As a rule of thumb any medication should be kept:
- below 25-30C
- not frozen
- out of the light
- dry
The US army has shown the typical 2 year expiry date on medications does not mean they are inactive. In fact they have a thing called the SLEP (Shelf Life Expiry Program) which in effect says don’t throw stockpiled medications out when they pass their expiry date.
http://www.astho.org/Programs/Preparedness/Public-Health-Emergency-Law/Emergency-Use-Authorization-Toolkit/Federal-Shelf-Life-Extension-Program-Fact-Sheet/
Please note that the US Army keeps their medications in environmentally controlled conditions, rather like wine buffs. Cool, dry and out of the light.
This article is interesting:
http://www.huffingtonpost.com/2012/10/09/expired-medications-drugs-potency-effective_n_1949481.html?ir=Australia
Be aware that tetracycline (for example) is an antibiotic medication that really does “goes off”. I have not looked up the reference but you can.
The fact is that these new meds have not been around long enough to really know.
A typical shelf life cool, dry and out of the light is 2 years so 2-3 months will not matter.