Pain drugs may affect memory:

A new class of pain drugs may also interfere with important brain functions like learning and memory, US researchers said on Wednesday. The finding may have implications for drug development, and it may also help explain some of the psychiatric side effects of the Sanofi-Aventis weight-loss pill rimonabant, which is sold in Europe as Acomplia, they said. The drugs block a specific pain receptor-a molecular doorway-known as TRPV1 "We’ve known that TRPV1 receptors are in the brain, but this is the first evidence of what they do there," Julie Kauer of Brown University in Rhode Island said in a statement.