Amantadine Side Effects: An Introduction
As with any medicine, side effects are possible with
amantadine hydrochloride (
Symmetrel®). However, not everyone who takes the drug will experience side effects. If side effects do occur, in most cases, they are minor and either require no treatment or are easily treated by you or your healthcare provider.
(This article covers many, but not all, of the possible side effects with amantadine. Your healthcare provider can discuss a more complete list of amantadine side effects with you.)
Side Effects of Amantadine to Report
Some side effects of amantadine are potentially serious and should be reported to your healthcare provider. Some of these side effects are common, while others are not. Common serious side effects (occurring in 1 to 5 percent of people) include:
Less common serious side effects (occurring in less than 1 percent of people) include but are not limited to:
- Intense, unusual urges, such as urges to gamble or engage in risky sexual activity
- Congestive heart failure (CHF)
- Psychosis
- Difficulty passing urine
- Difficulty breathing
- Memory loss (amnesia)
- Unusual, uncontrollable body movements
- High blood pressure (hypertension)
- Vision or eye problems
- Seizures
- Low white blood cell counts
- Suicidal thoughts or behaviors
- An irregular heart rhythm (arrhythmia)
- Neuroleptic malignant syndrome (NMS), a dangerous condition that can include:
- A high fever
- Stiff muscles
- Confusion
- Irregular pulse or blood pressure
- An increased heart rate (tachycardia)
- Sweating
- An irregular heart rhythm (arrhythmia)
- Signs of an allergic reaction, such as:
- Rash
- Hives
- Itching
- Swelling of the mouth or throat
- Wheezing
