[.
]Action/Kinetics:
Onset: 1 hr. t1/2: 4.5-6.5 hr. Time to peak levels: 3-4 hr. Duration: 6-12 hr. Changed in liver to inactive metabolites. Excreted through the kidneys.
Additional Uses:
Most useful for clients with poor general physical status who should receive a short-acting compound.
Tolbutamide sodium is used to diagnose pancreatic islet cell tumors. It causes blood glucose, in the presence of a tumor, to drop quickly after IV administration and remain low for 3 hr.
Additional Side Effects:
Melena (dark, bloody stools) in some clients with a history of peptic ulcer. Relapse or secondary failure may occur a few months after therapy has been started. May cause hyponatremia and a mild goiter.
Additional Drug Interactions:
- Alcohol / Photosensitivity reactions
- Sulfinpyrazone /
Effect of tolbutamide due to 
breakdown by liver
How Supplied:
Tolbutamide: Tablet: 500 mg; Tolbutamide sodium: Powder for injection: 1 g
Dosage
•Tablets
Diabetes mellitus.
Adults, initial: 1-2 g/day. Adjust dosage depending on response, up to 3 g/day. Usual maintenance: 0.25-3 g/day. A daily dose greater than 2 g is seldom required.
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