- Any prescription medications or over-the-counter medications including herbal products (eg, St. John's Wort, milk thistle), antacids and nonsteroidal anti-inflammatory medication for acute pain for more than 5 days within 30 days (or 5 elimination half-lives, whichever is longer) of commencing study drug dosing, with the exception of hormonal contraceptives (oral, implant, patch or injections), including Depo-Provera®. For drugs with an elimination half-life greater than 10 days, the prohibition of prior use will be extended to 60 days.