Walgreens, the US pharmacy chain which is set to merge with the UK's Alliance Boots company, was hit by a database failure last week that prevented it from filling out prescriptions for hours.
According to a mediareport, the technical issue occurred during a maintenance update of the company's prescription database. The company fills several hundred millions of prescriptions each year.
All 8,200 Walgreen stores in the US were affected by the technical glitch, and nearly half of them were unable to fill out prescriptions for several hours. The problem was resolved by Friday afternoon.
During the downtime, the system queued prescriptions to be filled when it was back online.
Earlier this month, Walgreens announced it will buy out the rest of the UK's high street chemist chain Alliance boots, and expanded its CIO's role into a global position.
Tim Theriault, chief information, innovation and improvement officer at the American pharmacy chain, will assume the role of executive vice-president and global chief information officer of Walgreens Boots Alliance.
The company is waiting for shareholders to approve the £9 billion deal to buy the remaining 55 percent stake in Boots that it does not yet own. It bought a 45 percent stake in the chemist in June 2012.