What are the Most Common Memantine Side Effects?

Memantine is a component in a number of different medications that can be prescribed for the management of severe or moderate cases of Alzheimer's disease. Taking this drug can result in several side effects, commonly including issues such as feeling lightheaded or drowsy; it can also cause stomach upset and vomiting. Some individuals can even develop an allergic reaction to the medication or experience other severe side effects, such as an irregular heartbeat.

Many individuals who begin taking the medication will experience mild side effects that fade as the body adjusts to the medication. These commonly include gastrointestinal effects such as vomiting, nausea, diarrhea or constipation. Some may see instances of weight loss, and a loss of appetite from the medication may help contribute to this. There may be some swelling in the extremities or around the eyes as well. The skin can also be impacted, and there may be instances of bruising easily or of a rash developing.

Some memantine side effects also impact the brain, which is to be expected because the medication acts by regulating the chemicals in the brain. Some individuals may feel dizzy or confused, or have unexplained feelings of anxiety, nervousness or anger. Since drowsiness and fatigue are also common side effects, care should be taken when first starting the drug to ensure the individual does not put him or herself in a potentially dangerous situation where alertness is crucial.

Occasionally, an individual will have an allergic reaction to the medication. This can manifest itself as an attack of hives. Some may also develop swelling in the face and neck, which can add to difficulties breathing. This is considered a serious reaction, and an allergy to the medication will generally result in it being changed.

There are some memantine side effects that are considered severe and should be reported to a medical professional as soon as they develop. Difficulty breathing, chest pain, and a fast or erratic heart beat can be signs of a serious reaction. Also, a loss of consciousness, numbness in different areas of the body, weakness, a loss of fine motor skills and a pale complexion can also be warning signs that the body is having a negative reaction to the drug. Some individuals may also develop severe mental side effects from memantine, such as audio or visual hallucinations, seizures and convulsions.

Some pre-existing conditions may increase the chances or severity of memantine side effects. Those with liver or kidney disease or cataracts may be at an increased risk. Other types of conditions centered around brain activity, such as epilepsy or seizures, can also increase the risk factor for memantine side effects.