Symmetrel Warnings and Precautions

There are many Symmetrel warnings and precautions that you should be aware of prior to starting the drug. For example, Symmetrel can make glaucoma, epilepsy, and kidney or liver problems worse. It is important to tell your healthcare provider about any medical conditions you have or any other medications you are taking before starting Symmetrel. Warnings and precautions also extend to women who are pregnant or breastfeeding.

Symmetrel: What Should I Tell My Healthcare Provider?

You should talk with your healthcare provider prior to taking Symmetrel® (amantadine hydrochloride) if you have:
Also, let your healthcare provider know if you are:
  • Pregnant or thinking of becoming pregnant
  • Breastfeeding.
Make sure to tell your healthcare provider about any other medications you are taking, including prescription and non-prescription medicines, vitamins, and herbal supplements.

Specific Symmetrel Warnings and Precautions

Some of the warnings and precautions to be aware of prior to taking Symmetrel include the following:
  • A Symmetrel overdose can be dangerous. Deaths have occurred from both intentional and unintentional overdoses of this drug.
  • People have attempted suicide while taking Symmetrel. This may be more likely to occur in people who have a psychiatric disorder or a history of substance abuse. It may also be related to some of the unusual Symmetrel side effects, such as agitation, hallucinations, depression, or anxiety.
  • Symmetrel may make congestive heart failure (CHF) worse or may actually cause it. Check with your healthcare provider before taking the drug if you have CHF or swelling in the hands, feet, or ankles, as this can be a sign of CHF.
  • The medication may worsen untreated acute angle-closure glaucoma (an eye condition).
  • People with Parkinson's disease should not suddenly stop taking Symmetrel, as serious problems could occur.
  • Symmetrel may increase the risk of seizures in people who have epilepsy or seizure disorders. If you have a history of seizures or epilepsy, check with your healthcare provider before taking this medication.
  • Symmetrel can cause a life-threatening condition called neuroleptic malignant syndrome (NMS). Some symptoms of NMS include:
    • A high fever
    • Stiff muscles
    • Confusion
    • Irregular pulse or blood pressure
    • A fast heart rate (tachycardia)
    • Sweating
    • An irregular heart rhythm (arrhythmia).
Tell your healthcare provider right away if you think you might have NMS.
  • If you have kidney or liver problems, your body may not handle the drug as well as it should. You may need a lower Symmetrel dosage and, in some cases, Symmetrel may not be recommended.
  • Do not drive or operate heavy machinery until you know exactly how Symmetrel affects you.


  • Intense, unusual urges have been reported in people taking Parkinson's disease medications (including Symmetrel). Examples include an intense desire to gamble or to engage in risky sexual behavior. Let your healthcare provider know right away if you experience any of these urges.
  • People with Parkinson's disease have an increased risk for melanoma (a type of skin cancer). At this time, it is not clear if this is caused by Parkinson's disease medications (such as Symmetrel) or other factors. It is a good idea to have regular skin checks to monitor for this problem.


  • Symmetrel can interact with a few different medications (see Symmetrel Drug Interactions).
  • Symmetrel is considered a pregnancy Category C medication. This means that it may not be safe for use during pregnancy, although the full risks are not known (see Symmetrel and Pregnancy).
  • Symmetrel passes through breast milk in humans. Therefore, if you are breastfeeding or plan to start, discuss this with your healthcare provider prior to taking the drug (see Symmetrel and Breastfeeding).
Written by/reviewed by: Kristi Monson, PharmD; Arthur Schoenstadt, MD
Last reviewed by: Kristi Monson, PharmD;
Last updated/reviewed:
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