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S H Sindrup

Publications and source records attributed to S H Sindrup.

At least 19 recordsLinked to original sources
PubMed2005

Algorithm for neuropathic pain treatment: an evidence based proposal.

New studies of the treatment of neuropathic pain have increased the need for an updated review of randomized, double-blind, placebo-controlled trials to support an evidence based algorithm to treat neuropathic pain conditions. Available studies were identified using a MEDLINE and EMBASE search. One hundred and five studies were included. Numbers needed to treat (NNT) and numbers needed to harm (NNH) were used to compare efficacy and safety of the treatments in different neuropathic pain syndromes. The quality of each trial was assessed. Tricyclic antidepressants and the anticonvulsants gabapentin and pregabalin were the most frequently studied drug classes. In peripheral neuropathic pain, the lowest NNT was for tricyclic antidepressants, followed by opioids and the anticonvulsants gabapentin and pregabalin. For central neuropathic pain there is limited data. NNT and NNH are currently the best way to assess relative efficacy and safety, but the need for dichotomous data, which may have to be estimated retrospectively for old trials, and the methodological complexity of pooling data from small cross-over and large parallel group trials, remain as limitations.

Algorithms↗
PubMed2005

Paroxetine, a cytochrome P450 2D6 inhibitor, diminishes the stereoselective O-demethylation and reduces the hypoalgesic effect of tramadol.

OBJECTIVE: Tramadol hydrochloride (INN, tramadol) exerts its antinociceptive action through a monoaminergic effect mediated by the parent compound and an opioid effect mediated mainly by the O-demethylated metabolite (+)-M1. O-demethylation is catalyzed by cytochrome P450 (CYP) 2D6. Paroxetine is a very potent inhibitor of CYP2D6. The objective of this study was to investigate the influence of paroxetine pretreatment on the biotransformation and the hypoalgesic effect of tramadol. METHODS: With and without paroxetine pretreatment (20 mg daily for 3 consecutive days), the formation of M1 and the analgesic effect of 150 mg of tramadol were studied in 16 healthy extensive metabolizers of sparteine in a randomized, double-blind, placebo-controlled, 4-way crossover study by use of experimental pain models. RESULTS: With paroxetine pretreatment, the area under the plasma concentration-time curve (AUC) of (+)- and (-)-tramadol was increased (37% [P = .001] and 32% [P = .002], respectively), and the corresponding AUCs of(+)- and (-)-M1 were decreased (67% [P = .0004] and 40% [P = .0008], respectively). (+)-M1 and (-)-M1 could be determined in all subjects throughout the study period regardless of paroxetine pretreatment. The sums of differences between postmedication and premedication values of pain measures differed between the placebo/tramadol and the placebo/placebo combination, with median values as follows: pressure pain tolerance threshold, 390 kPa (95% confidence interval [CI], 211 to 637 kPa) versus -84 kPa (95% CI, - 492 to -32 kPa) (P = .001); single sural nerve stimulation pain tolerance threshold, 25.8 mA (95% CI, 15.3 to 29.8 mA) versus 9.0 mA (95% CI, 1.5 to 14.8 mA) (P = .005); pain summation threshold, 10.7 mA (95% CI, 5.2 to 17.6 mA) versus 5.0 mA (95% CI, 2.8 to 11.2 mA) (P = .066); cold pressor pain, -4.2 cm x s (95% CI, -6.8 to -1.9 cm x s) versus -0.4 cm x s (-1.4 to 1.4 cm x s) (P = .002); and discomfort, -4.7 cm (95% CI, -10.6 to -2.8 cm) versus 0.5 cm (-0.1 to 1.4 cm) (P = .002). The sums of differences of the paroxetine/tramadol combination also differed from placebo/tramadol for some of the measures, with median values as follows: cold pressor pain, -2.2 cm x s (95% CI, -3.7 to -0.4 cm x s) (P = .036, compared with placebo/tramadol); and discomfort, -2.0 cm (95% CI, -5.6 to -1.2 cm) (P = .056). For the other measures, the hypoalgesic effect was retained on the paroxetine/tramadol combination, with median values as follows: pressure pain tolerance threshold, 389 kPa (95% CI, 141 to 715 kPa) (P = .278, compared with placebo/tramadol); single sural nerve stimulation pain tolerance threshold, 12.5 mA (95% CI, 6.2 to 28.3 mA) (P = .278); and pain summation threshold, 8.2 mA (95% CI, 4.4 to 14.6 mA) (P = .179). Paroxetine in combination with placebo showed no analgesic effect. CONCLUSIONS: It is concluded that paroxetine at a dosage of 20 mg once daily for 3 consecutive days significantly inhibits the metabolism of tramadol to its active metabolite M1 and reduces but does not abolish the hypoalgesic effect of tramadol in human experimental pain models, particularly in opioid-sensitive tests.

Adult↗
PubMed2004

Therapeutic outcome in neuropathic pain: relationship to evidence of nervous system lesion.

Treatment outcome in patients with neuropathic pain (NP) is often variable and disappointing. We tested the hypothesis that patients with clear evidence of nervous system lesion respond better to pharmacological treatment with documented effect on NP than patients with poor or no evidence of nervous system lesion. Furthermore, we examined whether specific symptoms or signs were associated with treatment outcome. A total of 214 patients with suspected non-cancer NP were divided into four groups with graded evidence of nervous system lesion based on medical history, bedside sensory examination, quantitative sensory tests, electrophysiology, and neuroimaging. Patients were treated with imipramine guided by plasma-drug concentrations. Gabapentin 2400 mg/day was given in case of treatment failure or if imipramine treatment was not possible. Two hundred patients completed the study. Global pain relief was similar in the four groups. There was no association between evidence of nervous system lesion and treatment outcome. Classical NP signs: abnormal temporal summation, cold and brush allodynia, and abnormal sensibility to temperature were also unrelated to outcome. Treatment outcome was similar in peripheral and central definite NP. Neither definite evidence of nervous system lesion nor abnormal sensory phenomena seems to predict for good outcome of therapy with imipramine or gabapentin in patients with suspected neuropathic pain.

Acetates↗
PubMed2003

Venlafaxine versus imipramine in painful polyneuropathy: a randomized, controlled trial.

BACKGROUND: Tricyclic antidepressants (TCA) are often used in the treatment of painful polyneuropathy. Venlafaxine is a serotonin and weak noradrenaline reuptake inhibitor antidepressant with a different profile of other pharmacologic actions from those of TCA. OBJECTIVE: To test if venlafaxine would relieve painful polyneuropathy and compare its possible efficacy with that of the TCA imipramine. METHODS: The study design was randomized, double blind, and placebo controlled, with a three-way crossover. Forty patients were assigned to one of the treatment sequences, and 29 completed all three study periods. The daily doses were venlafaxine 225 mg and imipramine 150 mg. During the three treatment periods, each of 4 weeks' duration, patients rated pain paroxysms, constant pain, and touch- and pressure-evoked pain by use of 0- to 10-point numeric rating scales. RESULTS: The sum of the individual pain scores during treatment week 4 was lower on venlafaxine (80% of baseline score; p = 0.006) and imipramine (77%; p = 0.001) than on placebo (100%) and did not show any statistical difference between venlafaxine and imipramine (p = 0.44). The individual pain scores for pain paroxysms, constant pain, and pressure-evoked pain showed a similar pattern, whereas touch-evoked pain was uncommon and was not altered by any of the drugs. Numbers needed to treat to obtain one patient with moderate or better pain relief were 5.2 for venlafaxine and 2.7 for imipramine. CONCLUSION: Venlafaxine relieves pain in polyneuropathy and may be as effective as imipramine.

Adult↗
PubMed2002

Statins and risk of polyneuropathy: a case-control study.

BACKGROUND: Several case reports and a single epidemiologic study indicate that use of statins occasionally may have a deleterious effect on the peripheral nervous system. The authors therefore performed a population-based study to estimate the relative risk of idiopathic polyneuropathy in users of statins. METHOD: The authors used a population-based patient registry to identify first-time-ever cases of idiopathic polyneuropathy registered in the 5-year period 1994 to 1998. For each case, validated according to predefined criteria, 25 control subjects were randomly selected among subjects from the background population matched for age, sex, and calendar time. The authors used a prescription register to assess exposure to drugs and estimated the odds ratio of use of statins (ever and current use) in cases of idiopathic polyneuropathy compared with control subjects. RESULTS: The authors verified a diagnosis of idiopathic polyneuropathy in 166 cases. The cases were classified as definite (35), probable (54), or possible (77). The odds ratio linking idiopathic polyneuropathy with statin use was 3.7 (95% CI 1.8 to 7.6) for all cases and 14.2 (5.3 to 38.0) for definite cases. The corresponding odds ratios in current users were 4.6 (2.1 to 10.0) for all cases and 16.1 (5.7 to 45.4) for definite cases. For patients treated with statins for 2 or more years the odds ratio of definite idiopathic polyneuropathy was 26.4 (7.8 to 45.4). CONCLUSIONS: Long-term exposure to statins may substantially increase the risk of polyneuropathy.

Aged↗
PubMed2001

The clinical picture of neuropathic pain.

Neuropathic pains refer to a heterogeneous group of pain conditions characterised by lesion or dysfunction of the normal sensory pathways. Clinical characteristics include: delayed onset of pain after nervous system lesion, pain in area of sensory loss, spontaneous and different evoked types of pains. It has so far only been possible to classify these pains on basis of underlying cause or on anatomical location. The mechanisms underlying neuropathic pain are not yet clear, but neuronal hyperexcitability in those neurons that have lost their normal patterned input seems to be a common denominator for many, if not all types, of neuropathic pains. Along these lines, a mechanism-based classification has recently been proposed, which is an attractive approach because it provides a frame for a rationally based therapy of neuropathic pains. The clinical manifestations of neuronal hyperexcitability due to nervous system lesions is described.

Animals↗
PubMed2001

Are users of lipid-lowering drugs at increased risk of peripheral neuropathy?

OBJECTIVE: To estimate the risk of peripheral neuropathy associated with use of lipid-lowering drugs. METHODS: Population-based dynamic cohort study based on data from general practices in the United Kingdom from 1991 to 1997. Three cohorts of individuals aged 40-74 years were identified: a cohort of 17,219 persons who received at least one prescription for lipid-lowering drugs in the period; a second cohort of patients with a hyperlipidaemia diagnosis who had not been prescribed lipid-lowering drugs (n = 28,974) and a third cohort comprised of 50,000 individuals from the general population. The incidence rates of peripheral neuropathy in the three cohorts were calculated and the relative risk of peripheral neuropathy in users of lipid-lowering drugs was compared with non-users from the general population cohort. RESULTS: The incidence rate of idiopathic peripheral neuropathy in users of lipid-lowering drugs was higher [0.73 per 10,000 person-years, 95% confidence interval (CI) 0.01-2.62] than in the hyperlipidaemia non-treated cohort (0.40 per 10,000 person-years, CI 0.05-1.46) and the general population cohort (0.46 per 10,000 person-years, CI 0.13-1.18). The raised risk of idiopathic peripheral neuropathy in users of lipid-lowering drugs was confined to current users of statins (relative risk 2.5, CI 0.3-14.2). These figures suggest one excess case of neuropathy for every 14,000 person-years of statin treatment. CONCLUSIONS: Because of the wide CIs, these results are inconclusive and should be interpreted with caution. However, although peripheral neuropathy as an adverse effect of the use of lipid-lowering drugs cannot be excluded, the magnitude of this untoward effect appears to be small.

Adult↗
PubMed2001

The analgesic effect of codeine as compared to imipramine in different human experimental pain models.

The hypoalgesic effect of single oral doses of 100 mg imipramine and 125 mg codeine was evaluated in a randomised, placebo-controlled, double-blind, 3-way cross-over experiment including 18 healthy volunteers. Pain tests were performed before and 90, 180, 270, 360 and 450 min after medication. The tests included determination of pain tolerance thresholds to pressure, pain detection/tolerance thresholds to single electrical sural nerve stimulation and pain summation at tolerance threshold to repetitive electrical sural nerve stimulation (temporal summation) and pain experienced during the cold pressor test, rated as peak pain intensity, pain average intensity and discomfort. Compared to placebo, imipramine significantly increased pressure pain tolerance threshold (P = 0.03) and increased pain tolerance threshold (P = 0.05) and pain summation threshold (P = 0.03), but not pain detection threshold to electrical stimulation. Imipramine did not cause significant changes in pain perception during the cold pressor test. Codeine significantly increased pressure pain tolerance threshold (P = 0.02), pain detection (P = 0.04) and pain tolerance threshold (P = 0.01) and pain summation threshold (P = 0.02) to electrical stimulation. In addition, codeine reduced the pain experienced during the cold pressor test (P = 0.04-0.003). It is concluded that both imipramine and codeine inhibit temporal pain summation, whereas only codeine reduces cold pressor pain. Pain summation may be a key mechanism in neuropathic pain. Imipramine has a documented effect on such pain conditions on temporal summation. The present study showed that codeine also inhibits temporal summation, which is in line with the clinical observations indicating that opioids relieve neuropathic pain.

Adrenergic Uptake Inhibitors↗
PubMed2001

Pain and dysesthesia in patients with spinal cord injury: A postal survey.

STUDY DESIGN: A postal survey. OBJECTIVES: To assess the prevalence and characteristics of pain and dysesthesia in a community based sample of patients with spinal cord injury (SCI) with special focus on neuropathic pain. SETTING: Community. Western half of Denmark. METHODS: We mailed a questionnaire to all outpatients (n = 436) of the Viborg rehabilitation centre for spinal cord injury. The questionnaire contained questions regarding cause and level of spinal injury and amount of sensory and motor function below this level. The words pain and unpleasant sensations were used to describe pain (P) and dysesthesia (D) respectively. Questions included location and intensity of chronic pain or dysesthesia, degree of interference with daily activity and sleep, presence of paroxysms and evoked pain or dysesthesia, temporal aspects, alleviating and aggravating factors, McGill Pain Questionnaire (MPQ) and treatment. RESULTS: Seventy-six per cent of the patients returned the questionnaire, (230 males and 100 females). The ages ranged from 19 to 80 years (median 42.6 years) and time since spinal injury ranged from 0.5 to 39 years (median 9.3 years). The majority (> 75%) of patients had traumatic spinal cord injury. Of the respondents, 77% reported having pain or unpleasant sensations, and 67% had chronic pain or unpleasant sensations at or below lesion. Forty-eight per cent reported that P/D could be evoked by non-noxious stimulation of the skin indicating that allodynia is present in almost half of the patients. Forty-three per cent of respondents took analgesics, 7% received antidepressants or anticonvulsants. CONCLUSION: This survey suggests that pain and dysesthesia are common and serious complaints in SCI patients. Unexpectedly, only 7% of the patients were treated with drugs considered to be most effective in neuropathic pain. This emphasizes the need for a continued research and education on P/D in SCI.

Adult↗
PubMed2001

Diagnostic yield by testing small fiber function in patients examined for polyneuropathy.

We assessed the diagnostic yield of adding quantitative sensory testing to the standard work-up for polyneuropathy in unselected patients. All patients aged 18 to 70 years referred to our department for electrodiagnosis with a tentative diagnosis of polyneuropathy and symptoms complying with predefined criteria were included in the study. We performed near nerve conduction studies in 4 nerves and determined heat and cold detection thresholds on hand and foot with a Thermotest (Somedic AB, Sweden). In order to uncover CNS diseases, somatosensory-evoked potentials were recorded in patients with abnormal quantitative sensory testing and normal nerve conduction studies. A total of 198 patients completed the study and 149 were considered to have polyneuropathy. Twenty-five patients remained undiagnosed and in 24 patients, other diseases were responsible for the symptoms. Of the patients with either polyneuropathy or no other diagnosis, 76% (n = 174) had abnormal nerve conduction. Abnormal cold sensation, heat sensation or abnormality in at least 1 of these and normal nerve conduction were found in 14, 12 and 17 patients. Of the 174 patients, 86% (95% CI 80-90%) had an abnormality in at least 1 of the tests (i.e. abnormal nerve conduction and/or abnormal quantitative testing of temperature sensation). In conclusion, quantitative testing of temperature sensation improves the diagnostic yield in patients examined for chronic polyneuropathy.

Adult↗
PubMed2001

Specific effect of venlafaxine on single and repetitive experimental painful stimuli in humans.

BACKGROUND: Tricyclic antidepressants relieve neuropathic pain, and the analgesic properties of tricyclic antidepressants are substantiated in human experimental pain models. It has been speculated that drugs with a selective inhibition of presynaptic reuptake of both serotonin and noradrenaline could have an analgesic effect comparable to the analgesic effect of tricyclic antidepressants. OBJECTIVE: Our objective was to evaluate the analgesic effect of the serotonin-noradrenaline reuptake inhibitor venlafaxine in human experimental pain models. METHOD: The study was carried out as a randomized, placebo-controlled, double-blind, crossover experiment that included 16 healthy volunteers. A 37.5-mg dose of venlafaxine was given orally 4 times with 12-hour intervals, and pain tests were performed before and 3 hours after the second and fourth doses. Pain tests included the determination of pain detection and tolerance thresholds to pressure, pain detection and tolerance thresholds on single electrical transcutaneous stimulation of the sural nerve, pain temporal summation on repetitive electrical sural nerve stimulation, and pain experienced during the cold pressor test. RESULTS: Venlafaxine increased thresholds for pain tolerance after single electrical stimulation (P =.005) and pain summation (P =.01) on repetitive stimulation but did not alter the thresholds for pain detection after single electrical sural nerve stimulation. Venlafaxine did not alter pain experienced during the cold pressor test or increase the pressure pain thresholds. CONCLUSION: Venlafaxine increases the pain tolerance threshold to electrical sural nerve stimulation and the threshold at which pain increases (pain summation). The impact of venlafaxine on pain summation in this experimental pain model on repetitive stimulation may indicate a potential analgesic effect for clinical neuropathic pain.

Adult↗
PubMed2001

Lipid-lowering drugs and risk of myopathy: a population-based follow-up study.

We conducted a population-based cohort study to estimate the risk of myopathy associated with use of lipid-lowering drugs. Using data from general practices in the United Kingdom in 1991 through 1997, we identified three cohorts of individuals 40 to 74 years of age. One cohort comprised 17,219 persons who had received at least one prescription for lipid-lowering drugs in the period; a second cohort consisted of patients with a hyperlipidemia diagnosis who had not been prescribed lipid-lowering drugs (N = 28,974); and a third cohort comprised 50,000 individuals from the general population with no diagnosis of hyperlipidemia. The incidence rate of myopathy in the cohort of users of lipid-lowering drugs was 2.3 per 10,000 person-years [95% confidence interval (95% CI) = 1.2-4.4], which exceeded the incidence rates observed in the nontreated hyperlipidemia cohort [0 per 10,000 person-years (95% CI = 0.0-0.4)] and the general population [0.2 per 10,000 person-years (95% CI = 0.1-0.4)]. The relative risks of myopathy in current users of fibrates and statins compared with nonusers were 42.4 (95% CI = 11.6-170.5) and 7.6 (95% CI = 1.4-41.3), respectively. Potential risk factors other than drug use could not explain our findings in the nested case-control analysis. We conclude that use of lipid-lowering drugs is associated with a substantially greater risk of myopathy, which is most pronounced for fibrates. The absolute risk of myopathy in users of lipid-lowering drugs is, however, small.

Adult↗
PubMed2000

Pharmacologic treatment of pain in polyneuropathy.

Tricyclic antidepressants and anticonvulsants have become the mainstay in the treatment of pain in polyneuropathy. Within the last decade, controlled trials have shown that numerous other drugs relieve such pain. To estimate the efficacy of the different treatments, the authors identified all placebo-controlled trials and calculated numbers needed to treat (NNT) to obtain one patient with more than 50% pain relief. The NNT was 2.6 for tricyclic antidepressants, 6.7 for selective serotonin reuptake inhibitors, 2.5 for anticonvulsant sodium channel blockers, 4.1 for the anticonvulsant calcium channel blocker gabapentin, and 3.4 for the mixed opioid and monoaminergic drug tramadol, as calculated from a sufficiently large number of patients. Favorable point estimates of NNT of 1.9 for the NMDA-antagonist dextromethorphan and 3.4 for L-dopa were determined from a limited number of data. For capsaicin, the NNT calculated from many exposed patients was 5.9, but most of the data are controversial owing to trial methodology. Finally, the NNT for the antiarrhythmic sodium channel blocker mexiletine was 38, but this value may be biased because of a lack of dichotomous data in several positive trials. Tricyclic antidepressants are at the moment still the drugs of first choice, and drugs such as gabapentin, carbamazepine, and tramadol may be tried if contraindications or tolerability problems are encountered with the tricyclics.

Anticonvulsants↗
PubMed1999

Statins and peripheral neuropathy.

Within the past 3 years seven cases of reversible peripheral neuropathy apparently caused by statins have been reported. Here we report seven additional cases associated with long-term statin therapy, in which other causes of neuropathy were thoroughly excluded. The neuropathy was in all cases axonal and with affection of both thick and thin nerve fibers. The symptoms of neuropathy persisted during an observation period lasting from 10 weeks to 1 year in four cases after statin treatment had been withdrawn. We suggest that long-term statin treatment may be associated with chronic peripheral neuropathy.

Action Potentials↗
PubMed1999

Tramadol relieves pain and allodynia in polyneuropathy: a randomised, double-blind, controlled trial.

It is generally believed that opioids relieve neuropathic pain less effectively than nociceptive pain and that they have no effect on some of the key characteristics of neuropathic pain such as touch-evoked pain (allodynia). Tramadol is an analgesic drug acting directly on opioid receptors and indirectly on monoaminergic receptor systems. The aim of this trial was to determine whether tramadol relieved painful polyneuropathy and reduced allodynia. The study design was randomised, double-blind, placebo-controlled and cross-over. After baseline observations, 45 patients were assigned to one of the two treatment sequences. The dose of tramadol slow-release tablets was titrated to at least 200 mg/day and at highest 400 mg/day. During the two treatment periods of 4 weeks duration, patients rated pain, paraesthesia and touch-evoked pain by use of 0-10 point numeric rating scales. Mechanical allodynia induced by stimulation with an electronic toothbrush was rated at the end of each treatment period with a similar scale. Thirty-four patients completed the study. Their ratings for pain (median 4 vs. 6, P=0.001), paraesthesia (4 vs. 6, P=0.001) and touch-evoked pain (3 vs. 5, P<0.001) were lower on tramadol than on placebo, as were their ratings of allodynia (0 vs. 4, P=0.012). The number needed to treat to obtain one patient with >/=50% pain relief was 4.3 (95% confidence interval 2.4-20). It is concluded that tramadol appears to relieve both ongoing pain symptoms and the key neuropathic pain feature allodynia in polyneuropathy.

Adult↗