Hello Dr. I know Isentress is available for once-daily dosing. This new dosage is two 600-mg tablets taken once a day. I am currently on 400 mg tablets taken twice a day. Although it would be easier to take a medication just once a day, wouldn’t I be better off to continue to take it twice a day if I can get the same effect but have to take 400 mg less of the drug daily? Wouldn’t that be a little easier on my kidneys to have to process less of a drug?

Response from Dr. Young

Yes, there is a new once-daily formulation of the HIV integrase inhibitor raltegravir, called Isentress HD. Isentress HD differs from the original twice-daily Isentress in formulation, resulting in better drug levels over a 24 hour period. Isentress HD is taken as 2, 600 mg tablets once daily while Isentress is 400 mg twice daily. The two cannot be interchanged. In a large clinical trial, there was no difference in effectiveness toxicity or side effect profile between the two formulations.

Since raltegravir (like other HIV integrase inhibitors) is metabolized by the liver, there’s no effect on kidneys.

We’ve found that our clinic patients who are taking twice daily Isentress have successfully transitioned to the newer, once-daily Isentress HD without issue, and indeed, most prefer the once-daily dosing, even if their daily pill number didn’t change.