Dithranol

Topical/Cutaneous
Subacute and chronic psoriasis

Patients w/ very fair skin: Conventional treatment: As 0.05% oint/paste: Apply onto the affected lesions for a few hr before washing off. May increase strength gradually as required from 0.5-1% and the duration of contact extended to overnight periods or longer.

Acute pustular psoriasis or inflamed skin.

Patient w/ fair skin. Childn. Pregnancy and lactation.

Burning sensation esp on perilesional skin, temporary staining of skin and hair; skin irritation and/or warmth feeling on application site.

Topical: C

Avoid eye contact and on sensitive skin area.

Symptoms: Burning and deep staining of the skin. Management: Rinse first w/ water only and then wash at a temp not exceeding 30°C.

May enhance the effect of photosensitising drugs. Propylene glycol-containing drugs may oxidise or inactivate dithranol. Withdrawal of long term steroids in psoriasis may cause rebound phenomenon.

Description:
Mechanism of Action: Dithranol reduces the mitotic rate and proliferation of epidermal cells in psoriasis by inhibiting DNA replication, cellular respiration and key cellular enzymes.
Pharmacokinetics:
Absorption: Penetrates more into skin w/ impaired stratum corneum barrier than into intact skin. Reaches max concentration after 30-60 min contact time.
Distribution: Distributed in the horny layer of the skin (high concentrations of unchanged dithranol) and in the dermal layers (small amounts of unoxidised dithranol and high concentrations of dithranol dimer).
Metabolism: Unstable dithranol is oxidised to danthron dimer and further to insoluble polymerisation products.
Excretion: Small amounts of oxidised dithranol have been detected in urine.

Store between 15-30°C. Protect from excessive heat.

Psoriasis, Seborrhea & Ichthyosis Preparations

D05AC01 - dithranol ; Belongs to the class of topical antracen derivative agent used in the treatment of psoriasis.

AFT Pharmaceuticals Ltd. Micanol data sheet 24 July 2007. Medsafe. http://www.medsafe.govt.nz/. Accessed 14/04/2016 .

Anon. Anthralin . Lexicomp Online. Hudson, Ohio. Wolters Kluwer Clinical Drug Information, Inc. https://online.lexi.com. Accessed 14/04/2016.

Buckingham R (ed). Dithranol. Martindale: The Complete Drug Reference [online]. London. Pharmaceutical Press. https://www.medicinescomplete.com. Accessed 14/04/2016 .

Joint Formulary Committee. Dithranol (Anthralin). British National Formulary [online]. London. BMJ Group and Pharmaceutical Press. https://www.medicinescomplete.com. Accessed 14/04/2016 .