Expert: Dr Alan Galbraith - 4/8/2009

Question
QUESTION: Respected Sir,

Many many regards from Harsvadan from India. I have a psoriasis for which I was first prescribed Betamethasone +salicylic acid 6 mg After 3 years, I was given clobetasol with slicylic acid Recently my dermatologist prescribed Mometasone with salicylic acid. I read in the leaflet that mometasone should not be used for more than 2 weeks and maximum is 50 mg. While I read elsewhere that Mometasone is mild potent steriod whereas clobetasol is very potent. My query is whether mometasone is mild as compared to clobetasole and whether prolonged use of either cause any problem ? Mometasone is very costly whereas clobetasole is cheaper To put it, cost of cream 10 gm having mometsaone with salicylic acid is  equal to clobetasole with salicylic acid 20 gm cream and that mometasone is said to be mild than clobetsaole. When I asked my dr as to why she is prescribing mometasone with salicylic acid, she said it is milder thatn clobetasole. I am confused. Should I continue clobetasole with salicylic acid or betamethasone with salicylic acid because my overall psoriasis is under control with all three molecule with occassional flare up that too mild. Can U guide me.

ANSWER: Dear Harsvadan

Good to hear from you again.

I need some more information from you before I can answer your question properly. I have to know the ester of the corticosteroid ie is it clobetasol propionate or is it clobetasone butyrate. I think you will mean the former but in case I am wrong can you tell me this? I'll answer tomorrow as I am just about to go to bed.


Regards

Alan Galbraith

---------- FOLLOW-UP ----------

QUESTION: it is clobetasol propionate I am eagerly awaiting your response. Alos let me know whether prolonged use of clobetasol/betamethasone or mometasone harmful as you will agree that psoriasis is  requires continuous treatment.

Secondly, my colleague who has also psoriasis is tellinf me that we have to keep on changing the cream i.e. clobetasole to betamethasone or like because after sometime, the same looses its efficacy. Is it so that we need to change the cream every interval. I think this is myth but unsure

Answer
Dear Harsvadan

Clobetasol propionate is more potent than the mometasone so should work better and I see no valid reason to change to the mometasone, especially when it is more expensive. These creams are used sometimes for many years in cases of psoriasis but sometimes can have detrimental effects on the skin and some due to absorption into the circulation. With the latter ointments cause more problems than the creams though. The main effect on the skin is atrophy (shrinkage and lack of tone. The systemic effects are reversible but you'd be better discussing this with your doctor as they are complicarted and I do not want to alarm you by giving you a list of symptoms which may not occur and are difficult to explain in layterms over the Internet, They involve suppression of adrenal gland function and you could Google adrenal insufficiency for details. If your dermatologist wants to change you to a less potent corticosteroid there are many much cheaper than mometasone.

Regards

Alan Galbraith