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Tiene GM Bauters
Department of Pharmacy
Ghent University Hospital
Chronic pain is a complex clinical problem. It may be defined as “pain that has lasted six months or longer, is ongoing, is due to non-life-threatening causes, has not responded to currently available methods, and may continue for the remainder of the patient’s life”.(1) As a result, chronic pain patients have a tendency to become deconditioned, depressed, anxious and socially isolated.
The complexity of chronic pain and the inadequacy of medical or surgical treatments alone mandate a comprehensive evaluation and treatment of the patient with chronic pain. Whereas acute pain can often be handled by a single specialty, chronic pain cannot.(2)
Furthermore, chronic pain patients tend to overconsume drugs, especially pain-relieving drugs and sedatives, anti-anxiety agents, antidepressants, muscle relaxants and anti-inflammatory medications.(3) As a consequence of polymedication, pharmacological treatment becomes more complicated due to an increased risk of adverse drug events. These risks are associated with age-related physiological changes and individual variability in drug metabolism related to several factors. In addition, co-medications can induce drug–drug interactions that depend on genetic factors related to the cytochrome P450 enzyme (CYP450).
A multidisciplinary centre for chronic pain treatment in adults was set up at the Ghent University Hospital (Belgium) in May 2005. The multidisciplinary staff, which is prepared to deal with both medical and psychological aspects of chronic pain, consists of anaesthesists, a rehabilitation physician, psychologists, a psychiatrist, pain nurses and a clinical pharmacist.
As a member of the multidisciplinary pain team, the role of the clinical pharmacist includes tasks such as obtaining drug information, recording and resolving medication-related problems, prevention of adverse drug events and opioid rotation.
All interventions made by the clinical pharmacist were analysed and evaluated, and their degree of acceptance by the physicians was summarised.
During a nine-month period, the medication data of patients attending the outpatient pain centre of the Ghent University Hospital were recorded and analysed on a regular basis within the multidisciplinary pain team treatment. Based on these data, interventions, including dose adjustment, identification of relevant interactions with other drugs, alertness of allergies or of actual or potential adverse drug events, were performed by the clinical pharmacist. Other interventions included changes in dose form or route of administration, order test/drug level for therapeutic drug monitoring (anti-epileptics), restriction of antimicrobial choice through the use of a hospital drug formulary and specific infection treatment guidelines of appropriate antibiotic use. In cases where interference with critical medications was possible, close clinical monitoring and/or dose adjustment was performed while discontinuations, or even avoidance, to prevent toxicity were advised.
Interventions were classified as follows:
All interventions were noted on a page and, if applicable, inserted in the patient’s file. They were then examined during the multidisciplinary patient discussion session.
Analysis and evaluation
For a total of 93 analysed patients, 114 interventions were recorded. The different types of interventions included: provision of information (8.7%); clinical intervention (90.4%); and the provision of a specific product (0.9%).
Clinical interventions were subdivided as follows:
An overview of the major therapeutic classes involved in the clinical interventions is displayed in Table 1.
Out of the 103 clinical interventions, 95.1% were approved by physicians. Of these, 75.7% were completely approved, while 19.4% were partially approved (ie, the physician was aware of the problem but decided to continue monitoring, for example, in the case of drug–drug interactions with risk of serotonin syndrome). Only 4.9% of clinical interventions were not approved, including a change of therapy and starting or stopping a therapy.
The high degree of acceptance of interventions highlights the role of the clinical pharmacist as a member of the multidisciplinary pain team in enhancing the safe and rational use of medicines in chronic pain patients. Although the team physicians are well experienced in the pharmacological approach to pain, the need for interventions by the pharmacist is noted. As most interventions involve analgesics and antidepressives, these medications should be analysed as a priority because of possible drug–drug interactions.
We believe that, apart from this type of clinical intervention, other tasks involving pharmacists could comprise:
It might be worth mentioning transmural care (defined as the interface between primary and secondary healthcare), through which drug information (use, dosage, etc) might be provided to patients. It is important that patients are informed about their medication before discharge.
As far as we know, this is the first report on clinical pharmacy activities in a Belgian pain clinic setting. We hope it will give the opportunity to other centres implementing multidisciplinary pain teams to optimise rational use of drugs in chronic pain patients. Finally, it must be mentioned that the described tasks are possible and important not only in the adult setting but also in paediatric populations.