DURHAM – Shares in life science giant IQVIA dropped 4.5 percent in trading so heavy that it triggered a halt Wednesday after the Food and Drug Administration raised “serious concerns” about some of the company’s “data and quality control procedures.”

IQVIA responded to the FDA announcement by saying the company had already discovered the problems and alerted customers in April.

“IQVIA’s internal processes had already identified the measurement conversion issue prior to the FDA’s notification. We notified our clients about this measurement conversion issue in April of this year.

“Ongoing steps have been undertaken to correct this measurement conversion issue in this offering,” the company said in a statement.

Shares later closed at $99.13, down $2.97 or 3 percent.

The FDA raised concerns after it “discovered a more than 20% discrepancy between the amount of prescription fentanyl actually sold in the U.S. over the last five years and IQVIA’s database,” according to Marketwatch.

In its response to the FDA announcement, IQVIA (NYSE: IQV) noted:

“Recently, we made a correction to a kilogram conversion measurement in the United States IQVIA National Sales Perspective (NSP) market research service affecting reported measurements for transdermal patches in the opioid market. This kilogram measurement is reported in the NSP market research service. This measurement conversion issue does not impact our widely used US and global dollar and unit information in NSP or information in any other IQVIA market research services, methodologies or offerings.

“IQVIA’s internal processes had already identified the measurement conversion issue prior to the FDA’s notification. We notified our clients about this measurement conversion issue in April of this year. Ongoing steps have been undertaken to correct this measurement conversion issue in this offering.

“We stand behind our data methodologies. We value our long-standing relationship with the FDA. We take the FDA’s concerns seriously and will continue working with the FDA to resolve these concerns to its satisfaction.”

IQVIA, formerly known as QuintilesIMS, maintains dual headquarters in the Triangle and Connecticut.