Indication |
Used in the management of diabetes mellitus type 2 (adult-onset). |
Pharmacodynamics |
Acetohexamide is an intermediate-acting, first-generation oral
sulfonylurea. It lowers blood sugar by stimulating the pancreatic beta
cells to secrete insulin and by helping the body use insulin
efficiently. The pancreas must produce insulin for this medication to
work. Acetohexamide has one-third the potency of chlorpropamide, and
twice the potency of tolbutamide; however, similar hypoglycemic efficacy
occurs with equipotent dosage of sulfonylureas. |
Mechanism of action |
Sulfonylureas such as acetohexamide bind to an ATP-dependent K+
channel on the cell membrane of pancreatic beta cells. This inhibits a
tonic, hyperpolarizing outflux of potassium, which causes the electric
potential over the membrane to become more positive. This depolarization
opens voltage-gated Ca2+ channels. The rise in intracellular
calcium leads to increased fusion of insulin granulae with the cell
membrane, and therefore increased secretion of (pro)insulin. |
Absorption |
Rapidly absorbed from the GI tract. |
Volume of distribution |
Not Available |
Protein binding |
90% |
Metabolism |
Extensively metabolized in the liver to the active metabolite
hydroxyhexamide, which exhibits greater hypoglycemic potency than
acetohexamide. Hydroxyhexamide is believed to be responsible for
prolonged hypoglycemic effects. |
Route of elimination |
Not Available |
Half life |
Elimination half-life of the parent compound is 1.3 hours and the
elimination half-life of the active metabolite is approximately 5-6
hours. |
Clearance |
Not Available |
Toxicity |
Oral, rat LD50: 5 gm/kg; Oral, mouse LD50:
>2500 mg/kg. Symptoms of an acetohexamide overdose include hunger,
nausea, anxiety, cold sweats, weakness, drowsiness, unconsciousness, and
coma. |