Generic name: Tolbutamide.

Orinase is an oral antidiabetic medication. It works by inducing the pancreas to secrete more insulin. 

Quick Facts About Orinase


Used to treat Type II (non-insulin-dependent) diabetes.

Orinase Dosage

Take 30 minutes prior to eating or according to your doctor’s specific instructions.

  • Usual adult dose: 1 to 2 grams initially. Maintenance therapy — ranges from 0.25 to 3 grams per day. Seniors — prescribed lower doses.
  • Usual child dose: not generally prescribed for children.
  • Missed dose: take as soon as possible, unless almost time for next dose. In that case, do not take missed dose; go back to regular schedule. Do not double doses.

Orinase Side Effects

Overdose symptoms:

low blood sugar. Signs of mild hypoglycemia (low blood sugar) — blurred vision, cold sweats, dizziness, fatigue, headache, hunger, light-headedness, nausea, nervousness, rapid heartbeat. Symptoms of more severe hypoglycemia — coma, pale skin, seizures, shallow breathing. If you suspect an overdose, immediately seek medical attention.

More common side effects: bloating, heartburn, nausea.

Less common or rare Orinase side effects: anemia and other H blood disorders; blistering; changes in taste; headache; hepatic porphyria (sensitivity to light, stomach pain, and nerve damage); hives; itching; redness of skin; skin eruptions; skin rash.


Inform your doctor before combining Orinase with:

adrenal corticosteroids (prednisone or cortisone), airway-opening medications (Proventil or Ventolin), anabolic steroids (testosterone), barbiturates (Seconal or phenobarbital), beta-blockers such as Inderal and Tenormin, blood thinners such as Coumadin, calcium channel blockers such as Cardizem and Procardia, chloramphenicol (Chloromycetin), cimetidine (Tagamet), clofibrate (Atromid-S), epinephrine (EpiPen), estrogens (Premarin), fluconazole (Diflucan), furosemide (Lasix), isoniazid (Laniazid or Rifamate), itraconazole (Sporanox), major tranquilizers such as Stelazine and Mellaril, MAO inhibitors such as Nardil, methyldopa (Aldomet), miconazole (Monistat), niacin (Nicobid or Nicolar), nonsteroidal anti-inflammatory medications such as Motrin and Naprosyn, oral contraceptives, phenytoin (Dilantin), probenecid (Benemid), rifampin (Rifadin), sulfa medications such as Bactrim and Septra, thiazide and other diuretics such as Diuril and HydroDIURIL, thyroid medications such as Synthroid.

Alcohol use may cause low blood sugar; use carefully.

Special Cautions

If pregnant or planning to become pregnant, inform your doctor immediately. Not known if Orinase appears in breast milk; however, other oral diabetes medications do.

Seniors may be prescribed a lower dose to minimize risk of low blood sugar (hypoglycemia).

Not generally prescribed for children.

  • Should not use in place of a sound diet and exercise.
  • Orinase is not insulin and should not be used as a substitute for insulin.
  • To help prevent hypoglycemia (low blood sugar), always keep a quick-acting sugar product handy.
  • Hypoglycemia risk increases by: missed meals, use of other medications, fever, trauma, infection, surgery, excessive exercise. Also at higher risk for hypoglycemia if you have: kidney or liver problems; lack of adrenal or pituitary hormone; are elderly, rundown, malnourished; or are using more than one glucose-lowering medication.
  • If allergic to Orinase, should not take.
  • Should not take if you have diabetic ketoacidosis (a life-threatening emergency with symptoms that include excessive thirst, nausea, fatigue, pain below breastbone, fruity breath).
  • Not to be used as the only therapy for treating Type I (insulin-dependent) diabetes.
  • Consult with your doctor before starting Orinase if you have a heart condition; may worsen condition.
  • Doctor should monitor glucose levels in blood and urine during therapy.
  • Doctor may switch you from Orinase to insulin if you experience injury, infection, surgery, or fever, leading to loss of control of diabetes.
  • Effectiveness may decrease over time.


HealthSurvey.org provides accurate and independent information prescription pills, over-the-counter medicines and natural products. This material is provided for educational purposes only and is not intended for medical advice, diagnosis or treatment. If you have questions about  dosage, or Orinase side effects, please contact your healthcare provider