Officials with the Ministry of Health are looking into problems with the PharmaNet computer system.
The province-wide network that links all B.C. pharmacies to a central set of data systems tells pharmacists how much drug coverage their customers have, and how much they will have to pay for a prescription.
A spokesman for London Drugs said the system was down at stores throughout the province for three hours Thursday morning, and for another hour in the afternoon.
Cal Sookachoff, the pharmacist at the West End Pharmacy in New Westminster, said he filled prescriptions and asked customers to pay on their next visit.
Other pharmacies said in some cases, customers were given a few pills from their prescription, and asked to return to pick up the rest later.
There's still no word on what caused the system to go down.
Every prescription dispensed in B.C. is entered into PharmaNet's system, including more than 47 million prescriptions in 2007 alone.
Along with tracking billing, the system protects patients from potentially dangerous medication errors, duplications and dangerous combinations of different medications.
In March, the Ministry of Health announced it would spend $14 million to upgrade the system, which is currently run on a private contract by Maximus BC and Systems Xcellence Inc. for the Ministry of Health's pharmaceutical services division.