For the patient assistance programs, they are usually tied specifically with the drug company for the drugs you are on.....some I have found are:
http://www.rxassist.org/
http://www.patientassistance.com/
www.needymeds.org/

google "patient assistance programs" & you get pages of options

The drug store I use is CVS....all over the US.....they seem to have some low cost drug assistance.....the cost changes from month to month & they go through different ones to find the least cost to the person......don't know exactly how it works....but I have purchased several months of my dog's heart medication for about $4.00.....a lot different than the $68 my vet wanted to charge for the same med.