Prescription medication is stocked at the Marin Medical Pharmacy in San Rafael. Pharmacist Benson Toy is alarmed by the skyrocketing costs of generic drugs, with some going up over 300 percent. Paul Chinn/San Francisco Chronicle photo

Pharmacist Benson Toy shakes ibuprofen into a pill counter. Nearly 80 percent of all the U.S. drugs dispensed are generics. Paul Chinn/San Francisco Chronicle photo

Advisory labels for prescription medications are arranged at the pharmacy. Paul Chinn/San Francisco Chronicle photo

Pharmacist Benson Toy shakes ibuprofen into a pill counter at the Marin Medical Pharmacy in San Rafael. Paul Chinn/San Francisco Chronicle photo