Mepivacaine

Mepivacaine reversibly blocks nerve impulses owing to its effects on ionic transport across the cell membrane.

Mepivacaine is an amide local anaesthetic. Mepivacaine has a rapid onset, a high potency of anaesthesia and a low toxicity.

Onset of action

When peripheral nerve block is performed, mepivacaine effect occurs within 5 minutes.

Analgesia duration

Pulp anaesthesia generally lasts 25 min following maxillary infiltration and 40 min following inferior alveolar block, whereas anaesthesia of soft tissue was maintained during 90 min and 165 min following maxillary infiltration and inferior alveolar block, respectively.

Absorption

The rate of systemic absorption of mepivacaine in humans depends mainly upon the total dose and concentration of administered drug, on the route of administration, on the vascularity of the administration site and on the concomitant administration of vasoconstrictors which decreases the rate of absorption.

Distribution

Mepivacaine is rapidly distributed into tissues. Although all tissues take up local anaesthetics, the highest concentrations are found in the more highly perfused organs such as lung and kidney.

Metabolism

As all amide-type local anaesthetics, mepivacaine is largely metabolised in the liver by microsomal enzymes. Over 50% is excreted as metabolites into the bile but these probably undergo entero-hepatic circulation as only small amounts appear in the faeces.

Elimination

The plasma elimination half-life has been reported to be 1.9 hours in adults. Metabolites are excreted in the urine with less than 10% of unchanged mepivacaine.

General toxicity studies (single dose and repeat-dose studies) were performed with mepivacaine demonstrating a good safety margin. In vitro and in vivo testing carried out on mepivacaine did not reveal any genotoxic effect of this product. No relevant reproductive and development toxicity study demonstrated teratogenic effects with mepivacaine.