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Medications and Drugs

Brand Names: Guanidine HCl

Generic Name: guanidine (Pronunciation: GWAN ih deen)

What is guanidine (Guanidine HCl)?

Guanidine improves the action of a chemical in the body that regulates muscle cells.

Guanidine is used to treat muscle weakness caused by Eaton-Lambert syndrome. Guanidine will not treat myasthenia gravis.

Guanidine may also be used for purposes other than those listed in this medication guide.

What are the possible side effects of guanidine (Guanidine HCl)?

Get emergency medical help if you have any of these signs of an allergic reaction: hives; difficulty breathing; swelling of your face, lips, tongue, or throat.

Call your doctor at once if you have any of these serious side effects:

  • easy bruising or bleeding, unusual weakness;
  • fever, chills, body aches, flu symptoms;
  • unusual thoughts, changes in behavior;
  • feeling light-headed, fainting;
  • confusion, hallucinations (seeing things that are not there);
  • weakness, lack of coordination;
  • numbness, coldness, or tingling in your face, lips, hands, or feet; or
  • fast or pounding heartbeats.

Other less serious side effects are more likely to occur, such as:

  • nausea, loss of appetite, diarrhea, stomach pain;
  • skin rash;
  • increased sweating; or
  • dry mouth, dry flaky skin.

Side effects other than those listed here may also occur. Talk to your doctor about any side effect that seems unusual or that is especially bothersome. You may report side effects to FDA at 1-800-FDA-1088.

What is the most important information I should know about guanidine (Guanidine HCl)?

Before taking this medication, tell your doctor if you have bone marrow depression or a weak immune system.

Take this medication exactly as it was prescribed for you. Do not take the medication in larger amounts, or take it for longer than recommended by your doctor.

Your doctor may occasionally change your dose to make sure you get the best results from this medication.

Guanidine can lower the blood cells that help your body fight infections. This can make it easier for you to bleed from an injury or get sick from being around others who are ill. To be sure your blood cells do not get too low, your blood will need to be tested on a regular basis. Your urine may also need to be tested. It is important that you not miss any scheduled visits to your doctor.

Report Problems to the Food and Drug Administration

You are encouraged to report negative side effects of prescription drugs to the FDA. Visit the FDA MedWatch website or call 1-800-FDA-1088.

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