Impact of Drugs in Litigation Q&A With Dr. Tennenhouse, Oct. 21-22, 2009

October 22, 2009

The following includes all questions and answers that were asked of Dr. Dan Tennenhouse during the webinar sessions titled “The Impact of Drugs in Litigation” on October 21st & 22nd, 2009. Check back soon to view the webinars in their entirety on this blog, and also on You Tube.

Question:
Is there a chart or some sort of reference material that would show the pharmacokinetics of various drugs?

Answer:
Not that I’m aware of. The pharmacokinetics of a specific drug in a specific patient are calculated using sophisticated mathematical formulae that must take into consideration the unique factors for that patient. You would ask your expert witness (usually a pharmacologist or clinical pharmacist) to do the calculation for you. What you don’t want is for your expert to omit essential factors when doing the calculation.

Question
Aren’t tissue samples a better indicator of the bioavailability.

Answer:
For drugs other than IV administered, the bioavailability depends on factors such as rate of uptake from the GI tract or from muscle injection sites. The drug enters the blood stream and bioavailability can then be measured by testing the drug’s blood level at various times. Bioavailability is based on level of drug in the “systemic circulation.” Tissue samples tell you how much of the drug has entered a specific tissue, which may vary with such factors as lipid solubility of the drug, but this may be quite misleading as to bioavailability. On the other hand, tissue levels may be a better measure than bioavailability of the actual effect of the drug on the target organ.

Question:
How does a litigator get around a physician’s disregard the warnings and side effects listed in a drug’s monograph as just a “placebo” effect.

Answer:
“Just” a placebo effect may reflect drug studies that showed no difference between a test group using the drug and a control group not using the drug. Any effect arising solely from patients’ belief they are taking the drug is placebo effect. However, placebo effect is often very real. Belief can impact brain chemistry which creates a real physical effect such as pain reduction. Discuss the placebo effect of the drug with your expert witness/consultant who may be able to lead you out of the problem by identifying physical changes resulting from the placebo effect.

Question:
Should physician’s be limited to prescribing drugs to the scope of their specialty (e.g. ritalin being prescribed for ADD by someone other than a psychiatrist?)

Answer:
This is not practical even though physicians often extend beyond their level of competence when prescribing. The problem is that patients cannot realistically be referred to the appropriate specialist for every drug they need. If I am treating a patient for a muscle strain and the patient mentions inability to sleep due to the pain, or incidental symptoms of a urinary tract infection, I cannot send the patient to a psychiatrist just for sleep medication or to a nephrologist/urologist just for urinary tract antibiotics. Physicians do sometimes cross the line when they undertake to treat a problem clearly beyond their competence, but scope of medical practice is difficult to define. A medical license covers all specialties of medicine, and it is very desirable for physicians to look beyond the limits of their own specialty when treating a patient. Otherwise, too many medical problems will “fall in the crack.”

Question:
Is there a way to tell between generic drug & brand name in the blood or urine — e.g. Lortab

Answer:
If you look at the Drug Finder, Chapter 40, in Attorneys Medical Deskbook 4th, you will find every drug listed alphabetically by both brand name and generic name. If generic, it will appear in all capital letters. Brand names appear in italics. For example, the entry you would seek is: “Lortab HYDROCODONE BITARTRATE, ACETAMINOPHEN [narcotic analgesic] Use: pain.”

Question:
Are off-label uses of drugs published in the Drug Compendia? If not, what methods do doctors learn about these off-label uses?

Answer:
Off-label use is frequently difficult to identify for attorneys. Off-label indications for drugs are not usually published in compendia. They appear piecemeal in the medical literature or are presented at medical conferences by experts in the field. Sometimes they are just word of mouth among physicians. “Hey, have you tried methylphenidate for resistant depression? It really works well for some patients who don’t respond to anti-depressants.” Methylphenidate is FDA-approved only for ADHD, so this is suggesting off-label use. Physicians in one specialty are often unaware of common off-label drug usage in other specialties, and there is probably some degree of off-label drug use in every specialty of medicine. The best way to identify off-label use is to ask the treating physician or an expert in the same specialty why the drug was used in a particular patient. Physicians who are careful record keepers will document the indication, but many won’t.

Following are the questions about the Medical Litigator Product Demonstration:

Question:
I am wonderng about the search query. Using Westlaw Boolean search rules, you are asking about

Answer:
Medical Litigator searches using Natural Language searching by default. In the instance of “Stroke Off Label Drug Use” it looks for documents that best match that search. So the documents that are returned will be the documents that have the largest percentage of the terms that are included in the search.

Question:
I stroke OR of OR label OR drug OR use, right?

Answer:
You do have the option of using Boolean Searching (Terms and connectors searching), by clicking on the ‘Terms and Connectors’ tab at the top of the Medical Litigator screen. In the search that was performed you are correct, the search would have been: Stroke OR Off OR Label OR Drug OR Use. So any document that had any of those terms would have returned. To do a Boolean search that would return the results you wanted, you would probably want to put the terms in the same sentence, for example: Stroke /s Off-Label /s drug /s use. Depending on the results you may want to expand your search: Stroke /p Off-Label /s drug /s use; or restrict your search: Stroke /s Off-Label /2 drug /2 use.