Dear Dr. Sherer, Why do you recommend taking Kaletra once a day rather than twice a day?

I've been taking Kaletra for 2 years and 4 months twice a day. Should I switch to once a day?

Thank you very much!

I recommend both, i.e., taking Kaletra once daily or twice daily, since both have been shown to be equally effective. I like to let patients choose what works for them.

The most recent US HHS guidelines -- which were just updated today, Nov 3, 2008 -- agree that either once or twice daily Kaletra are equally effective, and both appear on the preferred regimen list for initial antiretroviral therapy.

Once daily Kaletra achieves drug levels that are roughly 60% of those with twice daily dosing. This level is more than adequate to achieve high blood levels. If a patient on Kaletra has had previous regimens with PIs in them, I would be more cautious about using the drug once daily.

In your case, if everything is working fine and no changes are needed, then I would support your continuing to take your medications twice daily. Similarly, if you are taking Kaletra after many other regimens in which PIs were used, I would be cautious and discuss once daily dosing with your doctor.

However, you might find that once daily medications are more convenient and easier to take. If Kaletra is the first PI that you have taken, if you have had no or minimal side effects with your current regimen, and if the Kaletra is given with two other medications that also can be given once daily, then I would suggest that you talk to your doctor about changing your regimen to once daily, since it may be easier to take. The only difference in side effects with the once daily medication has been a slightly higher incidence of loose stools -- 10% vs 5% -- with once daily treatment.

As above, I suggest that you talk to your doctor about this discussion.