I am currently taking 90 mg every 4 hours... but it depends on what works best for you.

Every 3-4 hours is the best option, as it only lasts between 3-6 hours in the body.

Most doctors stick to every 4 hours, or some say 3 times a day, which is very imprecise. But I think that doctors worry that we, the patients, cannot cope with simple instructions like "every 4 hours" so hope that 3 times a day will be with each meal.