Pharmac says it welcomes a joint inquiry into four deaths - which have all been linked to the anti-epileptic drug, Logem

Chief Coroner Judge Deborah Marshall made the announcement today.

The deaths come after Pharmac pulled funding from the Lamictal and Arrow brands of the drug - which meant up to 11-thousand people were switched onto the generic Logem.

Pharmac medical director Dr Ken Clark says he wrote to Judge Marshall last month, offering full assistance to any investigation.

He's asked to have a full and early opportunity to have input into any inquiry where Pharmac's actions or decisions 'may be relevant'.