As a rule of thumb any medication should be kept:
- below 25-30C
- not frozen
- out of the light
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.
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:
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.