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Donepezil / memantine Side Effects

In Summary

Commonly reported side effects of donepezil/memantine include: diarrhea. Other side effects include: dizziness, nausea, vomiting, anorexia, and ecchymoses. See below for a comprehensive list of adverse effects.

For the Consumer

Applies to donepezil / memantine: oral capsule delayed release, oral capsule extended release

In addition to its needed effects, some unwanted effects may be caused by donepezil / memantine. In the event that any of these side effects do occur, they may require medical attention.

Major Side Effects

You should check with your doctor immediately if any of these side effects occur when 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

Minor Side Effects

Some of the side effects that can occur with donepezil / memantine may not need medical attention. As your body adjusts to the medicine during treatment these side effects may go away. Your health care professional may also be able to tell you about ways to reduce or prevent some of these side effects. If any of the following side effects continue, are bothersome or if you have any questions about them, check with your health care professional:

Incidence not known:
  • Constipation
  • decreased appetite
  • diarrhea
  • nausea
  • vomiting

For Healthcare Professionals

Applies to donepezil / memantine: oral capsule extended release

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]

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]

General

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]

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]

References

1. "Product Information. Namzaric (donepezil-memantine)." Forest Pharmaceuticals, St. Louis, MO.

Not all side effects for donepezil / memantine may be reported. You should always consult a doctor or healthcare professional for medical advice. Side effects can be reported to the FDA here.

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