This pain medicine case involves a male patient in Oklahoma with a known history of being a poor drug metabolizer. Shortly before the events of the incident in question, the patient sought treatment for abdominal pain from the defendant doctor. During this initial visit the patient was prescribed pain medication. The patient presented back to the defendant with complaints of vertigo, confusion, and difficulties talking and thinking. Nevertheless, the prescription was continued, and the man was told he would merely need a canalith re-positioning procedure to counteract the vertigo. Follow up care was sought by the patient again less than a month later. Medical documentation indicates that he presented in a wheelchair with noted dizziness and trouble walking. The patient then sought treatment from a new doctor shortly after this visit. Once again, his chief complaints were dizziness, nausea, and ataxia. The new doctor assessed the patient as having akathisia due to his use of prescribed medication. At this point he was advised to discontinue any use of the medication. The patient was diagnosed with probable drug induced dyskinesia with a high likelihood of irreversibility.
Question(s) For Expert Witness
- 1. Are you familiar with medication contraindications, side-effects, and possible interactions with other medications?
- 2. Should a patient that is a poor drug metabolizer be prescribed this drug?
Expert Witness Response E-033660
I am familiar with contraindications, side-effects, and possible interactions with other medications for the drug in question here. Certainly there is heightened risk of side effect with known poor metabolizers. Informed consent, making the patient aware of potential risks and discerning the benefits are key to guiding the rationale to continue therapy and shared decision making. This said, close follow up and providing the patient with detailed information on concerns to look out for is paramount. Indeed when symptoms appear discontinuing/suspending the medication is critical. Moreover, most use of this drug is for periods of time less than 3 months (incidentally the medication is typically prescribed as needed and not scheduled daily). The cumulative dosing over 5 months is unusual.
Expert Witness Response E-033208
I am familiar with side effects, contraindications, and interactions with this medication. A patient that is a known hypometabolizer probably should not be prescribed this medication. However, if risks and benefits are weighed and there are no other options, it can be initiated with monitoring of therapy. At this time, there is no reason to believe a hypometabolizer is the only reason a patient develops extrapyramidal symptoms; there are likely multiple genes affecting this outcome. Based on the vignette presented, a patient with this history and presentation should not be continued on this medication for as long as he was. A few years ago, the FDA placed a black-box warning about the use of this drug causing tardive dyskinesia and to limit its use to 12 weeks.