Antiepileptic drugs for the treatment of post-traumatic stress disorder

Molecular Descriptors and QSAR Models for Sedative Activity of Sesquiterpenes Administered to Mice via Inhalation

Essential oils are often utilized for therapeutic purposes and are composed of complex structural molecules, including sesquiterpenes, with high molecular weight and potential for stereochemistry. A detailed study on the properties of selected sesquiterpenes was conducted as part of a broader investigation on the effects of sesquiterpenes on the central nervous system. A set of 18 sesquiterpenes, rigorously selected from an original list of 114, was divided into 2 groups i.e., the training and test sets, with each containing 9 compounds. The training set was evaluated for the sedative activity in mice through inhalation, and all compounds were sedatives at any dose in the range of 4 × 10-4-4 × 10-2 mg/cage, except for curzerene. Molecular determinants of the sedative activities of sesquiterpenes were evaluated using quantitative structure-activity relationship (QSAR) and structure-activity relationship (SAR) analyses. An additional test set of six compounds obtained from the literature was utilized for validating the QSAR model. The parental carbonyl cation and an oxygen-containing groups are possible determinants of sedative activity. The QSAR study using multiple regression models could reasonably predict the sedative activity of sesquiterpenes with statistical parameters such as the correlation coefficient r2 = 0.82 > 0.6 and q2 LOO = 0.71 > 0.5 obtained using the leave-one-out cross-validation technique. Molar refractivity and the number of hydrogen bond acceptors were statistically important in predicting the activities. The present study could help predict the sedative activity of additional sesquiterpenes, thus accelerating the process of drug development.

Update on neurobiological mechanisms of fear: illuminating the direction of mechanism exploration and treatment development of trauma and fear-related disorders

Fear refers to an adaptive response in the face of danger, and the formed fear memory acts as a warning when the individual faces a dangerous situation again, which is of great significance to the survival of humans and animals. Excessive fear response caused by abnormal fear memory can lead to neuropsychiatric disorders. Fear memory has been studied for a long time, which is of a certain guiding effect on the treatment of fear-related disorders. With continuous technological innovations, the study of fear has gradually shifted from the level of brain regions to deeper neural (micro) circuits between brain regions and even within single brain regions, as well as molecular mechanisms. This article briefly outlines the basic knowledge of fear memory and reviews the neurobiological mechanisms of fear extinction and relapse, which aims to provide new insights for future basic research on fear emotions and new ideas for treating trauma and fear-related disorders.

Pharmacological strategies for post-traumatic stress disorder (PTSD): From animal to clinical studies

Post-traumatic stress disorder (PTSD) is a disabling psychiatric condition with a critical familiar, personal, and social impact. Patients diagnosed with PTSD show various symptoms, including anxiety, depression, psychotic episodes, and sleep disturbances, complicating their therapeutic management. Only sertraline and paroxetine, two selective serotonin reuptake inhibitors, are approved by different international agencies to treat PTSD. In addition, these drugs are generally combined with psychotherapy to achieve positive results. However, these pharmacological strategies present limited efficacy. Nearly half of the PTSD patients do not experience remission of symptoms, possibly due to the high prevalence of psychiatric comorbidities. Therefore, in clinical practice, other off-label medications are common, even though the effectiveness of these drugs needs to be further investigated. In this line, antipsychotics, antiepileptics, adrenergic blockers, benzodiazepines, and other emerging pharmacological agents have aroused interest as potential therapeutic tools to improve some specific symptoms of PTSD. Thus, this review is focused on the most widely used drugs for the pharmacological treatment of PTSD with a translational approach, including clinical and preclinical studies, to emphasize the need to develop safer and more effective medications.

Topiramate-induced ocular side effects in Egyptian patients, idiosyncratic versus dose-dependent effect, a prospective study

Background

To test the nature of the ocular side effects induced by topiramate (TPM) whether dose dependent or idiosyncratic, and to test various predictors that might influence the occurrence of those side effects.

Methods

Twenty patients treated with TPM were included in this study. Patients underwent ophthalmic assessment before and after 4 weeks of treatment by stable doses of oral TPM. We examined non-cycloplegic refraction (RF) in diopters, best corrected visual acuity (BCVA), intraocular pressure (IOP) in mmHg, and anterior chamber depth (ACD) in mm.

Results

There were no statistically significant differences between baseline and follow-up assessments in all tested ophthalmological parameters including errors of RF, ACD, IOP, and the BCVA. One case suffered from painful drop of vision in both eyes with elevated IOP and decreased ACD, and evident myopic shift 1 week after treatment with small dose of TPM. There was no significant effect of age, TPM dose, disease, and gender on all tested variables.

Conclusion

TPM can induce idiosyncratic, but not dose dependent, ocular side effects, namely myopic shifts and angle closure glaucoma. Those side effects were not disease, age, or gender dependent. However, ethnicity might play a role in induction of those side effects.

Voltage gated sodium channel inhibitors as anticonvulsant drugs: A systematic review on recent developments and structure activity relationship studies

Voltage-gated sodium channel blockers are one of the vital targets for the management of several central nervous system diseases, including epilepsy, chronic pain, psychiatric disorders, and spasticity. The voltage-gated sodium channels play a key role in controlling cellular excitability. This reduction in excitotoxicity is also applied to improve the symptoms of epileptic conditions. The effectiveness of antiepileptic drugs as sodium channel depends upon the reversible blocking of the spontaneous discharge without blocking its propagation. There are number of antiepileptic drug(s) which are in pipeline to flour the market to conquer abnormal neuronal excitability. They inhibit the seizures through the inhibition of complex voltage- and frequency-dependent ionic currents through sodium channels. Over the past decade, the sodium channel is one of the most explored targets to control or treat the seizure, but there has not been any game-changing discovery yet. Although there are large numbers of drugs approved for the treatment of epilepsy, however they are associated with several acute to chronic side effects. Many research groups have tirelessly worked for better therapeutic medication on this popular target to treat epileptic seizures. The review quotes briefly the developments of the approved examples of sodium channel blockers as anticonvulsant drugs. Medicinal chemists have tried the design and development of some more potent anticonvulsant drugs to minimize the toxicity that are discussed here, and an emphasis is given for their possible mechanism and the structure-activity relationship (SAR).

Advances in the pharmacotherapeutic management of post-traumatic stress disorder

Introduction: Post-traumatic stress disorder (PTSD), a mental disorder, is associated with anxiety, depression, and social awkwardness resulting from past traumatic episodes like natural disasters, accidents, terrorist attacks, war, rape, and sexual violence. It affects primarily the amygdala, cortex, and hippocampus where neurochemical changes result in altered behavior. PTSD patients display impaired fear extinction, and past events keep haunting them. The topic presents relevant sections like PTSD pharmacotherapy, associated challenges, and the novel targets and drugs for future research and therapy.Areas covered: The authors discuss the current pharmacotherapy like SSRIs, NDRIs, SNRIs, anticonvulsants, antidepressants, and benzodiazepines, used to attenuate the associated symptoms. However, the primary focus being the novel and potential targets which can be explored better to understand possible future research and advanced therapy in PTSD. For the same, an account of both preclinical and clinical studies has been covered.Expert opinion: Excessive adverse effects, limited efficacy, and lower patient compliance are some of the major challenges with conventional drugs. Moreover, they correct only fewer symptoms without halting the disease progression. Several agents are investigated in different preclinical and clinical phases, which can potentially overcome the pitfalls and limitations associated with conventional therapies.

Zonisamide as an Adjunctive Treatment to Cognitive Processing Therapy for Veterans With Posttraumatic Stress Disorder and Comorbid Alcohol Use Disorder: A Pilot Study

BACKGROUND AND OBJECTIVES

There are high rates of comorbid alcohol use disorder (AUD) among those who have posttraumatic stress disorder (PTSD). Ideally, treatment for comorbidity should address both disorders simultaneously. Zonisamide, an anticonvulsant, may be effective in decreasing alcohol use and may attenuate symptoms of PTSD. Treatment strategies can include medication in combination with a proven evidence-based psychotherapy designed to treat PTSD, such as cognitive processing therapy (CPT).

METHODS

This 12-week pilot study was designed to test feasibility, acceptability, and preliminary efficacy of zonisamide (400 mg) as an adjunct to CPT for veterans with PTSD and comorbid AUD. Veterans (n = 24) with PTSD and current alcohol dependence were randomized in a 3:1 ratio to receive zonisamide or placebo in a double-blind fashion. All subjects received CPT enhanced to include sessions addressing drinking behavior.

RESULTS

Subjects overall reported a significant decrease in drinking outcomes, craving, and symptoms of PTSD. Zonisamide was well-tolerated and easily administered with CPT, which was also well-tolerated. Exploratory analysis of comparison of groups suggests there was no advantage of zonisamide vs placebo in drinking or PTSD outcomes. There was a numeric but nonsignificant higher rate of abstinence with zonisamide (50%) vs placebo (33%).

CONCLUSION AND SCIENTIFIC SIGNIFICANCE

The interpretation of the results is limited by the pilot nature of this study. The combination of psychosocial treatment with medication management mimics real-world treatment. In order to isolate the individual contributions of medication vs psychotherapy a much larger study would need to be conducted. (Am J Addict 2020;29:515-524).

Topiramate as Monotherapy or Adjunctive Treatment for Posttraumatic Stress Disorder: A Meta-Analysis

Posttraumatic stress disorder (PTSD) is a chronic and debilitating condition for which clinicians sometimes turn to anticonvulsants as a treatment for symptoms. This study was a systematic review and meta-analysis of randomized controlled trials (RCT) that have assessed the efficacy of topiramate as monotherapy or adjunctive therapy, compared to placebo, for the treatment of PTSD in adults. Prescribers may be reluctant to turn to topiramate, given the commonly reported side effects of impaired cognition, sedation, fatigue, and headache. We searched PubMed, PsycInfo, and Cochrane Central databases for relevant trials. Five studies were identified as RCTs and thus met inclusion criteria; one additional nonpublished study was identified via phone contact with its authors. Of these six studies, one was excluded from the statistical meta-analysis due to its high dropout rate (16 of 40 participants). One of these studies was excluded from a stratified analysis of symptom types because this subscale data were unavailable.  For overall symptomatology, topiramate showed a medium, but not significant effect, standardized mean difference (SMD) = 0.55, p = .082. Topiramate showed a small and significant reduction of hyperarousal symptoms, SMD = 0.35, 95% CI [0.029, 0.689], p = .033. Topiramate did not significantly reduce reexperiencing symptoms, SMD = 0.29, 95% CI [-0.019, 0.597], p = .067, or avoidance symptoms, SMD = 0.20, 95% CI [-0.105, 0.509], p = .198. Results did not differ significantly between veteran and nonveteran subjects, or between topiramate as monotherapy and adjunctive therapy. Further studies on topiramate will clarify its role in PTSD treatment.

Novel pharmacological treatment strategies for posttraumatic stress disorder

INTRODUCTION

A wide range of medications have been studied for posttraumatic stress disorder (PTSD) and a number are registered for this indication. Nevertheless, current pharmacotherapies are only partially effective in some patients, and are minimally effective in others. Thus novel treatment avenues need to be explored. Areas covered: In considering novel pharmacological agents for the treatment of PTSD, this paper takes a translational approach. We outline how advances in our understanding of the underlying neurobiology of PTSD may inform the identification of potential new treatment targets, including glutamatergic, noradrenergic and opioid pathways. Expert commentary: Continued investigation of the neural substrates and signalling pathways involved in responses to trauma may inform the development of novel treatment targets for future drug development for PTSD. However, the translation of preclinical findings to clinical practice is likely to be complex and gradual.

Comparing Gabapentin with Clonazepam for Residual Sleeping Problems following Antidepressant Therapy in Patients with Major Depressive Disorder: A Randomized Clinical Trial

BACKGROUND AND OBJECTIVE

Residual sleeping disturbances after improvement of depression in major depressed patients are associated with more functional problems, increased relapses and more risk of becoming resistant to treatment. The aim of this study was to compare the efficacy of gabapentin with clonazepam for treating residual sleeping disturbances.

METHODS

This comparative trial was designed as a randomized, controlled, double-blind study. Sixty-three patients with a DSM-IV diagnosis of major depressive disorder (MDD) who had been treated with one of the selective serotonin reuptake inhibitors (SSRIs; fluoxetine, citalopram or sertraline) were included in the study. The patients' depression had improved [Hamilton Depression Rating Scale (HDRS) <10] but they were complaining of sleeping problems [Pittsburgh Sleep Quality Index (PSQI) >5; Insomnia Severity Index (ISI) >8]. Patients were randomized to receive a flexible dose of gabapentin (100-600 mg/day) or clonazepam (0.5-2 mg/day) beside their current antidepressant medication for a period of 4 weeks. Outcome measures were PSQI, ISI and Clinical Global Impression (CGI).

RESULTS

Our results demonstrated that similar to the clonazepam group, sleeping problems improved significantly in the gabapentin group at the end of the trial (PSQI: P = 0.001, Z = 3.549; ISI: P = 0.001, Z = 3.347). The two groups did not show a significant difference in treating residual sleep disturbances (PSQI: P = 0.234, Z = 1.432; ISI: P = 0.456, Z = 1.347).

CONCLUSION

This study revealed that gabapentin is comparable to clonazepam for treating sleeping problems associated with major depression.

Lamotrigine abolished aggression in a patient with treatment-resistant posttraumatic stress disorder

Lamotrigine is an antiepileptic drug with broad spectrum of actions, also approved for the treatment of bipolar disorder. Growing number of reports document the antiaggressive effect of lamotrigine in various psychiatric diseases. However, there has been only 1 study in the literature investigating the role of lamotrigine in posttraumatic stress disorder (PTSD), but its antiaggressive aspect was not observed. Although aggression is commonly associated with PTSD, there is paucity of data considering its management. We report a case of a patient with treatment-resistant PTSD, whose aggressive outbursts dominated his clinical picture and which were greatly improved after introducing lamotrigine in therapy. Our case suggests that lamotrigine may be useful in treating aggression and aggression-related symptoms in PTSD.

Baclofen add-on to citalopram in treatment of posttraumatic stress disorder

OBJECTIVE

Posttraumatic stress disorder (PTSD) is a chronic disabling illness, resulting from exposure to extreme traumatic event. Although different pharmacologic agents are suggested for treatment of PTSD, none have been completely effective in eliminating symptoms. The purpose of this study was to assess the use of baclofen as an add-on to citalopram in treatment of PTSD.

METHODS

In this double-blind clinical trial, 40 Iranian combat veterans with PTSD were randomly assigned to 2 groups. The first group received a combination treatment of 20 to 60 mg/d citalopram and 40 mg/d baclofen, and the second group received 20 to 60 mg/d citalopram plus placebo. Symptom severity was assessed by Clinician-Administered PTSD Scale at the beginning of the study and after 2, 4, 6, and 8 weeks. Global Assessment of Functioning and Hamilton Rating Scale for Anxiety and Depression were also used at the same periods. Data were analyzed with independent t test and paired t test using SPSS software version 13 (IBM, Armonk, NY).

RESULTS

Twenty-three male patients (baclofen group, 13 patients; placebo group, 10 patients) completed the study. Dropout from the treatment was not caused by adverse effects of the new medications in any of the subjects. Baclofen group showed significantly larger improvement in Clinician-Administered PTSD Scale total (P = 0.040), hyperarousal (P = 0.020), and avoidance (0.020) scores, Global Assessment of Functioning score (0.001), depression (P = 0.000), and anxiety (P = 0.000) after 8 weeks of treatment. No intergroup difference was found in improvement of reexperience symptoms (P = 0.740).

CONCLUSIONS

Baclofen showed to be an effective add-on to selective serotonin reuptake inhibitors in treatment of PTSD for better symptom recovery and functional improvement.

Naltrexone: Posttraumatic Stress Disorder

This Hospital Pharmacy feature is extracted from Off-Label Drug Facts, a quarterly publication available from Wolters Kluwer Health. Off-Label Drug Facts is a practitioner-oriented resource for information about specific drug uses that are unapproved by the US Food and Drug Administration. This new guide to the literature enables the health care professional or clinician to quickly identify published studies on off-label uses and determine if a specific use is rational in a patient care scenario. References direct the reader to the full literature for more comprehensive information before patient care decisions are made. Direct questions or comments regarding Off-Label Drug Uses to jgeneral@kumc.edu .

Topiramate and the vision: a systematic review

BACKGROUND AND PURPOSE

Topiramate (TPM) is a sulfa-derivative monosaccharide that is used mainly for treating epilepsy and preventing migraine. Within the gamut of side effects attributable to this drug, ophthalmologic manifestations are of crucial importance. In this study, for the first time, the aim was to provide a systematic literature review regarding this issue.

METHODS

For the time period 1996-2011, a PubMed search was made for the studies concerning the adverse/beneficial effects of TPM on vision. Overall, 404 citations out of a total of 2756 TPM-related studies were examined for relevance.

RESULTS

A total of 74 relevant studies were reviewed, 65 of which comprise small observational studies describing the ophthalmic side effects of TPM in 84 patients. Of these patients, 66 were affected by ciliochoroidal effusion syndrome as the cardinal ocular side effect of TPM (17 cases of myopic shift and 49 cases of angle closure glaucoma). A comprehensive statistical analysis is provided on these 66 subjects. Other rare side effects of TPM on the vision were also reviewed, including massive choroidal effusion, ocular inflammatory reactions, visual field defects, probable effects on retina, cornea, and sclera, and neuroophthalmologic complications. In addition, a framework is provided to classify these results.

DISCUSSION

Due to the expanding spectrum of indications for the administration of TPM, neurologists and psychiatrists should be aware of its diverse ocular side effects. In conclusion, ocular complications following this drug should be taken seriously and be subjected to ophthalmic counseling.

The contextual fear conditioning deficit presented by spontaneously hypertensive rats (SHR) is not improved by mood stabilizers

OBJECTIVES

We have recently reported that spontaneously hypertensive rats (SHR) present a contextual fear conditioning (CFC) deficit. This deficit is improved by antipsychotic drugs, potentiated by proschizophrenia manipulations and not altered by acute administration of carbamazepine, lamotrigine and valproic acid. Nevertheless, the effects of lithium-a classical mood stabilizer-or repeated treatment with these drugs were not evaluated. The main aim of the present study was to extend our previous work by investigating a possible beneficial effect of acute and/or chronic treatments with lithium or lamotrigine on the acquisition deficit of CFC presented by SHR.

METHODS

Rats were submitted to CFC task after an acute treatment with lithium and/or a repeated treatment with lithium and lamotrigine.

RESULTS

Our data revealed that the CFC deficit presented by SHR is not improved by acute or repeated treatment with lithium. Repeated lamotrigine treatment potentiated the deficit presented by SHR and impaired CFC in control animals (Wistar Rats).

CONCLUSIONS

These data reinforce the absence of beneficial effects of mood stabilizers on the emotional context processing impairment modeled by SHR.

Pharmacological treatment of PTSD - established and new approaches

A large proportion of humans will experience a traumatic event at least once in their lifetime, with up to 10% then going on to developing posttraumatic stress disorder (PTSD). In this review we will discuss established pharmacological interventions for PTSD as well as highlight novel therapeutic strategies undergoing extensive pre-clinical research as well as ongoing clinical research. Such strategies include prophylactic treatments and use of pharmacotherapy as adjunctive treatment with established trauma-focused psychological therapies. These potential treatment approaches include modulation of stress effects on memory consolidation after trauma (e.g., glucocorticoid, corticotropin-releasing factor and norepinephrine signalling modulators), as well as putative cognitive enhancers that target mechanisms of conditioned fear extinction and reconsolidation (e.g., glucocorticoid receptor modulators and modulators of glutamate signalling such as positive allosteric modulators of glutamate receptors, glycine transporter inhibitors, or glycine agonists). We will discuss evidence for and against these potential novel treatment strategies and their limitations. This article is part of a Special Issue entitled 'Post-Traumatic Stress Disorder'.

New perspectives in glutamate and anxiety

Anxiety and stress-related disorders, namely posttraumatic stress disorder (PTSD), generalized anxiety disorder (GAD), obsessive-compulsive disorder (ODC), social and specific phobias, and panic disorder, are a major public health issue. A growing body of evidence suggests that glutamatergic neurotransmission may be involved in the biological mechanisms underlying stress response and anxiety-related disorders. The glutamatergic system mediates the acquisition and extinction of fear-conditioning. Thus, new drugs targeting glutamatergic neurotransmission may be promising candidates for new pharmacological treatments. In particular, N-methyl-d-aspartate receptors (NMDAR) antagonists (AP5, AP7, CGP37849, CGP39551, LY235959, NPC17742, and MK-801), NMDAR partial agonists (DCS, ACPC), α-amino-3-hydroxyl-5-methyl-4-isoxazole-propionate receptors (AMPARs) antagonists (topiramate), and several allosteric modulators targeting metabotropic glutamate receptors (mGluRs) mGluR1, mGluR2/3, and mGluR5, have shown anxiolytic-like effects in several animal and human studies. Several studies have suggested that polyamines (agmatine, putrescine, spermidine, and spermine) may be involved in the neurobiological mechanisms underlying stress-response and anxiety-related disorders. This could mainly be attributed to their ability to modulate ionotropic glutamate receptors, especially NR2B subunits. The aim of this review is to establish that glutamate neurotransmission and polyaminergic system play a fundamental role in the onset of anxiety-related disorders. This may open the way for new drugs that may help to treat these conditions.

Treatment of civilian and combat-related posttraumatic stress disorder with topiramate

OBJECTIVE

To evaluate the use of topiramate for the treatment of posttraumatic stress disorder (PTSD).

DATA SOURCES

Ovid MEDLINE (1950 to June week 4, 2010), International Pharmaceutical Abstracts (1970 to May 2010), ISI Web of Science (1945 to July 3, 2010), and Iowa Drug Information Service (searched July 6, 2010) were searched using the terms posttraumatic stress disorder and topiramate. Guidelines and other sources were identified from bibliography searches.

STUDY SELECTION AND DATA EXTRACTION

All English-language human studies and case reports that evaluated the use of topiramate for treatment of PTSD were evaluated.

DATA SYNTHESIS

One case report, 1 case series, 2 open-label trials, and 1 placebo-controlled trial that used topiramate (monotherapy or adjunct) to treat civilian PTSD were identified and evaluated. The case report and case series reported subjective reduction of symptoms, and the open-label trials reported a significant reduction in PTSD Checklist-Civilian score. The placebo-controlled trial found no significant difference in Clinician-Administered PTSD Scale (CAPS) score. One open-label trial and 2 placebo-controlled trials that used topiramate in combat-related PTSD were identified and evaluated. The open-label trial reported a significant reduction in CAPS score, and 1 placebo-controlled trial reported a statistically significant difference in CAPS score. However, the other placebo-controlled trial found no significant differences. In some of the trials evaluated, the clinical significance of outcomes reported is difficult to determine. Adverse effects were reported throughout the trials but generally were not considered serious.

CONCLUSIONS

Based on the limited evidence available, topiramate is a possible alternative or adjunct option for patients with PTSD that is refractory to standard treatments.

Post-traumatic stress disorder: present and future

Post-traumatic stress disorder (PTSD) and acute stress disorder (ASD) differ from almost every other psychiatric diagnosis in that they may only be diagnosed with reference to an aetiological event - an external traumatic stressor. ASD occurs immediately after the stressor and is comparatively short-lived, while PTSD is a prolonged abnormal response that may take months to develop. The types of stressor leading to ASD and PTSD are identical and were intended to be tightly defined, involving a perceived threat of death, serious injury or loss of physical integrity. It is useful initially to distinguish ASD and PTSD from adjustment disorders, which are also diagnosed only after an observable life event. An adjustment disorder may be thought of as a gradual and prolonged response to stressful changes in a person's life. The range of stressors precipitating an adjustment disorder is potentially much broader than that precipitating ASD or PTSD, as a threat of death or injury is not needed. Indeed, a 'threat' as such is not needed, as the event may be a loss. Events such as job loss or the breakup of a relationship may lead to an adjustment disorder, as well as threats such as accidents or assaults. The diagnostic criteria for adjustment disorder do not specify what the immediate response, if any, to the precipitating stressor must be.

The first example of a significant active site conformational rearrangement in a carbonic anhydrase-inhibitor adduct: the carbonic anhydrase I-topiramate complex

Topiramate is a widely used antiepileptic drug, which has been demonstrated to act as an efficient weight loss agent. Since several studies have pointed out that is a potent in vitro inhibitor of several Carbonic anhydrase (CA) isozymes, it has been hypothesized that its anti-obesity properties could be ascribed to the inhibition of the CAs involved in de novo lipogenesis. Consequently, the study of the interactions of with all human CA isoforms represents an important step for the rational drug design of selective CA inhibitors to be used as anti-obesity drugs. In this paper we report the crystallographic structure of the adduct that forms with hCA I, showing for the first time a profound reorganization of the CA active site upon binding of the inhibitor. Moreover, a structural comparison with hCA II- and hCA VA- adducts, previously investigated, has been performed showing that a different H-bond network together with the movement of some amino acid residues in the active site may account for the different inhibition constants of toward these three CA isozymes.

Effect of topiramate on acid-base balance: extent, mechanism and effects

Topiramate is licensed for the treatment of epilepsy and for migraine prophylaxis, but is also used off-licence for a wide range of indications. With the increasing use of topiramate, reports have emerged that topiramate can cause metabolic acidosis in some patients. It does this by impairing both the normal reabsorption of filtered HCO(3)(-) by the proximal renal tubule and the excretion of H(+) by the distal renal tubule. This combination of defects is termed mixed renal tubular acidosis (RTA). The mechanism involves the inhibition of the enzyme carbonic anhydrase, which is consistent with the fact that genetic deficiency of carbonic anhydrase is associated with mixed RTA. Topiramate-induced RTA can make patients acutely ill, and chronically, can lead to nephrolithiasis, osteoporosis and, in children, growth retardation. There is no proven method for predicting or preventing the effect of topiramate on acid-base balance, but patients with a history of renal calculi or known RTA should not receive topiramate. The utility of regular monitoring of HCO(3)(-) levels has not been proven and is not routine practice currently. For patients with persistent RTA, topiramate should usually be discontinued as alternative agents are available.

Topiramate in combat-related posttraumatic stress disorder

BACKGROUND

Posttraumatic stress disorder (PTSD) is a disabling psychiatric disorder that is common among combat veterans and may lead to very poor sleep and disturbing nightmares.

OBJECTIVE

To examine the safety and effectiveness of topiramate as add-on therapy for the management of combat-related PTSD and to examine the effects of topiramate on sleep and alcohol consumption.

METHODS

We conducted an 8-week open-label pilot study of topiramate for male combat veterans (N = 43) with PTSD, with analysis of veterans who completed the protocol. Psychometric, sleep, and alcohol consumption assessments were conducted at baseline and at week 8.

RESULTS

Twenty-nine subjects completed the 8-week study. Significant reductions in Clinician Administered PTSD Scale scores were observed at the 8-week endpoint (from 86.3 +/- 21.1 to 67.1 +/- 25.1; p < 0.01). Decreases were seen in both Stanford Sleepiness Scale scores (from 10.5 +/- 0.72 to 9.0 +/- 0.58; p = 0.08) and Mississippi PTSD scores (from 120.4 +/- 6.5 to 111.5 +/- 20.9; p = 0.08), but the extent of the changes did not attain statistical significance for either scale. There was a significant reduction in the proportion of patients with nightmares (from 100% to 62%; p < 0.001) and patients who experienced anxiety that interfered with falling asleep (from 90% to 62%; p < 0.05). The proportion of patients with high-risk drinking patterns also decreased (from 31% to 14%). Two serious adverse events were reported during the study: an increase in low back pain and an episode of acute confusion.

CONCLUSIONS

When used in addition to other empiric therapy, topiramate may be effective at reducing general symptoms of combat-related PTSD and reducing high-risk alcohol intake and nightmares. Further randomized controlled trials of topiramate for the treatment of combat-related PTSD are warranted.

Lamotrigine in Therapy of Patient with Posttraumatic Stress Disorder: Case Report

Patient N-V, with diagnose of PTSD according to DSM-IV-TR, was hospitalized in Vrapce Psychiatric Hospital, Zagreb, during 2008. At admission he reported tension, anxiety, irritability, need for isolation form other people, insomnia and nightmares. He said he was waking up almost every night because of nightmares.

In the beginning of hospital treatment lamotrigine was introduced in therapy, in daily dosage of 25 mg, along with diazepam 10 mg daily and zolpidem 10 mg in the evening. After three days the daily dosage of lamotrigine was elevated to 50 mg. No side effects of treatment were observed and the daily dosage of lamotrigine was elevated to 100 mg after six days and again on 200 mg after ten days of continuous therapy with lamotrigine. The patient reported improvement of sleep - he said he the nightmares were less frequent and he did not wake up as often as before. Also, during second week of treatment he became less tensed. After three weeks of treatment he became even more relaxed and less irritable. Also, he became more active and able to endure conversation. Initial insomnia was reduced, and he was waking up only occasionally during night. The patient was discharged from hospital after six weeks of treatment. Recommended therapy at discharge was lamotrigine in daily dosage of 200 mg, 10 mg of zolpidem in the evening, and diazepam 5 mg in case of tension.

Oxcarbazepine for Treatment of Posttraumatic Stress Disorder and Alcohol Dependence: A Case Series

Objective:

To report 2 cases that examine the use of oxcarbazepine as treatment for individuals with posttraumatic stress disorder (PTSD) and comorbid alcohol dependence.

Case Summaries:

A 59-year-old male with a past psychiatric history significant for PTSD and alcohol dependence underwent alcohol detoxification and was subsequently prescribed oxcarbazepine 300 mg twice daily, which was titrated to 600 mg twice daily prior to discharge. He experienced significant reduction in PTSD symptoms including anxiety, nightmares, flashbacks, racing thoughts, and avoidance behaviors. Over time, he also experienced a reduction in alcohol cravings and decreased daily alcohol intake. A 62-year-old male with a past psychiatric history of PTSD and alcohol dependence was treated in the outpatient clinic. He experienced almost complete resolution of PTSD symptoms and any craving for alcohol within 4 months of starting oxcarbazepine treatment, which was initiated at 150 mg twice daily and increased to 600 mg/day during that time.

Discussion:

Both patients appeared to receive excellent symptomatic relief from their PTSD symptoms. Recurring symptoms, including nightmares and flashbacks, seemed to be particularly responsive to the treatment. Additionally, in both cases, it is possible that oxcarbazepine had a secondary beneficial effect by decreasing alcohol cravings, although this was not formally measured.

Conclusions:

Our experience with these patients suggests that oxcarbazepine could be an effective treatment for the symptoms of PTSD and may decrease alcohol cravings and consumption in patients with co-occurring alcohol dependence. Controlled studies examining the effectiveness of oxcarbazepine for treatment of patients with PTSD, including those with complicating alcohol dependence, are warranted.