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Tolazamide Side Effects

For the Consumer

Applies to tolazamide: oral tablet

As well as its needed effects, tolazamide may cause unwanted side effects that require medical attention.

Severity: Major

If any of the following side effects occur while taking tolazamide, check with your doctor immediately:

  • Abdominal or stomach pain
  • chills
  • clay-colored stools
  • dark urine
  • diarrhea
  • difficulty swallowing
  • dizziness
  • fast heartbeat
  • fever
  • headache
  • hives
  • itching
  • loss of appetite
  • puffiness or swelling of the eyelids or around the eyes, face, lips, or tongue
  • rash
  • shortness of breath
  • skin rash
  • tightness in chest
  • unpleasant breath odor
  • unusual tiredness or weakness
  • vomiting of blood
  • wheezing
  • yellow eyes or skin
Incidence not known:
  • Agitation
  • back, leg, or stomach pains
  • black, tarry stools
  • bleeding gums
  • blood in urine or stools
  • chest pain
  • coma
  • confusion
  • convulsions
  • cough or hoarseness
  • decreased urine output
  • depression
  • difficulty breathing
  • fast or irregular heartbeat
  • fatigue
  • fever with or without chills
  • fluid-filled skin blisters
  • general body swelling
  • general feeling of tiredness or weakness
  • hostility
  • increased thirst
  • irritability
  • itching of the skin
  • lethargy
  • light-colored stools
  • lower back or side pain
  • muscle pain or cramps
  • muscle twitching
  • nausea or vomiting
  • nosebleeds
  • painful or difficult urination
  • pale skin
  • pinpoint red spots on skin
  • rapid weight gain
  • seizures
  • sensitivity to the sun
  • skin thinness
  • sore throat
  • sores, ulcers, or white spots on the lips or in the mouth
  • stupor
  • swelling of the face, ankles, or hands
  • swollen or painful glands
  • unusual bleeding or bruising

If any of the following symptoms of overdose occur while taking tolazamide, get emergency help immediately:

Symptoms of overdose:
  • Anxiety
  • cold sweats
  • cool, pale skin
  • increased hunger
  • nervousness
  • nightmares
  • shakiness
  • slurred speech

Severity: Minor

Some tolazamide side effects may not need any medical attention. As your body gets used to the medicine these side effects may disappear. Your health care professional may be able to help you prevent or reduce these side effects, but do check with them if any of the following side effects continue, or if you are concerned about them:

Less common:
  • Indigestion
  • passing of gas
  • Feeling of constant movement of self or surroundings
  • sensation of spinning
Incidence not known:
  • Redness or other discoloration of skin
  • severe sunburn

For Healthcare Professionals

Applies to tolazamide: oral tablet


Gastrointestinal side effects have included nausea, epigastric fullness, and heart burn. These effects tend to be dose-related and may resolve upon a reduction in dose.[Ref]


Dermatologic side effects have included pruritus, erythema, urticaria, and morbilliform or maculopapular eruptions. Porphyria cutanea tarda and photosensitivity reactions have been reported with the use of sulfonylureas.[Ref]


Hematologic side effects have included leukopenia, agranulocytosis, thrombocytopenia, hemolytic anemia, aplastic anemia, and pancytopenia.[Ref]


Metabolic side effects have included hypoglycemia and hyponatremia. The syndrome of inappropriate antidiuretic hormone (SIADH) secretion has been reported with other sulfonylureas.[Ref]

Nervous system

Nervous system side effects have included dizziness and headache.[Ref]


General side effects have included weakness, fatigue, vertigo, and malaise.[Ref]


A 54-year-old woman with self-limiting cholestatic jaundice after treatment with chlorpropamide experienced a recurrence of jaundice following subsequent treatment with tolazamide. Discontinuation of tolazamide resulted in resolution of the jaundice, indicating a possible hepatic cross-sensitivity with chlorpropamide.[Ref]

Hepatic side effects have rarely included cholestatic jaundice.[Ref]


1. "Product Information. Tolinase (tolazamide)" Pharmacia and Upjohn, Kalamazoo, MI.

2. Shorr RI, Ray WA, Daugherty JR, Griffin MR "Individual sulfonylureas and serious hypoglycemia in older people." J Am Geriatr Soc 44 (1996): 751-5

3. Bridges ME, Pittman FE "Tolazamide-induced cholestasis." South Med J 73 (1980): 1072-4

4. Nakao NL, Gelb AM, Stenger RJ, Siegel JH "A case of chronic liver disease due to tolazamide." Gastroenterology 89 (1985): 192-5

It is possible that some side effects of tolazamide may not have been reported. These can be reported to the FDA here. Always consult a healthcare professional for medical advice.

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.