Memantine (Oral Route)

Side Effects

Drug information provided by: Merative, Micromedex®

Along with its needed effects, a medicine 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:

Less common

1. Bloating or swelling of the face, arms, hands, lower legs, or feet
2. blurred vision
3. dizziness
4. headache
5. nervousness
6. pounding in the ears
7. rapid weight gain
8. slow or fast heartbeat
9. tingling of the hands or feet
10. unusual weight gain or loss

Incidence not known

1. Abdominal or stomach pain
2. agitation
3. black, tarry stools
4. bleeding gums
5. blistering, peeling, or loosening of the skin
6. blood in the urine or stools
7. chest pain
8. coma
9. constipation
10. continuing vomiting
11. convulsions
12. dark-colored urine
13. decreased urine output
14. depression
15. fainting
16. fast, pounding, or irregular heartbeat or pulse
17. general feeling of tiredness or weakness
18. high fever
19. high or low blood pressure
20. hostility
21. increased sweating
22. indigestion
23. infection from breathing foreign substances into the lungs
24. itching
25. lethargy
26. light-colored stools
27. lip smacking or puckering
28. loss of consciousness
29. muscle twitching
30. no blood pressure
31. no breathing
32. no pulse
33. numbness or tingling in the face, arms, or legs
34. pain in the stomach, side, or abdomen, possibly radiating to the back
35. pain or swelling in the arms or legs without any injury
36. pain, tension, and weakness upon walking that subsides during periods of rest
37. pinpoint red spots on the skin
38. pounding, slow heartbeat
39. puffing of the cheeks
40. rapid or worm-like movements of the tongue
41. rapid weight gain
42. recurrent fainting
43. red irritated eyes
44. red skin lesions, often with a purple center
45. seizures
46. severe constipation
47. severe headache
48. severe muscle stiffness
49. severe vomiting
50. sores, ulcers, or white spots in the mouth or on the lips
51. stupor
52. sudden severe weakness
53. swelling of the face, ankles, or hands
54. total body jerking
55. trouble with speaking or walking
56. troubled breathing
57. twitching, twisting, or uncontrolled repetitive movements of the tongue, lips, face, arms, or legs
58. uncontrolled chewing movements
59. unusual bleeding or bruising
60. unusually pale skin
61. vomiting
62. yellow eyes and skin

Some side effects 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

1. Confusion

Less common

1. Anxiety
2. back pain
3. bladder pain
4. bloody or cloudy urine
5. change in walking and balance
6. chills
7. clumsiness or unsteadiness
8. cough producing mucus
9. coughing
10. diarrhea
11. difficult, burning, or painful urination
12. difficulty with breathing
13. difficulty with moving
14. discouragement
15. dry mouth
16. fear
17. feeling sad or empty
18. fever
19. frequent urge to urinate
20. general feeling of discomfort or illness
21. hyperventilation
22. insomnia
23. irritability
24. joint pain
25. loss of appetite
26. loss of bladder control
27. loss of interest or pleasure
28. lower back or side pain
29. muscle pain or stiffness
30. nausea
31. nervousness
32. pain
33. pain in the joints
34. restlessness
35. seeing, hearing, or feeling things that are not there
36. shortness of breath
37. sleepiness or unusual drowsiness
38. sore throat
39. tightness in the chest
40. tiredness
41. trouble with concentrating
42. trouble with sleeping
43. unusual tiredness or weakness
44. vomiting
45. wheezing

Incidence not known

1. Burning feeling in the chest or stomach
2. burning, numbness, pain, or tingling in all fingers except smallest finger
3. cold sweats
4. cool pale skin
5. decreased interest in sexual intercourse
6. difficulty with swallowing
7. general feeling of discomfort or illness
8. heartburn
9. inability to have or keep an erection
10. increased hunger
11. large amounts of fat in the blood
12. loss in sexual ability, desire, drive, or performance
13. nightmares
14. shakiness
15. slurred speech
16. stomach cramps
17. stomach upset
18. tenderness in the stomach area
19. watery or bloody diarrhea

Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.

Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.

• Precautions

Portions of this document last updated: Feb. 01, 2024

Copyright: © Merative US L.P. 1973, 2024. All rights reserved. Information is for End User's use only and may not be sold, redistributed or otherwise used for commercial purposes.