RABITO DITHRANOL OINTMENT

Indications

• Chronic lichenified eczema
• Subacute and chronic psoriasis
• Scaly scalp disorders such as psoriasis and seborrhoeic dermatitis

Dosage

Children: For children, consult product literature; typically, Dithranol 0.1–0.5% cream may be suitable for overnight treatment, while 1–2% cream can be used for a maximum of 1 hour.

Adults: For adults, the application of Dithranol cream varies based on the concentration and the specific product used; consult local protocols or product literature for guidance.

Mechanism of action

Dithranol inhibits the proliferation of keratinocytes and prevents T-cell activation, likely through mitochondrial dysfunction. It promotes cell differentiation and normalizes epidermal cell proliferation by blocking DNA synthesis and increasing the release of reactive oxygen species. This action leads to a reduction in mitotic activity within the hyperplastic epidermis, thereby controlling skin growth and keratinization.

Pharmacodynamics

Dithranol is an anti-psoriatic and anti-inflammatory agent that controls skin growth by reducing DNA synthesis and the mitotic activity in the epidermis. It normalizes the rate of cell proliferation and keratinization, leading to therapeutic effects in inflammatory skin conditions. Its effectiveness is attributed to its ability to promote lipid peroxidation and reduce elevated levels of endothelial adhesion molecules found in psoriatic patients.

Pharmacokinetics

Dithranol is applied topically and is not absorbed significantly through the skin. Due to its localized application, systemic exposure is minimal. The onset of action varies, with initial improvements often seen within a few weeks of consistent use. The half-life and metabolism details in humans are not well-defined due to its topical nature.

Adverse effects

• Skin reactions
• Photosensitivity reactions

Precautions

• Avoid contact with normal skin when applying to chronic extensor plaques
• Hands should be protected by gloves during application or washed thoroughly afterwards
• May stain skin, hair, and fabrics

Pregnancy

No adverse effects reported.

Breast-feeding

No adverse effects reported.

Storage

Store in a cool, dry place below 25°C. Keep out of reach of children.

Formulations

• Dithrocream 0.1% cream
• Dithrocream 0.5% cream
• Dithrocream 1% cream
• Dithrocream 2% cream

Mechanism of action

Anthralin inhibits the proliferation of keratinocytes (epidermal skin cells), prevents the action of T-cells, and promotes cell differentiation, likely through mitochondrial dysfunction. In addition, the production of free radicals may contribute to its anti-psoriatic effect. In vitro studies demonstrate that anthralin prolongs the prophase component of mitosis for keratinocytes and leukocytes. Prophase is the first step of mitosis, the process separating the duplicated genetic material carried in the nucleus of a parent cell into two identical daughter cells. In vivo studies demonstrate that anthralin blocks DNA synthesis and can increase the release of reactive oxygen species. Anthralin is believed to normalize the rate of epidermal cell proliferation and keratinization by reducing the mitotic activity of the epidermal hyperplasia in psoriasis. Anti-proliferative and anti-inflammatory effects of anthralin have been demonstrated on both psoriatic and healthy skin. The anti-proliferative effects of anthralin are thought to be due to a combination of inhibition of DNA synthesis and its strong reducing properties. The effectiveness of anthralin as an anti-psoriatic agent is partly owed to its ability to promote lipid peroxidation and reduce the concentration of endothelial adhesion molecules, which are found to be elevated in psoriatic patients,. Recent studies suggest that its ability to prevent T-lymphocyte activation and normalize keratinocyte differentiation may occur by a direct effect on mitochondria.

Pharmacodynamics

Anthralin is a natural anthraquinone derivative, anti-psoriatic and anti-inflammatory agent. It controls skin growth by reducing the synthesis of DNA and the mitotic activity in the hyperplastic epidermis, normalizing the rate of cell proliferation and keratinization.