easy locking medicine products?

Hi all, now that my husband and I both have a number of medications, especially medications that we tried but aren't using and are waiting for the next medication take-back day, we would love any ideas or recommendations for locking medicine. I was thinking of small cash-box style combo locks (b/c I will lose the keys) b/c we keep meds in multiple places (bedroom, bathroom, and kitchen), and maybe a locking pill cover for ones kept in a purse?