Effect of Taking IB Every Other Day

[cll2013-2025]

I had not taken any meds on a regular basis until starting IB 2 1/2 years ago. In the rare instance over my 75 years that I required an antibiotic for a couple weeks, the Rx was always too powerful for my system. In other words, my body would respond with a lesser amount of drug. Can this be true with IB? I've been taking IB every other day since early June. I've had 2 blood checks since then and the count is holding steady. Last night I noticed the largest bruise I've had in the 5 1/2 years of CLL - - 2" x 3". Now I'm wondering if the every other day plan is a mistake. Appreciate your comments.

[AussieNeil Partner Administrator]

The FDA approved dose for CLL is 420mg per day, or 3 x 140mg tablets. You haven't shared what dose you are taking on alternate days. Unexpected bruising might be due to low platelets caused by your CLL or perhaps a side effect of the Ibrutinib.

Some find that going to a lower dose per day helps reduce side effects. but I haven't heard of anyone being prescribed Ibrutinib on alternate days. You really need to discuss this with your specialist. Ibrutinib clears out of the blood reasonably quickly (half life of 4 to 6 hours) and given it is important to maintain inhibition of CLL, I would have thought taking Ibrutinib every other day would put you at risk of your CLL not being maintained under control and likely increase your risk of developing resistance.

Neil

[MsLockYourPosts Passed Volunteer]

I have seen this a couple of times, and given what I know about Imbruvica ( just reading - I do not take it) it sends up red flags for me. My question, every time, is how much experience has your doctor had with it. The opinion of someone who has researched this drug from early trials would bear more weight for me than that of a community general oncologist. This would also seem to be something to get a second opinion about.

As you are in the US,if a second opinion in person is not possible look at cllsociety.org/ They now offer the option of a second opinion on line with a CLL specialist for free.

[PlanetaryKim]

My personal opinion (as an ibrutinib user on reduced dose of 140 mg daily) is that it would be safer both in terms of side effects and in terms of effectively managing the CLL, to take a lower dose daily than the full dose every 2nd day. My understanding is that the BTK occupancy achieved by ibrutinib only lasts 24 hours, regardless of dosage. So if you dose every other day, you are controlling the CLL one day but not the next... Is this dosing plan coming from your doctor?

kim

[cll2013-2025 in reply to PlanetaryKim]

I cannot take a lower dose as the pill is the full 420 mg. I am trying this out and haven't discussed it with my oncologist.

I have heard variations of how long it stays in a person's system. The 24-hours is probably closest to the correct time.

[AussieNeil Partner Administrator in reply to cll2013-2025]

According to Drugs.com: drugs.com/ppa/ibrutinib.html, the elimination half life of Ibrutinib is 4 to 6 hours, so after 24 hours you indeed have very little Ibrutinib remaining in your body. At best you would have about 3% remaining after 30 hours. So you aren't maintaining control over your CLL and I suspect you are setting yourself up for the development of early resistance.

After public pressure, the manufacturer reversed their decision to move to the supply of one 420mg tablet, so you should be able to get the 140mg tablets to adjust your dose in discussion with your oncologist.