Carbamazepine for painful crises in Fabry's disease

Pain management strategies for neuropathic pain in Fabry disease--a systematic review

Background

Neuropathic pain is one of the key features of (classical) Fabry disease (FD). No randomized clinical trials comparing effectiveness of different pain management strategies have been performed. This review aims to give an overview of existing pain management strategies.

Methods

PubMed and Embase were searched up to September 2014 for relevant articles on treatment of neuropathic pain in FD.

Results

Seven-hundred-thirty-one articles were identified of which 26 were included in the analysis. Studies reported on 55 individuals in total, with group-sizes ranging from 1 to 8. Carbamazepine appeared most beneficial: complete pain relief in 5/25, partial relief in 17/25, and no benefit in 3/25 patients. Phenytoin resulted in complete relief in 1/27, partial relief in 12/27 and no benefit in 6/27 patients. In 8 patients a significant reduction in the frequency of pain attacks was described. Gabapentin caused partial relief in 6/7 and no relief in 1/7 patients. Little evidence was reported for SSNRI’s or treatment combinations. Adverse-effects were reported in all treatment strategies.

Conclusions

Only for carbamazepine, phenytoin and gabapentin there is evidence of effectiveness in neuropathic pain due to FD, but comparison of effectiveness between these drugs is lacking. In routine clinical practice adverse-effects may discourage use of carbamazepine and phenytoin in favor of second-generation antiepileptic drugs, but this is currently not supported by clinical evidence. This review suffers greatly from incomplete outcome reports and a predominance of case reports, which emphasizes the need for robust clinical trials and observational cohort studies.

WITHDRAWN. Anticonvulsant drugs for acute and chronic pain

BACKGROUND

Anticonvulsant drugs have been used in the management of pain since the 1960s. The clinical impression is that they are useful for chronic neuropathic pain, especially when the pain is lancinating or burning. Readers are referred to reviews of carbamazepine and gabapentin in T he Cochrane Library which replace the information on those drugs in this review. Other drugs remain unchanged at present in this review

OBJECTIVES

To evaluate the analgesic effectiveness and adverse effects of anticonvulsant drugs for pain management in clinical practice . Migraine and headache studies are excluded in this revision.

SEARCH STRATEGY

Randomised trials of anticonvulsants in acute, chronic or cancer pain were identified by MEDLINE (1966-1999), EMBASE (1994-1999), SIGLE (1980 to 1999) and the Cochrane Controlled Trials Register (CENTRAL/CCTR) (The Cochrane Library Issue 3, 1999). In addition, 41 medical journals were hand searched. Additional reports were identified from the reference list of the retrieved papers, and by contacting investigators. Date of most recent search: September 1999.

SELECTION CRITERIA

Randomised trials reporting the analgesic effects of anticonvulsant drugs in patients, with subjective pain assessment as either the primary or a secondary outcome.

DATA COLLECTION AND ANALYSIS

Data were extracted by two independent review authors, and trials were quality scored. Numbers-needed-to-treat (NNTs) were calculated from dichotomous data for effectiveness, adverse effects and drug-related study withdrawal, for individual studies and for pooled data.

MAIN RESULTS

Twenty-three trials of six anticonvulsants were considered eligible (1074 patients).The only placebo-controlled study in acute pain found no analgesic effect of sodium valproate.Three placebo-controlled studies of carbamazepine in trigeminal neuralgia had a combined NNT (95% confidence interval (CI)) for effectiveness of 2.5 (CI 2.0 to 3.4). A single placebo-controlled trial of gabapentin in post-herpetic neuralgia had an NNT of 3.2 (CI 2.4 to 5.0). For diabetic neuropathy NNTs for effectiveness were as follows: (one RCT for each drug) carbamazepine 2.3 (CI 1.6 to 3.8), gabapentin 3.8 (CI 2.4 to 8.7) and phenytoin 2.1 (CI 1.5 to 3.6).Numbers-needed-to-harm (NNHs) were calculated where possible by combining studies for each drug entity irrespective of the condition treated. The results were, for minor harm, carbamazepine 3.7 (CI 2.4 to 7.8), gabapentin 2.5 (CI 2.0 to 3.2), phenytoin 3.2 (CI 2.1 to 6.3). NNHs for major harm were not statistically significant for any drug compared with placebo.Phenytoin had no effect in irritable bowel syndrome, and carbamazepine little effect in post-stroke pain. Clonazepam was effective in one study of temporomandibular joint dysfunction.

AUTHORS' CONCLUSIONS

Although anticonvulsants are used widely in chronic pain surprisingly few trials show analgesic effectiveness. Only one study identified considered cancer pain. There is no evidence that anticonvulsants are effective for acute pain. In chronic pain syndromes other than trigeminal neuralgia, anticonvulsants should be withheld until other interventions have been tried. While gabapentin is increasingly being used for neuropathic pain the evidence would suggest that it is not superior to carbamazepine.

Anticonvulsant drugs for acute and chronic pain

BACKGROUND

Anticonvulsant drugs have been used in the management of pain since the 1960s. The clinical impression is that they are useful for chronic neuropathic pain, especially when the pain is lancinating or burning. Readers are referred to reviews of carbamazepine and gabapentin in the Cochrane Library which replace the information on those drugs in this review. Other drugs remain unchanged at present in this review

OBJECTIVES

To evaluate the analgesic effectiveness and adverse effects of anticonvulsant drugs for pain management in clinical practice . Migraine and headache studies are excluded in this revision.

SEARCH STRATEGY

Randomised trials of anticonvulsants in acute, chronic or cancer pain were identified by MEDLINE (1966-1999), EMBASE (1994-1999), SIGLE (1980-1999) and the Cochrane Controlled Trials Register (CENTRAL/CCTR) (Cochrane Library Issue 3, 1999). In addition, 41 medical journals were hand searched. Additional reports were identified from the reference list of the retrieved papers, and by contacting investigators. Date of most recent search: September 1999.

SELECTION CRITERIA

Randomised trials reporting the analgesic effects of anticonvulsant drugs in patients, with subjective pain assessment as either the primary or a secondary outcome.

DATA COLLECTION AND ANALYSIS

Data were extracted by two independent reviewers, and trials were quality scored. Numbers-needed-to-treat (NNTs) were calculated from dichotomous data for effectiveness, adverse effects and drug-related study withdrawal, for individual studies and for pooled data.

MAIN RESULTS

Twenty-three trials of six anticonvulsants were considered eligible (1,074 patients). The only placebo-controlled study in acute pain found no analgesic effect of sodium valproate. Three placebo-controlled studies of carbamazepine in trigeminal neuralgia had a combined NNT (95% confidence interval (CI)) for effectiveness of 2.5 (CI 2.0-3.4). A single placebo-controlled trial of gabapentin in post-herpetic neuralgia had an NNT of 3.2 (CI 2.4-5.0). For diabetic neuropathy NNTs for effectiveness were as follows: (one RCT for each drug) carbamazepine 2.3 (CI 1.6-3.8), gabapentin 3.8 (CI 2.4-8.7) and phenytoin 2.1 (CI 1.5-3.6).Numbers-needed-to-harm (NNHs) were calculated where possible by combining studies for each drug entity irrespective of the condition treated. The results were, for minor harm, carbamazepine 3.7 (CI 2.4-7.8), gabapentin 2.5 (CI 2.0-3.2), phenytoin 3.2 (CI 2.1-6.3). NNHs for major harm were not statistically significant for any drug compared with placebo. Phenytoin had no effect in irritable bowel syndrome, and carbamazepine little effect in post-stroke pain. Clonazepam was effective in one study of temporomandibular joint dysfunction.

AUTHORS' CONCLUSIONS

Although anticonvulsants are used widely in chronic pain surprisingly few trials show analgesic effectiveness. Only one studied considered cancer pain. There is no evidence that anticonvulsants are effective for acute pain. In chronic pain syndromes other than trigeminal neuralgia, anticonvulsants should be withheld until other interventions have been tried. While gabapentin is increasingly being used for neuropathic pain the evidence would suggest that it is not superior to carbamazepine.

Pediatric Fabry disease

BACKGROUND

Fabry disease is an underdiagnosed, treatable, X-linked, multisystem disorder.

OBJECTIVES

To test the hypothesis that quality of life and sweating are decreased among pediatric patients with Fabry disease, compared with control subjects, and to provide quantitative natural history data and novel clinical end points for therapeutic trials.

DESIGN

Prospective, cross-sectional, observational study.

SETTING

Referral to the National Institutes of Health.

PARTICIPANTS

Twenty-five male children with Fabry disease (mean age: 12.3 +/- 3.5 years) and 21 age-matched control subjects.

MAIN OUTCOME MEASURES

Quality of life (measured with the Child Health Questionnaire) and sweating (assessed with the quantitative sudomotor axon reflex test).

RESULTS

Quality of life scores for pediatric patients <10 years of age with Fabry disease, compared with published normative values, were 55 +/- 17 vs 83 +/- 19 for bodily pain and 62 +/- 19 vs 80 +/- 13 for mental health. Bodily pain scores for patients > or =10 years of age were 54 +/- 22 vs 74 +/- 23. Sweat volume in the Fabry disease group was 0.41 +/- 0.46 microL/mm2, compared with 0.65 +/- 0.44 microL/mm2 in the control group. Renal function, urinary protein excretion, and cardiac function and structure were normal for the majority of patients. The 3 patients with residual alpha-galactosidase A activity > or =1.5% of normal values were free of cornea verticillata and had normal serum and urinary globotriaosylceramide levels. All other children had glycolipid levels comparable to those of adult patients with Fabry disease. Acroparesthesia and cardiac abnormalities were generally present before anhidrosis and proteinuria. Mapping of the missense mutations on the crystallographic structure of alpha-galactosidase A revealed that the mutations were partially surface-exposed and distal to the active site among individuals with residual enzyme activity. Mutations associated with left ventricular hypertrophy (defined as left ventricular mass index of >51 g/m2.7) were localized near the catalytic site of the enzyme.

CONCLUSIONS

Despite the absence of major organ dysfunction, Fabry disease demonstrates significant morbidity already in childhood. We have identified important, potentially correctable or preventable, outcome measures for future therapeutic trials. Prevention of complications involving major organs should be the goal for long-term specific therapy.

Anticonvulsant drugs for acute and chronic pain

BACKGROUND

Anticonvulsant drugs have been used in the management of pain since the 1960s. The clinical impression is that they are useful for neuropathic pain, especially when the pain is lancinating or burning.

OBJECTIVES

To evaluate the analgesic effectiveness of anticonvulsant drugs compared to either placebo or other drugs in order to provide evidence-based recommendations for pain management in clinical practice and to identify a clinical research agenda. Adverse effects are also considered.

SEARCH STRATEGY

Randomised trials of anticonvulsants in acute, chronic or cancer pain were identified by Medline (Silver Platter 3.0, 3.1 and 3.11) from 1966 to February 1994. In addition, 40 medical journals were hand searched (published between 1950 and 1990). Additional reports were identified from the reference list of the retrieved papers, and contacting investigators. Date of the most recent searches: 1994.

SELECTION CRITERIA

Randomised trials reporting the analgesic effects of anticonvulsant drugs in patients, with pain assessment as either the primary or a secondary outcome.

DATA COLLECTION AND ANALYSIS

Data were extracted by two independent reviewers, and trials were quality scored. Numbers-needed-to-treat (NNTs) were calculated from dichotomous data for effectiveness, adverse effects and drug-related study withdrawal, for individual studies and for pooled data.

MAIN RESULTS

Twenty trials of four anticonvulsants were considered eligible (746 patients). The only placebo-controlled study in acute pain found no analgesic effect of sodium valproate. Three placebo-controlled studies of carbamazepine in trigeminal neuralgia had a combined NNT for effectiveness of 2.6, for adverse effects 3.4, and for severe effects (withdrawal from study) 24. Three placebo-controlled studies of diabetic neuropathy had a combined NNT for effectiveness of 3, for adverse effects 2.5, and for severe effects 20. Three placebo-controlled studies of migraine prophylaxis had a combined NNT for effectiveness of 2.4, for adverse effects 2.4 and for severe effects 39. Phenytoin had no effect in irritable bowel syndrome, and carbamazepine little effect in post-stroke pain. Clonazepam was effective in one study of temporomandibular joint dysfunction. No study compared one anticonvulsant with another. Anticonvulsants fared poorly against other treatments.

REVIEWER'S CONCLUSIONS

Although anticonvulsants are used widely in chronic pain surprisingly few trials show analgesic effectiveness. No trial compared different anticonvulsants. There is no evidence that anticonvulsants are effective for acute pain. In chronic pain syndromes other than trigeminal neuralgia anticonvulsants should be withheld until other interventions have been tried.

Anticonvulsant drugs for management of pain: a systematic review

OBJECTIVE

To determine effectiveness and adverse effects of anticonvulsant drugs in management of pain.

DESIGN

Systematic review of randomised controlled trials of anticonvulsants for acute, chronic, or cancer pain identified by using Medline, by hand searching, by searching reference lists, and by contacting investigators.

SUBJECTS

Between 1966 and February 1994, 37 reports were found; 20 reports, of four anticonvulsants, were eligible.

MAIN OUTCOME MEASURES

Numbers needed to treat were calculated for effectiveness, adverse effects, and drug related withdrawal from study.

RESULTS

The only placebo controlled study in acute pain found no analgesic effect of sodium valproate. For treating trigeminal neuralgia, carbamazepine had a combined number needed to treat of 2.6 for effectiveness, 3.4 for adverse effects, and 24 for severe effects (withdrawal from study). For treating diabetic neuropathy, anticonvulsants had a combined number needed to treat of 2.5 for effectiveness, 3.1 for adverse effects, and 20 for severe effects. For migraine prophylaxis, anticonvulsants had a combined number needed to treat of 1.6 for effectiveness, 2.4 for adverse effects, and 39 for severe effects. Phenytoin had no effect on the irritable bowel syndrome, and carbamazepine had little effect on pain after stroke. Clonazepam was effective in one study for temporomandibular joint dysfunction. No study compared one anticonvulsant with another.

CONCLUSIONS

Anticonvulsants were effective for trigeminal neuralgia and diabetic neuropathy and for migraine prophylaxis. Minor adverse effects occurred as often as benefit.

A histochemical and electron microscopic study of skeletal and cardiac muscle from a Fabry disease patient and carrier

Histochemical and electron microscopic studies were performed in an attempt to clarify the muscle pathology in an 18-year-old man with Fabry disease, showing proximal limb muscle atrophy, and his 52-year-old mother, who is a Fabry carrier with hypertrophic cardiomyopathy. Despite the relatively mild myopathic changes revealed by histochemistry, electron microscopy demonstrated the widespread accumulation of abundant lamellated bodies in myofibers, associated with increased glycogen granules and autophagic vacuoles. The cardiac muscle of the proband's mother revealed a mosaic pattern of normal-appearing and hypertrophic myofibers containing a number of ring-like, lamellated bodies. Although further studies are necessary to support our findings, skeletal muscle is apparently involved in patients with Fabry disease, and a mosaic pattern of cardiac muscle involvement possibly reflecting Lyonization, may be one of the characteristic findings of a Fabry disease carrier.