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APO-Go Pen Side Effects

Generic name: apomorphine

Medically reviewed by Last updated on Oct 18, 2023.

Note: This document contains side effect information about apomorphine. Some dosage forms listed on this page may not apply to the brand name APO-Go Pen.

Applies to apomorphine: subcutaneous solution. Other dosage forms:

Serious side effects of APO-Go Pen

Along with its needed effects, apomorphine (the active ingredient contained in APO-Go Pen) may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur while taking apomorphine:

More common

Incidence not known

Other side effects of APO-Go Pen

Some side effects of apomorphine may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects.

Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

More common

For Healthcare Professionals

Applies to apomorphine: compounding powder, subcutaneous solution, sublingual film.


The most commonly reported adverse reactions have included yawning, drowsiness/somnolence, dyskinesias, dizziness/postural hypotension, rhinorrhea, nausea, vomiting, hallucination/confusion, and edema/swelling of extremities.


This drug is known to cause severe nausea and vomiting when administered at recommended doses; because of this, premedication with antiemetics is recommended. In a clinical trial in which patients received premedication with trimethobenzamide, 31% and 11% of patients had nausea and vomiting, respectively.[Ref]

Very common (10% or more): Nausea and/or vomiting (30%)

Common (1% to 10%): Constipation, diarrhea

Uncommon (0.1% to 1%): Stomatitis, transient metallic taste[Ref]


Very common (10% or more): Orthostatic hypotension (up to 20%), chest pain/pressure/angina (15%)

Common (1% to 10%): Syncope, hypotension, edema/swelling of extremities, congestive heart failure

Rare (0.01% to 0.1%): QTc interval prolongation

Frequency not reported: Profound hypotension and loss of consciousness, thrombus formation, angina, myocardial infarction, cardiac arrest and/or sudden death, QTC prolongation[Ref]

Concomitant use of ondansetron with apomorphine has resulted in profound hypotension and loss of consciousness. Because of this, US labeling has concomitant use of 5HT3 antagonists and apomorphine as contraindicated.

Thrombus formation due to intravenous crystallization of apomorphine has occurred with IV administration; this drug should not be administered IV.

In clinical studies, 4% of patients receiving this drug experienced angina, myocardial infarction, cardiac arrest and/or sudden death. The specific incidence of each event is unknown; some cases of angina and myocardial infarction occurred in close proximity to apomorphine administration, while other cases of cardiac arrest and sudden death occurred at time not related to dosing.

In a placebo-controlled study, single apomorphine doses from 2 mg to 8 mg resulted in mean differences from placebo in QTc (as measured by Holter monitor) of 0, 1, and 7 milliseconds with 4, 6, and 8 mg does, respectively. In another study, single-doses of apomorphine 2 to 10 mg (mean 5.2 mg) resulted in a mean difference in QTc interval of about 3 milliseconds at 20- and 90-minutes post-dose. For the entire study, 2 patients exhibited larger QTc increases (greater than 60 milliseconds from pre-dose; 1 patient at 2 and 6 mg; 1 patient at 6 mg).[Ref]


For patients taking medications that increase central dopaminergic tone including this drug, there have been case reports of intense urges to gamble, increased sexual urges, intense urges to spend money uncontrollably, and the inability to control these urges.[Ref]

Very common (10% or more): Hallucinations (up to 14%)

Common (1% to 10%): Confusion, insomnia, depression

Frequency not reported: Impulse control/compulsive behaviors

Postmarketing reports: New or worsening mental status and behavioral changes including psychotic-like behavior, paranoid ideation, delusions, disorientation, aggressive behavior, agitation, and delirium[Ref]


Very common (10% or more): Falls (up to 30%)

Common (1% to 10%): Fatigue[Ref]

Nervous system

Very common (10% or more): Drowsiness or somnolence (up to 35%), dyskinesia (up to 35%)

Common (1% to 10%): Headache, aggravated Parkinson's disease, weakness

Frequency not reported: Falling asleep during activities of daily living


Very common (10% or more): Injection site reactions (26%)

Frequency not reported: Panniculitis[Ref]

Injection site reactions including bruising, granuloma, and pruritus have occurred with subcutaneous injections. Local induration and nodules (usually asymptomatic) often develop with continuous use. At higher doses, erythema, tenderness and induration at site of subcutaneous injection may occur. Panniculitis has been reported when a skin biopsy has been performed.[Ref]


Common (1% to 10%): Urinary tract infection

Uncommon (0.1% to 1%): Spontaneous penile erection

Rare (0.01% to 0.1%): Painful erection

Very rare (less than 0.01%): Priapism[Ref]


Common (1% to 10%): Ecchymosis

Uncommon (0.1% to 1%): Thrombocytopenia

Rare (0.01% to 0.1%): Coombs' positive hemolytic anemia, eosinophilia


Frequency not reported: Angioedema, anaphylaxis, bronchospasm

Sodium metabisulfite is an excipient in many apomorphine solutions. Angioedema and anaphylaxis and bronchospasm have been reported with this excipient in sulfite sensitive individuals.


Common (1% to 10%): Limb pain, arthralgia, back pain


Uncommon (0.1% to 1%): Increased lacrimation


Common (1% to 10%): Dehydration


Very common (10% or more): Yawning (40%), rhinorrhea (20%)

Common (1% to 10%): Pneumonia, dyspnea

Uncommon (0.1% to 1%): Breathing difficulties

Frequency not reported: Pulmonary embolism

Pulmonary embolism due to intravenous crystallization of apomorphine has occurred with IV administration; this drug should not be administered IV.


Uncommon (0.1% to 1%): Reduced facial hair growth, local and generalized rashes


Uncommon (0.1% to 1%): Transient rise in serum prolactin, loss of libido


1. (2004) "Product Information. Apokyn (apomorphine)." Mylan Pharmaceuticals Inc

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Some side effects may not be reported. You may report them to the FDA.