The effect of transcutaneous electrical nerve stimulation on sympathetic skin response

The aim of present study was to determine whether combination of transcutaneous electrical nerve stimulation (TENS) and acupuncture inhibits sympathetic nerve activity in healthy humans. Multiunit efferent postganglionic sympathetic activity was recorded with Toennies set. In this study, the aim was to obtain latency, amplitude and duration of sympathetic skin response (SSR) and skin temperature (ST) from both hands in 15 healthy subjects. Subjects randomly assigned and everybody participated in all the three groups [Control Group (CG), Acupuncture Group (AG) and Nerve Stimulation Group (NSG)]. TENS (2 Hz, 250 microsecond) was applied over the median nerve of the right elbow in NSG for 20 min, either, TENS was applied over (HE-7) point of the right hand in CG (TENS off) and AG (TENS on) for 20 min. SSR (lat, amp, dur) and ST data was recorded before TENS and for immediate, 5 min and 10 min post--TENS. ST was recorded in distal phalanx of index finger of both hands and SSR was recorded from both hands. TENS in CG did not affect ST and SSR following stimulation. TENS applied at AG and NSG caused a significant increase in ST (P = 0.001), significant increase in latency of SSR (P = 0.001), significant decrease in amplitude of SSR (P = 0.001) and no significant changes were observed in duration of SSR (P > 0.05). Then statistical analysis showed differences between both of groups (AG & NSG) for ST and SSR post--TENS. Transcutaneous electrical nerve stimulation inhibits sympathetic nerve activity in healthy humans.

[Pathological gambling behavior in a patient with Parkinson's disease treated with levodopa and bromocriptine]

The occurrence of a pathological gambling behavior in a 61-year-old patient with idiopathic Parkinson's disease treated with dopaminergic drugs is reported. This is the first case reported with bromocriptine. The main characteristics and the mechanism of this recently described and a unexpected, adverse drug reaction are discussed.

Perception of the risk of adverse drug reactions: differences between health professionals and non health professionals

AIMS

To investigate how risk of adverse drug reactions (ADRs) of several drug classes is perceived by health vs non health professionals.

METHODS

Four hundred health professionals (i.e. 278 general practitioners, 76 pharmacists and 46 pharmacovigilance professionals) and 153 non health professionals were interviewed. Visual analogue scales were used to define a score of perceived risk of ADRs associated with each drug class (ranking from 0 to 10).

RESULTS

Anticoagulants were ranked as the most dangerous drugs by general practitioners [median score (25th-75th centiles): 7.9 (6.7-9.0)], pharmacists [8.7 (7.8-9.7)] and pharmacovigilance professionals [8.1 (7.2-9.0)]. For non health professionals, the class ranked first was sleeping pills [8.7 (7.2-9.4)] followed by tranquillisers [8.2 (6.4-9.2)] and antidepressants [8.0 (5.9-9.1)]. Aspirin was listed in the last position by non health professionals [3.4 (1.5-5.4)].

CONCLUSIONS

There are major differences in the perception of risk of ADRs between health professionals and non health professionals.

Sleep attacks and antiparkinsonian drugs: a pilot prospective pharmacoepidemiologic study

A prospective survey was performed to characterize the prevalence of sleep attacks and to evaluate precipitating factors in a group of 236 patients with idiopathic Parkinson's disease. Sleep attacks were reported by 72 patients (30.5%). Multivariate analysis showed a marked association between the occurrence of sudden sleep episodes and first autonomic failure, followed by treatment with ropinirole and bromocriptine. The present work underlines the major contributing role of autonomic failure followed by dopamine agonists in the occurrence of such an event. Because a relationship between sleep attacks and not only ropinirole but also bromocriptine treatment was described, the present work suggests that sleep attacks are a common side effect of all dopamine agonists.

[Inter-regional differences in dysthyroidism due to amiodarone: comparison of spontaneous notifications in Aquitaine, Midi-Pyrenees and Languedoc-Roussillon]

Amiodarone hydrochloride is used in the treatment of ventricular and supraventricular arrhythmias. Because of its iodinated structure, thyroid dysfunction can occur during amiodarone therapy. The reported overall incidence is variable (2-24 per cent) and depends on several factors (past thyroid history, daily iodine intake,...). The present retrospective (1990-97) study was performed using the French pharmacovigilance database in order to compare the frequency of hypo- and hyperthyroidism in three areas in the South of France: Midi-Pyrénées, Aquitaine and Languedoc-Roussillon. For each case, the following data were recorded: age, sex, dysthyroidism history, dosage, duration and indication of amiodarone and delay to onset of dysthyroidism. We collected respectively 37, 50 and 9 cases of hypothyroidism in Midi-Pyrénées, Aquitaine and Languedoc-Roussillon and 20, 69 and 11 cases of hyperthyroidism respectively in the same areas. These data show the predominance of reported amiodarone-induced hyperthyroidism in Aquitaine and Languedoc-Roussillon. Hypothyroidism seems more frequent in Midi-Pyrénées, a non-maritime area. The sex ratio (male/female) was significantly different for the occurrence of hypothyroidism in Midi-Pyrénées (1.8 versus 0.5 in Aquitaine and 0.8 in Languedoc-Roussillon). The delay to onset of hypothyroidism was significantly shorter in Midi-Pyrénées (17.1 months +/- 24.5) when compared with Aquitaine (28.7 +/- 28.1) or Languedoc-Roussillon (43.4 +/- 45). Our results show an interregional difference in the occurrence of hypo/hyperthyroidism due to amiodarone.

A new method for encapsulation of living cells: preliminary results with PC12 cell line

A new method is described for encapsulation of living cells. PC12 rat adrenal pheochromocytoma cells, which have been shown to synthesize, store and release dopamine were employed. The particles are made first and the cells then incorporated in a gentle mechanical procedure. The morphology (by light and electron microscopic observation), stability, rheology, texture and permeability of these microcapsules provided by Kappa Biotech were investigated. Membrane permeability studies demonstrated exclusion of 69,000 Da human serum albumin, but equilibrium of D-glucose and inulin was within 24h, indicating a molecular weight cut-off in the 5000-70,000 Da range. The viability and the function of the encapsulated cells were evaluated by measuring the spontaneous release of dopamine by high performance liquid chromatography with electrochemical detection. The results show that dopamine-secreting cells can be sequestered in a semi-permeable capsule and still display good viability and proliferation for at least 1 month.

New polymeric sorbent for the solid-phase extraction of chlorophenols from water samples followed by gas chromatography-electron-capture detection

A polymeric material, polyaniline, was employed as a new sorbent for solid-phase extraction (SPE) of some environmental pollutants from water samples. Chlorophenols were extracted from aqueous samples by SPE using 120 mg polyaniline and determined by gas chromatography with electron-capture detection. The acetate esters of these phenols were formed by the direct addition of acetic anhydride to the organic extractant in the presence of K2CO3. Different conditions were applied to obtain higher retaining capacity and breakthrough volumes. The results compared with those obtained by other groups. The RSD for a river water sample spiked at sub-ppb level was lower than 10% (n = 3) and detection limits were between 3 and 110 ng(-1).

The effects of electrical nerve stimulation of the lower extremity on H-reflex and F-wave parameters

The main purpose of this study was to investigate the effects of electrical nerve stimulation on alpha motoneurons excitability. The electrophysiological parameters of H-reflex and F-wave were assessed for this object. These experiments was performed on ten non-athletic healthy men without neurologic disorders with mean age 25.6 years (SD 4.4) and three spastic hemiplegic patients with mean age 65.33 years (SD 6.32). In the experimental protocol, electrical stimulation (TENS) applied on common peroneal nerve with frequency 99 Hz and duration 0.25 ms for 30 minutes. H-reflex and F-wave of the soleus muscle were recorded in three stages sequenced immediately, 5 minutes and 10 minutes later on. The parameters such as amplitudes and latencies of H-reflex and F-wave were compared with the data of first record before stimulation. Finally, after 30 minutes application of TENS the following results were obtained: 1. The mean peak to peak amplitude of H-reflexes and F-waves were significantly decreased after application of TENS in normal subjects. (P < 0.05) 2. H/M ratios and F/M ratios were significantly decreased after application of TENS in normal subjects. (P < 0.05) 3. The mean latency of H-reflexes and F-waves were significantly increased after application of TENS in normal subjects. (P < 0.05) 4. In spastic patients, the mean peak to peak amplitude of H-reflexes and F-waves, H/M and F/M ratios were significantly decreased and the mean latencies of H-reflexes and F-waves were significantly increased after application of TENS. The reduction of amplitude of H-reflexes and F-waves, H/M and F/M ratios demonstrated reduction of spasticity in patients group. The above-mentioned parameters are parts of electrophysiological indicators about assessment of spasticity.

Detection and incidence of drug-induced liver injuries in hospital: a prospective analysis from laboratory signals

AIMS

Liver damage remains the most frequent type of adverse drug reaction (ADRs) that can lead to the withdrawal of a drug from the market. The abnormal laboratory data identified by computerized hospital information systems can be used in order to improve the detection of ADRs. Our objectives were to assess the detection and incidence of drug-induced liver abnormalities in a university hospital inpatient population and to evaluate the underreporting rate of drug-induced liver injury.

METHODS

We conducted a prospective study performed 1 week per month from June to October 1997. We selected patients by a computerized process using biochemistry laboratory data, based on serum enzyme values, alanine aminotransferase (over 2 fold normal) and alkaline phosphatase (over 1.5 fold normal).

RESULTS

Among 1976 ALT and 1814 AP assays performed during the period of the study, 156 (7.9%) and 159 (8.8%) tests, respectively, fell into the selected criteria. These concerned 147 patients. Among these patients, 13 (8.8%) cases of drug-induced liver injuries were suspected. Seven cases were asymptomatic. Six cases were classified as serious by these criteria: hospitalization to investigate the cause of health status impairment (4 patients), prolongation of hospitalization (1 patient) and life-threathening (1 patient). Using the hospitalization database, the incidence of drug-induced liver injuries was estimated as 6.6 per 1000 inpatients a week. Only 1 case was reported by physicians in the same period.

CONCLUSIONS

Computerization of biochemical data would allow the development of systems to improve detection of drug-induced injury. Moreover, underreporting remains important for such potentially serious ADRs, even in a university hospital.

Adverse drug reactions to selegiline: a review of the French pharmacovigilance database

The present pharmacoepidemiologic study was performed to characterize the profile of adverse drug reactions (ADRs) reported with selegiline, a monoamine oxidase B (MAO-B) inhibitor used in the treatment of Parkinson's disease and previously reported to induce an excess of mortality. The analysis was performed with use of the French Pharmacovigilance Database between 1989 and 1997. This database includes all ADRs reported by French practitioners (and especially "serious" and "unexpected" ADRs). Three different analyses were performed: identification of ADRs reported with selegiline, comparison with the ADR profile observed with other antiparkinsonian drugs, and a case/non-case study investigating the occurrence of cardiovascular ADRs with selegiline in comparison with other drugs in general and other antiparkinsonian drugs (e.g., levodopa [L-Dopa], dopamine agonists) in particular. The most often reported ADRs with selegiline were psychiatric (delirium, hallucinations, agitations), cardiovascular (orthostatic hypotension, arterial hypertension, etc.) and neurologic (sedation, abnormal movements, etc.). Psychiatric and cardiovascular ADRs were more frequently reported with selegiline than with L-Dopa or dopamine agonists. The case/ non-case study found an increased risk of cardiovascular ADRs (OR = 1.72; 95% Cl = 1.16-2.55)when selegiline was associated with L-Dopa. These data show that the profile of selegiline-induced ADRs differs from that of other antiparkinsonian drugs (L-Dopa, dopamine agonists) with more psychiatric and cardiovascular ADRs. We suggest that the higher frequency of cardiovascular ADRs could explain, at least partially, the previously reported increase in mortality rate.

Fluoxetine-induced pressor response in freely moving rats: a role for vasopressin and sympathetic tone

The present study was performed in order to assess, in freely moving rats, the cardiovascular effects of central administration of fluoxetine, a serotonin reuptake inhibitor. Two kinds of experiments were performed: 1) acute central administration of fluoxetine. and 2) chronic intraperitoneal administration of fluoxetine plus selegiline, a monoamine oxidase B inhibitor. Intracerebroventricular (i.c.v.) administration of fluoxetine (5-50 microg) induced an increase in blood pressure. This fluoxetine-induced pressor response reached its maximal 1 hour after injection without any significant change in heart rate. At the dose of 10 microg i.c.v., fluoxetine significantly increased mean blood pressure by 16 +/- 4 mmHg. This pressor response was reduced by an intravenous (i.v.) pretreatment with the alpha1-adrenoceptor antagonist, prazosin (500 microg kg(-1)) (+ 7 +/- 4 mmHg, P <0.05) or with the V1A-vasopressin receptor antagonist (20 microg kg(-1)) (+5 +/- 3 mmHg, P < 0.05). The pressor response was completely abolished by a concomitant pretreatment with prazosin plus the V1A-vasopressin receptor antagonist. Pretreatment with the beta-adrenoceptor antagonist, propranolol (1 mg kg(-1) i.v.), or the 5-HT2 receptor antagonist, ketanserine (5 mg kg(-1) i.v.), did not modify the fluoxetine-induced pressor response. In freely moving rats receiving fluoxetine (10 microg i.c.v.), vasopressin plasma levels were significantly higher (39 +/- 5 pg mL(-1) than in rats receiving 10 microL i.c.v. saline (14 +/- 4 pg mL(-1)). A 30 day intraperitoneal (i.p.) administration of fluoxetine in association with selegiline induced an increase in noradrenaline plasma levels and locomotor activity without any significant change in blood pressure and heart rate. These data suggest that, the pressor response elicited by central acute administration of fluoxetine is mediated by both an increase in sympathetic tone and vasopressin release. This observation could suggest the putative interest of alpha1-adrenoceptor and or V1A-vasopressin receptor antagonists in the treatment of "Serotonin Syndrome".

Mixed-level orthogonal array design for the optimization of solid-phase extraction of some pesticides from surface water

An orthogonal array design (OAD), OA32(4(1) x 2(28)), was employed as a chemometric method for the optimization of the solid-phase extraction (SPE) of atrazine, diazinon, ametryn and fenthion in surface water. Seven parameters: the type of eluting solvent, type of sorbent, flow-rate of eluting solvent, sample pH, sample volume, elution volume, addition of modifier and flow-rate of water sample were studied and optimized by a mixed-level OAD. The effects of these factors and some two-variable interactions on the recovery of the pesticides were quantitatively evaluated by the analysis of variance and percentage contribution techniques. The final optimized condition was employed for the SPE of selected micro-organic pollutants from Karoun river water, south of Iran. Atrazine and ametryn were tentatively identified and determined at the 0.7 and 0.9 microg l(-1) level, respectively.

Photosensitivity to ketoprofen: mechanisms and pharmacoepidemiological data

The topical use of nonsteroidal anti-inflammatory drugs (NSAIDs), widely used for moderate acute and chronic painful conditions, is one of several strategies used to improve the tolerability profile of NSAIDs, particularly with regard to gastric and renal adverse effects. However, topical NSAIDs can induce photosensitivity. Among the different NSAIDs used topically, ketoprofen has often been implicated in photosensitivity reactions. Photosensitivity includes both phototoxic and photoallergic reactions. Phototoxicity can be studied in the cell system and on biological targets such as cellular membranes or DNA. In hepatocyte cultures, data suggest that radical intermediates play a role in ketoprofen-photosensitised damage by cell membrane lysis. Photosensitised lysis of red blood cells has been employed as an indicator of membrane damage. Ketoprofen irradiation promotes the photolysis of erythrocyte suspensions. The drug is able to induce photoperoxidation of linoleic acid in the photo-induced lipid peroxidation process. The results obtained from the addition of radical scavengers suggest the involvement of free radicals in these processes. Ketoprofen may induce DNA damage in vitro upon irradiation. DNA, in the presence of ketoprofen, undergoes single strand breaks involving hydroxyl radicals as evidenced by the use of scavengers. Simultaneously with single strand breaks, pyrimidine dimers are formed by an energy transfer mechanism. The oxygen-dependence of both processes suggest competition between a radical process leading to DNA cleavage and a poorly efficient energy transfer between ketoprofen and pyrimidines at the origin of the dimerisation process. Photoallergy is due to a cell-mediated hypersensitivity response involving immunological reactions. Therefore, it only occurs in previously sensitised individuals and requires a latency period of sensitisation. Among NSAIDs, ketoprofen is the main drug involved in this photoallergic contact dermatitis. Cross-sensitivity reactions with other arylpropionic acid derivatives, such tiaprofenic acid, fenofibrate or oxybenzone-harbouring benzoyl ketone or benzophenone may also occur. Finally, the higher frequency of such adverse reactions with ketoprofen could be accounted for by its chemical structure and the variety of chemical reactions that give rise to phototoxic effects. The widespread and repeated use of these agents may lead to sensitisation, incurring a greater risk of systemic allergic reactions with oral NSAIDs or other drugs recognised to induce cross-reactions. Physicians and pharmacists should advise patients and inform them of the risks of topical NSAIDs which are often dispensed as over the counter drugs.

[Drug interactions: a prospective pilot study in primary health care]

The present prospective pilot study investigated putative drug interactions in primary health care. Among 110 outpatients, 50 were treated with more than one drug (maximum = 10). Among these 50 prescription forms, 21 concerned at least one drug interaction, with a total of 47 different drug interactions. Most of them (94 per cent) were explained by a pharmacodynamic mechanism. They were classified as 'requiring use precautions' (64 per cent), 'to be taken into account' (25 per cent) or 'inadvisable' (11 per cent). None of them was 'contraindicated'. Most often the drugs involved were diuretics, converting enzyme inhibitors or non-steroidal antiinflammatory drugs. Drug interactions, which concern around one in five prescription forms, remain an important topic in Clinical Pharmacology.

[Adverse effects of contrast media: results of a 6 months study]

The use of iodinated contrast agents is associated with adverse drug reactions (ADRs) (mainly allergic). Data from the literature suggest a frequency of ADRs ranging from 5 to 8 per cent for the whole group of iodinated contrast agents. The present systematic prospective study performed over a period of six months investigated ADRs in a Radiology Department of the University Hospital in Toulouse. After 1480 injections of iodinated contrast agents, only five ADRs (i.e. 0.34 per cent) were observed. However, the frequency remained higher in patients with a history of allergy (1.5 per cent). The low frequency of ADRs can be explained both by the use of mainly low osmolality contrast agents (75 per cent) and by systematic preventive management of risk (detailed questionnaire, choice of the contrast agent according to risk).

[Adverse effects of locally applied drugs]

Topical drugs, such as non-steroidal anti-inflammatory drugs (NSAIDs), are available without prescription and are widely used for moderate, acute and chronic painful conditions. However, the different characteristics of their adverse reactions remain largely unknown. The present work was undertaken in order to quantify ADRs reported to our centre with topical drugs during a period of 5 years. The retrospective study was performed using the spontaneous reports to the Midi-Pyrénées Pharmacovigilance Centre from 1993 to 1997. The following routes of administration were selected: cutaneous, ocular, pulmonary, vaginal, intra-articular, auricular, nasal, buccal and pharyngeal. One hundred and twenty-eight notifications were found in the database. Thirty-eight cases (29.7 per cent) were between 60 and 75 years old, 25 cases (19.5 per cent) between 45 and 60 years old and 22 cases (17.2 per cent) between 30 and 45 years old. The most frequently reported ADRs were cutaneous (n = 71, 55.5 per cent) cardiovascular (n = 16, 12.5 per cent), ocular (n = 13, 10.2 per cent), neurological (n = 12, 9.4 per cent) and oro-pharyngeal (n = 7, 5.4 per cent). Systemic ADRs (45 cases, 35 per cent) occurred mainly with aerosols (n = 10) and patches (n = 6). Twenty-seven reports (21 per cent) were classified as 'serious' including one death (misuse). The main pharmacotherapeutic agents involved were rheumatological [(n = 29) including 20 NSAIDs], dermatological (n = 27), ophthalmological (n = 16), pneumological (n = 15) and cardiovascular (n = 15) drugs. In 21 cases the rechallenge was positive. In eight cases (6.3 per cent), ADRs occurred after self-medication. This study underlines the importance of monitoring ADRs of topical drugs. The seriousness of such ADRs and the occurrence of systemic effects with such drugs seems rather frequent (as shown by topical NSAIDs-induced photosensitization).

Phenothiazine-induced acute colitis: a positive rechallenge case report

A case of phenothiazine-induced recrotizing colitis in a 41-year-old man is presented. A positive rechallenge was observed after introduction of another phenothiazine. The mechanism of this adverse drug reaction is discussed.

A study of salivary secretion in Parkinson's disease

Hypersialorrhea is frequently reported in patients with idiopathic Parkinson's Disease (PD). Excessive production of saliva, swallowing difficulties, or both could explain this complaint. Dopamine (DA) has been shown to modulate salivary secretion in a number of vertebrate and invertebrate species. The present study was performed to compare the unstimulated salivary flow in 83 patients with PD (8 untreated and 75 treated with levodopa + DA agonist) and in 65 age- and sex-matched control subjects. The Mann-Whitney U-test showed a significantly lower salivary flow in treated patients with PD (535 +/- 42 mg/2 min) (p < 0.002) and de novo patients (447 +/- 141) (p < 0.03) compared to controls (834 +/- 68 mg/2 min) with no relation with age or sex. Finally, the present study of reduced salivary flow in PD suggests that complaints of hypersialorrhea are not caused by a salivary defect, but could be explained by difficulties in swallowing. The decrease in salivary flow could be explained by autonomic dysfunction in PD.