Pharmacovigilance for psychiatrists: An introduction.

Abstract

Byline: Ravi. Rajkumar, George. Melvin Patients with psychiatric disorders are often managed with pharmacotherapy. Because of the chronic and relapsing nature of some of these disorders, most practice guidelines recommend that medications should be continued for several months or years. [sup][1],[2],[3] As a result, patients are at risk of experiencing a variety of adverse drug reactions (ADRs). At times, these ADRs can be life-threatening (such as neuroleptic malignant syndrome) [sup][4] or disabling (such as drug-induced tardive dyskinesia). [sup][5] It is important for psychiatrists to be aware of the processes involved in identifying and reporting ADRs, especially those that are new or unrecognized. These processes form the basis for the medical discipline of pharmacovigilance. Pharmacovigilance has been defined by the World Health Organization (WHO) as the science and activities related to the detection, assessment, understanding, and prevention of adverse drug effects. [sup][6] As such, pharmacovigilance is not a specialist activity: It is one that must be carried out by all those involved in caring for patients on medication, including doctors, nurses, and pharmacists. [sup][7],[8] The birth of pharmacovigilance has a close relationship to psychiatry. In the 1960s, thalidomide was widely used in several countries to treat insomnia during pregnancy - a common problem affecting many women. It was soon noticed by physicians that babies exposed to the drug in utero developed congenital malformations, and it was this tragedy - related to a drug that was marketed as a safe sedative - that was the beginning of the field of pharmacovigilance. [sup][9] This relationship has continued to the present day. In a recent review of nine major ADRs reported in Europe from 1995 to 2008, two of them involved psychotropics - seizures with bupropion, and suicidality in children taking SSRI antidepressants. [sup][10] While the latter was identified by a re-analysis of data from the pharmaceutical industry, the former was identified through physician reports. In an analysis of ADRs reported to the FDA between 1998 and 2005, many of the frequently implicated drugs were psychotropics [sup][11] - antipsychotics (clozapine, olanzapine, risperidone), antidepressants (duloxetine, sertraline, paroxetine, bupropion), mood stabilizers (carbamazepine, valproate, lamotrigine), and even anti-ADHD medication (atomoxetine). Now, as then, clinicians have a key role in identifying and reporting new or serious adverse drug effects. Why is Pharmacovigilance Important in Psychiatry? Pharmacovigilance activities are an important part of medical practice in general. A meta-analysis found that around 5% of hospitalizations in a general medical setting are due to adverse drug effects. [sup][12] A study in a general hospital in France found that 3% of new admissions were due to ADRs, and 6.6% of patients developed a significant ADR during their hospital stay. [sup][13] However, there are four reasons why this field is of special importance to psychiatrists. First, pharmacotherapy is the principal modality of management in several psychiatric disorders. Most drugs used in psychiatry are frequently associated with ADRs. Often, patients do not respond to initial drug therapy, and may require several trials of different medications. [sup][14],[15] Some patients may require a combination of various drugs - polypharmacy - which can increase the risk of adverse effects or drug interactions. [sup][16] Second, most clinical trials of psychotropics are conducted in ideal conditions - patients are selected according to stringent criteria, and comorbid medical conditions are usually excluded. These trials also tend to be short-term, lasting for a few weeks or months. By contrast, the patients we encounter in practice often have more complex presentations and comorbid medical illnesses, and they remain under our care for longer periods of time. …