therefore, the literature also recommends that it should no longer be used in dermatology (e.g., Westerhof, Kooyers, 2005).
