What to Know About Apokyn (Apomorphine Hydrochloride Injection)

Apokyn (apomorphine hydrochloride injection) is used to alleviate Parkinson’s disease symptoms during off periods. You can give it to yourself by injection.

Off periods are the times when you experience a re-emergence of your Parkinson’s disease symptoms. These periods occur as your Parkinson’s disease treatment wears off in-between your regularly scheduled doses.

Apokyn is thought to have its effect on Parkinson’s disease symptoms by stimulating the dopamine receptors in the brain. Parkinson’s disease is associated with decreased activation of these receptors.

Uses

Motor fluctuations are common in Parkinson’s disease, as the effects of the treatments can change throughout the day. Apokyn is used as-needed to relieve off-period symptoms when they occur. It is not used to prevent the effects of Parkinson’s disease.

You can use Apokyn only if you already regularly take standard prescription medications such as levodopa to control your Parkinson’s disease. 

Your healthcare provider may prescribe Apokyn for you if you experience any of the following symptoms when your medication wears off: 

• Tremors 
• Stiffness 
• Rigidity
• Bradykinesia (slow movements) 
• Difficulty initiating movements 

Off-Label Uses

This medication is not commonly prescribed off-label for treating medical conditions besides Parkinson’s disease. 

Before Use

Your healthcare provider will want to observe your off symptoms when deciding whether Apokyn would be right for you. Apokyn injection can worsen some symptoms of Parkinson's disease such as dyskinesia (involuntary movements caused by Parkinson's medications), and it can also lower your blood pressure.

Precautions and Contraindications

Apokyn must be used with caution for children and for pregnant women. There is an increased risk of side effects among elderly individuals.

Other Off-Period Medications

Inbrija (levodopa inhalation powder) was approved by the U.S. Food and Drug Administration (FDA) in 2019 for use in relieving off-period symptoms in Parkinson's disease. It is administered with an oral inhaler. It may be prescribed if you take Sinemet (carbidopa/levodopa) for the management of your Parkinson's disease symptoms.

Dosages

Apokyn is injected subcutaneously (underneath the skin). Your medical team will teach you how to administer the medication for yourself. It comes in a glass cartridge containing 30 milligrams (mg) of medicine, which also equals 3 milliliters (mL), You will inject the medication using a pen injector that comes with it. 

The recommended first dose is 0.2 mL (2 mg). It is recommended that you give yourself your first injection with medical supervision. This will ensure that you are injecting it properly and that you are medically observed for side effects, mainly hypotension. 

You will need to work with your healthcare provider to increase your dose if a higher dose is needed to alleviate your off symptoms. The maximum recommended dose is 0.6 mL per off period, with no more than one injection every two hours. You should not use a total of more than 2 mL (20 mg) per day. 

Modifications

If you have renal failure (kidney disease), it can affect your blood concentration of Apokyn, potentially causing toxicity. Your healthcare provider will recommend that you start with a dose of 0.1 mL (1 mg) and will increase your dose slowly to avoid toxicity if you have renal disease.

How to Take and Store

Your medicine should be stored at a temperature of 25 C (77 F). 

Side Effects

You can experience side effects from taking Apokyn. Dopamine receptors are prevalent in the brain and throughout the body. Activating these receptors has many effects besides the intended effect of reducing symptoms of Parkinson’s disease.

Common

Nausea and vomiting are very common side effects of Apokyn. This side effect is managed with trimethobenzamide (an anti-nausea medication), at a dose of 300 mg three times a day. Your healthcare provider will recommend that you start taking trimethobenzamide three days prior to your first dose of Apokyn.

You will likely be able to discontinue your anti-nausea treatment about two months after you begin taking Apokyn. 

Other common side effects of Apokyn include:

• Yawning 
• Drowsiness 
• Falling asleep during the day 
• Runny nose 
• Confusion 
• Edema (swelling of the hands or feet) 

Severe

Some of the less common side effects of Apokyn are dangerous, may potentially cause severe harm to your health, or could be life-threatening.

Severe side effects include:

• Pulmonary embolism (a blood clot in the lungs) 
• Very low blood pressure 
• Syncope (loss of consciousness) 
• Falling 
• Cardiac side effects, including prolonged QT interval and torsades de pointes or sudden death

Warnings and Interactions

This medication can interact with several other medications.

Using Apokyn when taking medications for lowering high blood pressure increases the risk of low blood pressure.

Antipsychotics, which counteract the effects of dopamine, can decrease the effects of Apokyn.

According to the manufacturer, Apokyn also must be used with caution if you take anti-nausea medications that are classified as 5HT3 antagonists.