Immediate-release versus controlled-release carbamazepine in the treatment of epilepsy

3D printing of bioactive materials for drug delivery applications

INTRODUCTION

Three-dimensional (3D) printing, also known as additive manufacturing (AM), is a modern technique/technology, which makes it possible to construct 3D objects from computer-aided design (CAD) digital models. This technology can be used in the progress of drug delivery systems, where porosity has played important role in attaining an acceptable level of biocompatibility and biodegradability with improved therapeutic effects. 3D printing may also provide the user possibility to control the dosage of each ingredient in order to a specific purpose, and makes it probable to improve the formulation of drug delivery systems.

AREAS COVERED

This article covers the 3D printing technologies, bioactive materials including natural and synthetic polymers as well as some ceramics and minerals and their roles in drug delivery systems.

EXPERT OPINION

This technology is feasible to fabricate drug products by incorporating multiple drugs in different parts in such a mode that these drugs can release from the section at a predetermined rate. Furthermore, this 3D printing technology has the possible to transform personalized therapy to various age-groups by design flexibility and precise dosing. In recent years, the potential use of this technology can be realized in a clinical situation where patients will acquire individualized medicine as per their require.

Immediate-release versus controlled-release carbamazepine in the treatment of epilepsy

BACKGROUND

Carbamazepine (CBZ) is a commonly used drug for epilepsy that is associated with troublesome adverse events including dizziness, double vision, drowsiness, poor co-ordination and unsteadiness. These adverse events often occur during peaks in drug plasma concentration. These adverse events may limit the daily dose of CBZ that can be tolerated and reduce the chances of seizure control in patients who require high doses. A controlled-release formulation of CBZ delivers the same dose over a longer period of time when compared to a standard immediate-release formulation, thereby reducing post-dose peaks in CBZ plasma concentration and potentially reducing adverse events.This is an updated version of the original Cochrane review published in Issue 12, 2014.

OBJECTIVES

To determine the efficacy of immediate-release CBZ (IR CBZ) versus controlled-release CBZ (CR CBZ) in patients diagnosed with epilepsy.The following review questions were investigated.(1) For newly diagnosed patients commencing CBZ, how do IR and CR formulations compare for efficacy and tolerability?(2) For patients on established treatment with IR CBZ but experiencing unacceptable adverse events, what is the effect on seizure control and the tolerability of a switch to a CR formulation versus remaining on the IR formulation?

SEARCH METHODS

We searched the Cochrane Epilepsy Group Specialized Register, CENTRAL, and MEDLINE (Ovid) from inception to 30 August 2016.

SELECTION CRITERIA

Randomised controlled trials comparing IR CBZ to CR CBZ in patients commencing monotherapy and patients presently treated with IR CBZ but experiencing unacceptable adverse events.Primary outcome measures included measures of seizure frequency, incidence of adverse events, proportion of patients with treatment failure and quality of life measures.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trials for inclusion, extracted the data and recorded relevant information on a standardised data extraction form. We used the Cochrane risk of bias tool to assess the methodological quality of included studies.The heterogeneity of the included trials with respect to the reporting of outcomes resulted in only a narrative, descriptive analysis being possible for both the categorical and time-to-event data.

MAIN RESULTS

Ten trials (296 participants) fulfilled the criteria for inclusion in this review. Only one study had a low risk of bias. Two studies had a high risk of bias and the rest of the studies were rated as unclear risk of bias. One trial included patients with newly diagnosed epilepsy and nine included patients on treatment with IR CBZ.Eight trials reported heterogeneous measures of seizure frequency with conflicting results. A statistically significant difference was observed in only one trial, with patients prescribed CR CBZ experiencing fewer seizures than patients prescribed IR CBZ.Nine trials reported measures of adverse events. There was a trend in favour of CR CBZ with four trials reporting a statistically significant reduction in adverse events compared to IR CBZ. A further two trials reported fewer adverse events with CR CBZ but the reduction was not statistically significant. One trial found no difference in adverse events, and another trial reported more adverse events in the CR CBZ group than the IR CBZ group, although the increase was not statistically significant.

AUTHORS' CONCLUSIONS

For this update no new eligible studies were identified and the conclusions drawn from the initial review remain unchanged.At present, data from trials do not confirm or refute an advantage for CR CBZ over IR CBZ for seizure frequency or adverse events in patients with newly diagnosed epilepsy.For trials involving epilepsy patients already prescribed IR CBZ, no conclusions can be drawn concerning the superiority of CR CBZ with respect to seizure frequency.There is a trend for CR CBZ to be associated with fewer adverse events when compared to IR CBZ. A change to CR CBZ may therefore be a worthwhile strategy in patients with acceptable seizure control on IR CBZ but experiencing unacceptable adverse events. The included trials were of small size and of poor methodological quality limiting the validity of this conclusion.Randomised controlled trials comparing CR CBZ to IR CBZ and using clinically relevant outcomes are required to inform the choice of CBZ preparation for patients with newly diagnosed epilepsy.

Immediate-release versus controlled-release carbamazepine in the treatment of epilepsy

BACKGROUND

Epilepsy is defined as the tendency to spontaneous, excessive neuronal discharge manifesting as seizures. It is a common disorder with an incidence of 50 per 100,000 per year and a prevalence of 0.5% to 1% in the developed world (Hauser 1993).Carbamazepine (CBZ) is a widely used antiepileptic drug that is associated with a number of troublesome adverse events including dizziness, double vision and unsteadiness. These often occur during peaks in drug plasma concentration. The occurrence of such adverse events may limit the daily dose that can be tolerated and reduce the chances of seizure control for patients requiring higher doses (Vojvodic 2002). A controlled-release formulation of carbamazepine delivers the same dose over a longer period of time when compared to a standard formulation, thereby reducing post-dose peaks and potentially reducing adverse events associated with peak plasma levels.

OBJECTIVES

To determine the efficacy of immediate-release CBZ (IR CBZ) versus controlled-release CBZ (CR CBZ) in patients diagnosed with epilepsy.The following review questions were investigated.(1) For newly diagnosed patients commencing CBZ, how do IR and CR formulations compare for efficacy and tolerability?(2) For patients on established treatment with IR CBZ but experiencing unacceptable adverse events, what is the effect on seizure control and the tolerability of a switch to a CR formulation versus remaining on the IR formulation?

SEARCH METHODS

We searched the Cochrane Epilepsy Group Specialized Register (10 November 2014), Cochrane Central Register of Controlled Trials (CENTRAL) via the Cochrane Register of Studies Online (CRSO) 11 November 2014, and MEDLINE (Ovid, 1946 to 11 November 2014).

SELECTION CRITERIA

Randomised controlled trials comparing IR CBZ to CR CBZ in patients commencing monotherapy and patients presently treated with IR CBZ but experiencing unacceptable adverse events.Primary outcome measures include seizure frequency, incidence of adverse events, proportion of patients with treatment failure and quality of life measures.

DATA COLLECTION AND ANALYSIS

The methodological quality of each study was assessed with respect to study design, type of control, method and concealment of allocation, blinding and completeness of follow up, and the presence of blinding for assessment of non-fatal outcomes. We did not make use of an overall quality score.Two review authors (GP, MS) independently extracted the data and recorded relevant information on a standardised data extraction form. The trials were assessed for inclusion.The heterogeneity of the included trials resulted in only a narrative, descriptive analysis being possible for both the categorical and time-to-event data.

MAIN RESULTS

Ten trials fulfilled the criteria for inclusion in this review. One trial included patients with newly diagnosed epilepsy and nine included patients on treatment with IR CBZ.Eight trials reported heterogeneous measures of seizure frequency with conflicting results. A statistically significant difference was observed in only one trial, with patients prescribed CR CBZ experiencing fewer seizures than patients prescribed IR CBZ.Nine trials reported measures of adverse events. There was a trend in favour of CR CBZ with four trials reporting a statistically significant reduction in adverse events compared to IR CBZ. A further two trials reported fewer adverse events with CR CBZ but the reduction was not statistically significant. One trial found no difference, with a further trial reporting increased adverse events in the CR CBZ group although the increase was not statistically significant.

AUTHORS' CONCLUSIONS

At present, data from trials do not confirm or refute an advantage for CR CBZ over IR CBZ for seizure frequency or adverse events in patients with newly diagnosed epilepsy.For trials involving epilepsy patients already prescribed IR CBZ, no conclusions can be drawn concerning the superiority of CR CBZ with respect to seizure frequency.There is a trend for CR CBZ to be associated with fewer adverse events when compared to IR CBZ. A change to CR CBZ may therefore be a worthwhile strategy in patients with acceptable seizure control on IR CBZ but experiencing unacceptable adverse events. The included trials were of small size, had poor methodological quality and possessed a high risk of bias, limiting the validity of this conclusion.Randomised controlled trials comparing CR CBZ to IR CBZ and using clinically relevant outcomes are required to inform the choice of CBZ preparation for patients with newly diagnosed epilepsy.

Immediate-release versus controlled-release carbamazepine in the treatment of epilepsy

BACKGROUND

Epilepsy is defined as the tendency to spontaneous, excessive neuronal discharge manifesting as seizures. It is a common disorder with an incidence of 50 per 100,000 per year and a prevalence of 0.5% to 1% (Hauser 1993) in the developed world.Carbamazepine (CBZ) is a widely used antiepileptic drug that is associated with a number of troublesome adverse events including dizziness, double vision and unsteadiness. These often occur during peaks in plasma concentration. The occurrence of such adverse events may limit the daily dose that can be tolerated and reduce the chances of seizure control for patients requiring higher doses (Vojvodic 2002). A controlled-release formulation of carbamazepine delivers the same dose over a longer period of time when compared to a standard formulation, thereby reducing post-dose peaks and potentially reducing adverse events associated with peak plasma levels.

OBJECTIVES

To determine the efficacy of immediate-release CBZ (IR CBZ) versus controlled-release CBZ (CR CBZ) in patients diagnosed with epilepsy. The following hypotheses were tested.(1) For newly diagnosed patients commencing CBZ, how do immediate-release and controlled-release formulations compare for efficacy and tolerability?(2) For patients on established treatment with immediate-release CBZ but experiencing unacceptable adverse events, what is the effect on seizure control and tolerability of a switch to a controlled-release formulation versus remaining on the immediate-release formulation?

SEARCH METHODS

We searched the Cochrane Epilepsy Group Specialised Register (5 September 2013), Cochrane Central Register of Controlled Trials (CENTRAL) (Issue 8, 2013) in The Cochrane Library and MEDLINE (1946 to 5 September 2013).

SELECTION CRITERIA

Randomised controlled trials comparing IR CBZ to CR CBZ in patients commencing monotherapy and patients presently treated with IR CBZ but experiencing unacceptable adverse events.Primary outcome measures include seizure frequency, incidence of adverse events, proportion with treatment failure and quality of life measures.

DATA COLLECTION AND ANALYSIS

The methodological quality of each study was assessed with respect to study design, type of control, method and the concealment of allocation, blinding and completeness of follow up, and the presence of blinding for assessment of non-fatal outcomes. We did not make use of an overall quality score.Two review authors (GP, MS) independently extracted the data and recorded relevant information on a standardised data extraction form. Results were assessed for inclusion.The heterogeneity of the included trials resulted in only a narrative, descriptive analysis being possible for both the categorical and time-to-event data.

MAIN RESULTS

Ten trials fulfilled the criteria for inclusion in this review. One trial included patients with newly diagnosed epilepsy and nine included patients on treatment with IR CBZ.Eight trials reported heterogeneous measures of seizure frequency with conflicting results. A statistically significant difference was observed in only one trial, with patients prescribed CR CBZ experiencing fewer seizures than patients prescribed IR CBZ.Nine trials reported measures of adverse events. There was a trend in favour of CR CBZ with four trials reporting a statistically significant reduction in adverse events compared to IR CBZ. A further two trials reported fewer adverse events with CR CBZ but the reduction was not statistically significant. One trial found no difference, with a further trial reporting increased adverse events in the CR CBZ group although not statistically significant.

AUTHORS' CONCLUSIONS

At present, data from trials do not confirm or refute an advantage for CR CBZ over IR CBZ for seizure frequency or adverse events in patients with newly diagnosed epilepsy.For trials involving epilepsy patients already prescribed IR CBZ, no conclusions can be drawn concerning the superiority of CR CBZ with respect to seizure frequency.There is a trend for CR CBZ to be associated with fewer adverse events when compared to IR CBZ. A change to CR CBZ may therefore be a worthwhile strategy in patients with acceptable seizure control on IR CBZ but experiencing unacceptable adverse events. The included trials were of small size, poor methodological quality and possessed a high risk of bias, limiting the validity of this conclusion.Randomised controlled trials comparing CR CBZ to IR CBZ and using clinically relevant outcomes are required to inform the choice of CBZ preparation for patients with newly diagnosed epilepsy.