Efficacy of desipramine in painful diabetic neuropathy: a placebo-controlled trial

Although amitriptyline relieves pain in many patients with painful diabetic neuropathy, side effects often preclude effective treatment. Desipramine has the least anticholinergic and sedative effects of the first generation tricyclic antidepressants. We compared a 6 week course of desipramine (mean dose, 201 mg/day) to active placebo in 20 patients with painful diabetic neuropathy in a double-blind crossover trial. Pain relief with desipramine was statistically significant in weeks 5 and 6. Eleven patients reported at least moderate relief with desipramine, compared to 2 with placebo. Pain relief tended to be greater in depressed patients, but relief was also observed in patients who did not show an antidepressant effect. We conclude that desipramine relieves pain in many patients with painful diabetic neuropathy, offering an alternative for patients unable to tolerate amitriptyline. Blockade of norepinephrine reuptake, an action shared by desipramine, amitriptyline, and other antidepressants proven effective in neuropathic pain, may mediate this analgesic effect.     

Randomized control trial of topical clonidine for treatment of painful diabetic neuropathy

A length-dependent neuropathy with pain in the feet is a common complication of diabetes (painful diabetic neuropathy). It was hypothesized that pain may arise from sensitized-hyperactive cutaneous nociceptors, and that this abnormal signaling may be reduced by topical administration of the α₂-adrenergic agonist, clonidine, to the painful area. This was a randomized, double-blind, placebo-controlled, parallel-group, multicenter trial. Nociceptor function was measured by determining the painfulness of 0.1% topical capsaicin applied to the pretibial area of each subject for 30 minutes during screening. Subjects were then randomized to receive 0.1% topical clonidine gel (n = 89) or placebo gel (n = 90) applied 3 times a day to their feet for 12 weeks. The difference in foot pain at week 12 in relation to baseline, rated on a 0–10 numerical pain rating scale (NPRS), was compared between groups. Baseline NPRS was imputed for missing data for subjects who terminated the study early. The subjects treated with clonidine showed a trend toward decreased foot pain compared to the placebo-treated group (the primary endpoint; P = 0.07). In subjects who felt any level of pain to capsaicin, clonidine was superior to placebo (P < 0.05). In subjects with a capsaicin pain rating ?2 (0–10, NPRS), the mean decrease in foot pain was 2.6 for active compared to 1.4 for placebo (P = 0.01). Topical clonidine gel significantly reduces the level of foot pain in painful diabetic neuropathy subjects with functional (and possibly sensitized) nociceptors in the affected skin as revealed by testing with topical capsaicin. Screening for cutaneous nociceptor function may help distinguish candidates for topical therapy for neuropathic pain.     

Alpha 2-adrenergic agonists. Use in chronic pain--a meta-analysis

alpha(2)-adrenergic agonists, mimicking the action of the inhibitory transmitter norepinephrine, cause antinociception due to postsynaptic inhibition of spinothalamic projection neurons, presynaptic inhibition at the central nervous system termination of primary sensory nerves, presynaptic inhibition of brainstem noradrenergic neurons and a generalized decrease in central nervous system sympathetic efferent activity. There is a mutual potentiation of antinociceptive effects of clonidine and morphine. Clonidine is used in chronic pain states for treatment of neuropathic, neuralgic and deafferentiating pain. Based on a meta-analysis of the studies published in the years 1996-1996, the therapeutic efficacy of systematically administered clonidine was evaluated in chronic pain states. Out of 403 screened published studies, only 9 fulfilled the selection criteria. Besides three case reports with successful clonidine treatment, four placebo-controlled studies could be analyzed treating the following chronic pain states: chest pain despite normal coronary angiograms; painful diabetic neuropathy; postherpetic neuralgia; hyperalgia in patients with sympathetically maintained pain and chronic low back pain. Although three studies demonstrated statistically significant improvement in pain scores, the improvement in pain relief in these cases was slight. Long-term treatment was successful in a few responders over a period of 17 months. Hyperalgesia caused by sympathetically maintained pain was relieved by topical (transdermal) application of clonidine. Based on this evaluation a grade C recommendation is derived, which relates to responders. Successful treatment is expected only in pain states with increased sympathetic nervous system activity. Therefore, in chronic pain, treatment with systemic clonidine is of no significant value.     

Impact of responder definition on the enriched enrollment randomized withdrawal trial design for establishing proof of concept in neuropathic pain

The objective of this study was to evaluate how enrichment for responders increases assay sensitivity in an enriched enrollment randomized withdrawal (EERW) proof-of-concept (POC) study in neuropathic pain. Adults with moderate to severe peripheral neuropathic pain entered a 3- to 4-day screening period, followed by a 12-day titration to the highest tolerated dose that provided pain control (pregabalin 50-200 mg t.i.d.), and then a 9-day maintenance period. Subjects were stratified as primary responders (?30%), secondary responders (?10% to <30%), or nonresponders (<10%) based on decrease in pain intensity and were randomized to placebo or pregabalin during the randomized withdrawal period. The primary endpoint was mean of average 24-h pain intensity during the last 3 days of treatment period relative to the 3 days before randomization. Time-to-efficacy-failure was the key secondary endpoint. Other features included not requiring discontinuation of current analgesic therapies and blinding investigators to study design elements that could contribute to non-treatment-related responses. Effect size (ES) (mean treatment difference/SD) was used to measure assay sensitivity. Pregabalin-treated subjects (n = 52) had significantly less pain than those receiving placebo (n = 51) (P ? .003). Effect size of the primary endpoint was 0.72 for primary responders and decreased if secondary and nonresponders were included in the analysis. The highest ES (1.68) was demonstrated for the endpoint time-to-efficacy-failure seen in primary responders with painful diabetic neuropathy. The EERW trial design using time-to-efficacy-failure may provide a sensitive and efficient method to conduct POC studies of novel therapies in patients with neuropathic pain.     

Lack of effect of clonidine and pentoxifylline in short-term therapy of diabetic peripheral neuropathy

The goal of this study was to confirm or rule out anecdotal reports of beneficial effects of clonidine and pentoxifylline in the treatment of painful diabetic peripheral neuropathy. Clonidine was administered to 16 subjects at two dosage levels (0.1 and 0.2 mg/day) and was compared to placebo in a crossover design, with each phase lasting 4 wk. Either pentoxifylline (400 mg 3 times/day) or placebo was given to 21 subjects in a 12-wk trial. Discomfort was characterized and rated with a subjective pain score (range 0-20). There was a significant decrease in pain score from baseline with both active drugs (P less than 0.05), but this was no better than the response to placebo (P less than 0.30 for clonidine and P less than 0.95 for pentoxifylline). This study does not demonstrate a short-term benefit of either clonidine or pentoxifylline in the treatment of peripheral neuropathy.     

Lacosamide in Painful Diabetic Neuropathy: An 18-Week Double-Blind Placebo-Controlled Trial

The efficacy and tolerability of oral lacosamide (200, 400, and 600 mg/day) was evaluated in patients with painful diabetic neuropathy in a double-blind, randomized, placebo-controlled trial. The primary target dose to be confirmed was lacosamide 400 mg/day. Efficacy was assessed by changes in pain scale scores from baseline, with changes over the last 4 weeks of the 12-week maintenance period regarded as the primary endpoint. Endpoint reductions in mean pain score were higher with all doses of lacosamide, reaching the level of significance with 400 mg/day (P = .05). Over the treatment period (titration + maintenance), pain relief was significantly higher than placebo with lacosamide 400 (P = .02) and 600 mg/day (P = .03). Lacosamide had an early-onset effect with significant reductions over placebo during the titration period. Nonparametric and mixed-model analysis approaches gave similar results, supporting significant efficacy at 400 mg/day. Secondary criteria such as Patient's Global Impression of Change, responder rates, and pain-free days provided additional support. Adverse events included dizziness, nausea, and headache. Incidence of cognitive and behavioral adverse events was low. This trial suggests that lacosamide has beneficial effects and may be a suitable treatment option for patients with diabetic neuropathic pain.PerspectiveThis study presents efficacy and safety results of a phase 3, double-blind, placebo-controlled trial of the anticonvulsant drug lacosamide in patients with painful diabetic neuropathy. Lacosamide treatment at a dose of 400 mg/day reduced diabetic neuropathic pain with a favorable safety and tolerability profile that may be suitable for patients with diabetes.     

Relief of painful diabetic peripheral neuropathy with pregabalin: a randomized, placebo-controlled trial.

This was a 6-week, randomized, double-blind, multicenter study evaluating the efficacy of pregabalin in the treatment of painful diabetic neuropathy. Two hundred forty-six men and women with painful diabetic neuropathy received pregabalin (150 or 600 mg/day by mouth) or placebo. The primary efficacy variable was mean pain score at the end of treatment. Efficacy results indicate that pregabalin 600 mg/day significantly decreased mean pain score to 4.3 (vs 5.6 for placebo, P = .0002) and increased the proportion of patients who had a > or =50% decrease from baseline pain (39% vs 15% for placebo, P = .002). Pregabalin also significantly reduced sleep interference, past week and present pain intensity, sensory and affective pain scores, and bodily pain and decreased by > or =50% the number of patients describing their pain as gnawing, sickening, fearful, and punishing-cruel. More patients receiving pregabalin 600 mg/day than placebo showed improvement, as rated on the Clinical and Patient Global Impression of Change scales, 73% vs 45% and 85% vs 47%, respectively. Pregabalin 150 mg/day was essentially no different from placebo. Dizziness was the most common side effect. These study results show pregabalin 600 mg/day to be safe and effective in reducing the pain and other associated symptoms of painful diabetic neuropathy. PERSPECTIVE: Painful diabetic peripheral neuropathy is a challenging neuropathic pain syndrome. This randomized controlled trial demonstrates that pregabalin, a new drug that interacts with the alpha2-delta protein subunit of the voltage-gated calcium channel, is an efficacious and safe treatment for the pain of this condition.     

Sodium valproate for painful diabetic neuropathy: a randomized double-blind placebo-controlled study

BACKGROUND: Various drugs are effective in the management of painful diabetic neuropathy, but none is completely satisfactory. We previously found sodium valproate to be effective and safe in a short-term study. AIM: To test the effectiveness and safety of sodium valproate in the management of painful diabetic neuropathy over 3 months. DESIGN: Randomized double-blind placebo-controlled study. METHODS: Consecutive attending patients with type 2 diabetes mellitus with painful neuropathy were asked to participate in the trial: 48 agreed. Five were excluded: three with HbA(1c) > 11, one with too low a pain level and one who withdrew consent. The remaining 43 were given either drug (group A) or placebo (group B). Each patient was assessed clinically. Quantitative assessment of pain was done by McGill Pain Questionnaire, Visual Analogue Score and Present Pain Intensity, at the beginning of the study, after 1 month and after 3 months. Motor and sensory nerve conduction velocities were measured initially and after 3 months. Liver function tests and other adverse drug-related effects were assessed periodically. RESULTS: Of the 43 patients, four dropped out: one in group A and three in group B. There was significant improvement in pain score in group A, compared to group B, at 3 months (p < 0.001). Changes in electrophysiological data were not significant. The drug was well-tolerated by all patients, except one, who had raised serum AST and ALT levels after 1 month of treatment, and whose treatment was discontinued. DISCUSSION: Sodium valproate is well-tolerated, and provides significant subjective improvement in painful diabetic neuropathy.     

Lacosamide in painful diabetic peripheral neuropathy: a phase 2 double-blind placebo-controlled study

BACKGROUND: Peripheral diabetic neuropathy affects between 20% and 45% of patients with diabetes. OBJECTIVE: To ascertain the effect of lacosamide on pain associated with peripheral diabetic neuropathy. METHODS: One hundred nineteen patients with a 1 to 5-year history of pain attributed to diabetic neuropathy and a score of > or =4 on the Likert pain scale entered the multicenter, randomized, double-blind, placebo-controlled trial. Lacosamide (N=60) titrated from 100 to 400 mg/d or maximum tolerated dose and placebo (N=59) were the trial interventions. Primary efficacy criterion was change in pain score on the 11-point Likert pain scale. Secondary assessments included Short-Form McGill Pain and Short-Form-36 Quality of Life Questionnaires, sleep/activity interference, pain intensity, Patient and Clinical Global Impression of Change, and Profile of Mood. Patients receiving at least 1 dose of medication underwent safety evaluation. RESULTS: Ninety-four patients (lacosamide 46; placebo 48) completed the trial. Lacosamide had significantly (P=0.039) better pain relief versus placebo (primary outcome). Improvements were also seen in secondary outcome measures. Adverse events occurred in 52 lacosamide and 44 placebo patients. Common adverse events, occurring in > or =5% of patients, were headache (lacosamide 18%, placebo 22%), dizziness (lacosamide 15%, placebo 8%), and nausea (lacosamide 12%, placebo 7%). Five lacosamide and 3 placebo patients withdrew for adverse events. DISCUSSION: Lacosamide seems to attenuate pain in diabetic neuropathy in doses up to 400 mg/d and improves quality of life issues.     

Pathophysiology and treatment of painful diabetic neuropathy

Diabetes is the most common cause of peripheral neuropathy, and painful diabetic neuropathy (PDN) affects approximately 30% of diabetic patients with neuropathy. It is extremely distressing for the patient and poses significant management difficulties because no treatment provides total relief, and side effects of therapy are a major limiting factor for titrating therapy. Understanding the pathogenesis of diabetic neuropathy may lead to the development of new treatments to prevent nerve damage, and a better understanding of the mechanisms that modulate pain may lead to more effective relief of painful symptoms. We provide an update on the pathogenesis, diagnosis, and treatment of PDN.     

A Randomized Clinical Trial of the Effectiveness of Photon Stimulation on Pain,Sensation, and Quality of Life in Patients With Diabetic Peripheral Neuropathy

ContextPeripheral neuropathy is one of the most common complications of diabetes.ObjectivesThe purpose of this study was to evaluate the effects of photon stimulation on pain intensity, pain relief, pain qualities, sensation and quality of life (QOL) in patients with painful diabetic peripheral neuropathy.MethodsIn this randomized, placebo-controlled trial, patients were assigned to receive either four photon stimulations (n = 63) or four placebo (n = 58) treatments. Pain intensity, pain relief, and pain qualities were assessed using self-report questionnaires. Sensation was evaluated using monofilament testing. QOL was measured using the Medical Outcomes Study Short Form-36 (SF-36). Multilevel regression model analyses were used to evaluate between-group differences in study outcomes.ResultsNo differences, over time, in any pain intensity scores (i.e., pain intensity immediately post-treatment, average pain, worst pain) or pain relief scores were found between the placebo and treatment groups. However, significant decreases, over time, were found in some pain quality scores, and significant improvements in sensation were found in patients who received the photon stimulation compared with placebo. In addition, patients in the treatment group reported significant improvements in SF-36 social functioning and mental health scores. Findings from a responder analysis demonstrated that no differences were found in the percentages of patients in the placebo and treatment groups who received 30% or more or 50% or more reduction in pain scores immediately post-treatment. However, significant differences were found in the distribution of the changes in pain relief scores, with most of the patients in the photon stimulation group reporting a slight (28.6%) to moderate (34.9%) improvement in pain relief from the beginning to the end of the study compared with no change in pain relief (43.1%) in the placebo group.ConclusionFour treatments with photon stimulation resulted in significant improvements in some pain qualities, sensation, and QOL outcomes in a sample of patients with a significant amount of pain and disability from their diabetes. A longer duration study is needed to further refine the photon stimulation treatment protocol in these chronically ill patients and to evaluate the sustainability of its effects.     

Intravenous adenosine alleviates neuropathic pain: a double blind placebo controlled crossover trial using an enriched enrolment design

Adenosine analogs produce analgesic actions in nociceptive paradigms and alleviate manifestations of neuropathic pain in nerve injury models in rodents. In humans, previous work indicates an analgesic effect for adenosine administered intravenously in postoperative and neuropathic pain. In this double blind placebo controlled crossover trial, we used an enriched enrolment design to determine the effects of intravenous adenosine (50 microg/kg/min over 60min) on neuropathic pain. In Phase 1 of the trial, adenosine was administered in an open label manner, while in Phase 2 adenosine was administered in a double blind placebo controlled manner to 23 adenosine responders who had experienced a 30% or greater response in the open trial. Outcome measures included the McGill pain questionnaire (MPQ), which generates a pain rating index (PRI), and contains a visual analog scale (VAS) of pain intensity, the neuropathy pain scale (NPS), and a VAS for pain relief. Subjects also graded the degree of allodynia and hyperalgesia using a VAS. Adenosine led to a significant reduction in spontaneous pain according to the MPQ-PRI, the MPQ-VAS and the VAS for pain relief. The NPS showed a pattern similar to the MPQ-PRI, with statistically significant reductions in scales 1 (intensity), 3 (hot), 6 (sensitive), 7 (itchy) and 9 (unpleasant). Adenosine also led to a significant reduction in pinprick hyperalgesia, but not in allodynia. Three patients from Phase 1 of the trial experienced long term resolution of their pain following intravenous adenosine (5,16,25 months). The results of this study support previous reports that indicate intravenous adenosine alleviates neuropathic pain and hyperalgesia.     

Spinal cord stimulation relieves chemotherapy-induced pain: a clinical case report

We present two patients with chemotherapy-induced painful neuropathy that had been poorly controlled with medications but successfully treated with spinal cord stimulation (SCS). A trial period of SCS provided effective pain relief in both patients who subsequently underwent permanent stimulator implantation. Psychophysical tests were performed before and after the implantation of trial and permanent stimulators. SCS improved pain scores and facilitated a reduction of medications. Both patients reported improved gait and one of them also reported an increase in leg flexibility. Psychophysical tests demonstrated an improvement in touch and sharpness detection thresholds. In summary, SCS offers a therapeutic option for patients with chemotherapy-induced peripheral neuropathy who have poor pain relief with standard medical treatment.     

Prolonged-release oxycodone enhances the effects of existing gabapentin therapy in painful diabetic neuropathy patients

Background: Neuropathic pain remains one of the most challenging pain syndromes; under‐diagnosed, poorly managed and associated with significant co‐morbidity. With standard therapeutic treatments, responders rarely exceed 50% pain relief and the majority suffer from residual pain. Titration to optimum dose is often limited by dose‐related adverse events. Aims: This randomized, double‐blind, placebo‐controlled study assessed the potential benefit of adding oxycodone (OxyContin® tablets) to gabapentin. The primary endpoint was to evaluate the analgesic efficacy of co‐administration of gabapentin and prolonged‐release oxycodone, whilst also evaluating the use of escape medication, sleep quality and global assessment of pain. Methods: Three hundred and thirty eight patients with moderate to severe painful diabetic neuropathy despite receiving their maximum tolerated dose of gabapentin, had oral prolonged‐release oxycodone or placebo tablets added to their therapy for up to 12weeks. Results: Oxycodone–gabapentin reduced pain score by 33% from baseline to end of treatment. The overall treatment effect was greater with oxycodone–gabapentin than with placebo–gabapentin (P=0.007). Oxycodone–gabapentin also significantly improved pain relief vs gabapentin alone (P=0.003). Oxycodone–gabapentin co‐administration was associated with less escape medication use (P=0.03) and fewer nights of disturbed sleep (P<0.05). Discontinuations due to lack of therapeutic effect were much lower (14% vs 54%) with oxycodone–gabapentin. The commonly seen opiate‐induced adverse events were not exacerbated by the combination of oxycodone and gabapentin. Conclusions: This study provides the first evidence that co‐administration of prolonged‐release oxycodone and existing gabapentin therapy has a clinically meaningful effect in painful diabetic neuropathy.     

Topical capsaicin in painful diabetic neuropathy. Effect on sensory function.

OBJECTIVE--To examine the effect of capsaicin on sensory function in painful diabetic neuropathy. RESEARCH DESIGN AND METHODS--We examined the effects of topical 0.075% capsaicin cream on thermal and vibration thresholds in 22 subjects with painful diabetic neuropathy who participated in a double-blind vehicle-controlled therapeutic trial. RESULTS--After 8 wk of use, there was no significant change in warm and vibration thresholds, but the cold threshold was significantly reduced by capsaicin and vehicle creams to an equal degree. In fewer subjects who used capsaicin cream in an open-label study, there was no significant effect on sensory thresholds after up to 32 wk of use. CONCLUSIONS--Although our results and those of others show no adverse effects of topical 0.075% capsaicin on human sensory function, even in subjects with preexisting neuropathic sensory impairment, the small number of subjects tested does not justify an inferential statement on safety. Further studies in more subjects are warranted to ensure the long-term safety of capsaicin for pain relief in humans.     

18. Painful Diabetic Polyneuropathy

In the industrialized world, polyneuropathy induced by diabetes mellitus (DM) is one of the most prevalent forms of neuropathy. Diabetic neuropathy can result from a direct toxic effect of glucose on nerve cells. Additionally, the damage of the nerve structures (central and peripheral) is accompanied by a microvascular dysfunction, which damages the vasa nervorum. More than 80% of the patients with DM‐induced polyneuropathy have a distal and symmetric presentation. The initial symptoms are: signs of diminished sensation, burning feet, which may occur particularly during the night and worsen when touched, and tingling sensation in the feet. Attacks of shooting pain may also occur. Proper control of DM is mandatory. Based on the recently published National Institute for Health and Clinical Excellence guidelines, treatment of painful diabetic neuropathy should start with duloxetine or amitriptyline if duloxetine is contraindicated. If pain relief is inadequate, monotherapy with amitriptyline or pregabalin, or combination therapy with amitriptyline and pregabalin should be considered. If pain relief is still insufficient, tramadol instead of or in combination with a second‐line agent should be considered. In patients who are unable to take oral medication, topical lidocaine can be considered for localized pain. There are currently four studies showing that spinal cord stimulation can potentially provide pain alleviation for the longer term in patients with painful diabetic polyneuropathy. Complications are mainly implant related, though infections also occur. The available evidence (2 C+) justifies spinal cord stimulation to be considered, preferably study related.     

循证护理、自我效能在糖尿病痛性神经病变中的联合应用

目的 探讨循证护理、自我效能在糖尿病痛性神经病变患者护理中联合应用的效果.方法 将84例糖尿病痛性神经病变患者随机分为两组.护理干预组应用循证护理的理论,针对研究对象的具体情况,提出循证问题,寻求最佳护理行为并实施干预,同时联合自我效能,为期1个月;对照组进行常规护理.结果 护理干预后干预组疼痛分值有明显下降,各项自我效能分值和护理满意度明显升高,同对照组比较有显著性差异(P＜0.05).结论 通过循证护理和自我效能的联合干预,能有效缓解糖尿病痛性神经病变患者的疼痛症状,减轻患者的痛苦,提高护理满意度.     

A Sumatriptan Iontophoretic Transdermal System for the Acute Treatment of Migraine

Objective.— Gastrointestinal symptoms, such as nausea and vomiting, occur almost universally at one time or another in patients during a migraine attack. One third of patients who experience migraine‐related nausea report that this symptom interferes with their ability to take oral medications. The sumatriptan iontophoretic transdermal system (NuPathe Inc., Conshohocken, PA, USA) uses proprietary technology to circumvent the gastrointestinal tract while delivering triptan therapy. This phase III randomized, double‐blind, placebo‐controlled trial evaluated the efficacy and tolerability of this system for the acute treatment of migraine. Methods.— Patients were randomized to treat a single moderate‐to‐severe migraine attack with the sumatriptan iontophoretic transdermal system or placebo. The primary end point was the proportion of patients who were headache pain‐free 2 hours after patch activation. Other end points included the proportions of patients who reported headache pain relief, and freedom from nausea, photophobia, and phonophobia; rescue medication use; and tolerability. Results.— Four hundred sixty‐nine patients were treated. Significantly more patients treated with the sumatriptan iontophoretic transdermal system compared with placebo experienced freedom from headache pain, nausea, photophobia, and phonophobia 2 hours after patch activation, experienced rapid and sustained headache pain relief, and used less rescue medication. Treatment‐emergent adverse events were reported by 50% and 44% of patients treated with the sumatriptan iontophoretic transdermal system and placebo, respectively. Most events were transient mild‐to‐moderate application‐site reactions. Conclusions.— The sumatriptan iontophoretic transdermal system is effective and well tolerated, and may be particularly useful in patients with migraine‐related gastrointestinal symptoms such as nausea.     

Efficacy of dronabinol as an adjuvant treatment for chronic pain patients on opioid therapy.

We assessed the efficacy of dronabinol (Marinol capsules; Solvay Pharmaceuticals, Brussels, Belgium), a synthetic Delta(9)-THC (tetrahydrocannabinol), in 30 patients taking opioids for chronic pain to determine its potential analgesic effects as an adjuvant treatment. Phase I of this 2-phase study was a randomized, single-dose, double-blinded, placebo-controlled, crossover trial in which subjects were randomly administered either 10 mg or 20 mg of dronabinol or identical placebo capsules over the course of three, 8-hour visits. Baseline self-report measures, hourly ratings of pain intensity, pain relief, pain bothersomeness, treatment satisfaction, mood, side effects, and blood serum levels were obtained. Phase II was an extended open-label titrated trial of dronabinol as add-on medication to patients on stable doses of opioids. Results of the Phase I study showed that patients who received dronabinol experienced decreased pain intensity and increased satisfaction compared with placebo. No differences in benefit were found between the 20 mg and 10 mg doses. In the Phase II trial, titrated dronabinol contributed to significant relief of pain, reduced pain bothersomeness, and increased satisfaction compared with baseline. The incidence of side effects was dose-related. Overall, the use of dronabinol was found to result in additional analgesia among patients taking opioids for chronic noncancer pain. PERSPECTIVE: This study examines the effect of adding a cannabinoid to the regimen of patients with chronic pain who report significant pain despite taking stable doses of opioids. The results of our preliminary study suggest that dronabinol, a synthetic THC, may have an additive effect on pain relief.     

A Randomized Controlled Pilot Study of a Cognitive-Behavioral Therapy Approach for Painful Diabetic Peripheral Neuropathy

The purpose of the present pilot study was to assess the efficacy of cognitive-behavioral therapy (CBT) for painful diabetic peripheral neuropathy. This was a randomized, treatment as usual (TAU), controlled, nonblinded intervention pilot study with a 4-month follow-up conducted in a VA medical center. It was hypothesized that participants who received CBT, as compared to those who received TAU, would report significant decreases on self-report measures of pain severity, interference, and depressive symptoms from pretreatment to 4-month follow-up. Participants meeting inclusion criteria were randomly assigned to 1 of the study conditions. Of the 20 eligible participants, 12 were randomized to CBT and 8 were randomized to TAU. Participants randomized to CBT showed significant decreases on measures of pain severity (B = ?.54) and pain interference (B = ?.77) from pretreatment to 4-month follow-up. There were no significant changes in the TAU participants' scores on measures of pain severity (B = .00) or pain interference (B = ?.09). Neither CBT nor TAU participants showed significant changes in their levels of depressive symptoms from pretreatment to 4-month follow-up. CBT may be an effective treatment approach for reducing pain severity and interference associated with painful diabetic peripheral neuropathy.PerspectiveThe results of this study suggest that engaging patients in CBT for painful diabetic peripheral neuropathy may provide them the skills to become more active and experience less pain.