On 08/03/2017 10:07, Bill wrote:

Because of my persistent bad back

I find that the maximum dosage of Ibuprofen (400 mg) does not work for
me at all, even taken over a prolonged period. But a couple of doses of
600 mg does. Be aware of the serious risks from overdosing, though. And,
this is not a recommendation, just a comment on my personal experience.