Meglitinides (Benzoic acid derivatives)

SYNTHESIS AND DRUG PROFILE

Meglitinides (Benzoic acid derivatives)

The meglitinides are similar in structure to sulphonylureas. The sulphonylurea and meglitinide classes  of oral hypoglycaemic drugs are referred to as endogenous insulin secretagogues because they induce the pancreatic release of endogenous insulin.

Mode of action: Even though, these are not sulphonylureas they act on sulphonylurea receptors as well as the other variant receptors and closes the ATP dependent k+ channels, leading to insulin secretion by depolarization.

i. Meglitinide

Synthesis

ii. Repaglinide (Repide, Repa, Eurepa)

Synthesis

Properties and uses: Repaglinide is a white powder, practically insoluble in water, soluble in methanol, and methylene chloride. It stimulates insulin release and is used in the treatment of diabetes mellitus.

Assay: Dissolve the sample in methanol and add anhydrous acetic acid and titrate against 0.1 M perchloric acid. Determine the end point potentiometrically

Dose: The usual initial dose for adults is 0.5 mg, taken within 30 min of main meals. Initial doses of 1 or 2 mg may be used in patients who have had previous hypoglycaemic treatment. Dose may be adjusted at intervals of 1–2 week up to 4 mg before meals; maximum dose is 16 mg daily.

iii. Nateglinide

Metabolism: It is metabolized in the liver and 16% is excreted in the urine unchanged. The major metabolites are hydroxyl derivative (CYP2C9 70%, CYP3A4 30%) that are further conjugated to the glucuronide derivative (Fig 1.1).

Uses: It is used as an oral hypoglycaemic agent in type II diabetic mellitus.