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Guanidine Side Effects

Applies to guanidine: oral tablet

In addition to its needed effects, some unwanted effects may be caused by guanidine. In the event that any of these side effects do occur, they may require medical attention.

Major Side Effects

You should check with your doctor immediately if any of these side effects occur when taking guanidine:

Incidence not known:
  • Ammonia-like breath odor
  • black, tarry stools
  • bleeding gums
  • blood in the urine or stools
  • blurred vision
  • burning, crawling, itching, numbness, prickling, "pins and needles", or tingling feelings
  • change in frequency or amount of urine
  • chest pain
  • chills
  • cloudy urine
  • cold sensations in the hands and feet
  • confusion
  • cough
  • dizziness, faintness, or lightheadedness when getting up suddenly from a lying or sitting position
  • fast, irregular, pounding, or racing heartbeat or pulse
  • fever
  • increased thirst
  • loss of appetite
  • nausea or vomiting
  • painful or difficult urination
  • pale skin
  • pinpoint red spots on the skin
  • shakiness in the legs, arms, hands, or feet
  • shortness of breath, especially with exercise
  • sore throat
  • sores, ulcers, or white spots on the lips or in the mouth
  • sweating
  • swollen glands
  • unsteadiness, trembling, or problems with muscle control
  • unusual bleeding or bruising
  • unusual tiredness or weakness
  • weight loss

Minor Side Effects

Some of the side effects that can occur with guanidine may not need medical attention. As your body adjusts to the medicine during treatment these side effects may go away. Your health care professional may also be able to tell you about ways to reduce or prevent some of these side effects. If any of the following side effects continue, are bothersome or if you have any questions about them, check with your health care professional:

Incidence not known:
  • Abdominal or stomach cramps
  • burning, itching, and pain in hairy areas
  • crying for no reason
  • dry mouth
  • dryness and scaling of the skin
  • false or unusual sense of well-being
  • feeling irritated
  • feeling of warmth
  • feeling paranoid
  • jitteriness
  • large, flat, blue or purplish patches in the skin
  • mood or mental changes
  • pinpoint red or purple spots on the skin
  • quick to react or overreact emotionally
  • rash
  • redness of the face, neck, arms, and occasionally, upper chest
  • restlessness
  • seeing or hearing things that are not there

Not all side effects for guanidine may be reported. You should always consult a doctor or healthcare professional for medical advice. Side effects can be reported to the FDA here.

Disclaimer: Every effort has been made to ensure that the information provided is accurate, up-to-date and complete, but no guarantee is made to that effect. In addition, the drug information contained herein may be time sensitive and should not be utilized as a reference resource beyond the date hereof. This material does not endorse drugs, diagnose patients, or recommend therapy. This information is a reference resource designed as supplement to, and not a substitute for, the expertise, skill , knowledge, and judgement of healthcare practitioners in patient care. The absence of a warning for a given drug or combination thereof in no way should be construed to indicate safety, effectiveness, or appropriateness for any given patient. does not assume any responsibility for any aspect of healthcare administered with the aid of materials provided. 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 substances you are taking, check with your doctor, nurse, or pharmacist.