The HPB said "there is no conclusive evidence to establish that the protease inhibitors are the cause of these spontaneous bleeding episodes" but warned that it is important to investigate any safety concern that arises early in the use of this new class of HIV drugs because clinical experience is limited. Questions about specific drugs should be addressed to the manufacturer. Unexpected spontaneous bleeding events should be reported to the Canadian Adverse Drug Reaction Monitoring Program (613 957-0337) or the Bureau of Pharmaceutical Assessment (613 954-6493).