Tolazamide Dosage

Applies to the following strengths: 250 mg; 100 mg; 500 mg

Usual Adult Dose for Diabetes Type 2

Initial dose: 100 to 250 mg orally once a day

Adjust dose based on blood glucose response

Maintenance dose: Average 250 to 500 mg/day; range: 100 to 1000 mg per day

For doses greater than 500 mg, the dose maybe divided and given twice a day

Maximum dose: 1000 mg per day

Comments:

For patients with a fasting blood glucose less than 200 mg/dL, the usual starting dose is 100 mg per day.
Patients will generally have no further response to doses greater than 1000 mg/day
Transferring patients from other antidiabetic regimens should be done conservatively: see dose adjustment section.

Use: As an adjunct to diet to lower blood glucose in patients with type 2 diabetes whose hyperglycemia cannot be controlled by diet alone.

Usual Geriatric Dose for Diabetes Type 2

Initial dose: 100 mg orally once a day

Renal Dose Adjustments

Use with caution; initial and maintenance dosing should be conservative to avoid hypoglycemic reactions.

Liver Dose Adjustments

Use with caution; initial and maintenance dosing should be conservative to avoid hypoglycemic reactions.

Dose Adjustments

Elderly, debilitated, or malnourished patient: Initial and maintenance dosing should be conservative to avoid hypoglycemic reactions.

Transferring Patients from other Oral Antidiabetic Therapy:

If receiving less than 1 g/day of tolbutamide: initial tolazamide dose should be 100 mg orally per day.
If receiving greater than 1 g/day of tolbutamide: initial tolazamide dose should be 250 mg orally per day.
Tolazamide 250 mg is approximately equal to chlorpropamide 250 mg.
Patients should be observed carefully in the first 1 to 2 weeks for hypoglycemia due to the possibility of overlapping effects.

Transferring Patients from Insulin Therapy:

For patients on 20 units per day or less of insulin: Discontinue insulin and start tolazamide 100 mg orally once a day
For patients on 20 to 40 units per day of insulin: Discontinue insulin and start tolazamide 250 mg orally once a day
For patients requiring more than 40 units of insulin per day: Decrease insulin dose by 50% and start tolazamide 250 mg orally once a day.

Adjust tolazamide dose weekly (or more often in the group previously requiring more than 40 units per day).

Precautions

Safety and efficacy have not been established in patients younger than 18 years.

Consult WARNINGS section for additional precautions

Dialysis

Data not available

Other Comments

Administration advice:
Take orally once a day in the morning

For doses greater than 500 mg, divide the dose and take twice a day

Storage requirements:

Protect from light

General:

Hypoglycemia may occur, especially in the elderly, debilitated, or malnourished patient, in patients receiving combination therapy, and/or those with renal, hepatic or adrenal insufficiency; dose reduction of this drug may be necessary.
This drug should not be used in patients with type 1 diabetes mellitus or diabetic ketoacidosis.
Hemolytic anemia may occur in glucose 6-phosphate dehydrogenase (G6PD) deficient patients; consider a non-sulfonylurea alternative.
When a patient stabilized on any diabetic regimen is exposed to stress such as fever, trauma infection, or surgery, it may be necessary to stop this drug and administer insulin.

Monitoring:
Regular clinical and laboratory evaluations are necessary to determine minimum effective dose and detect primary or secondary failure.

Clinical status should be checked within the first 4 to 8 weeks and regularly, thereafter
Laboratory monitoring including periodic fasting blood glucose, self-monitoring of blood glucose, and urine testing (i.e., glucose and ketones) should be done more frequently during drug initiation and with changing doses; glycosylated hemoglobin levels (HbA1c) should be done as clinically warranted.

Patient advice:

Patients should understand the importance of exercise and dietary control in the management of their disease.
Patients should understand that alcohol ingestion, intense or prolonged exercise, skipping meals, illness, or lifestyle changes may increase their risks for hypoglycemia; they should know how to recognize the symptoms of hypoglycemia and be prepared to treat it.
Patients should be careful about driving and use of machinery, especially when at risk for hypoglycemia.
Patients should speak with their health care provider during periods of stress such as fever, trauma, or illness, as their diabetes management may need to be changed.
Advise patient to speak to physician or health care professional if pregnant, intend to become pregnant, or are breastfeeding.