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Antiepileptic drug monotherapy for epilepsy: a network meta-analysis of individual participant data.The Cochrane Database of Systematic... Jun 2017Epilepsy is a common neurological condition with a worldwide prevalence of around 1%. Approximately 60% to 70% of people with epilepsy will achieve a longer-term... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Epilepsy is a common neurological condition with a worldwide prevalence of around 1%. Approximately 60% to 70% of people with epilepsy will achieve a longer-term remission from seizures, and most achieve that remission shortly after starting antiepileptic drug treatment. Most people with epilepsy are treated with a single antiepileptic drug (monotherapy) and current guidelines from the National Institute for Health and Care Excellence (NICE) in the United Kingdom for adults and children recommend carbamazepine or lamotrigine as first-line treatment for partial onset seizures and sodium valproate for generalised onset seizures; however a range of other antiepileptic drug (AED) treatments are available, and evidence is needed regarding their comparative effectiveness in order to inform treatment choices.
OBJECTIVES
To compare the time to withdrawal of allocated treatment, remission and first seizure of 10 AEDs (carbamazepine, phenytoin, sodium valproate, phenobarbitone, oxcarbazepine, lamotrigine, gabapentin, topiramate, levetiracetam, zonisamide) currently used as monotherapy in children and adults with partial onset seizures (simple partial, complex partial or secondary generalised) or generalised tonic-clonic seizures with or without other generalised seizure types (absence, myoclonus).
SEARCH METHODS
We searched the following databases: Cochrane Epilepsy's Specialised Register, CENTRAL, MEDLINE and SCOPUS, and two clinical trials registers. We handsearched relevant journals and contacted pharmaceutical companies, original trial investigators, and experts in the field. The date of the most recent search was 27 July 2016.
SELECTION CRITERIA
We included randomised controlled trials of a monotherapy design in adults or children with partial onset seizures or generalised onset tonic-clonic seizures (with or without other generalised seizure types).
DATA COLLECTION AND ANALYSIS
This was an individual participant data (IPD) review and network meta-analysis. Our primary outcome was 'time to withdrawal of allocated treatment', and our secondary outcomes were 'time to achieve 12-month remission', 'time to achieve six-month remission', 'time to first seizure post-randomisation', and 'occurrence of adverse events'. We presented all time-to-event outcomes as Cox proportional hazard ratios (HRs) with 95% confidence intervals (CIs). We performed pairwise meta-analysis of head-to-head comparisons between drugs within trials to obtain 'direct' treatment effect estimates and we performed frequentist network meta-analysis to combine direct evidence with indirect evidence across the treatment network of 10 drugs. We investigated inconsistency between direct estimates and network meta-analysis via node splitting. Due to variability in methods and detail of reporting adverse events, we have not performed an analysis. We have provided a narrative summary of the most commonly reported adverse events.
MAIN RESULTS
IPD was provided for at least one outcome of this review for 12,391 out of a total of 17,961 eligible participants (69% of total data) from 36 out of the 77 eligible trials (47% of total trials). We could not include IPD from the remaining 41 trials in analysis for a variety of reasons, such as being unable to contact an author or sponsor to request data, data being lost or no longer available, cost and resources required to prepare data being prohibitive, or local authority or country-specific restrictions.We were able to calculate direct treatment effect estimates for between half and two thirds of comparisons across the outcomes of the review, however for many of the comparisons, data were contributed by only a single trial or by a small number of participants, so confidence intervals of estimates were wide.Network meta-analysis showed that for the primary outcome 'Time to withdrawal of allocated treatment,' for individuals with partial seizures; levetiracetam performed (statistically) significantly better than both current first-line treatments carbamazepine and lamotrigine; lamotrigine performed better than all other treatments (aside from levetiracetam), and carbamazepine performed significantly better than gabapentin and phenobarbitone (high-quality evidence). For individuals with generalised onset seizures, first-line treatment sodium valproate performed significantly better than carbamazepine, topiramate and phenobarbitone (moderate- to high-quality evidence). Furthermore, for both partial and generalised onset seizures, the earliest licenced treatment, phenobarbitone seems to perform worse than all other treatments (moderate- to high-quality evidence).Network meta-analysis also showed that for secondary outcomes 'Time to 12-month remission of seizures' and 'Time to six-month remission of seizures,' few notable differences were shown for either partial or generalised seizure types (moderate- to high-quality evidence). For secondary outcome 'Time to first seizure,' for individuals with partial seizures; phenobarbitone performed significantly better than both current first-line treatments carbamazepine and lamotrigine; carbamazepine performed significantly better than sodium valproate, gabapentin and lamotrigine. Phenytoin also performed significantly better than lamotrigine (high-quality evidence). In general, the earliest licenced treatments (phenytoin and phenobarbitone) performed better than the other treatments for both seizure types (moderate- to high-quality evidence).Generally, direct evidence and network meta-analysis estimates (direct plus indirect evidence) were numerically similar and consistent with confidence intervals of effect sizes overlapping.The most commonly reported adverse events across all drugs were drowsiness/fatigue, headache or migraine, gastrointestinal disturbances, dizziness/faintness and rash or skin disorders.
AUTHORS' CONCLUSIONS
Overall, the high-quality evidence provided by this review supports current guidance (e.g. NICE) that carbamazepine and lamotrigine are suitable first-line treatments for individuals with partial onset seizures and also demonstrates that levetiracetam may be a suitable alternative. High-quality evidence from this review also supports the use of sodium valproate as the first-line treatment for individuals with generalised tonic-clonic seizures (with or without other generalised seizure types) and also demonstrates that lamotrigine and levetiracetam would be suitable alternatives to either of these first-line treatments, particularly for those of childbearing potential, for whom sodium valproate may not be an appropriate treatment option due to teratogenicity.
Topics: Adult; Amines; Anticonvulsants; Carbamazepine; Child; Cyclohexanecarboxylic Acids; Epilepsies, Partial; Epilepsy; Epilepsy, Generalized; Fructose; Gabapentin; Humans; Isoxazoles; Lamotrigine; Levetiracetam; Network Meta-Analysis; Oxcarbazepine; Phenobarbital; Phenytoin; Piracetam; Remission Induction; Topiramate; Triazines; Valproic Acid; Zonisamide; gamma-Aminobutyric Acid
PubMed: 28661008
DOI: 10.1002/14651858.CD011412.pub2 -
BMC Medicine May 2017Pregnant women with epilepsy frequently experience seizures related to pregnancy complications and are often prescribed anti-epileptic drugs (AEDs) to manage their... (Comparative Study)
Comparative Study Meta-Analysis
BACKGROUND
Pregnant women with epilepsy frequently experience seizures related to pregnancy complications and are often prescribed anti-epileptic drugs (AEDs) to manage their symptoms. However, less is known about the comparative safety of AED exposure in utero. We aimed to compare the risk of congenital malformations (CMs) and prenatal outcomes of AEDs in infants/children who were exposed to AEDs in utero through a systematic review and Bayesian random-effects network meta-analysis.
METHODS
MEDLINE, EMBASE, and Cochrane CENTRAL were searched from inception to December 15, 2015. Two reviewers independently screened titles/abstracts and full-text papers for experimental and observational studies comparing mono- or poly-therapy AEDs versus control (no AED exposure) or other AEDs, then abstracted data and appraised the risk of bias. The primary outcome was incidence of major CMs, overall and by specific type (cardiac malformations, hypospadias, cleft lip and/or palate, club foot, inguinal hernia, and undescended testes).
RESULTS
After screening 5305 titles and abstracts, 642 potentially relevant full-text articles, and 17 studies from scanning reference lists, 96 studies were eligible (n = 58,461 patients). Across all major CMs, many AEDs were associated with higher risk compared to control. For major CMs, ethosuximide (OR, 3.04; 95% CrI, 1.23-7.07), valproate (OR, 2.93; 95% CrI, 2.36-3.69), topiramate (OR, 1.90; 95% CrI, 1.17-2.97), phenobarbital (OR, 1.83; 95% CrI, 1.35-2.47), phenytoin (OR, 1.67; 95% CrI, 1.30-2.17), carbamazepine (OR, 1.37; 95% CrI, 1.10-1.71), and 11 polytherapies were significantly more harmful than control, but lamotrigine (OR, 0.96; 95% CrI, 0.72-1.25) and levetiracetam (OR, 0.72; 95% CrI, 0.43-1.16) were not.
CONCLUSION
The newer generation AEDs, lamotrigine and levetiracetam, were not associated with significant increased risks of CMs compared to control, and were significantly less likely to be associated with children experiencing cardiac malformations than control. However, this does not mean that these agents are not harmful to infants/children exposed in utero. Counselling is advised concerning teratogenic risks when the prescription is written for a woman of childbearing age and before women continue with these agents when considering pregnancy, such as switching from polytherapy to monotherapy with evidence of lower risk and avoiding AEDs, such as valproate, that are consistently associated with CMs. These decisions must be balanced against the need for seizure control.
SYSTEMATIC REVIEW REGISTRATION
PROSPERO CRD42014008925.
Topics: Abnormalities, Drug-Induced; Adult; Anticonvulsants; Bayes Theorem; Child; Epilepsy; Female; Humans; Infant; Network Meta-Analysis; Pregnancy; Pregnancy Complications; Pregnancy Outcome; Young Adult
PubMed: 28472982
DOI: 10.1186/s12916-017-0845-1 -
Carbamazepine versus phenobarbitone monotherapy for epilepsy: an individual participant data review.The Cochrane Database of Systematic... Dec 2016This is an updated version of the original Cochrane Review, first published in Issue 1, 2003 and updated in 2015. This review is one in a series of Cochrane Reviews... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
This is an updated version of the original Cochrane Review, first published in Issue 1, 2003 and updated in 2015. This review is one in a series of Cochrane Reviews investigating pair-wise monotherapy comparisons.Epilepsy is a common neurological condition in which abnormal electrical discharges from the brain cause recurrent unprovoked seizures. It is believed that with effective drug treatment, up to 70% of individuals with active epilepsy have the potential to become seizure-free and go into long-term remission shortly after starting drug therapy with a single antiepileptic drug in monotherapy.Worldwide, carbamazepine and phenobarbitone are commonly used broad-spectrum antiepileptic drugs, suitable for most epileptic seizure types. Carbamazepine is a current first-line treatment for partial onset seizures, and is used in the USA and Europe. Phenobarbitone is no longer considered a first-line treatment because of concerns over associated adverse events, particularly documented behavioural adverse events in children treated with the drug. However, phenobarbitone is still commonly used in low- and middle-income countries because of its low cost. No consistent differences in efficacy have been found between carbamazepine and phenobarbitone in individual trials; however, the confidence intervals generated by these studies are wide, and therefore, synthesising the data of the individual trials may show differences in efficacy.
OBJECTIVES
To review the time to withdrawal, remission, and first seizure of carbamazepine compared with phenobarbitone when used as monotherapy in people with partial onset seizures (simple or complex partial and secondarily generalised) or generalised onset tonic-clonic seizures (with or without other generalised seizure types).
SEARCH METHODS
For the latest update, we searched the following databases on 18 August 2016: the Cochrane Epilepsy Group Specialised Register, the Cochrane Central Register of Controlled Trials (CENTRAL) via the Cochrane Register of Studies Online (CRSO), MEDLINE (Ovid, from 1946), the US National Institutes of Health Ongoing Trials Register (ClinicalTrials.gov), and the World Health Organization International Clinical Trials Registry Platform (ICTRP). Previously we also searched SCOPUS (from 1823) as an alternative to Embase, but this is no longer necessary, because randomised controlled trials (RCTs) and quasi-RCTs in Embase are now included in CENTRAL. We handsearched relevant journals and contacted pharmaceutical companies, original trial investigators, and experts in the field.
SELECTION CRITERIA
RCTs in children or adults with partial onset seizures or generalised onset tonic-clonic seizures with a comparison of carbamazepine monotherapy versus phenobarbitone monotherapy.
DATA COLLECTION AND ANALYSIS
This was an individual participant data (IPD) review. Our primary outcome was 'time to withdrawal of allocated treatment', and our secondary outcomes were 'time to achieve 12-month remission', 'time to achieve six-month remission', 'time to first seizure post-randomisation', and 'adverse events'. We used Cox proportional hazards regression models to obtain study-specific estimates of hazard ratios (HRs) with 95% confidence intervals (CIs), with the generic inverse variance method used to obtain the overall pooled HR and 95% CI.
MAIN RESULTS
IPD were available for 836 participants out of 1455 eligible individuals from six out of 13 trials; 57% of the potential data. For remission outcomes, HR > 1 indicated an advantage for phenobarbitone, and for first seizure and withdrawal outcomes, HR > 1 indicated an advantage for carbamazepine.The main overall results (pooled HR adjusted for seizure type, 95% CI) were HR 1.50 for time to withdrawal of allocated treatment (95% CI 1.15 to 1.95; P = 0.003); HR 0.93 for time to achieve 12-month remission (95% CI 0.72 to 1.20; P = 0.57); HR 0.99 for time to achieve six-month remission (95% CI 0.80 to 1.23; P = 0.95); and HR 0.87 for time to first seizure (95% CI 0.72 to 1.06; P = 0.18). Results suggest an advantage for carbamazepine over phenobarbitone in terms of time to treatment withdrawal and no statistically significant evidence between the drugs for the other outcomes. We found evidence of a statistically significant interaction between treatment effect and seizure type for time to first seizure recurrence (Chi² test for subgroup differences P = 0.03), where phenobarbitone was favoured for partial onset seizures (HR 0.76, 95% CI 0.60 to 0.96; P = 0.02) and carbamazepine was favoured for generalised onset seizures (HR 1.23, 95% CI 0.88 to 1.77; P = 0.27). We found no evidence of an interaction between treatment effect and seizure type for the other outcomes. However, methodological quality of the included studies was variable, with 10 out of the 13 included studies (4 out of 6 studies contributing IPD) judged at high risk of bias for at least one methodological aspect, leading to variable individual study results, and therefore, heterogeneity in the analyses of this review. We conducted sensitivity analyses to examine the impact of poor methodological aspects, where possible.
AUTHORS' CONCLUSIONS
Overall, we found evidence suggestive of an advantage for carbamazepine in terms of drug effectiveness compared with phenobarbitone (retention of the drug in terms of seizure control and adverse events) and evidence suggestive of an association between treatment effect and seizure type for time to first seizure recurrence (phenobarbitone favoured for partial seizures and carbamazepine favoured for generalised seizures). However, this evidence was judged to be of low quality due to poor methodological quality and the potential impact on individual study results (and therefore variability (heterogeneity) present in the analysis within this review), we encourage caution when interpreting the results of this review and do not advocate that the results of this review alone should be used in choosing between carbamazepine and phenobarbitone. We recommend that future trials should be designed to the highest quality possible with considerations for allocation concealment and masking, choice of population, choice of outcomes and analysis, and presentation of results.
Topics: Adult; Anticonvulsants; Carbamazepine; Child; Epilepsies, Partial; Epilepsy, Generalized; Epilepsy, Tonic-Clonic; Humans; Phenobarbital; Randomized Controlled Trials as Topic; Remission Induction; Seizures
PubMed: 27976799
DOI: 10.1002/14651858.CD001904.pub3 -
The Cochrane Database of Systematic... Nov 2016There is evidence that certain antiepileptic drugs (AEDs) are teratogenic and are associated with an increased risk of congenital malformation. The majority of women... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
There is evidence that certain antiepileptic drugs (AEDs) are teratogenic and are associated with an increased risk of congenital malformation. The majority of women with epilepsy continue taking AEDs throughout pregnancy; therefore it is important that comprehensive information on the potential risks associated with AED treatment is available.
OBJECTIVES
To assess the effects of prenatal exposure to AEDs on the prevalence of congenital malformations in the child.
SEARCH METHODS
We searched the Cochrane Epilepsy Group Specialized Register (September 2015), Cochrane Central Register of Controlled Trials (CENTRAL) (2015, Issue 11), MEDLINE (via Ovid) (1946 to September 2015), EMBASE (1974 to September 2015), Pharmline (1978 to September 2015), Reprotox (1983 to September 2015) and conference abstracts (2010-2015) without language restriction.
SELECTION CRITERIA
We included prospective cohort controlled studies, cohort studies set within pregnancy registries and randomised controlled trials. Participants were women with epilepsy taking AEDs; the two control groups were women without epilepsy and women with epilepsy who were not taking AEDs during pregnancy.
DATA COLLECTION AND ANALYSIS
Three authors independently selected studies for inclusion. Five authors completed data extraction and risk of bias assessments. The primary outcome was the presence of a major congenital malformation. Secondary outcomes included specific types of major congenital malformations. Where meta-analysis was not possible, we reviewed included studies narratively.
MAIN RESULTS
We included 50 studies, with 31 contributing to meta-analysis. Study quality varied, and given the observational design, all were at high risk of certain biases. However, biases were balanced across the AEDs investigated and we believe that the results are not explained by these biases.Children exposed to carbamazepine (CBZ) were at a higher risk of malformation than children born to women without epilepsy (N = 1367 vs 2146, risk ratio (RR) 2.01, 95% confidence interval (CI) 1.20 to 3.36) and women with untreated epilepsy (N = 3058 vs 1287, RR 1.50, 95% CI 1.03 to 2.19). Children exposed to phenobarbital (PB) were at a higher risk of malformation than children born to women without epilepsy (N = 345 vs 1591, RR 2.84, 95% CI 1.57 to 5.13). Children exposed to phenytoin (PHT) were at an increased risk of malformation compared with children born to women without epilepsy (N = 477 vs 987, RR 2.38, 95% CI 1.12 to 5.03) and to women with untreated epilepsy (N = 640 vs 1256, RR 2.40, 95% CI 1.42 to 4.08). Children exposed to topiramate (TPM) were at an increased risk of malformation compared with children born to women without epilepsy (N = 359 vs 442, RR 3.69, 95% CI 1.36 to 10.07). The children exposed to valproate (VPA) were at a higher risk of malformation compared with children born to women without epilepsy (N = 467 vs 1936, RR 5.69, 95% CI 3.33 to 9.73) and to women with untreated epilepsy (N = 1923 vs 1259, RR 3.13, 95% CI 2.16 to 4.54). There was no increased risk for major malformation for lamotrigine (LTG). Gabapentin (GBP), levetiracetam (LEV), oxcarbazepine (OXC), primidone (PRM) or zonisamide (ZNS) were not associated with an increased risk, however, there were substantially fewer data for these medications.For AED comparisons, children exposed to VPA had the greatest risk of malformation (10.93%, 95% CI 8.91 to 13.13). Children exposed to VPA were at an increased risk of malformation compared with children exposed to CBZ (N = 2529 vs 4549, RR 2.44, 95% CI 2.00 to 2.94), GBP (N = 1814 vs 190, RR 6.21, 95% CI 1.91 to 20.23), LEV (N = 1814 vs 817, RR 5.82, 95% CI 3.13 to 10.81), LTG (N = 2021 vs 4164, RR 3.56, 95% CI 2.77 to 4.58), TPM (N = 1814 vs 473, RR 2.35, 95% CI 1.40 to 3.95), OXC (N = 676 vs 238, RR 3.71, 95% CI 1.65 to 8.33), PB (N = 1137 vs 626, RR 1.59, 95% CI 1.11 to 2.29, PHT (N = 2319 vs 1137, RR 2.00, 95% CI 1.48 to 2.71) or ZNS (N = 323 vs 90, RR 17.13, 95% CI 1.06 to 277.48). Children exposed to CBZ were at a higher risk of malformation than those exposed to LEV (N = 3051 vs 817, RR 1.84, 95% CI 1.03 to 3.29) and children exposed to LTG (N = 3385 vs 4164, RR 1.34, 95% CI 1.01 to 1.76). Children exposed to PB were at a higher risk of malformation compared with children exposed to GBP (N = 204 vs 159, RR 8.33, 95% CI 1.04 to 50.00), LEV (N = 204 vs 513, RR 2.33, 95% CI 1.04 to 5.00) or LTG (N = 282 vs 1959, RR 3.13, 95% CI 1.64 to 5.88). Children exposed to PHT had a higher risk of malformation than children exposed to LTG (N = 624 vs 4082, RR 1.89, 95% CI 1.19 to 2.94) or to LEV (N = 566 vs 817, RR 2.04, 95% CI 1.09 to 3.85); however, the comparison to LEV was not significant in the random-effects model. Children exposed to TPM were at a higher risk of malformation than children exposed to LEV (N = 473 vs 817, RR 2.00, 95% CI 1.03 to 3.85) or LTG (N = 473 vs 3975, RR 1.79, 95% CI 1.06 to 2.94). There were no other significant differences, or comparisons were limited to a single study.We found significantly higher rates of specific malformations associating PB exposure with cardiac malformations and VPA exposure with neural tube, cardiac, oro-facial/craniofacial, and skeletal and limb malformations in comparison to other AEDs. Dose of exposure mediated the risk of malformation following VPA exposure; a potential dose-response association for the other AEDs remained less clear.
AUTHORS' CONCLUSIONS
Exposure in the womb to certain AEDs carried an increased risk of malformation in the foetus and may be associated with specific patterns of malformation. Based on current evidence, LEV and LTG exposure carried the lowest risk of overall malformation; however, data pertaining to specific malformations are lacking. Physicians should discuss both the risks and treatment efficacy with the patient prior to commencing treatment.
Topics: Abnormalities, Drug-Induced; Anticonvulsants; Cardiovascular Abnormalities; Craniofacial Abnormalities; Epilepsy; Female; Humans; Infant, Newborn; Musculoskeletal Abnormalities; Neural Tube Defects; Pregnancy; Pregnancy Complications
PubMed: 27819746
DOI: 10.1002/14651858.CD010224.pub2 -
The Cochrane Database of Systematic... Nov 2016Any type of seizure can be observed in Alzheimer's disease (AD). Antiepileptic drugs seem to prevent the recurrence of epileptic seizures in most people with AD. There... (Review)
Review
BACKGROUND
Any type of seizure can be observed in Alzheimer's disease (AD). Antiepileptic drugs seem to prevent the recurrence of epileptic seizures in most people with AD. There are pharmacological and non-pharmacological treatments for epilepsy in people with AD. There are no current systematic reviews to evaluate the efficacy and tolerability of the treatment. This review aims to review those different modalities.
OBJECTIVES
To assess the efficacy and tolerability of the treatment of epilepsy for people with Alzheimer's disease (AD) (including sporadic AD and dominantly inherited AD).
SEARCH METHODS
We searched the Cochrane Epilepsy Group Specialized Register (1 February 2016), the Cochrane Central Register of Controlled Trials (1 February 2016), MEDLINE (Ovid, 1 February 2016) and ClinicalTrials.gov (1 February 2016). In an effort to identify further published, unpublished and ongoing trials, we searched ongoing trials' registers, reference lists and relevant conference proceedings, and contacted authors and pharmaceutical companies.
SELECTION CRITERIA
We included randomised and quasi-randomised controlled trials investigating treatment for epilepsy in people with AD, with the outcomes of proportion of seizure freedom or experiencing adverse events.
DATA COLLECTION AND ANALYSIS
Two review authors independently screened the titles and abstracts of identified records, selected studies for inclusion, extracted data, cross-checked the data for accuracy and assessed the methodological quality. We performed no meta-analyses due to the limited available data.
MAIN RESULTS
We included one randomised controlled trial with 95 participants. Concerning the proportion of participants with seizure freedom, no significant differences were found in levetiracetam (LEV) versus lamotrigine (LTG) (risk ratio (RR) 1.20, 95% confidence interval (CI) 0.53 to 2.71), in levetiracetam versus phenobarbital (PB) (RR 1.01, 95% CI 0.47 to 2.19), or in LTG versus PB (RR 0.84, 95% CI 0.35 to 2.02). It seemed that LEV could improve cognition and LTG could relieve depression; while PB and LTG could worsen cognition, and LEV and PB could worsen mood. We judged the quality of the evidence to be very low.
AUTHORS' CONCLUSIONS
This review does not provide sufficient evidence to support LEV, PB and LTG for the treatment of epilepsy in people with AD. Regarding the efficacy and tolerability, no significant differences were found between LEV, PB and LTG. In the future, large randomised, double-blind, controlled, parallel-group clinical trials are required to determine the efficacy and tolerability of treatment for epilepsy in people with AD.
Topics: Aged; Aged, 80 and over; Alzheimer Disease; Anticonvulsants; Cognition; Depression; Epilepsy; Female; Humans; Lamotrigine; Levetiracetam; Male; Phenobarbital; Piracetam; Randomized Controlled Trials as Topic; Triazines
PubMed: 27805721
DOI: 10.1002/14651858.CD011922.pub2 -
Clinical Neuropharmacology 2016Our study aimed to determine whether data obtained from the medical literature can be used to estimate the therapeutic index of 5 antiepileptic drugs (AEDs):... (Review)
Review
OBJECTIVES
Our study aimed to determine whether data obtained from the medical literature can be used to estimate the therapeutic index of 5 antiepileptic drugs (AEDs): carbamazepine, lamotrigine, phenobarbital, phenytoin, and valproate.
METHODS
We performed a literature search using PubMed and EMBASE to collect published safety, efficacy, and therapeutic monitoring data for 5 AEDs and extracted all relevant information into a drug- and study-specific drug database. For each AED, we summarized (1) type, severity, and incidence of toxicity-related adverse events and toxicity-associated range of drug doses or concentrations; (2) effective versus toxic concentration and dose (therapeutic range); and (3) therapeutic drug monitoring practices. We defined therapeutic index as the ratio of the minimum toxic concentration to the minimum effective concentration.
RESULTS
We reviewed a total of 810 full-text articles and extracted data from 163. The literature suggests that the therapeutic index of phenytoin is 2. The therapeutic indices of phenobarbital and valproate exceed 2. There were insufficient data to precisely quantify the therapeutic indices of carbamazepine and lamotrigine.
CONCLUSIONS
For some drugs, this approach offers a low-cost method of therapeutic index estimation. Our results can serve as preliminary data for future trials and as guidance for US Food and Drug Administration decision making regarding narrow therapeutic index classification.
Topics: Anticonvulsants; Databases, Bibliographic; Drug Monitoring; Epilepsy; Humans; Treatment Outcome
PubMed: 27428884
DOI: 10.1097/WNF.0000000000000172 -
BMC Veterinary Research May 2016The safety profile of anti-epileptic drugs (AEDs) is an important consideration for the regulatory bodies, owners and prescribing clinicians. Information on their... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
The safety profile of anti-epileptic drugs (AEDs) is an important consideration for the regulatory bodies, owners and prescribing clinicians. Information on their adverse effects still remains limited. A systematic review including a meta-analytic approach was designed to evaluate existing evidence for the safety profile of AEDs in canine patients. Electronic searches of PubMed, CAB Direct and Google scholar were carried out without date or language restrictions. Conference proceedings were also searched. Peer-reviewed full-length studies reporting adverse effects of AEDs in epileptic and healthy non-epileptic dogs were included. Studies were allocated to three groups based on their design. Individual studies were evaluated based on the quality of evidence (study design, study group sizes, subject enrolment quality and overall risk of bias) and the outcome measures reported (proportion of specific adverse effects for each AED, prevalence and 95% confidence interval of the affected population in each study and comparative odds ratio of adverse effects for AEDs).
RESULTS
Ninety studies, including six conference proceedings, reporting clinical outcomes of AEDs' adverse effects were identified. Few studies were designed as blinded randomised controlled clinical trials. Many studies included low canine populations with unclear criteria of subject enrolment and short treatment periods. Direct comparisons suggested that imepitoin and levetiracetam might have a better safety profile than phenobarbital, whilst the latter might have a better safety profile than potassium bromide. However, none of these comparisons showed a statistically significant difference. Comparisons between other AEDs were not possible as a considerable amount of studies lacked power calculations or adequate data to allow further statistical analysis. Individual AED assessments indicated that levetiracetam might be one of the safest AEDs, followed by imepitoin and then phenobarbital and potassium bromide; these findings were all supported by a strong level of evidence. The safety profile in other AEDs was variable, but weak evidence was found to permit firm conclusions or to compare their safety to other AEDs.
CONCLUSIONS
This systematic review provides objective evaluation of the most commonly used AEDs' adverse effects. Adverse effects usually appeared mild in all AEDs and subsided once doses and/or serum levels were monitored or after the AED was withdrawn. Although phenobarbital might be less safe than imepitoin and levetiracetam, there was insufficient evidence to classify it as an AED with a high risk of major adverse effects. It is important for clinicians to evaluate both AEDs' effectiveness and safety on an individual basis before the selection of the appropriate monotherapy or adjunctive AED therapy.
Topics: Animals; Anticonvulsants; Dogs; Epilepsy; Outcome and Process Assessment, Health Care
PubMed: 27206489
DOI: 10.1186/s12917-016-0703-y -
The Cochrane Database of Systematic... May 2016Seizures are common following perinatal asphyxia and may exacerbate secondary neuronal injury. Barbiturate therapy has been used for infants with perinatal asphyxia in... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Seizures are common following perinatal asphyxia and may exacerbate secondary neuronal injury. Barbiturate therapy has been used for infants with perinatal asphyxia in order to prevent seizures. However, barbiturate therapy may adversely affect neurodevelopment leading to concern regarding aggressive use in neonates.
OBJECTIVES
To determine the effect of administering prophylactic barbiturate therapy on death or neurodevelopmental disability in term and late preterm infants following perinatal asphyxia.
SEARCH METHODS
We used the standard search strategy of the Cochrane Neonatal Review group to search the Cochrane Central Register of Controlled Trials (CENTRAL, 2015, Issue 11), MEDLINE via PubMed (1966 to 30 November 2015), EMBASE (1980 to 30 November 2015), and CINAHL (1982 to 30 November 2015). We also searched clinical trials databases, conference proceedings, and the reference lists of retrieved articles for randomized controlled trials (RCT) and quasi-RCTs.
SELECTION CRITERIA
We included all RCTs or quasi-RCTs of prophylactic barbiturate therapy in term and late preterm infants without clinical or electroencephalographic evidence of seizures compared to controls following perinatal asphyxia.
DATA COLLECTION AND ANALYSIS
Three review authors independently selected, assessed the quality of, and extracted data from the included studies. We assessed methodologic quality and validity of studies without consideration of the results. The review authors independently extracted data and performed meta-analyses using risk ratios (RR) and risk differences (RD) for dichotomous data and mean difference for continuous data with 95% confidence intervals (CI). For significant results, we calculated the number needed to treat for an additional beneficial outcome (NNTB) or for an additional harmful outcome (NNTH).
MAIN RESULTS
In this updated review, we identified nine RCTs of any barbiturate therapy in term and late preterm infants aged less than three days old with perinatal asphyxia without evidence of seizures. Eight of these studies compared prophylactic barbiturate therapy to conventional treatment (enrolling 439 infants) and one study compared barbiturate therapy to treatment with phenytoin (enrolling 17 infants). Prophylactic barbiturate therapy versus conventional treatment: one small trial reported a decreased risk of death or severe neurodevelopmental disability for barbiturate therapy (phenobarbital) versus conventional treatment (RR 0.33, 95% CI 0.14 to 0.78; RD -0.55, 95% CI -0.84 to -0.25; NNTB 2, 95% CI 1 to 4; 1 study, 31 infants) (very low quality evidence).Eight trials comparing prophylactic barbiturate therapy with conventional treatment following perinatal asphyxia demonstrated no significant impact on the risk of death (typical RR 0.88, 95% CI 0.55 to 1.42; typical RD -0.02, 95% CI -0.08 to 0.05; 8 trials, 429 infants) (low quality evidence) and the one small trial noted above reported a significant decrease in the risk of severe neurodevelopmental disability (RR 0.24, 95% CI 0.06 to 0.92; RD -0.43, 95% CI -0.73 to -0.13; NNTB 2, 95% CI 1 to 8; 1 study, 31 infants) (very low quality evidence).A meta-analysis of the six trials reporting on seizures in the neonatal period demonstrated a statistically significant reduction in seizures in the prophylactic barbiturate group versus conventional treatment (typical RR 0.62, 95% CI 0.48 to 0.81; typical RD -0.18, 95% CI -0.27 to -0.09; NNTB 5, 95% CI 4 to 11; 6 studies, 319 infants) (low quality evidence). There were similar results in subgroup analyses based on type of barbiturate and Sarnat score. Prophylactic barbiturate therapy versus other prophylactic anticonvulsant therapy: one study reported on prophylactic barbiturate versus prophylactic phenytoin. There was no significant difference in seizure activity in the neonatal period between the two study groups (RR 0.89, 95% CI 0.07 to 12.00; 1 trial, 17 infants).
AUTHORS' CONCLUSIONS
We found only low or very low quality evidence addressing the use of prophylactic barbiturates in infants with perinatal asphyxia. Although the administration of prophylactic barbiturate therapy to infants following perinatal asphyxia did reduce the risk of seizures, there was no reduction seen in mortality and there were few data addressing long-term outcomes. The administration of prophylactic barbiturate therapy for late preterm and term infants in the immediate period following perinatal asphyxia cannot be recommended for routine clinical practice. If used at all, barbiturates should be reserved for the treatment of seizures. The results of the current review support the use of prophylactic barbiturate therapy as a promising area of research. Future studies should be of sufficient size and duration to detect clinically important reductions in mortality and severe neurodevelopmental disability and should be conducted in the context of the current standard of care, including the use of therapeutic hypothermia.
Topics: Anticonvulsants; Asphyxia Neonatorum; Barbiturates; Humans; Infant; Infant, Newborn; Infant, Premature; Neurodevelopmental Disorders; Phenobarbital; Phenytoin; Randomized Controlled Trials as Topic; Seizures; Thiopental
PubMed: 27149645
DOI: 10.1002/14651858.CD001240.pub3 -
Carbamazepine versus phenobarbitone monotherapy for epilepsy: an individual participant data review.The Cochrane Database of Systematic... Jul 2015This is an updated version of the original Cochrane review published in Issue 1, 2003, of the Cochrane Database of Systematic Reviews.Epilepsy is a common neurological... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
This is an updated version of the original Cochrane review published in Issue 1, 2003, of the Cochrane Database of Systematic Reviews.Epilepsy is a common neurological condition in which abnormal electrical discharges from the brain cause recurrent unprovoked seizures. It is believed that with effective drug treatment, up to 70% of individuals with active epilepsy have the potential to become seizure-free and go into long-term remission shortly after starting drug therapy with a single antiepileptic drug (AED) in monotherapy.Worldwide, carbamazepine (CBZ) and phenobarbitone (PB) are commonly used broad-spectrum antiepileptic drugs, suitable for most epileptic seizure types. Carbamazepine is a current first-line treatment for partial onset seizures in the USA and Europe. Phenobarbitone is no longer considered a first-line treatment because of concerns over associated adverse events, particularly documented behavioural adverse events in children treated with the drug. However, PB is still commonly used in low- and middle-income countries because of its low cost. No consistent differences in efficacy have been found between CBZ and PB in individual trials; however, the confidence intervals generated by these studies are wide, and therefore, synthesising the data of the individual trials may show differences in efficacy.
OBJECTIVES
To review the time to withdrawal, remission, and first seizure of CBZ compared with PB when used as monotherapy in people with partial onset seizures (simple or complex partial and secondarily generalised) or generalised onset tonic-clonic seizures (with or without other generalised seizure types).
SEARCH METHODS
We searched the following databases up to September 2014: the Cochrane Epilepsy Group Specialized Register, the Cochrane Central Register of Controlled Trials (CENTRAL) in the Cochrane Library (2014, Issue 8), MEDLINE (from 1946), Scopus (from 1823), the US National Institutes of Health Ongoing Trials Register (www.clinicaltrials.gov), and the World Health Organization International Clinical Trials Registry platform (WHO ICTRP). We handsearched relevant journals and contacted pharmaceutical companies, original trial investigators, and experts in the field.
SELECTION CRITERIA
Randomised controlled trials in children or adults with partial onset seizures or generalised onset tonic-clonic seizures with a comparison of CBZ monotherapy versus PB monotherapy.
DATA COLLECTION AND ANALYSIS
This was an individual participant data (IPD) review. Our primary outcome was 'Time to withdrawal of allocated treatment', and our secondary outcomes were 'Time to 12-month remission', 'Time to 6-month remission', and 'Time to first seizure postrandomisation'. We used Cox proportional hazards regression models to obtain study-specific estimates of hazard ratios (HRs) with 95% confidence intervals (CIs), with the generic inverse variance method used to obtain the overall pooled HR and 95% CI.
MAIN RESULTS
Individual participant data were available for 836 participants out of 1455 eligible individuals from 6 out of 13 trials, 57% of the potential data. For remission outcomes, HR > 1 indicated an advantage for PB, and for first seizure and withdrawal outcomes, HR > 1 indicated an advantage for CBZ.The main overall results (pooled HR adjusted for seizure type, 95% CI) were HR 1.50 for time to withdrawal of allocated treatment (95% CI 1.15 to 1.95, P = 0.003); HR 0.93 for time to 12-month remission (95% CI 0.72 to 1.20, P = 0.57); HR 0.99 for time to 6-month remission (95% CI 0.80 to 1.23, P = 0.95); and HR 0.87 for time to first seizure (95% CI 0.72 to 1.06, P = 0.18). Results suggest an advantage for CBZ over PB in terms of time to treatment withdrawal and no statistically significant evidence between the drugs for the other outcomes. We found evidence of a statistically significant interaction between treatment effect and seizure type for time to first seizure recurrence (Chi² test for subgroup differences P = 0.03), where PB was favoured for partial onset seizures (HR 0.76, 95% CI 0.60 to 0.96, P = 0.02) and CBZ was favoured for generalised onset seizures (HR 1.23, 95% CI 0.88 to 1.77, P = 0.27). However, methodological quality of the included studies was variable, with 10 out of the 13 included studies (4 out of 6 studies contributing IPD) judged as high risk of bias for at least 1 methodological aspect, leading to variable individual study results and therefore heterogeneity in the analyses of this review. We conducted sensitivity analyses to examine the impact of poor methodological aspects where possible.
AUTHORS' CONCLUSIONS
Overall, we found evidence suggestive of an advantage for CBZ in terms of drug effectiveness compared with PB (retention of the drug in terms of seizure control and adverse events) and evidence of an association between treatment effect and seizure type for time to first seizure recurrence (PB favoured for partial seizures and CBZ favoured for generalised seizures). Given the varying quality of studies included in this review and the impact of poor methodological quality on individual study results (and therefore variability (heterogeneity) present in the analysis within this review), we recommend caution when interpreting the results of this review and do not recommend that the results of this review alone should be used in choosing between CBZ and PB. We recommend that future trials should be designed to the highest quality possible with considerations for allocation concealment and masking, choice of population, choice of outcomes and analysis, and presentation of results.
Topics: Adult; Anticonvulsants; Carbamazepine; Child; Epilepsies, Partial; Epilepsy, Generalized; Epilepsy, Tonic-Clonic; Humans; Phenobarbital; Randomized Controlled Trials as Topic
PubMed: 26204241
DOI: 10.1002/14651858.CD001904.pub2 -
PloS One 2015Intracerebral hemorrhage (ICH) is a subtype of stroke associated with high morbidity and mortality rates. No proven treatments are available for this condition.... (Review)
Review
Intracerebral hemorrhage (ICH) is a subtype of stroke associated with high morbidity and mortality rates. No proven treatments are available for this condition. Iron-mediated free radical injury is associated with secondary damage following ICH. Deferoxamine (DFX), a ferric-iron chelator, is a candidate drug for the treatment of ICH. We performed a systematic review of studies involving the administration of DFX following ICH. In total, 20 studies were identified that described the efficacy of DFX in animal models of ICH and assessed changes in the brain water content, neurobehavioral score, or both. DFX reduced the brain water content by 85.7% in animal models of ICH (-0.86, 95% CI: -.48- -0.23; P < 0.01; 23 comparisons), and improved the neurobehavioral score by -1.08 (95% CI: -1.23- -0.92; P < 0.01; 62 comparisons). DFX was most efficacious when administered 2-4 h after ICH at a dose of 10-50 mg/kg depending on species, and this beneficial effect remained for up to 24 h postinjury. The efficacy was higher with phenobarbital anesthesia, intramuscular injection, and lysed erythrocyte infusion, and in Fischer 344 rats or aged animals. Overall, although DFX was found to be effective in experimental ICH, additional confirmation is needed due to possible publication bias, poor study quality, and the limited number of studies conducting clinical trials.
Topics: Animals; Cerebral Hemorrhage; Deferoxamine; Disease Models, Animal; Mice; Rats; Siderophores; Swine; Treatment Outcome
PubMed: 26000830
DOI: 10.1371/journal.pone.0127256