Last updated Feb. 7, 2022, by Teresa Carvalho, MS
Fact-checked by Ana de Barros, PhD
Apokyn (apomorphine hydrochloride) is used by injection to treat loss of body movement control in patients with advanced Parkinson’s disease between doses of levodopa treatment. It has the same effect as dopamine, a naturally occurring chemical messenger found in the brain. Low levels of dopamine are associated with Parkinson’s disease.
How Apokyn works
The U.S. Food and Drug Administration approved Apokyn in April 2004 to treat “off episodes” in people with advanced Parkinson’s disease. These episodes occur when levodopa-based treatments stop being effective, causing Parkinson’s motor symptoms to return, and can happen at any time of the day, multiple times a day.
Apokyn works by imitating the activity of dopamine in the brain to carry signals between brain cells, thereby helping with mobility. It does not prevent “off” episodes, but helps to improve symptoms when an “off” episode has begun.
Apokyn in clinical trials
The effectiveness of Apokyn to treat “off” episodes in patients with advanced Parkinson’s disease was established in three controlled clinical trials, leading to its approval in the U.S.
A Phase 4 open-label study (NCT01770145) of Apokyn injections was conducted in Parkinson’s patients with morning akinesia (absence of movement) resulting from delayed onset of their morning levodopa dose.
The study found that a once-daily injection of Apokyn significantly reduced time-to-on (the time when levodopa therapy is working) in patients experiencing delayed onset of their morning levodopa dose, and was well-tolerated in most patients.
A Phase 3 study (NCT02339064) assessed the safety and tolerability of a continuous subcutaneous (under-the-skin) infusion of Apokyn in 99 people with advanced Parkinson’s, whose “off” episodes remained uncontrolled with levodopa (or levodopa/carbidopa) and at least one other class of therapies. The primary objective of the study was to measure the percentage of daily “off” time while patients were awake. The results revealed that maintenance treatment with Apokyn was generally well-tolerated and associated with reduced “off” time by about 2.5 hours compared with the beginning of the study.
Another Phase 3 study (NCT02864004) is currently recruiting participants to assess the use of an Apokyn pump on quality of life for Parkinson’s patients in the earlier stages of the disease, when motor complications have just developed. The study is being conducted in France and expects to enroll 192 participants and be completed by June 2025.
Apokyn may be used up to five times a day, or as prescribed by a physician. The therapy is taken as a small injection under the skin, using a device similar to the one used for insulin injection in people with diabetes.
The medication starts working as soon as 10 minutes after the injection, with most people feeling relief from the “off” episode within 20 minutes. It’s usually effective for up to 90 minutes, so patients should not stop taking their other Parkinson’s medications.
Apokyn should not be taken with medicines for nausea, vomiting, or irritable bowel syndrome, as serious side effects may occur, such as severely low blood pressure and loss of consciousness.
Common side effects caused by Apokyn include nausea, vomiting, drowsiness, dizziness, involuntary muscle movement, chest pain, pale skin, increased sweating, flushing, swelling of the upper and lower limbs, yawning, runny nose, and itching, bruising or hardening of the skin at the injection site.
More information may be found on the therapy’s label.
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