Country: South Africa
Language: English
Source: South African Health Products Regulatory Authority (SAHPRA)
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METPHAGE 500 mg (Tablets) METPHAGE 850 mg (Tablets) SCHEDULING STATUS: S3 PROPRIETARY NAME (and dosage form): METPHAGE 500 mg (Tablets) METPHAGE 850 mg (Tablets) COMPOSITION: Each METPHAGE 500 mg tabletcontains 500 mg metformin hydrochloride Each METPHAGE 850 mg tablet contains 850 mg metformin hydrochloride PHARMACOLOGICAL CLASSIFICATION: A 21.2 Oral Hypoglycaemic PHARMACOLOGICAL ACTION: Metformin is a biguanide oral anti-hyperglycaemic agent. Its mode of action is thought to be increased peripheral glucose utilisation mediated by increased insulin sensitivity and inhibition of increased hepatic and renal gluconeogenesis. Absorption: After an oral dose of metformin, Tmaxis reached in 2.5 hours. Absolute bioavailability of a 500 mg or 850 mg metformin tablet is approximately 50-60% in healthy subjects. After an oral dose, the non-absorbed fraction recovered in faeces was 20-30%. After oral administration, metformin absorption is saturable and incomplete. It is assumed that the pharmacokinetics of metformin absorption is non-linear. At the usual metformin doses and dosing schedules, steady state plasma concentrations are reached within 24 to 48 hours and are generally less than 1 microgram/mL. In controlled clinical trials, maximum metformin plasma levels (Cmax) did not exceed 4 microgram/mL, even at maximum doses. Food decreases the extent and slightly delays the absorption of metformin; following administration of a dose of 850 mg, a 40% lower plasma peak concentration, a 25% decrease in AUC (area under the curve) and a 35 minute prolongation of time to peak plasma concentration were observed. The clinical relevance of these decreases is unknown. Distribution: Plasma protein binding is negligible. Metformin partitions into erythrocytes. The blood peak is lower than the plasma peak a Read the complete document