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Guanidine HCl

Generic Name: guanidine (GWAN ih deen)
Brand Name: Guanidine HCl

What is Guanidine HCl?

This medicine HCl improves the release of a chemical in the brain that sends nerve signals to your muscles to control movement.

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

This medicine HCl may also be used for purposes not listed in this medication guide.

Important Information

Follow all directions on your medicine label and package. Tell each of your healthcare providers about all your medical conditions, allergies, and all medicines you use.

Before taking this medicine

You should not use This medicine HCl if you are allergic to it.

To make sure This medicine HCl is safe for you, tell your doctor if you have:

  • a weak immune system (caused by disease or by using certain medicine).

It is not known whether This medicine HCl will harm an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant while using this medicine.

Guanidine can pass into breast milk and may harm a nursing baby. You should not breast-feed while using this medicine.

How should I take Guanidine HCl?

Follow all directions on your prescription label. Your doctor may occasionally change your dose to make sure you get the best results. Do not take this medicine in larger or smaller amounts or for longer than recommended.

Tell your doctor if you have any changes in weight. This medicine HCl doses are based on weight, and any changes may affect the dose.

This medicine HCl can lower blood cells that help your body fight infections and help your blood to clot. You may get an infection or bleed more easily. Call your doctor if you have unusual bruising or bleeding, or signs of infection (fever, chills, body aches).

While using This medicine HCl, you may need frequent blood tests. You may also need urine tests to check your kidney function.

Store at room temperature away from moisture and heat.

What happens if I miss a dose?

Take the missed dose as soon as you remember. Skip the missed dose if it is almost time for your next scheduled dose. Do not take extra medicine to make up the missed dose.

What happens if I overdose?

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

Overdose symptoms may include diarrhea, vomiting, tremors, and severe muscle spasms or twitching.

What should I avoid while taking Guanidine HCl?

Avoid being near people who are sick or have infections. Tell your doctor at once if you develop signs of infection.

Guanidine HCl side effects

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

Call your doctor at once if you have:

  • easy bruising, unusual bleeding (nose, mouth, vagina, or rectum), purple or red pinpoint spots under your skin;

  • pale skin, feeling light-headed or short of breath, rapid heart rate, trouble concentrating;

  • fever, chills, sore throat, cold or flu symptoms, swelling or redness;

  • loss of balance or coordination;

  • a light-headed feeling, like you might pass out;

  • pink or red urine, swelling, rapid weight gain, little or no urinating;

  • pounding heartbeats or fluttering in your chest; or

  • confusion, hallucinations, unusual thoughts or behavior.

Common side effects may include:

  • numbness, tingling, or cold feeling (especially in your face, hands, or feet);

  • dry mouth, upset stomach, loss of appetite;

  • nausea, diarrhea, stomach cramps;

  • feeling nervous, jittery, or irritable;

  • tremors or shaking;

  • increased sweating; or

  • dry or scaly skin, redness or crusting around your hair follicles.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

See also: Side effects (in more detail)

What other drugs will affect Guanidine HCl?

Tell your doctor about all medicines you use, and those you start or stop using during your treatment with This medicine HCl, especially drugs that weaken the immune system such as cancer medicine, steroids, and medicines to prevent organ transplant rejection.

Other drugs may interact with guanidine, including prescription and over-the-counter medicines, vitamins, and herbal products. Tell each of your health care providers about all medicines you use now and any medicine you start or stop using.

Where can I get more information?

  • Your pharmacist can provide more information about Guanidine HCl.
  • Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use this medication only for the indication prescribed.
  • Disclaimer: Every effort has been made to ensure that the information provided by Cerner Multum, Inc. ('Multum') is accurate, up-to-date, and complete, but no guarantee is made to that effect. Drug information contained herein may be time sensitive. Multum information has been compiled for use by healthcare practitioners and consumers in the United States and therefore Multum does not warrant that uses outside of the United States are appropriate, unless specifically indicated otherwise. Multum's drug information does not endorse drugs, diagnose patients or recommend therapy. Multum's drug information is an informational resource designed to assist licensed healthcare practitioners in caring for their patients and/or to serve consumers viewing this service as a supplement to, and not a substitute for, the expertise, skill, knowledge and judgment of healthcare practitioners. The absence of a warning for a given drug or drug combination in no way should be construed to indicate that the drug or drug combination is safe, effective or appropriate for any given patient. Multum does not assume any responsibility for any aspect of healthcare administered with the aid of information Multum provides. The information contained herein is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. If you have questions about the drugs you are taking, check with your doctor, nurse or pharmacist.

Copyright 1996-2012 Cerner Multum, Inc. Version: 2.01.

Date modified: February 01, 2018
Last reviewed: June 30, 2014