Sunday, August 14, 2005

Question about mometasone

We received this question by email. Any thoughts?

"I am a private practice pulmonologist and was just detailed re: mometasone DPI. The only dose is 220 ug, but it comes in 30, 60 and 120 dose units. The company is telling us that once the DPI is removed from the foil packaging the drug expires in 45 days. This seems to be a ploy to prevent 220 ug QD use with the 120 dose unit, which would be one of the most economical ICS. I searched the web looking data on mometasone stability, and it seems to be a stable molecule. Does anyone know any data? I smell a scam."

2 comments - CLICK HERE to read & add your own!:

Jeff H said...

The package insert contains the statement "Discard the inhaler 45 days after opening the foil pouch or when dose counter reads “00,” whichever comes first."

It comes in 30, 60, and 120 "unit" dose packs, with each dose 220mcg. The package insert also notes that the 60 unit pack is for "more than one inhalation daily" and that the 120 unit insert is for "more than two inhalations daily."

Looking at the recommended dosing, they show that for patients previously maintained on oral steroids, this drug can be titrated to 880 mcg/d. That's 4 inhalations, or 120 "units"/month.

So, it looks like the information you got was accurate, but that the detailer didn't know the dosing recommendations. Most patients should be maintained on doses of 220-440 mcg/d (one 30 unit or one 60 unit dose pack/month).

There is no comment about stability. I suspect the worry with > than 45 days is continued exposure to moisture/humidity (hence the statement "Store in a dry place at 25°C (77°F)" in the package insert. Obviously, moisture/humidity would not be a concern while in the foil packaging.

That said, the last part is pure speculation.

Baleeiro said...

I couldn't find anything on shelflife on Pubmed. The FDA site was not very useful either.
The PI for NAsonex does not contain that short shelflife warning so it might be something specific about the anhydrous powder (moisture as suggested by Jeff H).