Retracted scientific work still gets cited
Science has a news focus on scientific misconduct. A particular study tracked the citation of papers that were already retracted. They found that scientists keep citing retracted papers.
Some editors contacted by Science said that they do not have the resources to look up every citation in every paper to help purge the literature of citations to retracted work. In my opinion this is not such a complicated problem. If journals agreed to submit to a central repository all retractions, then the citations could very easily be checked against the database and removed. Even with such an automatic system , scientists should have the responsibility to keep up with the works being retracted in their fields.
Since retractions are publicly announced by the journals pubmed has already some of this information available. If you search for retraction in the title in pubmed you can see several of these announcements (not all are retractions). In some cases, when you search for a the title of a retracted paper you can see in pubmed a link to the retraction but this is not always the case. All that is needed is for publishing houses to agree on a single format to publish retractions and repositories to make sure all retractions are appended to the former entries to the same publication.