Antinociceptive activity of Thyme (Thymus vulgaris L. ) and interactions with neurotropics and analgesics

The plant world represents an important source of potential therapeutic agents, but concomitant administration of herbal and conventional medications may result in interactions with subsequent beneficial or adverse effects. This study was designed to examine the analgesic effect of thyme tincture and thyme syrup, two commonly used thyme formulations, and their interactions with codeine, paracetamol, pentobarbital and diazepam in mice. The identification and quantification of thymol and carvacrol were carried out by GC/MS and GC/FID. The analgesic activity was studied using a hot plate method. Effects of thyme syrup on diazepam-induced motor coordination impairment in rotarod test and on pentobarbital-induced sleeping time were also determined. Thymol (175.3 µg/mL and 9.73 µg/mL) and carvacrol (10.54 µg/mL and 0.55 µg/mL) concentrations were measured in tincture and syrup, respectively. Thyme syrup and tincture exhibited effective analgesic activity in the hot plate pain model. Pretreatment with thyme formulations reduced analgesic activity of codeine, and potentiated the analgesic activity of paracetamol. Co-administration of thyme formulations has led to potentiation of diazepam and pentobarbital depressive central nervous system effects. Thyme formulations interacted with tested conventional drugs, probably through interference with their metabolic pathways and succeeding altered concentrations and pharmacological effects.

Curcumin Reverses the Diazepam-Induced Cognitive Impairment by Modulation of Oxidative Stress and ERK 1/2/NF-κB Pathway in Brain.

Oxidative stress and inflammation can be involved in cognitive dysfunction associated with neurodegenerative disorders. Diazepam (DZP) administration has been chosen to simulate the memory impairment. The aim of this study was to evaluate the effects of curcumin (CUR) on spatial cognition, ambulatory activity, and blood and brain oxidative stress levels. The ERK/NF-κB signaling pathway and the histopathological changes in the hippocampus and frontal lobe, in diazepam-treated rats, were also analyzed. The animals were divided into 4 groups: control, carboxymethylcellulose (CMC) + CUR, CMC + DZP, and CUR + CMC + DZP. CUR (150 mg/kg b.w.) was orally administered for 28 days. DZP (2 mg/kg b.w.) was intraperitoneally administered 20 minutes before the behavioral tests (open field test, Y-maze, and elevated plus maze). CUR improved the spontaneous alternation behavior, decreased the oxidative stress levels, both in the blood and in the hippocampus, and downregulated the extracellular signal-regulated kinase (ERK 1/2)/nuclear transcription factor- (NF-) κB/pNF-κB pathway in the hippocampus and the iNOS expression in the hippocampus and frontal lobe of the DZP-treated rats. Histopathologically, no microscopic changes were found. The immunohistochemical signal of iNOS decreased in the DZP and CUR-treated group. Thus, our findings suggest that curcumin administration may improve the cognitive performance and may also have an antioxidant effect.

[THE STUDY OF THE EFFECTS OF ANXYOLYTIC, ANTIOXIDANT, IMMUNOCORRECTOR AND HYPERBARIC OXYGENATION ON THE DYNAMICS OF MAIN BLOOD GAS AND ELECTROLYTE INDICES AND BEHAVIORAL RESPONSE IN EXPERIMENTAL STRESS MODEL].

Experiments on the model of immobilization stress in albino mice showed that a combination of mexidol, thymogen, and hyperbaric oxygenation reduced adverse effects of diazepam on behavioral response of animals in the black-and-white chamber and elevated cross maze tests and led to optimization of the blood gas composition as manifested by increased oxygen tension, normalization of the partial pressure of carbon dioxide, and restoration of the acid-base balance and blood bicarbonate level. The proposed combined treatment can be recommended for the treatment of patients with stress-induced pathology.

Urinary diazepam metabolite distribution in a chronic pain population.

Diazepam is often used as an adjuvant to pain therapy. Cytochrome P450 (CYP) 3A4 and 2C19 metabolize diazepam into the active metabolites: nordiazepam, temazepam and oxazepam. Owing to diazepam's side-effect profile, mortality risk and potential for drug-drug interactions with CYP 3A4 and/or CYP 2C19 inhibitors, urine drug testing (UDT) could be a helpful monitoring tool. This was a retrospective data analysis that evaluated urine specimens from pain management practices for the distribution of diazepam metabolites with and without CYP 3A4 and 2C19 inhibitors. Intersubject nordiazepam, temazepam and oxazepam geometric mean fractions were 0.16, 0.34 and 0.47, respectively. Intrasubject geometric mean fractions were 0.157, 0.311 and 0.494, respectively. Sex, but not age or urinary pH, had an effect on metabolite fractions. Methadone significantly increased temazepam and oxazepam urinary fractions via CYP3A4 inhibition, whereas fluoxetine and esomeprazole increased nordiazepam fractions via CYP2C19 inhibition. Although more studies are needed, these results suggest the viability of UDT for increased monitoring for therapy and possible drug-drug interactions.

Safety of subcutaneous microinjections (mesotherapy) in musicians.

OBJECTIVE: Determine the safety and tolerance of mesotherapy as a technique for the treatment of musculoskeletal complaints in musicians. METHOD: 67 patients (55.2% women) were subjected to a total of 267 mesotherapy sessions. A mesotherapy needle or normal needle was used randomly. The drugs employed were thiocolchicoside and diazepam as muscular relaxants, pentoxifylline or buflomedil as vasodilators, and piroxicam as an anti-inflammatory, as directed. A visual analogue scale was used to quantify the pain produced by the microinjections as well as the degree of immediate and midterm side effects as reported on a standard questionnaire. RESULTS: A mean of 155.5 microinjections were performed per session, of which 45.6% were perceived as painful by the patient with a mean severity of 4.3 out of 10. The pain reduced to 0.5 out of 10 after 24 hours. The most sensitive areas were the levator scapulae and splenius muscles. Systemic symptoms were reported by 5.99% of the musicians after the mesotherapy sessions (muscular weakness 1.5%, rash 1.5%, drowsiness 1.1% and itching 1.1%, being the most frequent). The mean severity of these symptoms was 2.77 out of 10. In all cases the symptoms had completely disappeared after 24 hours. No patient referred to signs of local or systemic infection. CONCLUSIONS: The application of drugs by means of subcutaneous injections (mesotherapy) in musicians is a technique that is safe, well tolerated, and without any severe complications.

Glutamate receptor antagonism in inferior colliculus attenuates elevated startle response of high anxiety diazepam-withdrawn rats.

Rats segregated according to low (LA) or high (HA) anxiety levels have been used as an important tool in the study of fear and anxiety. Since the efficacy of an anxiolytic compound is a function of the animal's basal anxiety level, it is possible that chronic treatment with a benzodiazepine (Bzp) affects LA and HA animals differently. Based on these assumptions, this study aimed to provide some additional information on the influence of acute, chronic (18 days) and withdrawal effects (48 h) from diazepam (10 mg/kg), in rats with LA or HA levels, on startle response amplitude. For this purpose, the elevated plus-maze (EPM) test was used. In addition, the role of glutamate receptors of the central nucleus of the inferior colliculus (cIC), the most important mesencephalic tectum integrative structure of the auditory pathways and a brain region that is linked to the processing of auditory information of aversive nature, was also evaluated. Our results showed that, contrary to the results obtained in LA rats, long-term treatment with diazepam promoted anxiolytic and aversive effects in HA animals that were tested under chronic effects or withdrawal from this drug, respectively. In addition, since Bzp withdrawal may function as an unconditioned stressor, the negative affective states observed in HA rats could be a by-product of GABA-glutamate imbalance in brain systems that modulate unconditioned fear and anxiety behaviors, since the blockade of alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionate (AMPA) and N-methyl-D-aspartate (NMDA) glutamate receptors in the cIC clearly reduced the aversion promoted by diazepam withdrawal.

[The withdrawal syndrome in benzodiazepine dependence and its management]. / Managementul sindromului de abstinenta in dependenta la benzodiazepine.

UNLABELLED: The authors present the result of an observational study about the withdrawal syndrome in benzodiazepine dependence, and the aspect of identifying withdrawal symptoms, effective communication with the patient and the structure of withdrawal programmes. MATERIAL AND METHOD: The study included a number of 22 pacients hospitalised in the Drug-Dependence Clinic of Iasi between January 2006 - December 2008. RESULTS: The present article consists of data covering current issues in the area of withdrawal syndrome in benzodiazepine dependence. The most prescribed benzodiazepines were diazepam (10 cases), followed by alprazolam (5 cases) and nitrazepam (4 cases). The clinical manifestations such as anxiety, insomnia, concentration problems, fatigability were present at all patients.

The aqueous extracts of Passiflora alata and Passiflora edulis reduce anxiety-related behaviors without affecting memory process in rats.

Several species of Passiflora have been employed widely as a folk medicine because of sedative and tranquillizer activities. In this study, we evaluate the effects on anxiety and memory process of two popularly used Passiflora species. To this aim, male Wistar rats (weighing 250-300 g) were intraperitoneally injected with the aqueous extract of Passiflora alata or Passiflora edulis (25, 50, 100, or 150 mg/kg; single injection) 30 minutes prior to the elevated plus-maze test, inhibitory avoidance test, or habituation to an open-field apparatus. The effects of both species of Passiflora were compared with that of diazepam (1 mg/kg), a standard anxiolytic drug. Our findings revealed that, similar to diazepam, the treatment with P. alata (100 and 150 mg/kg) and P. edulis (50, 100, and 150 mg/kg) induced anxiolytic-like effects in rats. Memory was not affected by the treatment with any dose of P. alata or P. edulis, but diazepam disrupted memory process in rats. Phytochemical analysis showed that the content of flavonoids of the aqueous extract of P. edulis is almost twice that of P. alata. These differences in contents of flavonoids could explain the lower active doses of the aqueous extract of P. edulis in inducing anxiolytic-like effects compared to P. alata. In conclusion, our findings suggest that, distinct from diazepam, the aqueous extract of both species of Passiflora induced anxiolytic-like effects in rats without disrupting memory process.

Potentially inappropriate prescribing to hospitalised patients.

PURPOSE: The objective of this study was to evaluate the prevalence of potential drug-drug interactions (DDIs) in hospitalised patients in correlation with patient's age and number of drugs prescribed and to determine the prevalence of inappropriate drugs prescribed to elderly patients. METHODS: Drugs prescribed during 1 day to all hospitalised patients at seven wards of Department of Medicine in University Hospital Rijeka were recorded by reviewing patient medical charts. Potential DDIs were evaluated using a list of potentially harmful drug combinations compiled from the literature. Beers criteria were used to identify potentially inappropriate medications in patients aged 65 years or older. RESULTS: The study included 225 patients that received a total of 1301 drugs. Twenty-two percent of the patients receiving drug therapy were prescribed drug combinations that are potentially harmful. The most common potentially harmful drug combination was an ACE inhibitor with a potassium supplement (33.9% of all combinations). In the multivariate analysis, age and number of drugs are significantly associated with potential DDIs (r = 0.8629). One quarter of elderly patients received a drug potentially inappropriate considering their age. The most commonly prescribed potentially inappropriate drug was amiodarone, followed by diazepam. CONCLUSION: Polypharmacy and older age have been proven to be important risk factors for potential drug interactions. We identified a high rate of prescribing potentially inappropriate medications among elders. Results of this study indicate that particular caution should be given when prescribing drugs to patients already receiving drugs and to elderly patients, considering the risk of drug-related problems.

Combined approach for high-throughput preparation and analysis of plasma samples from exposure studies.

In drug discovery today, drug exposure is determined in preclinical efficacy and safety studies and drug effects are related to measured concentrations rather than to the administered dose. This leads to a strong increase in the number of bioanalytical samples, demanding the development of higher throughput methods to cope with the increased workload. Here, a combined approach is described for the high-throughput preparation and liquid chromatography/tandem mass spectrometry (LC/MS/MS) analysis of drug levels in plasma samples from the preclinical efficacy and safety studies, i.e. exposure studies. Appropriate pharmacokinetic (PK) compartmental models were fitted to data from PK screening studies in the rat, which were subsequently used to simulate the expected plasma concentrations of the respective exposure studies. Information on the estimated drug concentrations was used to dilute the samples to appropriate concentration levels. A Tecan Genesis RSP liquid handling system was utilized to perform automated plasma sample preparation including serial dilution of standard solutions, dilution of plasma samples, addition of internal standard solution and precipitation with acetonitrile. This robotic sample preparation process permitted two studies of 1-96 samples each to be run simultaneously. To ensure the performance of this method the accuracy and precision for diazepam were examined. Two novel drugs were used to illustrate the suggested approach. In conclusion, our method for sample preparation of exposure samples, based on the combined use of PK simulations, a liquid handling system and a fast LC/MS/MS method, increased the throughput more than three times and minimized the errors, while maintaining the required accuracy and precision.

The effect of chronic diazepam administration on lipid peroxidation and Ca2+ -ATPase activity in rat liver.

Chronic administration of diazepam (DZP) caused an increase in malondialdehyde (MDA) levels and a decrease in glutathione (GSH) content. DZP also markedly lowered Ca2+ATPase activity. Treatment with Se plus vitamin E reduced MDA levels and increased GSH content. Our results suggest that, increased lipid peroxidation together with alteration in Ca2+ -ATPase activity may play a role in DZP induced hepatic injury and Se plus vitamin E treatment may contribute to the attenuation of DZP induced hepatotoxicity.

Validation of a motor activity system by a robotically controlled vehicle and using standard reference compounds.

INTRODUCTION: A series of experiments were undertaken to evaluate the accuracy, precision, specificity, and sensitivity of an automated, infrared photo beam-based open field motor activity system, the MotorMonitor v. 4.01, Hamilton-Kinder, LLC, for use in a good laboratory practices (GLP) Safety Pharmacology laboratory. METHODS: This evaluation consisted of two phases: (1) system validation, employing known inputs using the EM-100 Controller Photo Beam Validation System, a robotically controlled vehicle representing a rodent and (2) biologic validation, employing groups of rats treated with the standard pharmacologic agents diazepam or D-amphetamine. The MotorMonitor's parameters that described the open-field activity of a subject were: basic movements, total distance, fine movements, x/y horizontal ambulations, rearing, and total rest time. These measurements were evaluated over a number of zones within each enclosure. RESULTS: System validation with the EM-100 Controller Photo Beam Validation System showed that all the parameters accurately and precisely measured what they were intended to measure, with the exception of fine movements and x/y ambulations. Biologic validation using the central nervous system depressant diazepam at 1, 2, or 5 mg/kg, i.p. produced the expected dose-dependent reduction in rat motor activity. In contrast, the central nervous system stimulant D-amphetamine produced the expected increases in rat motor activity at 0.1 and 1 mg/kg, i.p, demonstrating the specificity and sensitivity of the system. DISCUSSION: Taken together, these studies of the accuracy, precision, specificity, and sensitivity show the importance of both system and biologic validation in the evaluation of an automated open field motor activity system for use in a GLP compliant laboratory.

Attenuation of benzodiazepine dependence in mice by a tri-substituted benzoflavone moiety of Passiflora incarnata Linneaus: a non-habit forming anxiolytic.

PURPOSE: A tri-substituted benzoflavone moiety (BZF) recently isolated from the methanol extract of aerial parts of the plant Passiflora incarnata Linneaus had exhibited encouraging results in countering the dependence produced by addiction-prone substances like morphine, nicotine, cannabinoids and ethyl alcohol, during the studies performed by the authors. Since the BZF moiety had exhibited significant anxiolytic properties at 10 mg/kg p.o. dose in mice, therefore, it was desirable to evaluate this potential phyto-moiety (BZF) for its own dependence-liabilities It was also deemed viable to evaluate BZF moiety for its possible usefulness in countering the dependence-liabilities associated with the chronic use of benzodiazepines keeping in light their tremendous clinical use in the management of anxiety and insomnia. METHODS: Different groups of mice were administered BZF alone (10, 50 or 100 mg/kg, p.o.), and concomitantly with diazepam (20 mg/kg, p.o.) in a 21-days treatment regimen, followed by no treatments for the next 72-hours. The withdrawal effects in the form of ambulatory behavior of the treated animals were recorded on the 25th day using an Actophotometer. RESULTS: The BZF-alone (three doses) treated mice exhibited a normal ambulatory behavior on 25th day. Mice groups receiving co-treatments, i.e., BZF-diazepam concomitantly, also exhibited a normal ambulatory behavior in a dose-dependent manner, i.e., the higher dose of BZF (100 mg/kg) being more effective in countering the withdrawal effects of chronically administered diazepam than the lower doses (10 or 50 mg/kg). CONCLUSIONS: The studies revealed that the chronic administration of the BZF moiety (three doses), did not exhibit any dependence-liability of its own, even upon an abrupt cessation. Additionally, the BZF co-treatments with diazepam also prevented the incurrence of diazepam-dependence, which might be because of the aromatase enzyme inhibiting properties associated with the BZF moiety.

[The anxiolytic effect of ondansetron and its capacity to eliminate the benzodiazepine abstinence syndrome in rats]. / Anksioliticheskii éffekt ondansetrona i ego sposobnost' ustraniat' benzodiazepinovyi abstinentnyi sindrom u krys.

Ondansetron (GR38032F, zofran)--a specific blocker of 5-HT3-receptors in a dose range of 0.05 to 0. mg/kg causes an anxiolytic effect in experiments on mice and rats on a model of elevated plus maze. The drug does not produce a sedative and myorelaxant effect. A 0.05 mg/kg dose of ondansetron reduces the level of anxiety and convulsive manifestations which are induced by discontinuation of long-term diazepam administration. The results of the study bear evidence of selectivity of the anxiolytic effect of ondansetron in intact animals and its effectiveness in rats with diazepam abstinence.

['Weight reduction preparations' from Thailand: unexpected complication for the traveller]. / 'Afslankmiddelen' uit Thailand: onverwachte reizigerszorg na terugkeer.

Two series of Thai 'slimming agents' purchased apparently without a medical consultation or prescription (one directly in Thailand and the other one indirectly in the Netherlands) were submitted for chemical analysis. Fenfluramine and diazepam were present in both series. One series also yielded phenolphtalein and vitamin B substances, while sennosides were found in the other series. Apparently travellers may unwittingly take along potent medicines when they return from far countries.

Use of inhalational and intravenous sedation in dentistry.

Having gained knowledge of the advantages of inhalational and intravenous sedation many dental practitioners use these techniques to supplement local anaesthesia for dental procedures. Inhalational sedation is commonly carried out with nitrous oxide and oxygen while isoflurane in oxygen has also been tried out. Intravenous sedation is commonly carried out with midazolam or diazepam given as a single titrated dose to an end point which does not result in anaesthesia. When sedation with benzodiazepines is carried out, the specific antagonist, flumazenil should always be available for use in emergencies such as accidental oversedation, iatrogenic overdose or paradoxical reactions. Patient controlled sedation with midazolam, the modern technique of intravenous sedation, is comparable to anaesthetist controlled sedation and patients may be administered increments of one milligram at one minute intervals. Computer controlled sedation has been carried out with propofol. Mortality following sedation is low in the United Kingdom, partly due to the strict guidelines of the General Dental Council in the United Kingdom.

Selective cyclodextrin inhibition of alfaxolone-induced ataxia.

The effect of the use of a number of popular solubility treatments was examined on alfaxolone- and diazepam-induced ataxia. The effects of diazepam were not significantly altered by solution in cyclodextrin, Alkamuls EL-620 or a mixture of propylene glycol and ethanol. The effects of alfaxolone were not altered by solution in Alkamuls EL-620, but were significantly lessened by solution in cyclodextrin. In a dose-response experiment, the ED50 of alfaxolone increased from 15.3 mg kg-1 (in Alkamuls EL-620) to 25.6 mg kg-1 (in hydroxypropyl-beta-cyclodextrin). The results suggest that although cyclodextrins are popular and effective solubilizers, their use must be considered carefully in the context of the experiments in which they are to be used.

Generalized periarticular myositis ossificans as a complication of pharmacologically induced paralysis.

To our knowledge, no previous direct associations have been made between generalized myositis ossificans and pharmacological therapy. We report a case of generalized periarticular myositis ossificans associated with the use of curare and diazepam. The previously reported associations of myositis ossificans with tetanus and burns may be misleading. It is possible that it is not the disease process itself (e.g., tetanus, severe burn) that precipitates heterotopic ossification, but the treatment of these ailments. These observations suggest the importance of early mobilization and restrained use of immobilizing drugs. Further investigation is warranted with regard to the predisposing factors of generalized myositis ossificans and to its prevention.

Chinese herbal medicine induced acute renal failure.

A patient with acute interstitial nephritis secondary to ingestion of a Chinese herbal medicine adulterated with mefenamic acid is presented. Following hemodialysis and cessation of the medication the patient's renal function returned to normal.