| name | Hydroquinone |
| classification | Skin-lightening agent, Tyrosinase inhibitor |
| pharmacokinetics | Hydroquinone is readily absorbed through the skin. It inhibits tyrosinase, an enzyme involved in melanin production. The elimination half-life varies, but is generally considered to be relatively short, with significant amounts being cleared within 24-48 hours. Metabolism primarily occurs in the liver. |
| suggested dosage | Hydroquinone is typically available in various concentrations (e.g., 2%, 4%, 6%, 8%). Dosage and frequency depend heavily on the individual's skin condition and response, and should be determined by a dermatologist. Self-treating with hydroquinone is not recommended and can be harmful. Use only under medical supervision. |
| indications | Treatment of hyperpigmentation, such as melasma (chloasma), freckles, age spots, and post-inflammatory hyperpigmentation (PIH). |
| safety in pregnancy | Hydroquinone use in pregnancy is generally considered to be a category C drug, meaning that risks to the fetus have not been ruled out. There are insufficient data to confirm safety, therefore the use of hydroquinone during pregnancy should be avoided. If a woman of childbearing age is prescribed hydroquinone, careful consideration of the need for the treatment must be made. |
| safety in breastfeeding | Hydroquinone is not known to be excreted in breast milk. However, its safety during breastfeeding has not been definitively studied, so use is discouraged. |
| side effects | | 1 | Skin irritation (e.g., redness, dryness, itching) | | 2 | Skin discoloration (e.g., hypopigmentation – lightening of skin in treated areas) | | 3 | Photosensitivity (increased skin sensitivity to sunlight) | | 4 | Allergic reactions (e.g., rash, hives) | | 5 | Contact dermatitis |
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| alternatives | |
| contraindications | | 1 | Known hypersensitivity or allergy to hydroquinone | | 2 | Open skin lesions or wounds in the treatment area | | 3 | Use in children below the recommended age (often not appropriate under 18) |
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| interactions | Hydroquinone may interact with other medications or topical agents. Consult with a physician before use if other medications are being taken. |
| warnings and precautions | | 1 | Start with a low concentration and gradually increase as tolerated. | | 2 | Avoid prolonged sun exposure when using hydroquinone. | | 3 | Apply sunscreen with high SPF daily to protect the treated skin. | | 4 | Do not use in large amounts or areas. | | 5 | Discontinue use if skin irritation occurs. | | 6 | Use under a physician's supervision for effective and safe treatment | | 7 | Be aware of the potential for hyperpigmentation in other skin areas after stopping treatment |
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| additional informations | | 1 | Hydroquinone should only be used for skin-related hyperpigmentation issues, as there are other potential treatments for other skin conditions. | | 2 | Long-term use of high concentrations of hydroquinone should be avoided unless medically necessary and closely monitored. | | 3 | Hydroquinone should not be used as a replacement for sun protection measures. Always use sunscreen! |
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| patient specific considerations | | age | 25 | | weight | 70 kg | | notes | The patient's age and weight do not significantly alter the drug's safety profile in this instance. However, a consultation with a dermatologist is essential to determine the appropriate concentration and usage method. |
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