How long in terms of hours does a person have to wait to take colcryss otherwise known as colchicine if he had eaten grapefruit?

Answer 1

Persons taking colchicine are advised not to consume grapefruit at all, for the duration of their treatment. The risk being that grapefruit interacts with colchicine in a way which elevates the potency of the drug, increasing serum concentration levels, potentially leading to overdosing/toxicity side-effects. The level of reaction a person experiences correlates to how much grapefruit they consume - the greater the amount of grapefruit, the bigger the reaction.

Although you are thinking ahead to your next dose, it is important to point out that colchicine has a half-life (time it takes for half of it to be excreted from your system) of about 10 hours, and assuming your drug regime is twice-daily, there would still have been some colchicine in your system when you consumed the grapfruit. It is because of this that there is no "safe" time in the day to ingest grapefruit.

In this instance, the safest thing is probably to wait at least four hours between consuming the grapefruit and your dose of colcincine, since by this time you should have digested most of the grapefruit. However if your dosing regime is "once daily", just move it to as late in the day as possible and gradually move it back to your usual time over the subsequent few days.