Experience With Apomorphine On-Demand Therapy in PD

Peter A. LeWitt, MD: In the United States, apomorphine has been marketed for about 15 years. I was involved in the original pivotal studies where it was tested in much the same fashion that it had been used in Europe in the 1980s, where it was first introduced. Subcutaneous apomorphine has an onset of effect that in our study led to more than 90% of OFF episodes being reverted to ON. We found very good tolerability of this medication in most patients when trimethobenzamide was used 3 times per day,in advance of doses.

Typically, this is thought to be a 4- to 5-hour antinausea effect. But what we have discovered over the years—and this has been published as well—is that many, if not most, patients don't need any antinausea drug, especially trimethobenzamide, for preventing adverse effects from apomorphine. It's more or less a mandatory plan to use it when patients are first started out on apomorphine and being titrated to find their optimal dose.

Certainly, some patients will experience adverse effects even with trimethobenzamide being given because it's hard to predict who is very sensitive to the therapy. We use a home care nurse to do that testing when patients are OFF in the morning to find out if they find the drug to be tolerable. But unfortunately, it's hard to predict whether someone is going to have a hypotensive episode, faint from the drug, or have severe vomiting, even with the lowest dose. The first experiences of getting started are the most uncertain.

But once a patient has had a uniform set of experiences with the drug, it might be that they can omit the use of trimethobenzamide as well as take personal responsibility for their own injections. Some patients have caregivers draw up the syringe and administer the drug into that patient’s arm or belly. But after a while, most patients can learn how to do it themselves. It becomes second nature.

One of the concerns about apomorphine is that of needle phobia. How many patients really want to stick themselves with needles? The diabetes community has certainly voted that this becomes a part of your life. In fact, the needles that are used for apomorphine injection are the same size range as those used for diabetes. Patients tell me that quite honestly, about half of injections are not even felt as needle sticks.

I think that the patient who starts to try this out, with a little bit of encouragement from physicians, will find that this is an acceptable therapy, especially given that the benefits of having control over OFF time can have a huge impact in improving quality of life. It may take caregivers and people in the support system to be part of that group of viewpoints that say, “Try it. See what it can do for you and then make your decision on how much you hate it,” before the patient says, “No way, I would never go there.” This is one of those forms of therapy that I've been quite positive toward because there are so many people who've used this. It's been a game changer for their independence, their self-confidence, and their safety going out into the world.