Second-line antituberculosis drug exposure thresholds predictive of adverse events in multidrug-resistant tuberculosis treatment

OBJECTIVES

This study aimed to investigate the association between drug exposure and adverse events (AEs) during the standardized multidrug-resistant tuberculosis (MDR-TB) treatment, as well as to identify predictive drug exposure thresholds.

METHODS

We conducted a prospective, observational multicenter study among participants receiving standardized MDR-TB treatment between 2016 and 2019 in China. AEs were monitored throughout the treatment and their relationships to drug exposure (e.g., the area under the drug concentration-time curve from 0 to 24 h, AUC0-24 h) were analyzed. The thresholds of pharmacokinetic predictors of observed AEs were identified by boosted classification and regression tree (CART) and further evaluated by external validation.

RESULTS

Of 197 study participants, 124 (62.9%) had at least one AE, and 15 (7.6%) experienced serious AEs. The association between drug exposure and AEs was observed including bedaquiline, its metabolite M2, moxifloxacin and QTcF prolongation (QTcF >450 ms), linezolid and mitochondrial toxicity, cycloserine and psychiatric AEs. The CART-derived thresholds of AUC0-24 h predictive of the respective AEs were 3.2 mg·h/l (bedaquiline M2); 49.3 mg·h/l (moxifloxacin); 119.3 mg·h/l (linezolid); 718.7 mg·h/l (cycloserine).

CONCLUSIONS

This study demonstrated the drug exposure thresholds predictive of AEs for key drugs against MDR-TB treatment. Using the derived thresholds will provide the knowledge base for further randomized clinical trials of dose adjustment to minimize the risk of AEs.

The effectiveness and adverse effects of D-cycloserine compared with placebo on social and communication skills in individuals with autism spectrum disorder

BACKGROUND

Symptoms of autism spectrum disorder (ASD) have been associated, in part, with the dysfunction of N-methyl-D-aspartate (NMDA) glutamate receptors at excitatory synapses and glutamate abnormalities. Medications related to glutamatergic neurotransmission, such as D-cycloserine - which is a partial agonist of the NMDA glutamate receptor - are potential treatment options for the core features of ASD. However, the potential effect of D-cycloserine on the social and communication skills deficits of individuals with ASD has not been thoroughly explored and no systematic reviews of the evidence have been conducted.

OBJECTIVES

To assess the efficacy and adverse effects of D-cycloserine compared with placebo for social and communication skills in individuals with ASD.

SEARCH METHODS

In November 2020, we searched CENTRAL, MEDLINE, Embase, six other databases and two trials registers. We also searched the reference lists of relevant publications and contacted the authors of the included study, Minshawi 2016, to identify any additional studies. In addition, we contacted pharmaceutical companies, searched manufacturers' websites and sources of reports of adverse events.  SELECTION CRITERIA: All randomised controlled trials (RCTs) of any duration and dose of D-cycloserine, with or without adjunct treatment, compared to placebo in individuals with ASD.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected studies for inclusion, extracted relevant data, assessed the risk of bias, graded the certainty of the evidence using the GRADE approach, and analysed and evaluated the data. We provide a narrative report of the findings as only one study is included in this review.

MAIN RESULTS

We included a single RCT (Minshawi 2016) funded by the United States Department of Defense. It was conducted at two sites in the USA: Indiana University School of Medicine and Cincinnati Children's Hospital Medical Centre. In the included study, 67 children with ASD aged between 5 and 11 years were randomised to receive either 10 weeks (10 doses) of (50 mg) D-cycloserine plus social skills training, or placebo plus social skills training. Randomisation was carried out 1:1 between D-cycloserine and placebo arms, and outcome measures were recorded at one-week post-treatment. The 'risk of bias' assessment for the included study was low for five domains and unclear for two domains. The study (67 participants) reported low certainty evidence of little to no difference between the two groups for all outcomes measured at one week post-treatment: social interaction impairment (mean difference (MD) 3.61 (assessed with the Social Responsiveness Scale), 95% confidence interval (CI) -5.60 to 12.82); social communication impairment (MD -1.08 (measured using the inappropriate speech subscale of the Aberrant Behavior Checklist (ABC)), 95% CI -2.34 to 0.18); restricted, repetitive, stereotyped patterns of behaviour (MD 0.12 (measured by the ABC stereotypy subscale), 95% CI -1.71 to 1.95); serious adverse events (risk ratio (RR) 1.11, 95% CI 0.94 to 1.31); non-core symptoms of ASD (RR 0.97 (measured by the Clinical Global Impression-Improvement scale), 95% CI 0.49 to 1.93); and tolerability of D-cycloserine (RR 0.32 (assessed by the number of dropouts), 95% CI 0.01 to 7.68).  AUTHORS' CONCLUSIONS: We are unable to conclude with certainty whether D-cycloserine is effective for individuals with ASD. This review included low certainty data from only one study with methodological issues and imprecision. The added value of this review compared to the included study is we assessed the risk of bias and evaluated the certainty of evidence using the GRADE approach. Moreover, if we find new trials in future updates of this review, we could potentially pool the data, which may either strengthen or decrease the evidence for our findings.

Effect of D-Cycloserine on the Effect of Concentrated Exposure and Response Prevention in Difficult-to-Treat Obsessive-Compulsive Disorder: A Randomized Clinical Trial

IMPORTANCE

Evidence is lacking for viable treatment options for patients with difficult-to-treat obsessive-compulsive disorder (OCD). It has been suggested that D-cycloserine (DCS) could potentiate the effect of exposure and response prevention (ERP) treatment, but the hypothesis has not been tested among patients with difficult-to-treat OCD.

OBJECTIVE

To evaluate whether DCS potentiates the effect of concentrated ERP among patients with difficult-to-treat OCD.

DESIGN, SETTING, AND PARTICIPANTS

The study was a randomized placebo-controlled triple-masked study with a 12-month follow-up. Participants were adult outpatients with difficult-to-treat OCD. A total of 220 potential participants were referred, of whom 36 did not meet inclusion criteria and 21 declined to participate. Patients had either relapsed after (n = 100) or not responded to (n = 63) previous ERP treatment. A total of 9 specialized OCD teams within the public health care system in Norway participated, giving national coverage. An expert team of therapists from the coordinating site delivered treatment. Inclusion of patients started in January 2016 and ended in August 2017. Data analysis was conducted February to September 2019.

INTERVENTIONS

All patients received individual, concentrated ERP treatment delivered during 4 consecutive days in a group setting (the Bergen 4-day treatment format) combined with 100 mg DCS, 250 mg DCS, or placebo.

MAIN OUTCOMES AND MEASURES

Change in symptoms of OCD and change in diagnostic status. Secondary outcomes measures included self-reported symptoms of OCD, anxiety, depression, and quality of life.

RESULTS

The total sample of 163 patients had a mean (SD) age of 34.5 (10.9) years, and most were women (117 [71.8%]). They had experienced OCD for a mean (SD) of 16.2 (10.2) years. A total of 65 patients (39.9%) were randomized to receive 100 mg DCS, 67 (41.1%) to 250 mg of DCS, and 31 (19.0%) to placebo. Overall, 91 (56.5%) achieved remission at posttreatment, while 70 (47.9%) did so at the 12-month follow-up. There was no significant difference in remission rates among groups. There was a significant reduction in symptoms at 12 months, and within-group effect sizes ranged from 3.01 (95% CI, 2.38-3.63) for the group receiving 250 mg DCS to 3.49 (95% CI, 2.78-4.18) for the group receiving 100 mg DCS (all P < .001). However, there was no significant effect of treatment group compared with placebo in obsessive-compulsive symptoms (250 mg group at posttreatment: d = 0.33; 95% CI, -0.10 to 0.76; 100 mg group at posttreatment: d = 0.36; 95% CI, -0.08 to 0.79), symptoms of depression and anxiety (eg, Patient Health Questionnaire-9 score among 250 mg group at 12-month follow-up: d = 0.30; 95% CI, -0.17 to 0.76; Generalized Anxiety Disorder-7 score among 100 mg group at 12-month follow-up: d = 0.27; 95% CI, -0.19 to 0.73), and well-being (250 mg group: d = 0.10; 95% CI, -0.42 to 0.63; 100 mg group: d = 0.34; 95% CI, -0.19 to 0.86). No serious adverse effects were reported.

CONCLUSIONS AND RELEVANCE

In this study, DCS did not potentiate ERP treatment effect, but concentrated ERP treatment was associated with improvement.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT02656342.

Gitelman-like Syndrome with Kanamycin Toxicity

A 22 year-old lady with multi-drug-resistant pulmonary tuberculosis was on Kanamycin, Cycloserine, Ethionamide, Pyrazinamide and Moxifloxacin since more than two months. She presented with muscle cramps and carpopedal spasm. Investigation revealed hypokalemia and metabolic alkalosis. She also had hypomagnesemia, hypochloremia and hypocalciuria. Serum urea and creatinine levels were normal. Patient was treated with intravenous and oral potassium chloride. Kanamycin was stopped. Metabolic alkalosis and hypokalemia improved gradually over one month. Biochemical parameters were like Gitelman's syndrome but it reversed with stoppage of Kanamycin. Gitelman-like syndrome with Kanamycin toxicity has not been reported in literature previously.

A randomized, placebo-controlled trial of D-cycloserine for the enhancement of social skills training in autism spectrum disorders

BACKGROUND

Researchers have demonstrated that d-cycloserine (DCS) can enhance the effects of behavioral interventions in adults with anxiety and enhances prosocial behavior in animal models of autism spectrum disorders (ASD). This study extended upon this background by combining DCS with behavioral social skills therapy in youth with ASD to assess its impact on the core social deficits of ASD. We hypothesized that DCS used in combination with social skills training would enhance the acquisition of social skills in children with ASD.

METHODS

A 10-week, double-blind, placebo-controlled trial of DCS (50 mg) given 30 min prior to weekly group social skills training was conducted at two sites. Children with ASD were randomized to receive 10 weeks (10 doses) of DCS or placebo in a 1:1 ratio.

RESULTS

No statistically significant difference attributable to drug treatment was observed in the change scores for the primary outcome measure, the Social Responsiveness Scale (SRS), total score (p = 0.45), or on secondary outcome measures.

CONCLUSIONS

The results of this trial demonstrated no drug-related short-term improvement on the primary outcome measure, or any of the secondary outcome measures. However, an overall significant improvement in SRS total raw score was observed from baseline to end of treatment for the entire group of children with ASD. This suggests a need to further study the efficacy of the social skills training protocol. Limitations to the current study and areas for future research are discussed.

TRIAL REGISTRATION

ClinicalTrials.govNCT01086475.

Profile of adverse drug reactions in drug resistant tuberculosis from Punjab

OBJECTIVE

The aim of the study was to elucidate the profile of adverse drug reactions (ADRs) associated with second-line anti-tubercular treatment for drug-resistant tuberculosis.

MATERIAL AND METHODS

ADR profile of diagnosed drug-resistant tuberculosis cases on supervised second-line anti-tubercular drug regimen under Programmatic Management of Drug-resistant Tuberculosis under Revised National Tuberculosis Control Programme, were studied over two years' period. Adverse reactions were categorised into mild, moderate and severe types with subsequent systematic data-analysis.

RESULTS

Out of total 207 patients in the study, 81.16% reported with adverse drug reactions. Out of total 195 adverse events, 63.58%, 18.46% and 17.94% were of mild, moderate and severe types respectively. Gastrointestinal events, hepatitis, hearing impairment, arthralgia, psychosis, hypothyroidism, visual disturbances, giddiness, peripheral neuropathy, skin reactions, swelling or pain at injection site, anorexia and sleep disturbances were important amongst these. High proportion of drug and/or alcohol abuse was an important observation. The offending drug(s) had to be terminated in 12.08% of the patients.

CONCLUSION

Early detection, management and pharmaco-vigilance reporting of ADRs remain key factors in the management of drug-resistant tuberculosis with remarkable relevance of the need for early diagnosis and treatment of 'drug-sensitive tuberculosis', to prevent emergence of drug-resistant tuberculosis.

A trial of D-cycloserine to treat stereotypies in older adolescents and young adults with autism spectrum disorder

OBJECTIVES

Autism spectrum disorders (ASDs) have core impairments in social communication as well as the presence of repetitive, stereotypic behaviors and restricted interests. Older adolescents and young adults are particularly impacted by these deficits. Preclinical data implicate glutamatergic dysfunction in the pathophysiology of ASDs. D-Cycloserine (DCS), a partial glycineB agonist at the N-methyl-D-aspartic acid receptor site, has been shown to improve sociability in mouse models and a small human study. The sensitivity of the obligatory glycineB co-agonist binding site may change with daily administration of DCS as a result of agonist-induced desensitization. The efficacy of a "pulsed" once-weekly administration versus "daily" administration of DCS was compared.

METHODS

Males and females, ages 14 to 25 years, with a Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition Text Revision diagnosis of an ASD were enrolled in a double-blind, randomized 10-week trial consisting of 8 weeks of active drug with either weekly or daily administration of 50 mg of DCS followed by a 2-week follow-up visit.

RESULTS

For the purposes of this study, no statistical or clinical differences existed between the 2 dosage groups on the Aberrant Behavior Checklist subscale 3, which measures stereotypies/repetitive movements. When combining groups, a statistically significant decrease of 37% was found from baseline to week 8 when study drug was completed using a linear mixed effects model (P = 0.003).

CONCLUSIONS

D-Cycloserine was shown to be effective in improving stereotypic symptoms in older adolescents and young adults with ASDs measured by the Aberrant Behavior Checklist subscale 3. In addition, DCS was safe and well tolerated.

Serious treatment related adverse drug reactions amongst anti-retroviral naïve MDR-TB patients

BACKGROUND

Globally treatment outcomes for multidrug-resistant Mycobacterium tuberculosis (MDR-TB) remain poor and this is compounded by high drug toxicity. Little is known about the influence of adverse drug reactions (ADRs) on treatment outcomes in South Africa.

METHODS

We evaluated the impact of severe ADRs among a prospective cohort of MDR-TB patients in South Africa (2000-2004). The HIV-infected study participants were anti-retroviral naïve.

RESULTS

Of 2,079 patients enrolled, 1,390 (66.8%) were included in this analysis based on known HIV test results (39.1% HIV-infected). At least one severe ADR was reported in 83 (6.9%) patients with ototoxicity being the most frequent ADR experienced (38.9%).

CONCLUSIONS

We found that being HIV-infected but antiretroviral naïve did not increase occurrence of SADRs in patients on second-line anti-tuberculosis drugs. Early screening and proactive management of ADRs in this patient population is essential, especially given the rollout of decentralized care and the potential for overlapping toxicity of concomitant MDR-TB and HIV treatment.

[Pharmacological activity of runihol and S-adenosyl-L-methionine in rats with experimental liver damage by reserve antituberculosis drugs]

The hepatoprotective action of runihol and S-adenosyl-L-methionine (ademethionine) has been studied in a group of 47 white outbred male rats with model liver injury induced by reserve antituberculosis drugs (PAS, prothionamide, cycloserine). The ability of test drugs to correct structural and functional liver disorders is established. Both runihol and ademethionine favored decrease in the signs of structural and functional liver disorders induced by reserve antituberculosis drugs, Showing mixed type of action, the test drugs promoted recovery of the liver parenchyma and reduced manifestations of hepatocyte dystrophy to the same extent, without manifestations of necrobiotic processes and a mononuclear infiltration.

[Rezonizat and cycloserine in complex therapy of drug resistant tuberculosis (comparative studies)]

An open comparative investigation of the Russian drugs rezonizat and cycloserine was performed. The studies made it possible to recommend the use of rezonizat in complex therapy of patients with drug resistant tuberculosis. Higher activity and better tolerability of rezonizat vs. cycloserine was shown.

[A case of multi-drug resistant tuberculosis showing psychiatric adverse effect by cycloserine]

A 45-year-old man with multi-drug resistant tuberculosis were referred to our hospital for treatment. We started chemotherapy with cycloserine (CS), ethionamide (TH), kanamycin (KM), pyrazinamide (PZA), para-aminosalicylic acid (PAS) and gatifloxacin (GFLX). Two months later, psychosis and seizure occurred and worsened day after day. We suspected that these symptoms were due to CS. After stopping CS, psychosis and seizure disappeared. After surgical operation, positive tubercle bacilli in sputum converted to negative both on smear and culture. He was successfully discharged from our hospital. We should take care on side effects with second-line drugs that are often used in treating multi-drug resistant tuberculosis.

Clinical perspectives on the combination of D-cycloserine and cognitive-behavioral therapy for the treatment of anxiety disorders

In a particular success for translational research agendas, characterization of the neuronal circuits underlying fear extinction, and basic research in animal extinction paradigms, has led to intervention studies examining the use of D-cycloserine (DCS) to enhance therapeutic learning from exposure-based cognitive-behavioral therapy (CBT). In this article, we review these intervention studies, and discuss DCS augmentation of CBT relative to more traditional combination-treatment strategies in the treatment of anxiety disorders. We offer an accounting, based on evidence for internal context effects, of current limitations in the combination of antidepressant or benzodiazepine medications with CBT and discuss the advantages of isolated-dosing strategies with DCS relative to these limitations. This strategy is contrasted with the chronic-dosing applications of DCS for schizophrenia and Alzheimer's disease, and future directions for isolated-dosing strategies are discussed.

Treatment and follow-up of HIV-negative multidrug-resistant tuberculosis patients in an infectious diseases reference hospital, Buenos Aires, Argentina

SETTING

An Argentinean reference hospital specialising in infectious diseases.

OBJECTIVE

To assess the outcomes of all human immunodeficiency virus (HIV) negative multidrug-resistant tuberculosis (MDR-TB) patients referred to or diagnosed at Hospital Muñiz.

DESIGN

Clinical study for the period 1996-1999, with follow-up until June 2002.

RESULTS

One hundred and forty-one adult patients (52.5% female) with resistance to two to seven drugs were studied. Fifty patients (35.5%) had not been treated previously. The most frequently used second-line drugs were 5-F-quinolones, cycloserine and ethionamide in susceptibility based individually tailored three- to five-drug regimens. Hospital admission was associated with treatment success. Forty-five episodes of severe toxicity occurred. Treatment was successful in 51.8% of cases, but follow-up of 73 patients yielded 11.9% relapse. The mortality rate was 19.1% and default was 19.9%. Logistic regression analysis was statistically significant for treatment success in relation to patient admission, residence and resistance pattern.

CONCLUSION

The burden of MDR-TB in this setting--prolonged infection, treatment cost and difficulties, low rates of cure and treatment adherence and high rates of fatality and relapse--can be improved by strengthening TB control programme activities and fighting against poverty and HIV/AIDS.

Psychiatric issues in the management of patients with multidrug-resistant tuberculosis

INTRODUCTION

Psychiatric issues present a challenge in the treatment of patients with multidrug-resistant tuberculosis (MDR-TB). Both baseline psychiatric disorders and development of psychiatric complications related to anti-tuberculosis drugs and psychosocial factors require aggressive management.

SETTING

A community-based non-governmental health organization in Lima, Peru.

OBJECTIVE

To review the literature for psychiatric complications associated with anti-tuberculosis medications, to describe the incidence and prevalence of depression, anxiety and psychosis among individuals receiving MDR-TB therapy, and to detail the management approach used in this cohort.

METHODS

A retrospective case series was performed among the first 75 patients to receive individualized MDR-TB therapy in Lima, Peru, between 1996 and 1999.

RESULTS

Baseline depression and baseline anxiety were observed in respectively 52.2% and 8.7% of this cohort. Most individuals with baseline depression experienced improvement of depressive symptoms during the course of TB therapy. The incidence of depression, anxiety and psychosis during MDR-TB treatment was 13.3%, 12.0% and 12.0%, respectively. While the majority of individuals with depression, anxiety and psychosis required psychiatric pharmacotherapy, cycloserine was successfully continued in all but one case.

CONCLUSION

Psychiatric comorbidities are not a contra-indication to MDR-TB therapy. Management of psychiatric complications is possible without compromising anti-tuberculosis treatment.

D-Cycloserine added to risperidone in patients with primary negative symptoms of schizophrenia

BACKGROUND

D-Cycloserine, a partial agonist at the glycine recognition site of the NMDA receptor has previously been shown to improve negative symptoms when added to conventional antipsychotics and to worsen negative symptoms when added to clozapine. The purpose of this study was to examine the effects of D-cycloserine when added to risperidone on negative symptoms of schizophrenia.

METHOD

Ten patients with schizophrenia who were treated with risperidone completed consecutive two week trials of placebo and four doses of D-cycloserine. Clinical assessments were videotaped and were scored by a rater who was blind to temporal sequence.

RESULTS

D-Cycloserine at a dose of 50mg/day was associated with significant reduction in negative symptoms (mean=10%). Ratings of depression, extrapyramidal side effects, and cognitive function were unchanged. Serum concentrations of glutamate and serine increased significantly on this dose of D-cycloserine.

CONCLUSIONS

This preliminary study suggests that combination of D-cycloserine, 50mg/day, with risperidone may improve negative symptoms of schizophrenia over a narrow dose range. The degree of improvement appears to be intermediate between improvement of negative symptoms observed with combination of D-cycloserine with conventional antipsychotics and worsening of negative symptoms observed with combination of D-cycloserine with clozapine in previous trials of identical design.

[Pharmacological support of exposure therapy in anxiety disorders. Animal experiment studies]

The fear-potentiated startle paradigm (i.e., the enhancement of the startle response in the presence of an aversive conditioned stimulus) is a valuable cross-species model for the study of the neuronal mechanisms underlying fear and anxiety as well as of the cognitive control of those aversive states. Walker et al. present data from a study in rats indicating that extinction of fear in the fear-potentiated startle paradigm is enhanced by the partial agonist of the N-methyl-D-aspartate receptor D-cycloserine (DCS). The authors therefore suggest tests of DCS in clinical trials as a potential pharmacotherapeutic adjuvant for exposition therapies in fear and anxiety disorders.

D-cycloserine for Alzheimer's disease

BACKGROUND

Evidence supports a role for the NMDA receptors in learning and memory. These can be modulated by the antibiotic D-cycloserine in such a way that the effect of the excitatory transmitter substance glutamate is enhanced. A study on healthy subjects pretreated with scopolamine to mimic Alzheimer's disease showed a positive effect of D-cycloserine at low doses.

OBJECTIVES

To assess the efficacy and safety of D-cycloserine in patients with Alzheimer's disease.

SEARCH STRATEGY

The trials were identified from a search of the Specialized Register of the Cochrane Dementia and Cognitive Improvement Group on 14 June 2001 using the terms: cycloserine, D-cycloserine, Alzheimer*.

SELECTION CRITERIA

Randomized, double-blinded and unconfounded trials comparing D-cycloserine with a control treatment.

DATA COLLECTION AND ANALYSIS

Two larger and two smaller randomized controlled trials were identified. The clinical global impression scale was used in all studies and was a primary outcome measure.

MAIN RESULTS

It was not possible to extract the results from the first phases of the two crossover studies and therefore the meta-analyses are based on the two parallel group 6-month studies. There was no indication of a positive effect favouring D-cycloserine for the numbers showing improvement at 6 months as assessed by the Clinical Global Impression for any dose. The number of withdrawals for any reason before end of treatment at 6 months was significantly in favour of placebo (fewer withdrawals) compared with D-cycloserine for dose levels of 30 mg/day (OR 2.94, 95% CI 1.52, 5.70) and 100 mg/day (OR 3.23, 95% CI 1.67, 6.25). There was no significant difference between treatment, (2, 10, 30, 100, or 200 mg/day) and placebo for the number of withdrawals due to adverse events by six months.

REVIEWER'S CONCLUSIONS

The lack of a positive effect of D-cycloserine on cognitive outcomes in controlled clinical trials with statistical power high enough to detect a clinically meaningful effect means that D-cycloserine has no place in the treatment of patients with Alzheimer's disease.

Pharmacokinetics of cycloserine under fasting conditions and with high-fat meal, orange juice, and antacids

STUDY OBJECTIVES

To determine the effect of a high-fat meal, orange juice, and antacids on absorption of a single oral dose of cycloserine and to estimate its population pharmacokinetic parameters.

DESIGN

Randomized, four-period, crossover study.

SETTING

Clinical research center.

PATIENTS

Twelve healthy volunteers.

INTERVENTIONS

Subjects received single doses of cycloserine 500 mg after a 12-hour fast (reference), with a high-fat meal, with orange juice, and with antacids. They also received clofazimine 200 mg, ethionamide 500 mg, and p-aminosalicylic acid granules 6000 mg.

MEASUREMENTS AND MAIN RESULTS

Plasma samples were collected for 48 hours and assayed by validated high-performance capillary electrophoresis assay. Concentration-time data were analyzed with noncompartmental, one-compartment, and population methods. The maximum concentration (Cmax) of cycloserine was decreased (p=0.02) by the high-fat meal. No other statistically significant differences were observed for Cmax and area under the curve from time zero to infinity across the four treatments. The high-fat meal significantly (p<0.0001) delayed time to maximum concentration by 4.7 times compared with that of the reference (1.1 hr).

CONCLUSION

The pharmacokinetics of cycloserine were minimally affected by orange juice and antacids, whereas the high-fat meal delayed absorption. Administering cycloserine without a high-fat meal avoids potential alterations in the pattern of absorption.

D-cycloserine increases positive symptoms in chronic schizophrenic patients when administered in addition to antipsychotics: a double-blind, parallel, placebo-controlled study

A hypofunction of the glutamatergic system and NMDA receptors in schizophrenia has been hypothesized. Therefore, stimulation of these receptors could be of benefit to patients with schizophrenia. D-cycloserine has been used for this purpose. This study reports the effects of 100 mg D-cycloserine, when added to typical antipsychotics in chronic schizophrenic patients exhibiting prominent negative symptoms, using a placebo-controlled, double-blind, parallel, design. D-cycloserine slightly worsened psychotic symptoms and general psychopathology as compared to placebo. D-cycloserine failed to change negative symptoms and had no effect on extrapyramidal symptoms. The exacerbation of schizophrenic symptoms may be explained by the antagonistic effects of this dose of D-cycloserine at the glycine recognition site of the NMDA receptor due to competition with the endogenous agonist glycine. Another explanation for the increase in psychopathology may be an interaction with the effects of antipsychotics on NMDA mediated neurotransmission. Thus, D-cycloserine in this study did not ameliorate schizophrenic symptoms. However, the fact that they actually worsened suggests that NMDA systems may be involved in the pathogenesis of schizophrenia. Further placebo-controlled studies with lower dosages of D-cycloserine, preferably in drug-free patients, are necessary to evaluate if D-cycloserine is of use for the treatment of patients with schizophrenia.

The partial NMDA agonist D-cycloserine stimulates LH secretion in healthy volunteers

D-Cycloserine, a partial agonist of the glycine recognition site of the N-methyl-D-aspartate (NMDA) receptor, may serve as a probe for human cerebral NMDA receptor function. Since NMDA receptors are involved in neuroendocrine secretion, changes in pituitary secretion in response to D-cycloserine administration could serve as a model for NMDA receptor activity. The effects of an oral dose of 500 mg D-cycloserine were assessed in a neuroendocrine challenge paradigm in 20 healthy male volunteers, using a double-blind, randomized placebo-controlled crossover design. Luteinizing hormone (LH) and cortisol secretion was studied, since preclinical studies indicate that these hormones increase in response to NMDA receptor stimulation. Furthermore, plasma homovanillic acid (HVA) secretion was studied, as NMDA receptors are suggested to be involved in the regulation of dopaminergic neurotransmission. D-cycloserine was readily absorbed and did not induce side-effects or changes in vital signs and mood scores. D-Cycloserine stimulated LH secretion and induced a significant rise of the area under the plasma concentration time curve of LH. D-Cycloserine did not stimulate cortisol or plasma HVA secretion. These neuroendocrine effects suggest that D-cycloserine may be used to assess human NMDA receptor function in cerebral disorders, such as schizophrenia.

Behavioral and neuroendocrine effects of the partial NMDA agonist D-cycloserine in healthy subjects

The effect of D-cycloserine, a partial agonist of the N-Methyl-D-Aspartate (NMDA) receptor, were assessed in a (neuroendocrine) challenge paradigm to to examine NMDA systems in male healthy volunteers, using a double-blind, placebo-controlled crossover design. Oral D-cycloserine (15, 50, and 150 mg) was readily absorbed and its plasma concentration increased dose-dependently. Behavioral and hormonal responses were measured for 240 minutes after administration of the drug. D-cycloserine was well tolerated and did not induce side-effects according to the Visual Analog Scales (VAS), the Brief Psychiatric Rating Scale (BPRS) and the Adverse Events Checklist (AEC) & codes. D-cycloserine failed to elicit a neuroendocrine response as evaluated by cortisol, prolactin, and luteinizing hormone (LH) plasma levels. The present result suggests that D-cycloserine can readily be administered to healthy volunteers but that, in the dosages used, neuroendocrine secretion fails to serve as a model for testing NMDA receptor function in humans.

Cycloserine-induced Stevens-Johnson syndrome in an AIDS patient with multidrug-resistant tuberculosis

We report a case of cycloserine-induced Stevens-Johnson syndrome (SJS) in a 38-year-old male with the acquired immune deficiency syndrome (AIDS) and multidrug resistant tuberculosis (MDR-TB). The patient developed a cutaneous reaction after 60 days of therapy with ofloxacin, streptomycin (SM), pyrazinamide (PZA), ethambutol (EMB), and cycloserine (CSN). All drugs were stopped and the rash improved. Due to the severity of his disease, anti-tuberculosis drugs were resumed, one at a time. The patient developed a recurrent rash consistent with SJS, which began when CSN was restarted. CSN was stopped and the SJS began to gradually resolve with palliative treatment despite continuation of the other anti-tuberculosis drugs. However, the patient's overall condition gradually deteriorated and he died. To our knowledge, this is the first case of probable CSN-related SJS.

Evaluation of cycloserine in the treatment of Alzheimer's disease

This multicenter study evaluated the efficacy and safety of cycloserine and measured its effects on explicit and implicit memory tests in patients with Alzheimer's disease (AD). Four hundred ten patients with AD, aged 50 years or older, were enrolled in this parallel-group, double-blind, placebo-controlled, randomized trial of 5, 15, or 50 mg cycloserine or placebo twice daily, and 403 entered the double-blind treatment phase. Two hundred sixty-five patients completed the entire 26-week treatment phase. There were no baseline differences among the four treatment groups. Cognitive Drug Research (CDR) efficacy assessments showed no differences between active treatments and placebo from baseline to study weeks 2, 6, 14, or 26. Patients receiving 15 mg of cycloserine improved significantly on one section of an implicit memory test. No differences among treatments were observed for any other assessment scales evaluated. The incidence and severity of adverse events were similar across treatment groups. Cycloserine was well tolerated but did not demonstrate consistent evidence of efficacy during the course of therapy. Higher doses may be necessary to achieve efficacy in the AD population and do not appear to be precluded by the adverse event profile seen in this study.

[Ofloxacin-cycloserine-protionamide-INH combination against treatment refractory lung tuberculosis]

Multiresistant tuberculoses are on the increase. The conversion rates in "additional" therapy are only modest. 17 multiresistant patients and 6 treatment-refractory tuberculoses were treated by us with ofloxacin-cycloserin-protionamide-INH. 16 of these patients were HIV positive. 21 patients converted after 3 months of treatment by the latest. 3 patients died of HIV syndrome. There was otherwise no difference between HIV positive and HIV negative patients. As a rule, the combination was well tolerated. In multiresistant tuberculosis, it is mandatory to administer at least 3 drugs to which there is no resistance.

d-cycloserine adjuvant therapy to conventional neuroleptic treatment in schizophrenia: an open-label study

D-cycloserine, a partial agonist at the strychnine-insensitive glycine site of the NMDA receptor complex, was tested as adjuvant treatment to conventional neuroleptics in chronic schizophrenic volunteers. The drug was administered, o.a.d., at the daily dose of 250 mg for six weeks. Mental status outcome measures were completed at the end of each week of treatment. The major finding was a deterioration of the patients' clinical condition, specifically of their psychotic symptoms. These preliminary results are discussed among others in view of d-cycloserine pharmacologic properties and recent findings on the interaction between NMDA agonists and dopamine system. This study, finally, suggests the need for a controlled dose-finding trial to establish the activity and a therapeutic "window" of this drug in schizophrenia.

Effect of HIV treatment on cognition, behavior, and emotion

Although not the most common cause, drug therapy does cause changes in cognition, emotion, or behavior in HIV-infected patients. Clinicians need to be aware of the range of known side effects of drugs for HIV infection. Clinicians also must be vigilant to the possibility of a side effect not previously reported because experience with these drugs, especially in combination with one another, is limited.

D-cycloserine treatment of Alzheimer disease

Degeneration of cortical glutamatergic projections may contribute to the cognitive decline in Alzheimer disease (AD). To evaluate whether 1glutamate system stimulation might confer symptomatic benefit, we administered D-cycloserine, a putative partial indirect agonist at certain N-methyl-D-aspartate (NMDA) glutamate receptors, to 12 patients with probable AD. The patients (seven men, five women) had a mean age of 65 +/- 8.4 years; Mini Mental State Examination scores ranged from 15 to 25. A dose escalation phase, in which cycloserine was given in daily oral doses from 25 to 500 mg (total of six dose levels, 1 week per dose), was followed by a "best dose" crossover comparison with placebo under double-blind conditions. The crossover phase consisted of 2 weeks of cycloserine and 2 weeks of placebo, separated by a 1-week washout period. We observed no significant or consistent effect on neuropsychological outcome measures. The results suggest that short-term potentiation of NMDA-mediated glutamatergic transmission may not prove useful in the symptomatic treatment of Alzheimer dementia.

Cycloserine as a urinary tract antiseptic

A short historical review and pharmacological data indicating the suitability of cycloserine for long-term low-dose prophylaxis of urinary tract infection are presented.

A controlled trial of daily and intermittent rifampicin plus ethambutol in the retreatment of patients with pulmonary tuberculosis: results up to 30 months

In a controlled clinical trial in Hong Kong, 575 Chinese adults with smear-positive isoniazid-resistant pulmonary tuberculosis, who had previously been treated with first-line chemotherapy, were allocated at random to regimens of rifampicin plus ethambutol daily (ER7), twice-weekly (ER2), once-weekly (ER1), or daily for 2 months and then once-weekly (ER7ER1), or to a standard retreatment regimen of daily ethionamide plus pyrazinamide plus cycloserine (EtZC). The ER7 patients were allocated to 12 or 18 months of chemotherapy, and the remainder to 18 months. As assessed at 18 months, a favourable response was achieved in 87 per cent of 91 ER7 patients, 79 per cent of 84 ER2, 81 per cent of 53 ER1, 87 per cent of 62 ER7ER1, and in 88 per cent of 68 EtZC patients (93 per cent of 59 EtZC patients if those with ethionamide-resistant strains pretreatment are excluded). As assessed at 18 and 30 months the ER7 regime was as effective as the control EtZC regimen, and 18 months of chemotherapy on the ER7 regimen conferred no benefit over 12 months. No patient on either regimen relapsed after 18 months. Adverse reactions were uncommon on the daily rifampicin regimen but relatively common on the intermittent and control regimens. The commonest reaction to the intermittent regimens was the 'flu' syndrome, which was associated with the presence of circulating rifampicin-dependent antibodies (P less than 0-001).