Adjunctive agents in the management of chronic pain

Review of clinical pharmacokinetics and pharmacodynamics of clonidine as an adjunct to opioids in palliative care

Clonidine is an α-adrenoceptor agonist acting on receptors in the brain and peripheral tissues, leading to a reduction in sympathetic outflow and release of certain neurotransmitters. Clonidine has multiple uses across various medical conditions. One of its uses is as adjuvant to anaesthetic and analgesic agents specially opioids, mostly administered through intravenous and epidural routes. The opioids, effective in cancer pain management, are associated with various side effects such as sedation, pruritus, constipation, nausea, respiratory depression, tolerance and dependence. Combination of clonidine with opioids seems to help to achieve better pain management and less need of opioids. Use of clonidine in palliative care has been less common, but it is gradually gaining recognition for its potential benefits in managing symptoms like cancer pain and agitation. This combination approach has been explored in palliative care settings, including cancer pain and agitation, where patients experience complex and refractory symptoms. It seems to be well tolerated and gives better symptom relief. The available literature on clonidine's use in cancer pain and agitation management, especially in subcutaneous form, is limited and outdated. Therefore, the optimal dosing, safety profile and overall effectiveness of subcutaneous clonidine requires further exploration through prospective research studies.

Are psychedelic medicines the reset for chronic pain? Preliminary findings and research needs

Chronic pain is a leading cause of disability, reduced productivity, healthcare seeking, and a contributor to opioid overdose in the United States. For many people, pain can be satisfactorily managed by existing medicines and comprehensive psychosocial treatments. For others, available treatments are either ineffective or not acceptable due to side effects and concerns about risks. Preliminary evidence suggests that some psychedelics may be effective for certain types of pain and/or improved quality of life with increased functionality and reduced disability and distress in people whose pain may never be completely relieved. Efficacy in these quality-of-life related outcomes would be consistent with the "reset in thinking" about chronic pain management increasingly called for as a more realistic goal for some people than complete elimination of pain. This commentary summarizes the rationale for conducting more basic research and clinical trials to further explore the potential for psychedelics in chronic pain management. And, if shown to be effective, to determine whether the effects of psychedelics are primarily due to direct antinociceptive or anti-inflammatory mechanisms, or via increased tolerability, acceptance, and sense of spirituality, that appear to at least partially mediate the therapeutic effects of psychedelics observed in psychiatric disorders such as major depression. This commentary represents a collaboration of clinical and more basic scientists examining these issues and developing recommendations for research ranging from neuropharmacology to the biopsychosocial treatment factors that appear to be as important in pain management as in depression and other disorders in which psychedelic medicines are under development.

D-limonene exhibits superior antihyperalgesic effects in a β-cyclodextrin-complexed form in chronic musculoskeletal pain reducing Fos protein expression on spinal cord in mice

Chronic musculoskeletal pain is one of the main symptoms found in Fibromyalgia with unclear etiology and limited pharmacological treatment. The aim of this study was to complex LIM in β-cyclodextrin (LIM-βCD) and then evaluate its antihyperalgesic effect in an animal model of chronic musculoskeletal pain. Differential scanning calorimetry and scanning electron microscopy was used for the characterization of the inclusion complex. Male Swiss mice were used for experimental procedures where mechanical hyperalgesia, thermal hyperalgesia, muscular strength, Fos immunofluorescence was studied after induction of hyperalgesia. Mechanism of action was also investigated through tail flick test and capsaicin-induced nociception. Endothermic events and morphological changes showed that the slurry complex method was the best method for the complexation. After induction of hyperalgesia, the oral administration of LIM-βCD (50mg/kg) significantly increased the paw withdrawal threshold compared to uncomplexed limonene. Fos immunofluorescence showed that both compounds significantly decreased the number of Fos-positive cells in the dorsal horn. In nociceptive tests, FLU was able to reverse the antinociceptive effect of LIM-βCD. After intraplantar administration of capsaicin, LIM was able to significantly decrease time to lick. LIM-βCD has antihyperalgesic action superior to its uncomplexed form, with possible action in the dorsal horn of the spinal cord. These results suggest the possible applicability of LIM, uncomplexed or complexed with βCD, in conditions such as FM and neuropathic pain, for which there are currently only limited pharmacological options.

Analgesic use by ageing and elderly patients with chronic non-malignant pain: a qualitative study

Background Analgesics are used in the management of chronic non-malignant pain (CNMP), a condition which is highly prevalent among older adults. CNMP may not only be physically distressing but also complicated by psychosocial and economic factors. An individual’s perception and use of analgesics may be influenced by a range of factors such as perceptions of risk or benefits, ability to purchase medication or access to non-pharmacological therapies or specialist care. Objective The aim of this study was to describe the perceptions and experiences of analgesics by ageing and elderly individuals with CNMP and identify factors that influence their use. Setting Telephone interviews with 28 members of Chronic Pain Ireland aged ≥50. Method In-depth semi-structured interviews; audio-recorded, transcribed verbatim, and thematically analysed. Main outcome measure Experiences and perceptions of ageing and elderly individuals with CNMP taking analgesics. Results A combination of factors specific to the patient and arising from outside influences informed perceptions and experiences of analgesics. Pain severity, perceived efficacy of analgesics, occurrence of adverse-effects and concerns about addiction/dependence were identified as internal factors influencing medication use. External factors included views of family members, access to specialised care and the individual’s interaction with healthcare professionals (HCPs). Conclusion Individuals with CNMP regard analgesics as an important method for managing pain and are relied upon when other interventions are difficult to access. HCPs in primary care, who are the main point of contact for patients, need to take into account the various factors that may influence analgesic use when consulting with this patient group.

Pregabalin in Chemotherapy Induced Neuropathic Pain

Chemotherapeutic agents belonging to vinca alkaloids, taxanes, and antitubulins produce peripheral neuropathy for which there is no validated treatment. Pregabalin, a gamma-aminobutyric acid analog, is known to inhibit theα2δ subunit of the voltage-gated calcium channel. Earlier studies and case reports have shown pregabalin to be effective in treating neuropathic pain. We present a case series of patients with chemotherapy-induced peripheral neuropathy who were successfully treated with pregabalin with reduction in the hyperalgesia, allodynia, and improvement in the quality of life.

Treatment of Neuropathic Pain

OPINION STATEMENT

Neuropathic pain is notoriously variable in its severity and impact on patients, as well as in its response to treatment. Certain therapies for neuropathic pain have better evidence for their use; however, it is apparent that although some therapies provide relief for only a minority of patients, the relief may be significant. Without a trial of therapy, there is no way to know if that relief is achievable. Our treatment experiences have shown that occasionally unexpected benefit is obtained through a thorough investigation of all options, even in the setting of failure of those with the most compelling evidence or indication. Chronic neuropathic pain is generally best treated with regularly dosed medications, balancing efficacy and tolerability. Evidence supports first-line trials of anticonvulsants, tricyclic antidepressants, and serotonin-norepinephrine reuptake inhibitors, alone or in certain combinations. While opioid medications, particularly methadone, can be effective in treating neuropathic pain, they are best used only in refractory cases and by experienced clinicians, due to concerns for both short- and long-term safety. Some therapies have a long history of successful use for certain syndromes (e.g., carbamazepine for trigeminal neuralgia pain), but these should not be considered to the exclusion of other more recent, less-supported therapies (e.g., botulinum toxin A for the same), particularly in refractory cases. We find the principles of palliative care highly applicable in the treatment of chronic neuropathic pain, including managing expectations, mutually agreed-upon meaningful outcomes, and a carefully cultivated therapeutic relationship.

A comparative efficacy of amitriptyline, gabapentin, and pregabalin in neuropathic cancer pain: a prospective randomized double-blind placebo-controlled study

Neuropathic pain is difficult to diagnose and difficult to treat with certainty. So the aim of the study was to evaluate comparative clinical efficacy of pregabaline with amitriptyline and gabapentin in neuropathic cancer pain. A total of 120 patients with cancer having severe neuropathic cancer pain were enrolled in the study after taking approval from Institutional Ethics Committee and divided in to 4 groups: group AT-amitriptyline, group GB-gabapentin, group PG-pregabalin, and group PL-placebo. Oral morphine was used for rescue analgesic for continued pain. Pain score (Visual Analogue scale) and secondary outcome measures such as intensity of lancinating, dysesthesia, and burning on numerical rating scale, Global satisfaction score (GSS), Eastern Co-operative Oncology Group scoring (ECOG), and adverse effects were assessed. At the end of study there was significant decrease in pain score in group PG as compared to the other groups; group AT (P = .003), group GB (P = .042), and group PL (P = .024). Percentage of patients with lancinating pain and dysesthesia were significantly less in group PG as compared to groups GB and PL. All the patients in group PL needed rescue morphine. After 4 visits, maximum improvement in ECOG scoring and GSS scoring was observed in group PG patients. Our results suggested that all antineuropathic drugs are effective in relieving cancer-related neuropathic pain. There was statistically and clinically significant morphine sparing effect of pregabaline in relieving neuropathic cancer pain and neuropathic symptoms as compared to other antineuropathic drugs.

The effect of pregabalin on pain-related sleep interference in diabetic peripheral neuropathy or postherpetic neuralgia: a review of nine clinical trials

OBJECTIVE

Postherpetic neuralgia and painful diabetic peripheral neuropathy are common chronic neuropathic pain conditions associated with sleep disturbances. Pregabalin is indicated in the treatment of neuropathic pain. The objective of this review is to summarize the efficacy and safety of pregabalin in painful diabetic peripheral neuropathy and postherpetic neuralgia and the effect of pregabalin on sleep interference in these patients.

METHODS

MEDLINE and ISI Web of Knowledge databases were searched for randomized double-blind, placebo-controlled clinical trials of pregabalin reporting sleep measures in addition to pain endpoints in patients with painful diabetic peripheral neuropathy and postherpetic neuralgia published from inception through March 2009.

RESULTS

Nine trials met the inclusion criteria, providing data for a total of 2399 patients with painful diabetic peripheral neuropathy or postherpetic neuralgia treated twice or three times per day with pregabalin (75-600 mg/day) or placebo on a fixed or flexible schedule. Interpretation of sleep outcomes in two studies may be limited by trial inclusion criteria which permitted benzodiazepines for sleep problems. Also, none of the studies reported objective sleep measures. Pregabalin was well tolerated. Pregabalin (150-600 mg/day) significantly reduced pain and improved pain-related sleep interference.

CONCLUSIONS

In addition to an analgesic benefit, pregabalin may decrease pain-related sleep interference in patients with painful diabetic peripheral neuropathy and postherpetic neuralgia.

Opioid Treatment of Chronic Pain in Patients with Addiction

Patients with a history of drug or alcohol addiction may present to physicians with pain complaints. The medical literature is weak on the treatment of pain with opioids in patients in recovery or active addiction. This is because inconsistent criteria were used to define addiction and the types of chronic pain. There are clear differences between physical dependence, tolerance, and addiction. Addiction is different from pseudoaddiction and must be determined by the patient's behavior after appropriate pain management. Long-acting opioids are often the medications of choice for moderate to severe pain control. Short-acting opioids can be used for breakthrough pain. There are many other medications that can enhance pain control as adjunctive analgesics. Drug-seeking behavior may be seen with either active addiction or pseudoaddiction, or as part of deviant behavior such as drug diversion. A way to distinguish between these conditions is by giving the patient appropriate pain medication and observing the pattern of behavior to determine which is causing the drug-seeking behavior. Safe prescribing of medications with abuse potential includes use of a medication agreement, setting goals with the patient, giving appropriate amounts of pain medication, monitoring with pill counts and drug screens, and careful documentation. Even patients with a history of addiction can benefit from opioid pain medications if monitored appropriately.

Cancer-related pain and quality of life in prostate cancer patients: assessment using the Functional Assessment of Prostate Cancer Therapy

The objective of this study was to assess disease-associated pain and quality of life (QOL) in patients with prostate cancer (PC). A total of 102 PC patients (clinical stage B, C: 20, D2: 82) patients were enrolled. QOL was assessed using the Functional Assessment of Cancer Therapy, General and Prostate (FACT-G/P). Disease-specific pain response was assessed using the visual analog scale and the face rating scale. In patients with stage D2 PC, mean age, serum prostate-specific antigen level, and performance status were 72.5 +/- 7.1 years (range, 55-88), 217 +/- 467 ng/mL (range, 0.1-2600), and 1.4 (0-4), respectively. The score of physical well-being and FACT-P was significantly lower in stage D2 patients, compared with those of stage B/C (P = 0.02, 0.0088, respectively). Performance status, extent of disease, and the visual analog scale were related with a poor QOL score (P = 0.0054, 0.01, <0.0001, respectively). Thirty-two patients (39%) had disease-specific pain, and 25 patients received a related treatment. Ten patients under morphine analgesics maintained better QOL in almost all domains, compared with the seven patients without any painkillers. Combined use of FACT and pain scales enhances the objective assessment of QOL and pain status in PC patients. Control of disease-associated pain is crucial to improving QOL in stage D2 PC patients.

Pharmacological evaluation of morphine and non-opioid analgesic adjuvants in a mouse model of skin cancer pain

Using a mouse model of advanced skin cancer which has mixed nociceptive-neuropathic pain, we evaluated the analgesic effects of morphine and analgesic adjuvants. Morphine hydrochloride (10--30 mg/kg, oral) and mexiletine hydrochloride (10--30 mg/kg, intraperitoneal) dose-dependently inhibited thermal hyperalgesia. Baclofen (10 mg/kg, subcutaneous) suppressed thermal hyperalgesia, without effects at lower doses of 1 and 5 mg/kg. Ketamine hydrochloride (50 mg/kg, oral) was without effect. Analgesic tolerance was observed after 6th administration of morphine, and it was not developed until at least 7th administration of mexiletine and baclofen. This mouse model of skin cancer may be useful for the pharmacological evaluation of the effects of opioids and analgesic adjuvants on mixed nociceptive-neuropathic pain of advanced cancer.

Overview on pathophysiology and newer approaches to treatment of peripheral neuropathies

Peripheral neuropathies are extremely heterogeneous nosological entities. One of the most common symptoms is pain, the underlying mechanisms of which are numerous and complex. Inflammation, reparative processes, and anatomical and gene expression alterations lead to chronic pain, the persistence of which is sustained by peripheral and central sensitisation mechanisms. Treatment of peripheral neuropathies is targeted to its symptomatic and aetiological features. For pain relief, several types of drugs may be used, notably antidepressants (e.g. tricyclic antidepressants, selective serotonin reuptake inhibitors, and both serotonin and noradrenaline [norepinephrine] reuptake inhibitors), antiepileptic drugs (e.g. carbamazepine, phenytoin, lamotrigine, valproic acid, gabapentin, topiramate and pregabalin), NSAIDs and opioid analgesics. Aetiological therapy is aimed at modifying the pathophysiological mechanisms underlying the neuropathy, some of which are common in different neuropathic conditions. Certain drugs are known to exert more than one action on different pathophysiological mechanisms. This is the case with acetyl-L-carnitine (ALC), which can be considered both a symptomatic therapy that can be used in any kind of painful neuropathy, and an aetiological therapy, at least in diabetic neuropathy and neuropathies induced by nucleoside reverse transcriptase inhibitors and cancer chemotherapeutic agents. ALC acts via several mechanisms, inducing regeneration of injured nerve fibres, reducing oxidative stress, supporting DNA synthesis in mitochondria, and enhancing nerve growth factor concentrations in neurons.

Peripheral Neuropathy Related to Chemotherapy

OBJECTIVES

To review the evidence base for prevention and intervention of chemotherapy-induced peripheral neuropathy (PN).

DATA SOURCES

Medical and nursing literature.

CONCLUSION

Many small studies that reported positive findings have either not been validated in large prospective, randomized controlled trials (RCT), or have not been further studied. Prevention strategies based on RCTs include the use of xaliproden to reduce the incidence of grade 3 PN in patients receiving oxaliplatin-based regimens, and dose reduction or interruption until recovery. There are gaps in the literature of nurse-sensitive outcome studies for nursing assessment and intervention

IMPLICATIONS FOR NURSING PRACTICE

Nurses need to be knowledgeable about the evidence, or lack of it, on strategies to prevent and manage chemotherapy-induced PN. Nurses also need to measure the effectiveness of interventions for PN, such as exercise, patient teaching about self-care strategies, and develop and/or participate in well-designed intervention studies regarding the prevention and management of PN.

Cancer pain: an update of pharmacological approaches in pain therapy

PURPOSE OF REVIEW

This review discusses clinically oriented data on advances in pharmacological research of cancer pain therapy carried out during the last year. The aim is to ascertain whether well known guidelines for cancer pain prove to be adequate or require modification.

RECENT FINDINGS

There are alternatives to morphine, which is the standard drug, including oxycodone or methadone, with the problem of equivalence doses in the case of opioid rotation. Depending on the underlying pathophysiological mechanisms, adjuvant drugs are recommended, such as antidepressants and anticonvulsants for neuropathic pain, or bisphosphonates for metastasis bone pain. Current and future research will offer receptor-specific acting new drugs or old drugs under new indications.

SUMMARY

The recommendations of the World Health Organization ladder remain the mainstay of cancer pain management. These recommendations, however, are based more on expert opinions than on evidence-based data.

Functional abdominal pain syndrome

Functional abdominal pain syndrome (FAPS) differs from the other functional bowel disorders; it is less common, symptoms largely are unrelated to food intake and defecation, and it has higher comorbidity with psychiatric disorders. The etiology and pathophysiology are incompletely understood. Because FAPS likely represents a heterogeneous group of disorders, peripheral neuropathic pain mechanisms, alterations in endogenous pain modulation systems, or both may be involved in any one patient. The diagnosis of FAPS is made on the basis of positive symptom criteria and a longstanding history of symptoms; in the absence of alarm symptoms, an extensive diagnostic evaluation is not required. Management is based on a therapeutic physician-patient relationship and empirical treatment algorithms using various classes of centrally acting drugs, including antidepressants and anticonvulsants. The choice, dose, and combination of drugs are influenced by psychiatric comorbidities. Psychological treatment options include psychotherapy, relaxation techniques, and hypnosis. Refractory FAPS patients may benefit from a multidisciplinary pain clinic approach.

Adjunctive pharmacological management of persistent, nonmalignant pain in older individuals

Chronic or persistent pain is a common comorbidity of aging, primarily due to the relatively high frequency of pain-associated disorders in this population (e.g., inflammatory and noninflammatory musculoskeletal disease, zoster infection, diabetes, stroke, and peripheral and central neurological diseases). Acetaminophen, nonsteroidal anti-inflammatory drugs and opioids are important long-term analgesics in this age group. However, adjunctive agents are also important in the management of persistent pain in the elderly, especially neuropathic pain. Oral antiepileptic drugs, mexiletine, baclofen, tricyclic antidepressants, selective serotonin–norepinephrine dual reuptake inhibitors and intranasal/injectable calcitonin are the subjects of this review of the management of persistent, nonmalignant pain in the elderly. While some of these agents are considered narrow-spectrum analgesics (e.g., baclofen in trigeminal neuralgia and calcitonin in bone pain), most are broad-spectrum analgesics, useful in neuropathic pain syndromes of multiple etiologies. Within the antiepileptic drug class, gabapentin and carbamazepine can be considered first-line agents, followed by lamotrigine and pregabalin as second-line agents, and the other most recently approved drugs as third-line or ‘salvage’ agents. The tricyclic antidepressants have numerous precautions/contraindications and tolerability issues in this population, thus reducing their utility. Duloxetine and venlafaxine are the only useful analgesics among the modern antidepressants. Challenges for the future include not only the search for more effective and less toxic adjunctive analgesics for the elderly, but also translating our knowledge of current and future analgesics into effective therapies in the ‘real world’ community and institutional settings where elderly people live. There is no justification in our society today for anyone to live with untreated or undertreated persistent pain.

Treatment of pain in older patients

Pain in older adults is a highly prevalent problem. While the basis of pain management in older individuals is similar to that for younger patients, it may differ in terms of presentation, assessment, and management. This article explores the basic concepts of pain control with a focus on older patients with cancer and highlights issues clinicians should consider when treating these individuals.

Oxcarbazepine, topiramate, zonisamide, and levetiracetam: potential use in neuropathic pain

BACKGROUND

Oxcarbazepine, topiramate, zonisamide, and levetiracetam are the antiepileptic drugs (AEDs) most recently approved by the US Food and Drug Administration. Based on the experience with carbamazepine, gabapentin, and lamotrigine, these newer AEDs are being investigated for the management of neuropathic pain.

OBJECTIVE

This article reviews preclinical and clinical data on the efficacy and tolerability of these 4 AEDs in the management of neuropathic pain, as well as the pharmacokinetics, drug-interaction potential, adverse effects, and dosing of these agents, with an emphasis on their use in older individuals.

METHODS

Relevant studies were identified through a MEDLINE search of the Englidh-language literature published between 1986 and May 2003, a review of the reference lists of identified articles, and abstracts from the annual meetings of the American Academy of Neurology (1986-2002) and the 2003 Annual Meeting of the American Pain Society. Search terms were oxcarbazepine, topiramate, zonisamide, and levetiracetam.

RESULTS

Oxcarbazepine and topiramate have been effective in animal models of neuropathic pain. Thirty-four publications on the efficacy and tolerability of the 4 agents were identified (25 case reports/case series, 6 randomized parallel-group studies, and 3 randomized crossover studies). The 9 randomized studies were restricted to oxcarbazepine and topiramate, and 23 (68%) publications were available in abstract form only. These preliminary data suggest that the 4 newer AEDs may be useful in a wide variety of neuropathic pain syndromes; however, additional data, including full-length peer-reviewed reports, are necessary before their true analgesic potential in neuropathic pain can be determined. All 4 agents have pharmacodynamic interactions with other psychotherapeutic drugs, potentiating adverse central nervous system events such as sedation. With the exception of levetiracetam, these drugs also have pharmacokinetic interactions with other drugs, although to a somewhat lesser extent than carbamazepine. These agents have some unique adverse effects not frequently monitored by clinicians, such as hyponatremia, nephrolithiasis, acute myopia with secondary angle-closure glaucoma, and weight loss.

CONCLUSIONS

Based on preliminary data, oxcarbazepine, topiramate, zonisamide, and levetiracetam may be useful in the treatment of a wide variety of neuropathic pain syndromes, although full publication of the results of controlled trials is awaited. These agents are associated with specific adverse effects not commonly monitored by clinicians. Of the 4, levetiracetam appears to be easiest to use (ie, no need for dose adjustment in organ dysfunction, no need for laboratory monitoring) and best tolerated, and has not been associated with the unique toxicities seen with oxcarbazepine, topiramate, and zonisamide. The ultimate role of these agents in the therapeutic armamentarium against pain requires further research and experience. In the interim, these 4 agents should be used to treat neuropathic pain in the elderly only when carbamazepine, gabapentin, or lamotrigine cannot be used or when the response to the aforementioned agents is suboptimal.

Chronic pelvic pain: an integrated approach to diagnosis and treatment

Chronic pelvic pain affects upward of 15% of women and is a frustrating condition for both patients and physicians. Chronic pelvic pain is not a disease, but a syndrome that results from a complex interaction between neurologic, musculoskeletal, and endocrine systems that is further influenced by behavioral and psychologic factors. Traditional approaches to this disorder have been surgical, although long-term success rates have been disappointing. Placebo response to surgery is common, and many conditions that contribute to the pain cannot be identified or treated with a surgical approach. Many patients will require a combination of both pharmacologic and nonpharmacologic treatments in addition to various types of invasive procedures. It is now recognized that many disorders contribute to the chronic pelvic pain symptom complex; thus, an integrated multidisciplinary approach to diagnosis and treatment is essential to achieve the greatest success.

TARGET AUDIENCE

Obstetricians & Gynecologists, Family Physicians.

LEARNING OBJECTIVES

After completion of this article, the reader will be able to describe the pathophysiology of chronic pelvic pain, to outline the evaluation of a patient with chronic pelvic pain, and to explain the treatment options for patients with chronic pelvic pain.

Gabapentin: Neuropathy (Diabetic)

Off-Label Drug Uses

This Hospital Pharmacy feature is extracted from Off-Label DrugFacts, a quarterly publication available from Facts and Comparisons. Off-Label DrugFacts is a practitioner-oriented resource for information about specific FDA-unapproved drug uses. This new guide to the literature will enable the health care professional/clinician to quickly identify published studies on off-label uses and to determine if a specific use is rational in a patient care scenario. The most relevant data are provided in tabular form so that the reader can easily identify the scope of information available. A summary of the data—including, background, study design, patient population, dosage information, therapy duration, results, safety, and therapeutic considerations—precedes each table of published studies. References direct the reader to the full literature for more comprehensive information prior to patient care decisions. Direct questions or comments on “Off-Label Drug Uses” to hospitalpharmacy@drugfacts.com .

Demographics, assessment and management of pain in the elderly

The prevalence of pain increases with each decade of life. Pain in the elderly is distinctly different from pain experienced by younger individuals. Cancer is a leading cause of pain; however, other conditions that cause pain such as facet joint arthritis (causing low back pain), polymyalgia rheumatica, Paget's disease, neuropathies, peripheral vascular disease and coronary disease most commonly occur in patients over the age of 50 years. Poorly controlled pain in the elderly leads to cognitive failure, depression and mood disturbance and reduces activities of daily living. Barriers to pain management include a sense of fatalism, denial, the desire to be 'the good patient', geographical barriers and financial limitations. Aging causes physiological changes that alter the pharmacokinetics and pharmacodynamics of analgesics, narrowing their therapeutic index and increasing the risk of toxicity and drug-drug interactions. CNS changes lead to an increased risk of delirium. Assessment among the verbal but cognitively impaired elderly is satisfactorily accomplished with the help of unidimensional and multidimensional pain scales. A comprehensive physical examination and pain history is essential, as well as a review of cognitive function and activities of daily living. The goal of pain management among the elderly is improvement in pain and optimisation of activities of daily living, not complete eradication of pain nor the lowest possible drug dosages. Most successful management strategies combine pharmacological and nonpharmacological (home remedies, massage, topical agents, heat and cold packs and informal cognitive strategies) therapies. A basic principle of the pharmacological approach in the elderly is to start analgesics at low dosages and titrate slowly. The WHO's three-step guideline to pain management should guide prescribing. Opioid choices necessitate an understanding of pharmacology to ensure safe administration in end-organ failure and avoidance of drug interactions. Adjuvant analgesics are used to reduce opioid adverse effects or improve poorly controlled pain. Adjuvant analgesics (NSAIDs, tricyclic antidepressants and antiepileptic drugs) are initiated prior to opioids for nociceptive and neuropathic pain. Preferred adjuvants for nociceptive pain are short-acting paracetamol (acetaminophen), NSAIDs, cyclo-oxygenase-2 inhibitors and corticosteroids (short-term). Preferred drugs for neuropathic pain include desipramine, nortriptyline, gabapentin and valproic acid. Drugs to avoid are pentazocine, pethidine (meperidine), dextropropoxyphene and opioids that are both an agonist and antagonist, ketorolac, indomethacin, piroxicam, mefenamic acid, amitriptyline and doxepin. The type of pain, and renal and hepatic function, alter the preferred adjuvant and opioid choices. Selection of the appropriate analgesics is also influenced by versatility, polypharmacy, severity and type of pain, drug availability, associated symptoms and cost.

Antidepressant use in psychiatry and medicine: importance for dental practice

BACKGROUND

Many dental patients receive antidepressant therapy. However, antidepressants taken with other drugs may increase the risk of complications that require special dental precautions and care.

METHODS

The authors conducted a retrospective study of 1,800 randomly selected patient records and evaluated the prevalence of using antidepressants and other medications concurrently. They analyzed antidepressant intake relative to drug classification and mechanism of action, age, sex and associated potential for clinical complications such as xerostomia, orthostatic hypotension and interaction with vasoconstrictors. The potential for additive adverse effects between antidepressants and other medications also was analyzed.

RESULTS

Three hundred eighty-one (21 percent) of the 1,800 patient records indicated that patients were being treated with 412 antidepressants. Female subjects out-numbered male subjects by an approximate 2.3:1 ratio. Selective serotonin reuptake inhibitors were most commonly prescribed, followed by tricyclic antidepressants, atypical and third-generation antidepressants, and monoamine oxidase inhibitors. Based on reported medication intake, almost 58 percent of subjects in the antidepressant group were receiving treatment with two or more medications that had the potential for producing xerostomia. Two hundred fifty-seven (67 percent) of the 381 records documented intake of an antidepressant or other medication with orthostatic hypotension potential.

CONCLUSIONS

Three hundred eighty-one patients reported that they were receiving antidepressant therapy for psychiatric and other medical reasons. Potential adverse effects and interactions with other medications have direct implications for dental treatment.

CLINICAL IMPLICATIONS

Patients receiving antidepressant therapy are at risk of developing xerostomia and orthostatic hypotension, as well as experiencing the adverse effects of interaction with vasoconstrictors. Dentists must take appropriate precautions in treating these patients.

Lamotrigine in mood disorders

Lamotrigine is an anticonvulsant drug with good efficacy and safety in the treatment of epilepsy. There is now substantial evidence that lamotrigine is also useful in treating resistant depression, rapid cycling bipolar affective disorder, depressive episodes in bipolar affective disorder and in the maintenance phase or prophylaxis of bipolar affective disorder. There are possible roles in managing mood changes in borderline personality disorder, reducing chronic pain and treating schizoaffective disorder. The general range of doses found effective in affective disorders is from 50 to 300 mg daily. Clinical use seems to involve a titration of dose upwards over several weeks until the desired effect is obtained. However, further definitive double-blind, randomised controlled trials against gold standard treatments are required. Lamotrigine has a preferable side-effect profile compared to standard agents for bipolar affective disorder such as lithium or carbamazepine. Further research is certainly warranted and, given its tolerability, could point to lamotrigine as the treatment of choice for some affective disorders.