A great deal of attention has focused on the possibility that people with a deep response to their CML medication may be able to stop treatment at some point. But perhaps a more important question is: why keep taking a medication every day? Is this necessary, or can I take a break now and then?
Many people do slip off the path of daily treatment from time to time. Recent studies have indicated that adherence to the medication regimen appears to be high – about 80-90% (Henk and colleagues. Clin Ther 2015;37:124-133; Dicus and colleagues. J Oncol Pharm Pract 2014; epublished June 5, 2014). But these numbers can be a bit misleading. Adherence is often defined as taking more than 80% of a medication as prescribed, which isn’t the ideal. And people have a tendency to be a little less diligent about their medication with time, with only two-thirds keeping to the program after a few years (Trivedi and colleagues. J Manag Care Pharm 2014;20:1006-1015).
Adherence to treatment has become an important issue in large part because many cancer drugs (such as the TKIs for CML) are now oral medications. Adherence wasn’t an issue when chemotherapies could only be administered by infusion in hospital.
Is 80% adherence to a CML medication good enough?
A study looked at how a person’s response to a TKI varied according to how well they kept to the medication regimen (Marin and colleagues. J Clin Oncol 2010;28:2381-2388; free full text at http://jco.ascopubs.org/content/28/14/2381.full.pdf+html). Overall, if a person took 90% or more of their medication, their chance of achieving a major molecular response (MMR; a 3-log reduction in BCR-ABL transcripts) over the course of six years of treatment was 94%. If they took less than 90%, their chances of achieving this same level of response was only 14%. Indeed, in the group that took 80% or less of their medication – so skipping 6 days a month – the likelihood of achieving MMR was 0.
So 80% adherence is far from good enough. Regular treatment is needed to reliably suppress the leukemia cells and prevent CML from progressing.
Here are a few tips to help you adhere more closely to what your doctor has prescribed.
1. Talk to your hematologist if you’re having problems with medication side effects, such as swelling, muscle cramps or bone pain. These can often be eased with a few simple strategies.
2. A common problem is simply forgetting to take the medication. So give yourself reminders – a note on the fridge or bathroom mirror, or an alarm your cell phone or tablet. Try using a pill box marked with the days of the week. Make pill taking part of your daily routine and schedule it, e.g. after you brush your teeth in the morning and/or at night. You can take Gleevec or Sprycel around mealtime, but you’ll need to take Tasigna on an empty stomach.
3. Don’t get caught short. If you’re planning a trip (even for a day or two), plan to visit the pharmacy to make sure you have enough pills while you’re away. Keep your medications in your hand luggage, not your checked bag, in case you arrive at your destination and your luggage doesn’t. Jot down your prescription number, and the telephone numbers of your pharmacist and doctor (with a copy to a family member) in case you need an emergency refill.