Igraine's probably going to get herself into shitload of trouble with the Wraith.  Instead of attempting to locate the one Amaury dropped, she's just going to get him another brick of cocaine.  She'd have no real way of tracking it down other than by attempting to retrace Amaury's steps.  Would she know where Vlad's home is and that Amaury had went there earlier?  Unless vampire heightened senses can in fact track down traces of drugs like airport security dogs, but that means she would eventually locate the Ventrue nest.  That would be a load of trouble and perhaps just the discovery she needs to really make a name for herself.