BOSTON (AP) — Massachusetts Attorney General Maura Healey says she’s concerned about recent price hikes in the cost of a drug used to reverse heroin overdoses.

Healey’s office on Thursday sent a letter to California-based Amphastar Pharmaceuticals Inc. asking for more information about the cost of the drug naloxone — also marketed under the brand name Narcan.

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Healey points to reports that she says indicate the cost of the drug has increased 111 percent — from $19.56 to $41.43 for a 2-milliliter dose — since June 2014.

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A few months earlier in March 2014, former Gov. Deval Patrick declared a public health emergency, citing an increase in heroin and opiate overdoses.

Healey says she’s heard from local law enforcement and public health workers worried about their ability to maintain supplies of the drug.

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