Donepezil / Memantine Side Effects

Medically reviewed by Drugs.com. Last updated on Oct 21, 2024.

Applies to donepezil / memantine: oral capsule extended release.

Serious side effects

Along with its needed effects, donepezil / memantine 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 donepezil / memantine:

Incidence not known

• bloody or black, tarry stools
• chest pain or discomfort
• decreased urination
• lightheadedness, dizziness, or fainting
• pain in the lower abdomen, groin, upper back or sides
• seizures
• severe stomach pain
• slow or irregular heartbeat
• sweating
• trouble breathing
• unusual tiredness
• vomiting of blood or material that looks like coffee grounds

Other side effects

Some side effects of donepezil / memantine 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:

Incidence not known

• constipation
• decreased appetite
• diarrhea
• nausea
• vomiting

For healthcare professionals

Applies to donepezil / memantine: oral capsule extended release, oral kit.

General adverse events

The most common adverse reactions in patients receiving memantine ER were headache, diarrhea, and dizziness. The most common adverse reactions in patients receiving donepezil were diarrhea, anorexia, vomiting, nausea, and ecchymosis.^[Ref]

Nervous system

Memantine:

• Common (1% to 10%): Headache, dizziness, somnolence

Donepezil:

• Common (1% to 10%): Headache, dizziness, somnolence
• Postmarketing reports: Convulsions, neuroleptic malignant syndrome^[Ref]

Gastrointestinal

Memantine:

• Common (1% to 10%): Diarrhea, constipation, abdominal pain, vomiting
• Postmarketing reports: Pancreatitis

Donepezil:

• Very common (10% or more): Diarrhea (10%)
• Common (1% to 10%): Vomiting, anorexia, nausea
• Postmarketing reports: Abdominal pain, pancreatitis^[Ref]

Respiratory

Memantine:

• Common (1% to 10%): Influenza^[Ref]

Cardiovascular

Memantine:

• Common (1% to 10%): Hypertension, hypotension
• Postmarketing reports: Congestive cardiac failure

Donepezil:

• Common (1% to 10%): Hypertension, hemorrhage, syncope
• Postmarketing reports: Heart block (all types)^[Ref]

Dermatologic

Memantine:

• Postmarketing reports: Stevens Johnson Syndrome

Donepezil:

• Common (1% to 10%): Eczema
• Postmarketing reports: Rash^[Ref]

Hematologic

Memantine:

• Postmarketing reports: Agranulocytosis, leukopenia (including neutropenia), pancytopenia, thrombocytopenia, thrombotic thrombocytopenic purpura

Donepezil:

• Common (1% to 10%): Ecchymosis
• Postmarketing reports: Hemolytic anemia^[Ref]

Hepatic

Memantine:

• Postmarketing reports: Hepatitis

Donepezil:

• Postmarketing reports: Cholecystitis, hepatitis^[Ref]

Metabolic

Donepezil:

• Common (1% to 10%): Increased creatinine phosphokinase, dehydration, hyperlipidemia
• Postmarketing reports: Hyponatremia^[Ref]

Musculoskeletal

Memantine:

• Common (1% to 10%): Back pain

Donepezil:

• Common (1% to 10%): Back pain^[Ref]

Other

Memantine:

• Common (1% to 10%): Increased weight

Donepezil:

• Very common (10% or more): Accident (13%), infection (11%)
• Common (1% to 10%): Fever, pain, chest pain^[Ref]

Psychiatric

Memantine:

• Common (1% to 10%): Anxiety, depression, aggression
• Postmarketing reports: Suicidal ideation

Donepezil:

• Common (1% to 10%): Insomnia, nervousness, hallucinations, hostility, depression, confusion, emotional lability, personality disorder
• Postmarketing reports: Agitation, confusion, hallucinations^[Ref]

Renal

Memantine:

• Common (1% to 10%): Urinary incontinence
• Postmarketing reports: Acute renal failure

Donepezil:

• Common (1% to 10%): Urinary incontinence^[Ref]

Further information

Donepezil/memantine side effects can vary depending on the individual. Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Note: Medication side effects may be underreported. If you are experiencing side effects that are not listed, submit a report to the FDA by following this guide.

Medical Disclaimer