05 Jun Medico-legal Issues Related to Medications: Complex Considerations
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Medic-olegal Issues Related to Medications: Complex Considerations
Written by Dr Chris Alderman, Pharmacist
Medication use is essentially universal in contemporary medicine. The huge growth of new pharmacotherapy options that are available to modern clinicians offers unprecedented choice in the prevention and management of a wide range of disease states, as well as meaningful strategies to reduce symptoms and enhance quality of life, even when a “cure” cannot reasonably be anticipated.
All of this choice for prescribers can prove to be somewhat confusing and staying abreast of the nuances of an ever-changing range of options can be a difficult challenge for busy doctors. Even so, maintaining a working knowledge of the clinical pharmacology is essential for safe and effective prescribing, and to be able to assess possible medication-related issues in a wide range of commonly encountered situations.
The scientific disciplines related to medication usage are of considerable complexity and address a range of concepts relevant to safe and effective pharmacotherapy. This in itself has led to the use of range of new terminologies that appear in literature related to clinical pharmacology. For example, pharmacoepidemiology is a relatively new branch of the clinical sciences that relates to the study of medication usage in large populations – the techniques that are used in pharmacoepidemiology can provide very useful information for clinicians seeking to better understand the potential benefits and problems associated with medication use in the individual patient.
One concept that offers a superior framework for the consideration of optimal use of medications is the notion of “medication-related problems.”1 This concept is not new but has actually been in use since the early 1990s. Essentially, because the adverse effects and drug interactions associated with medications are so prominent and relatively obvious, it is clear that these issues receive the majority of attention in relation to the potential problems associated with drug therapy.
The more contemporary framework actually includes eight different categories of medication-related problems, and it is clear that each of these can have relevance in the setting of a medico-legal assessment (refer figure 1). Using a systematic approach to assess for actual or potential medication-related problems can be useful for clinicians seeking to understand the potential for drug therapy to contribute to morbidity experienced by patients they are assessing.
Other concepts receiving a good deal of attention are polypharmacy and deprescribing. Although there are various different definitions, many agree that polypharmacy involves the concurrent use of five or more medicines on a regular basis: It is clear that this definition will apply to many people undergoing medico-legal assessment.
Although polypharmacy is common in the context of multiple comorbidities, it is noteworthy that the likelihood of medication related problems increases exponentially as the number of medications taken rises. Deprescribing involves more than simply stopping medications – there are a number of steps in this complex process, which should involve comprehensive risk assessment and consumer consultation.
Pharmacogenomics is another discipline of increasing relevance in modern clinical practice. It is clear that the genetic profile of an individual can have a profound influence upon the way in which they will respond to any given medication treatment.
Much of this variability can be related to variation in the expression of genes governing the activity of a hepatic enzymes involved in drug metabolism. In many cases, if the metabolic biotransformation
of a drug is diminished because of genetic characteristics, the result will be an increase in serum concentrations which may bring with it and increased propensity for adverse effects.
However, this is not always the case – for example, diminished conversion of orally administered codeine to the more active moiety (morphine) may actually decrease the therapeutic effects of the drug. It is also clear that certain trends in genetic characteristics may be observed among particular ethnic groups, which can mean that people from certain backgrounds may be expected to have a greater likelihood of a different response to a particular medication.
Pharmacogenomic profiling can now be undertaken through non-invasive techniques that are simple and inexpensive to access.
Figure 1: Eight categories of medication-related problem, with examples
Examples of Medication-Related Problems
- A medication is required but has not been prescribed. Person with a history of DVT has had joint replacement therapy and is immobile but has not been prescribed thromboprophylaxis.
- A medication that is not clearly indicated continues to be prescribed. Opioid treatment initiated after an acute injury continued despite recovery from initial trauma.
- A medication has been prescribed, but another medication would be a better choice. Tricyclic antidepressant prescribed for an older person with cognitive difficulties.
- A medication has been prescribed, but the dose is insufficient to be effective. The dose of an analgesic is insufficient to provide reliable pain relief
- A medication has been prescribed, but the dose is too high. High-dose pregabalin causing excessive sedation but not conferring additional relief from neuropathic pain
- An adverse drug reaction has occurred. Numerous examples such as NSAID-induced renal impairment or gastritis
- There is a drug interaction. May be either pharmacokinetic or pharmacodynamic in nature
- Other issues are compromising the potential efficacy or safety of medication treatment. Examples include sub-optimal adherence, opioid misuse, modification of dose forms that results in altered characteristics (e.g. crushing a slow release tablet, cutting a transdermal patch)
Medico-legal Issues Related to Medications
It is increasingly common for questions related to the effects of medication to be raised in requests for medico-legal reports. Sometimes the issues relate to the relative efficacy of different approaches to management, but in recent times many referrals relate to possible adverse effects related to the use of medicines.
Examples of the issues under consideration include things like whether medications can lead to dental damage (in some cases this is possible though mechanisms such as diminished to saliva production and drug-induced bruxism), upper gastrointestinal symptoms such as reflux, lower GI symptoms such as constipation, sexual dysfunction and cognitive dulling (which may have occupational ramifications such as impaired capacity to drive or operate machinery). In some cases these issues may be amenable to specific interventions to manage the symptoms identified, or it may be possible to substitute an alternative treatment that does not cause the same issues. A detailed pharmacological review can be helpful to identify medication related issues.
A structured assessment of potential causality in relation to possible adverse effects of medicines can also prove to
be useful: this would normally include consideration of a variety of factors including the possibility of other plausible causes for the phenomenology observed, analysis of the time course for the evolution of the possible reaction, consideration of previous reports of similar effects, dose-response relationships, the effects of re-challenge, and other factors.
With an increasing range of medication options available to modern clinicians, the complexity of the factors associated with their use continues to grow. And awareness of the potential problems associated
with medications is important whenever considering the overall management provided for individual patients. A detailed medication review is one way to assist in exploring these matters.
*All views, opinions and conclusions expressed are those of the authors and/or speakers and do not necessarily reflect the view, opinion, conclusion and/or policy of ExamWorks and its affiliates.