Valproic acid related idiosyncratic drug induced hepatotoxicity in a glioblastoma patient treated with temozolomide.

Glioblastoma patients undergoing treatment with surgery followed by radiation and temozolomide chemotherapy often develop a state of immunosuppression and are at risk for opportunistic infections and reactivation of hepatitis and herpes viruses. We report the case of a 48-year-old glioblastoma patient who developed acute cholestatic hepatitis with hepatic failure during adjuvant treatment with temozolomide and the integrin inhibitor cilengitide. A viral hepatitis was excluded and valproic acid treatment was stopped. Upon normalisation of the liver tests, temozolomide treatment was resumed without perturbation of the liver tests. Valproic acid related idiosyncratic drug induced hepatotoxicity should be considered as a differential diagnosis in glioblastoma patients undergoing adjuvant therapy.

Toxic and drug-induced peripheral neuropathies: updates on causes, mechanisms and management.

PURPOSE OF REVIEW: This review discusses publications highlighting current research on toxic, chemotherapy-induced peripheral neuropathies (CIPNs), and drug-induced peripheral neuropathies (DIPNs). RECENT FINDINGS: The emphasis in clinical studies is on the early detection and grading of peripheral neuropathies, whereas recent studies in animal models have given insights into molecular mechanisms, with the discovery of novel neuronal, axonal, and Schwann cell targets. Some substances trigger inflammatory changes in the peripheral nerves. Pharmacogenetic techniques are underway to identify genes that may help to predict individuals at higher risk of developing DIPNs. Several papers have been published on chemoprotectants; however, to date, this approach has not been shown effective in clinical trials. SUMMARY: Both length and nonlength-dependent neuropathies are encountered, including small-fiber involvement. The introduction of new diagnostic techniques, such as excitability studies, skin laser Doppler flowmetry, and pharmacogenetics, holds promise for early detection and to elucidate underlying mechanisms. New approaches to improve functions and quality of life in CIPN patients are discussed. Apart from developing less neurotoxic anticancer therapies, there is still hope to identify chemoprotective agents (erythropoietin and substances involved in the endocannabinoid system are promising) able to prevent or correct painful CIPNs.

Antibiotic-dependent correlation between drug-induced killing and loss of luminescence in Streptococcus gordonii expressing luciferase.

Measuring antibiotic-induced killing relies on time-consuming biological tests. The firefly luciferase gene (luc) was successfully used as a reporter gene to assess antibiotic efficacy rapidly in slow-growing Mycobacterium tuberculosis. We tested whether luc expression could also provide a rapid evaluation of bactericidal drugs in Streptococcus gordonii. The suicide vectors pFW5luc and a modified version of pJDC9 carrying a promoterless luc gene were used to construct transcriptional-fusion mutants. One mutant susceptible to penicillin-induced killing (LMI2) and three penicillin-tolerant derivatives (LMI103, LMI104, and LMI105) producing luciferase under independent streptococcal promoters were tested. The correlation between antibiotic-induced killing and luminescence was determined with mechanistically unrelated drugs. Chloramphenicol (20 times the MIC) inhibited bacterial growth. In parallel, luciferase stopped increasing and remained stable, as determined by luminescence and Western blots. Ciprofloxacin (200 times the MIC) rapidly killed 1.5 log10 CFU/ml in 2-4 hr. Luminescence decreased simultaneously by 10-fold. In contrast, penicillin (200 times the MIC) gave discordant results. Although killing was slow (< or = 0.5 log10 CFU/ml in 2 hr), luminescence dropped abruptly by 50-100-times in the same time. Inactivating penicillin with penicillinase restored luminescence, irrespective of viable counts. This was not due to altered luciferase expression or stability, suggesting some kind of post-translational modification. Luciferase shares homology with aminoacyl-tRNA synthetase and acyl-CoA ligase, which might be regulated by macromolecule synthesis and hence affected in penicillin-inhibited cells. Because of resemblance, luciferase might be down-regulated simultaneously. Luminescence cannot be universally used to predict antibiotic-induced killing. Thus, introducing reporter enzymes sharing mechanistic similarities with normal metabolic reactions might reveal other effects than those expected.

Neuropathies périphériques d'origine médicamenteuse [Drug-induced peripheral neuropathy].

Drug-induced peripheral neuropathies are common, secondary to multiple drug classes, in particular chemotherapeutic agents. They have an important impact on patients' quality of life. In recent years, significant progress has been made in the understanding of some pathophysiological mechanisms. The use of more objective assessment tools should allow the development of individualized and more effective therapeutic strategies.

Pharmacogenetic Study on Risperidone Long-Acting Injection: Influence of Cytochrome P450 2D6 and Pregnane X Receptor on Risperidone Exposure and Drug-Induced Side-Effects.

Risperidone is metabolized by polymorphic enzymes, and a large variability in plasma concentration and therapeutic response is observed. Risperidone long-acting injection (RLAI) avoids the first-pass effect, and little is known about the influence of gene polymorphisms involved in its pharmacokinetics. The influence on plasma concentrations of risperidone (RIS), its metabolite 9-hydroxy-risperidone, and on adverse effects were investigated for polymorphisms of cytochrome P450 2D6 (CYP2D6) (*3, *4, *5, *6), CYP3A (CYP3A4*1B, CYP3A4 rs4646437, CYP3A5*3, CYP3A7*1C), ABCB1 (1236C>T, 2677G>T, 3435C>T), NR1/2 coding for pregnane X receptor (rs1523130, rs2472677, rs7643645), and for CYP3A activity measured by a phenotyping test. Forty-two patients with at least 4 consecutive unchanged doses of RLAI were included in a multicenter cross-sectional study. A 55% lower dose-adjusted plasma levels of RIS were observed for CYP2D6 ultrarapid metabolizers (n = 5) as compared with CYP2D6 intermediate metabolizers (P < 0.007). NR1/2 polymorphism (rs7643645A>G) influenced RIS exposure with a 2.8-fold lower active moiety (P = 0.031) in GG compared with the AA genotype. This was confirmed in a second independent cohort (n = 16). Furthermore, high-density lipoprotein cholesterol was positively correlated with CYP3A activity (P = 0.01), and the NR1/2 (rs2472677) polymorphism was associated with different adverse effects including prolactin plasma levels adjusted for age and sex. In conclusion, our results confirmed the influence of CYP2D6 genotype on plasma levels of RIS. This is the first report on the influence of NR1/2 polymorphisms on RLAI exposure and on drug-induced adverse effects. These results should be validated in larger cohorts.

Drug-induced linear IgA bullous dermatosis probably induced by furosemide.

Linear IgA bullous dermatosis (LABD) is an autoimmune disease, characterized by linear deposition of IgA along the basement membrane zone. Drug-induced LABD is rare but increasing in frequency. A new case of drug-induced LABD associated with the administration of furosemide is described.

Psychotropic drug-induced weight gain and other metabolic complications in a Swiss psychiatric population.

PURPOSE: To describe the weight gain-related side-effects of psychotropic drugs and their consequences on metabolic complications (hypercholesterolemia, obesity) in a Swiss cohort of psychiatric patients. METHOD: This cross-sectional observational study was performed in an out-patient psychiatric division with patients having received for more than 3 months the following drugs: clozapine, olanzapine, quetiapine, risperidone, lithium, and/or valproate. Clinical measures and lifestyle information (smoking behaviour, physical activity) were recorded. RESULTS: 196 inclusions were completed. Weight gain (≥10% of initial weight) following drug treatment was reported in 47% of these patients. Prevalence of obesity (BMI ≥ 30), hypercholesterolemia (≥6.2 mmol/L) and low HDL-cholesterol (<1.0 mmol/L in men, <1.3 mmol/L in women) were present in 38%, 21%, and 27% of patients, respectively. A higher standardised dose, an increase of appetite following medication introduction, the type of medication (clozapine or olanzapine > quetiapine or risperidone > lithium or valproate), and the gender were shown to be significantly associated with evolution of BMI. CONCLUSION: High prevalence of obesity and hypercholesterolemia was found in an out-patient psychiatric population and confirms drug-induced weight gain complications during long-term treatment. The results support the recently published recommendations of monitoring of metabolic side-effects during treatment with atypical antipsychotics. Moreover, the weight gain predictors found in the present study could help to highlight patients with special health care management requirement.

Mirtazapine in drug-induced excessive sweating.

Excessive sweating is a well-known side effect of a selective serotonin reuptake inhibitor treatment, but little is known about the impact of sweating on treatment discontinuation or the general quality of life of patients. In this case report, we present a patient suffering from excessive sweating induced by escitalopram. When mirtazapine was administered as an additional treatment, a dose-dependent reduction of drug-induced excessive sweating was observed. Taking into account the particular serotonin antagonistic properties of mirtazapine, its eventual influence on the regulation of body temperature and diaphoresis in the central nervous system is discussed.

Guide pratique des effets indésirables médicamenteux chez les seniors [Drug-induced adverse events in the elderly: a traveler's guide].

Elderly people are prone to drug-induced adverse events (AEs), which often manifest as an atypical clinical picture. The differential diagnosis of any new symptom or alteration in the general state of health in the elderly must, therefore, include AEs. This article offers a practical tool designed to help clinicians to rapidly identify which drugs may induce which kind of frequent symptoms or syndromes.

Drug-induced mitochondrial dysfunction and cardiotoxicity.

Mitochondria has an essential role in myocardial tissue homeostasis; thus deterioration in mitochondrial function eventually leads to cardiomyocyte and endothelial cell death and consequent cardiovascular dysfunction. Several chemical compounds and drugs have been known to directly or indirectly modulate cardiac mitochondrial function, which can account both for the toxicological and pharmacological properties of these substances. In many cases, toxicity problems appear only in the presence of additional cardiovascular disease conditions or develop months/years following the exposure, making the diagnosis difficult. Cardiotoxic agents affecting mitochondria include several widely used anticancer drugs [anthracyclines (Doxorubicin/Adriamycin), cisplatin, trastuzumab (Herceptin), arsenic trioxide (Trisenox), mitoxantrone (Novantrone), imatinib (Gleevec), bevacizumab (Avastin), sunitinib (Sutent), and sorafenib (Nevaxar)], antiviral compound azidothymidine (AZT, Zidovudine) and several oral antidiabetics [e.g., rosiglitazone (Avandia)]. Illicit drugs such as alcohol, cocaine, methamphetamine, ecstasy, and synthetic cannabinoids (spice, K2) may also induce mitochondria-related cardiotoxicity. Mitochondrial toxicity develops due to various mechanisms involving interference with the mitochondrial respiratory chain (e.g., uncoupling) or inhibition of the important mitochondrial enzymes (oxidative phosphorylation, Szent-Györgyi-Krebs cycle, mitochondrial DNA replication, ADP/ATP translocator). The final phase of mitochondrial dysfunction induces loss of mitochondrial membrane potential and an increase in mitochondrial oxidative/nitrative stress, eventually culminating into cell death. This review aims to discuss the mechanisms of mitochondrion-mediated cardiotoxicity of commonly used drugs and some potential cardioprotective strategies to prevent these toxicities.

Evaluation of drug-induced neurotoxicity based on metabolomics, proteomics and electrical activity measurements in complementary CNS in vitro models.

The present study was performed in an attempt to develop an in vitro integrated testing strategy (ITS) to evaluate drug-induced neurotoxicity. A number of endpoints were analyzed using two complementary brain cell culture models and an in vitro blood-brain barrier (BBB) model after single and repeated exposure treatments with selected drugs that covered the major biological, pharmacological and neuro-toxicological responses. Furthermore, four drugs (diazepam, cyclosporine A, chlorpromazine and amiodarone) were tested more in depth as representatives of different classes of neurotoxicants, inducing toxicity through different pathways of toxicity. The developed in vitro BBB model allowed detection of toxic effects at the level of BBB and evaluation of drug transport through the barrier for predicting free brain concentrations of the studied drugs. The measurement of neuronal electrical activity was found to be a sensitive tool to predict the neuroactivity and neurotoxicity of drugs after acute exposure. The histotypic 3D re-aggregating brain cell cultures, containing all brain cell types, were found to be well suited for OMICs analyses after both acute and long term treatment. The obtained data suggest that an in vitro ITS based on the information obtained from BBB studies and combined with metabolomics, proteomics and neuronal electrical activity measurements performed in stable in vitro neuronal cell culture systems, has high potential to improve current in vitro drug-induced neurotoxicity evaluation.

Expositions médicamenteuses pendant la grossesse: une approche différenciée [Drug exposure during pregnancy: a differentiated approach].

Numerous drug exposures do occur unintentionally at the beginning of pregnancy. On the other hand, pursuing drug treatment may be necessary in women who wish to be pregnant. In these situations risk evaluation has to be done in a precise and differentiated manner, taking into account at the same time the risk for the fetus and maternal health. Teratovigilance services are able to give a thorough information enabling to avoid unwarranted drug arrests or pregnancy terminations. In return, physician's catamnesis about the outcome of the pregnancy exposed to one or several therapeutic agents will increase the bulk of knowledge health professionals and pregnant women have at their disposal.

Risperidone-induced symptomatic hyperprolactinaemia in adolescents.

Studies performed in adult patients unambiguously demonstrate a marked effect of risperidone on prolactin blood levels, with possible clinical effects related to hyperprolactinemia, such as gynecomastia and galactorrhea. However, the largest study performed in children and adolescents showed a weak effect of risperidone on prolactin concentrations during short-term treatment and a negligible effect during long-term treatment, which was probably because of the relatively low dosages of risperidone used [approximately 0.04 mg/(kg x d)]. Among the 10 psychotic adolescents treated with risperidone in our unit, we had 3 cases of gynecomastia in 3 male patients and 2 cases of galactorrhea in 2 female patients. The prolactin blood levels in these cases and in 3 other patients without apparent prolactin-related side effects were all above the normal range (median, 59 ng/mL; range, 30-123 ng/mL). Thus, risperidone administered to adolescents at doses commonly used for the treatment of psychotic symptoms can strongly increase prolactin levels, with clinical consequences such as gynecomastia and/or galactorrhea. Given that the long-term effects of antipsychotic drug-induced hyperprolactinemia are not well documented, especially regarding osteopenia, infertility, growth, and pubertal delay, risperidone should be administered with caution to children and adolescents.

Levodopa in the treatment of Parkinson's disease: an old drug still going strong.

After more than 40 years of clinical use, levodopa (LD) remains the gold standard of symptomatic efficacy in the drug treatment of Parkinson's disease (PD). Compared with other available dopaminergic therapies, dopamine replacement with LD is associated with the greatest improvement in motor function. Long-term treatment with LD is, however, often complicated by the development of various types of motor response oscillations over the day, as well as drug-induced dyskinesias. Motor fluctuations can be improved by the addition of drugs such as entacapone or monoamine oxidase inhibitors, which extend the half-life of levodopa or dopamine, respectively. However, dyskinesia control still represents a major challenge. As a result, many neurologists have become cautious when prescribing therapy with LD. This review summarizes the available evidence regarding the use of LD to treat PD and will also address the issue of LD delivery as a critical factor for the drug's propensity to induce motor complications.