My pharmacy switched me from tri-sprintec to tri-previfem this month. why would they do that? should i be concerned?

Generic substitution: There are many medications that have generics choices. Pharmacies will often switch between generics depending on cost to them. You don't need to be worried. If you do notice a change in side effects you can consider changing pharmacies or ask your doctor to change your prescription.

Because that is: The generic they made a deal with both pills are generic but you may or may not like the new pill as much since it may have different amounts of hormones, i always prescribe brand name pills for my pts, use generics for other meds, my #1 pill is loloestrin by law a brand name has to have 90% of the active drug and most have 98%, a generic only has to have 72% at the least which can cause problems!