The tornado that struck a major Pfizer pharmaceutical plant in North Carolina on Wednesday «almost completely destroyed» the plant’s warehouse, which stored raw materials, packaging supplies and finished drugs waiting to be shipped to hospitals across the United States, Pfizer CEO Albert Bourla said during a news conference Friday.

The company is working with the Food and Drug Administration, which on Friday said it was still trying to gauge the impact the natural disaster could have on the nation’s drug supply. The Rocky Mount, North Carolina-based plant made about 150 drugs, many of which are used by hospitals, including fentanyl and morphine for pain control and anesthetics for surgery. Half of the drugs made at the facility are on the FDA’s list of essential drugs, according to the United States Pharmacopeia, a group that tracks drug supply chains.

A USP Review released It found out on Friday that many of the drugs were already at risk of shortages before the tornado struck.

The Pfizer plant is «obviously a major contributor to the US supply chain,» said Vimala Raghavendran, the organization’s vice president of information product development.

Assessing the damage will be difficult, according to Pfizer, since only a small number of people have limited access to the facility due to the dangers still presented by the tornado.

“We are closely watching the situation as it evolves,” Chanapa Tantibanchachai, an FDA spokesman, said in an email.

Michael Ganio, senior director of pharmaceutical practice and quality for the American Society of Health System Pharmacists (ASHP), said it’s likely easier to recover from damage to warehouses that stock supplies and finished goods, ramping up production again.

Repairing or replacing the equipment to make the drugs would be a more challenging and time-consuming process, he added.

Bourla said the production facility was not damaged. Still, he told her, the company is exploring alternative manufacturing locations.

Pfizer saying in a statement that it is moving what it can to nearby sites for storage. The facility will remain closed while the damage continues to be assessed.

The Pfizer Rocky Mount facility produces nearly 25% of the drugmaker’s sterile injectable drugs used in US hospitals and is one of the largest facilities for these drugs in the world, according to the drug manufacturer website. Sterile injectable drugs refer to any drug that is injected, either intravenously or as a shot, and is not contaminated.

Among the drugs made at the facility are anesthetics used to sedate patients during surgery and intubation, including propofol and etomidate, said Mittal Sutaria, senior vice president of pharmacy contracts and program services at Vizient, a group dedicated to preventing drug shortages.

The facility also manufactures pain relievers for pain control; powerful antibiotics such as vancomycin; and neuromuscular blockers such as cisatracurium and succinylcholine, which are used during surgical procedures, Sutaria said.

The natural disaster comes as the nation’s drug supply is already under strain. As of the end of June, there were 309 active drug shortages in the US, the most in nearly a decade, according to the ASHP.

Problems at the Pfizer plant have the potential to push the United States past 320 active drug stockouts, the highest ever reported, Ganio said. “I am absolutely concerned,” he said.

It would mean that more patients cannot access the medicines they need.

“We are working with distributors to request that they immediately implement proactive management of any product anticipated to be affected to help minimize additional supply chain stress,” said Vizient’s Sutaria.

The last time a natural disaster caused a critical drug shortage in the US was in 2017, after Hurricane Maria struck a Baxter manufacturing plant in Puerto Rico, cutting off the supply of amino acids used to feed sick patients and saline, used to administer intravenous drugs.

It took about a year for the shortages caused by Hurricane Maria to ease, Ganio said.

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nicole duarte contributed.