APO-go PEN: Uses, Dosage & Side Effects

What Is APO-go PEN and What Is It Used For?

APO-go PEN contains apomorphine hydrochloride, a medication belonging to a class of drugs known as dopamine agonists. Each milliliter of APO-go PEN solution contains 10 mg of apomorphine hydrochloride. The pen is designed as a multi-dose, non-refillable injection device that allows patients to self-administer precise subcutaneous doses quickly and conveniently whenever they experience motor fluctuations related to their Parkinson’s disease.

Parkinson’s disease is a progressive neurological condition caused by the gradual loss of dopamine-producing neurons in a brain region called the substantia nigra. As dopamine levels decline, patients experience a range of motor symptoms including tremor, rigidity, bradykinesia (slowness of movement), and postural instability. The primary treatment for Parkinson’s disease is levodopa, which is converted to dopamine in the brain. However, as the disease progresses, many patients develop motor fluctuations — unpredictable periods of good motor control (“on” periods) alternating with episodes of impaired mobility (“off” periods). These off episodes can be deeply disabling, leaving patients unable to move, speak, or carry out daily activities.

Apomorphine works differently from oral Parkinson’s medications. Rather than being converted to dopamine like levodopa, apomorphine directly stimulates both D1-like and D2-like dopamine receptors in the striatum, the part of the brain responsible for coordinating movement. This direct receptor activation bypasses the degenerating nigrostriatal pathway entirely, meaning that apomorphine’s effectiveness does not depend on the declining capacity of remaining neurons to convert precursor drugs into active dopamine. Furthermore, because it is administered subcutaneously rather than orally, apomorphine avoids the absorption variability and delayed gastric emptying that often affect oral medications in Parkinson’s disease patients.

The key clinical advantage of APO-go PEN is its rapid onset of action. After subcutaneous injection, peak plasma concentrations are reached within approximately 10–20 minutes, and clinical improvement is typically noticed within 4–12 minutes. This makes it an invaluable rescue therapy for patients who experience sudden, unpredictable off episodes that cannot be adequately managed by adjustments to their oral medication regimen. A typical patient may use between 1 and 10 injections per day, depending on the frequency and severity of their motor fluctuations.

APO-go PEN is approved by the European Medicines Agency (EMA) and regulatory authorities in multiple countries for the treatment of motor fluctuations (“off” episodes) in patients with Parkinson’s disease who have previously been treated with levodopa and/or other dopamine agonists. It is intended for use alongside existing Parkinson’s medication, not as a replacement. The pen is also available in a continuous infusion formulation (APO-go Pumpfill, 5 mg/ml) for patients requiring more sustained apomorphine delivery.

What Should You Know Before Using APO-go PEN?

Before your doctor prescribes APO-go PEN, a thorough medical evaluation will be performed. This includes an electrocardiogram (ECG) to assess your heart rhythm and a comprehensive review of all medications you are currently taking. The ECG will be repeated during the first days of treatment and at other intervals as your doctor considers necessary. You must also provide a complete medical history, with particular attention to any cardiac conditions. If you experience symptoms that could be related to your heart during treatment — such as palpitations, fainting, or near-fainting episodes — contact your doctor immediately. Similarly, report any new diarrhea or any newly started medications.

Contraindications

APO-go PEN must not be used in the following situations. These are absolute contraindications, meaning the medication should never be administered under these circumstances:

• Age under 18 years: APO-go PEN is not approved for use in children or adolescents. The safety and efficacy have not been established in this population.
• Respiratory depression: Patients with significant breathing difficulties should not use apomorphine, as it may further compromise respiratory function.
• Dementia or Alzheimer’s disease: Apomorphine is contraindicated in patients with cognitive impairment due to dementia, as it may worsen confusion and increase the risk of hallucinations.
• Psychotic disorders: Patients with psychiatric conditions characterized by hallucinations, delusions, confusion, or loss of contact with reality should not use this medication.
• Hepatic insufficiency: Patients with significant liver problems should not use APO-go PEN, as impaired liver function may affect the metabolism and clearance of the drug.
• Severe dyskinesia or dystonia: Patients who already experience severe involuntary movements or inability to move despite levodopa treatment should not use apomorphine.
• Allergy to apomorphine or excipients: Do not use if you are allergic to apomorphine hydrochloride, sodium metabisulfite, or any other component of the formulation.
• Long QT syndrome: Patients with a personal or family history of long QT syndrome (an abnormal ECG finding associated with dangerous heart rhythms) must not use this medication.
• Concurrent ondansetron use: APO-go PEN must not be used together with ondansetron (an anti-nausea medication), as this combination can cause profound hypotension (dangerously low blood pressure) and loss of consciousness.

Warnings and Precautions

Talk to your doctor, pharmacist, or nurse before using APO-go PEN if any of the following apply to you:

• Kidney problems: Impaired renal function may affect how apomorphine is processed in your body, potentially requiring dose adjustments or closer monitoring.
• Lung problems: Respiratory conditions may be affected by apomorphine. Your doctor will assess whether the benefits outweigh the risks in your specific situation.
• Heart problems: Cardiovascular disease requires extra caution, as apomorphine can affect blood pressure and heart rhythm. Regular cardiac monitoring is essential.
• Orthostatic hypotension: If you frequently feel dizzy or lightheaded when standing up, apomorphine may worsen this symptom. Your doctor may need to adjust your blood pressure medications.
• Blood pressure medications: If you are taking antihypertensive drugs, the blood-pressure-lowering effects of apomorphine may be additive, increasing the risk of postural hypotension.
• Nausea or vomiting: If you suffer from persistent nausea, inform your doctor. Co-treatment with domperidone is essential and may need dose adjustment.
• Psychiatric symptoms: If you have any mental health symptoms such as hallucinations or confusion related to your Parkinson’s disease, apomorphine may exacerbate these.
• Elderly or frail patients: Older adults may be more susceptible to side effects, particularly orthostatic hypotension and confusion. Lower starting doses and slower titration are typically recommended.

Pregnancy and Breastfeeding

APO-go PEN should not be used during pregnancy unless the potential benefit clearly outweighs the risk to the unborn child. If you are pregnant, think you may be pregnant, or are planning to become pregnant, consult your doctor or pharmacist before using this medication. Your doctor will discuss the individual risks and benefits with you.

It is not known whether apomorphine or its metabolites are excreted in human breast milk. If you are breastfeeding or planning to breastfeed, discuss this with your doctor. A decision will be made whether to discontinue breastfeeding or to discontinue therapy, taking into account the benefit of breastfeeding for the child and the benefit of treatment for the mother.

Driving and Operating Machinery

APO-go PEN can cause drowsiness and excessive sleepiness, including sudden sleep episodes that may occur without warning. Do not drive motor vehicles or operate tools or machinery if this medication affects you in this way. You are responsible for assessing whether you are fit to drive or perform tasks requiring alertness. If you experience sudden onset of sleep while engaging in daily activities, particularly while driving, stop the activity and contact your doctor before resuming driving.

Important Information About Ingredients

APO-go PEN contains sodium metabisulfite (E223), which in rare cases can cause severe allergic reactions with symptoms such as rash, itching, breathing difficulties, swelling of the eyelids, face, or lips, or swollen or red tongue. If you experience any of these symptoms, seek emergency medical attention immediately. The product also contains less than 1 mmol sodium (23 mg) per 10 ml, meaning it is essentially sodium-free.

How Does APO-go PEN Interact with Other Drugs?

Drug interactions with APO-go PEN can affect both its efficacy and safety profile. Apomorphine’s dopaminergic mechanism of action means it can interact with a wide range of medications that affect dopamine pathways, cardiac function, or blood pressure regulation. It is essential to inform your doctor about all medications you are currently taking, have recently taken, or plan to take, including prescription drugs, over-the-counter products, and herbal supplements.

Major Interactions

Minor Interactions

If you are using both levodopa and apomorphine, your doctor should arrange regular blood tests. This monitoring helps detect potential hematological changes, including hemolytic anemia (abnormal breakdown of red blood cells), which has been observed as an uncommon side effect in patients receiving combination therapy. Your doctor will inform you if any dosage adjustments are needed for apomorphine or any of your other medications.

What Is the Correct Dosage of APO-go PEN?

The amount and frequency of APO-go PEN injections are tailored to your individual needs. Treatment is always initiated in a specialist clinic setting where your response to the medication can be carefully assessed and the optimal dose determined. Your doctor will explain how to recognize the signs that indicate when you need to use the medication — typically the onset of an “off” episode characterized by freezing, immobility, or severe slowness of movement.

Before beginning treatment with APO-go PEN, domperidone therapy must be started at least 2 days in advance. Domperidone is an antiemetic that prevents the nausea and vomiting caused by apomorphine’s potent dopamine receptor stimulation in the chemoreceptor trigger zone. Without domperidone pre-treatment, the initial doses of apomorphine are likely to cause severe gastrointestinal distress.

Adults

During the initial dose-titration phase at the specialist clinic, your doctor will start with a low test dose (typically 1–2 mg) and gradually increase until the optimal dose that reliably turns off your motor symptoms is identified. Once the correct dose has been established, you will set it on the pen’s dosing dial, and this setting is retained for subsequent injections — you do not need to reconfigure the dose each time.

Children and Adolescents

APO-go PEN is not approved for use in children and adolescents under 18 years of age. Parkinson’s disease is exceedingly rare in this age group, and the safety and efficacy of apomorphine have not been established in pediatric populations. If a young patient has a movement disorder that may benefit from dopaminergic rescue therapy, alternative treatments should be discussed with a specialist in pediatric neurology.

Elderly Patients

Elderly patients, particularly those who are frail or have multiple comorbidities, may be more susceptible to the side effects of apomorphine, particularly orthostatic hypotension (a drop in blood pressure upon standing) and neuropsychiatric effects such as confusion and hallucinations. Initial dose titration should be performed with extra caution in older adults, and lower starting doses may be appropriate. Regular monitoring of blood pressure, both lying down and standing, is recommended throughout treatment.

Missed Dose

APO-go PEN is used on an as-needed basis rather than on a fixed schedule. You should use the medication when you next experience an off episode that requires treatment. Do not use a double dose to compensate for a missed one. If you are unsure about when or how to use your medication, contact your doctor, pharmacist, or nurse.

Overdose

Stopping Treatment

Do not stop using APO-go PEN without first consulting your doctor. Sudden discontinuation of dopaminergic therapy can, in rare cases, lead to a condition called neuroleptic malignant-like syndrome, which is characterized by high fever, muscle rigidity, altered consciousness, and autonomic instability. Your doctor will advise you on how to safely reduce or discontinue your apomorphine therapy if this becomes necessary.

What Are the Side Effects of APO-go PEN?

Like all medicines, APO-go PEN can cause side effects, although not everybody gets them. If you experience an allergic reaction — such as rash, breathing difficulties, or swelling of the face, lips, throat, or tongue — stop using APO-go PEN and seek immediate medical attention at the nearest emergency department.

Side effects are listed below by frequency, based on how often they have been reported in clinical studies and post-marketing surveillance. Understanding the frequency classification helps patients and caregivers appreciate how likely they are to experience each effect and when to seek medical advice.

If you experience any behavioral changes such as an inability to resist impulses, unusual urges, or compulsive behaviors (gambling, spending, eating, or sexual behavior), tell your doctor immediately. These impulse control disorders are recognized class effects of dopamine agonist medications and may require dose reduction or discontinuation. Patients and caregivers should remain vigilant for these symptoms throughout the duration of treatment.

How Should You Store APO-go PEN?

Proper storage of APO-go PEN is essential to maintain the stability and effectiveness of the apomorphine solution. Apomorphine is sensitive to both light and oxidation, and degraded solution can be identified by a change in color from clear and colorless to green. Using degraded solution is both ineffective and potentially harmful.

• Temperature: Store at or below 25°C (77°F). Do not freeze.
• Light protection: Keep the pen in its original carton when not in use to protect from light exposure.
• In-use shelf life: Once a pen is first opened, it may be used for up to 48 hours. After 48 hours, discard the pen even if solution remains.
• Visual inspection: Before each use, check that the solution is clear, colorless, and free from visible particles. Do not use if the solution has turned green or appears cloudy.
• Expiry date: Do not use after the expiration date printed on the label and carton. The expiration date refers to the last day of that month.
• Needle disposal: Always remove the needle from the pen before storage. Dispose of used needles in a designated sharps container. When the container is full, return it to your pharmacy or dispose of it according to local regulations.
• Pen disposal: Used APO-go PEN devices should be returned to a pharmacy for proper disposal. Do not discard medications in household waste or down the drain, as this helps protect the environment.

Keep this and all medications out of the sight and reach of children. If you are traveling with APO-go PEN, ensure the pen is kept within the recommended temperature range and protected from direct sunlight. A cool bag may be useful for travel in warm climates, but avoid freezing.

What Does APO-go PEN Contain?

Understanding the full composition of your medication helps identify potential allergens and allows informed discussions with your healthcare team about excipient sensitivities.

APO-go PEN is a non-refillable multi-dose injection pen containing a clear glass cartridge filled with apomorphine solution. The solution should be clear, practically colorless, odorless, and free from visible particles. The pen is available in packs of 1, 5, or 10 pens, and in multi-packs containing 5 cartons of 5 pens each. Not all pack sizes may be marketed in every country.

The pen does not come with needles. You should use pen needles no longer than 12.7 mm (1/2 inch) and no thinner than 30 gauge (30G). Standard insulin pen needles are compatible with APO-go PEN. Always use a new, sterile needle for each injection.