Orphenadrine induces secondarily generalized convulsive status epilepticus in rats.

The current study was aimed to assess the convulsant potency of orphenadrine (ORPH) in rats together with a screen of different conventional antiepileptic drugs (AEDs) on their efficacy to suppress it. ORPH was administered intraperitoneally (i.p.) in doses of 50-80 mg/kg in male Wistar rats. The latency to first seizure, the number of seizure episodes and the duration of overt status epilepticus (SE) as well as the incidence of deaths was scored with simultaneous electroencephalographic (EEG) recordings. Subsequently, the effects of conventional AEDs on ORPH-evoked (80 mg/kg) seizure incidence were studied. ORPH dose-dependently induced seizures in increasing number of animals, reaching 100% at a dose of 80 mg/kg, associated with low mortality and no drug-related neurotoxicity. Epileptic attacks started as complex partial fits consisting of stereotyped behavior, limb movements, head shaking and myoclonic twitches of the body. Subsequently, an overt generalized convulsive SE appeared, lasting for approximately 2h. Among conventional AEDs: carbamazepine, ethosuximide and phenytoin had no effect while valproate (p<0.001), diazepam (p<0.01), and phenobarbital (p<0.001) dose-dependently suppressed seizure activity. All the above characteristics make the new model, a useful, easy to perform experimental tool to study the pathophysiology of SE as well as the effects of new AEDs.

Opiate sparing effect of fixed combination of diclophenac and orphenadrine after unilateral total hip arthroplasty: A double-blind, randomized, placebo-controlled, multi-centre clinical trial.

Multimodal pain management combines analgesics to improve analgesia and reduce side effects. This study investigates the fixed combination of diclophenac and orphenadrin (Neodolpasse(®) Infusion Solution) in patients after unilateral total hip arthroplasty (THA). This prospective, randomized, double-blind, placebo-controlled, multi-centre clinical study enrolled 120 patients receiving patient-controlled analgesia (PCA). Isotonic saline was infused as placebo. The primary efficacy goal was defined as reduction of PCA analgesics used over the first 24 h post-surgery. The study used a three-stage group sequential test design with two interim analyses. Analgesia was monitored by visual analogue scale and verbal rating. Infusion of the Neodolpasse(®) Infusion Solution resulted in a significant reduction in the PCA analgesic requirements by approximately 30% (38.7 ± 21.3 mg vs. 55.9 ± 31.1 mg; p = 0.0004) while maintaining adequate analgesia and patient safety. This study demonstrates that Neodolpasse(®) Infusion Solution significantly reduces PCA analgesic requirements without compromising analgesic effectiveness and safety in THA patients.

The use of antipsychotic and anticholinergic antiparkinson drugs in Norway after the withdrawal of orphenadrine.

AIMS: Extrapyramidal side-effects induced by antipsychotic drugs are treated with dose reduction or substitution with another antipsychotic drug or by the addition of anticholinergic antiparkinson agents. The withdrawal of orphenadrine from the Norwegian market provided a possibility to investigate to what degree these alternative measures were taken in clinical practice. METHODS: Data were drawn from the Norwegian Prescription Database on the sales of antipsychotics and one of the two anticholinergic antiparkinson agents marketed in 2004, orphenadrine and biperiden, to a total of 39 758 outpatients. The patients were reinvestigated in 2007. The consequences of the withdrawal of orphenadrine from the Norwegian market in 2005 regarding dosing, switching and cessation of antipsychotics and use of anticholinergics were assessed for orphenadrine users compared with biperiden users. RESULTS: Of the patients originally using orphenadrine, 28.4% stopped using the drug without reducing the antipsychotic dose or replacing orphenadrine with another anticholinergic agent. The corresponding number for biperiden users was 19.3%. Only 11.8% of patients switched to another antipsychotic drug, but they used significantly lower antipsychotic doses than those who stayed on the same drug. CONCLUSION: The use of anticholinergic antiparkinson agents could be seen as superfluous for at least one-third of patients.

The use and potential abuse of anticholinergic antiparkinson drugs in Norway: a pharmacoepidemiological study.

WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT: Anticholinergic antiparkinson drugs are used to ameliorate extrapyramidal symptoms caused by either Parkinson's disease or antipsychotic drugs, but their use in the treatment of Parkinson's disease is assumed to be in decline. Patients with psychotic conditions have a high prevalence of abuse of drugs, including anticholinergic antiparkinson drugs. WHAT THIS STUDY ADDS: Anticholinergic antiparkinson drugs in Norway were primarily prescribed to patients using antipsychotic medication. The risk of abuse of this group of drugs was small, even among patients who probably abused other drugs. AIMS: The use of anticholinergic antiparkinson drugs is assumed to have shifted from the therapy of Parkinson's disease to the amelioration of extrapyramidal adverse effects induced by antipsychotic drugs. There is a considerable body of data suggesting that anticholinergic antiparkinson drugs have a potential for abuse. The aim was to investigate the use and potential abuse of this class of drugs in Norway. METHODS: Data were drawn from the Norwegian Prescription Database on sales to a total of 73 964 patients in 2004 of biperiden and orphenadrine, and use in patients with Parkinson's disease or in patients who were also prescribed antipsychotic agents. Possible abuse of these drugs was assessed by the level of use, skewedness of use, indications of drug-seeking behaviour and concomitant use of benzodiazepine tranquillizers, a group of prescription drugs with a recognized potential for abuse. RESULTS: Anticholinergic antiparkinson drugs were prescribed to 4.5% of all outpatients who used antipsychotic drugs. This outnumbered sales to patients with Parkinson's disease by >20 to 1. We found indications of abuse of benzodiazepine tranquillizers among patients using antipsychotics, but there were no clear indications of abuse of anticholinergics, even among patients who were strongly suspected of abuse of benzodiazepines. CONCLUSIONS: Anticholinergic antiparkinson drugs were used primarily by patients with psychotic illnesses. These patients have a very high prevalence of legal and illegal drug abuse, but the risk of abuse of anticholinergic antiparkinson drugs seemed small.

Efficacy and safety of combined piroxicam, dexamethasone, orphenadrine, and cyanocobalamin treatment in mandibular molar surgery.

Third molar extraction is a common procedure frequently accompanied by moderate or severe pain, and involves sufficient numbers of patients to make studies relatively easy to perform. The aim of the present study was to determine the efficacy and safety of the therapeutic combination of 10 mg piroxicam, 1 mg dexamethasone, 35 mg orphenadrine citrate, and 2.5 mg cyanocobalamin (Rheumazin) when compared with 20 mg piroxicam alone (Feldene) in mandibular third molar surgery. Eighty patients scheduled for removal of the third molar were included in this randomized and double-blind study. They received (vo) Rheumazin or Feldene 30 min after tooth extraction and once daily for 4 consecutive days. Pain was determined by a visual analogue scale and by the need for escape analgesia (paracetamol). Facial swelling was evaluated with a measuring tape and adverse effects and patient satisfaction were recorded. There was no statistically significant difference in facial swelling between Rheumazin and Feldene (control group). Both drugs were equally effective in the control of pain, with Rheumazin displaying less adverse effects than Feldene. Therefore, Rheumazin appears to provide a better risk/benefit ratio in the mandibular molar surgery. Since the side effects resulting from nonsteroidal anti-inflammatory drug administration are a severe limitation to the routine use of these drugs in clinical practice, our results suggest that Rheumazin can be a good choice for third molar removal treatment.

Efficacy and safety of combined piroxicam, dexamethasone, orphenadrine, and cyanocobalamin treatment in mandibular molar surgery

Third molar extraction is a common procedure frequently accompanied by moderate or severe pain, and involves sufficient numbers of patients to make studies relatively easy to perform. The aim of the present study was to determine the efficacy and safety of the therapeutic combination of 10 mg piroxicam, 1 mg dexamethasone, 35 mg orphenadrine citrate, and 2.5 mg cyanocobalamin (Rheumazin®) when compared with 20 mg piroxicam alone (Feldene®) in mandibular third molar surgery. Eighty patients scheduled for removal of the third molar were included in this randomized and double-blind study. They received (vo) Rheumazin or Feldene 30 min after tooth extraction and once daily for 4 consecutive days. Pain was determined by a visual analogue scale and by the need for escape analgesia (paracetamol). Facial swelling was evaluated with a measuring tape and adverse effects and patient satisfaction were recorded. There was no statistically significant difference in facial swelling between Rheumazin and Feldene (control group). Both drugs were equally effective in the control of pain, with Rheumazin displaying less adverse effects than Feldene. Therefore, Rheumazin appears to provide a better risk/benefit ratio in the mandibular molar surgery. Since the side effects resulting from nonsteroidal anti-inflammatory drug administration are a severe limitation to the routine use of these drugs in clinical practice, our results suggest that Rheumazin can be a good choice for third molar removal treatment.

Torsades de pointes in congenital long QT syndrome following low-dose orphenadrine.

We report the case of a woman, affected by congenital long QT syndrome (LQTS), who experienced three syncopal episodes shortly after the assumption of a low dose of orphenadrine. The ECG revealed a QT interval of 600 ms, and the corrected QT interval (QTc) was 537 ms. No structural cardiac disease was demonstrated by echocardiography. Orphenadrine treatment was discontinued. During the first 12 h of monitoring, three short-lasting, asymptomatic episodes of torsades de pointes occurred. No other sustained ventricular arrhythmia was revealed at Holter monitoring in the following days. During the ensuing 6 months, the patient remained asymptomatic, and the QTc did not change. Orphenadrine is an analogue of diphenhydramine, an antihistaminic drug that produces sodium channel blockade similar to that caused by quinidine and other Class Ia antiarrhythmic drugs. Our case rises the suspicion that orphenadrine could cause life-threatening arrhythmias in LQTS even at a low dose, and independently from concomitant assumption of potentially QT-prolonging drugs.

Analgesic effects of low-dose intravenous orphenadrine in the state of capsaicin hyperalgesia. A randomised, placebo-controlled, double-blind cross-over study using laser somatosensory evoked potentials obtained from capsaicin-irritated skin in healthy volunteers.

The present investigation aimed to elucidate the analgesic efficacy of 30 mg of intravenous orphenadrine citrate (CAS 4682-36-4) in a human pain model. Eighteen healthy female and male subjects were enrolled and received single infusions of 30 mg orphenadrine citrate and matching placebo in two periods which were separated by a 1 week washout period. The study was designed as a randomised, double-blind, placebo-controlled, two-period, cross-over trial. The intended neurogenic inflammation and hyperalgesia were induced by topical, occlusive application of 1% capsaicin solution (INCI: Capsicum frutescens, containing capsaicinoides from Capsicum annuum annuum, CAS 84603-55-4) for 30 min on defined skin areas of the back. The pain response to CO2 laser pulses applied to the capsaicin pre-treated skin was measured by event related Vertex-EEG recordings. This technique allowed studying the influence of orphenadrine citrate on the (central) P2-component and the (peripheral) Ni-component of the pain response (LSEP). Both, orphenadrine citrate and placebo were given as intravenous infusions over 60 min. Orphenadrine citrate exerted a significant reduction in central and peripheral components of the pain response when compared to placebo. The effect on the central component was highly significant and more pronounced than the peripheral effect of the drug. The analgesic effect developed fast, was already present during infusion, was ongoing, and exceeded the observational period of 4 h after start of infusion. In summary, orphenadrine citrate was able to exert an analgesic/anti-hyperalgesic effect in a low-dose paradigm (30 mg dose) which was predominantly due to central/spinal mechanisms in this capsaicin model with laser somatosensory evoked potentials.

[Results of efficacy study with diclofenac/orphenadrine infusions in patients with musculoskeletal diseases and functional disorders]. / Ergebnisse einer Anwendungsbeobachtung mit Diclofenac/Orphenadrin-Infusionen bei Patienten mit muskuloskelettalen Krankheiten und Funktionsstörungen.

During a post-marketing surveillance study, 641 patients (age range 18 to 86 years) with painful rheumatic diseases, mostly of vertebral etiology, were given ready-for-use infusions containing a combination of the non-steroid antiphlogistic agent diclofenac (75 mg) and the muscle relaxing agent orphenadrine (30 mg) parenterally for 7 days. The goal of the study was to investigate efficacy, tolerability, and acceptance of this intravenous therapy in wide use in physicians' practices. At the end of treatment, the global evaluation resulted in a score of 1.6 on a scale of 1 (very good) to 4 (insufficient). The tolerability score was 1.3 and the acceptability score was 1.5. Only 20 patients (3.1%) had adverse effects, most of which were of gastrointestinal nature. The medication proved appropriate for use in the treatment of painful spine syndromes, inflammatory osteoarthritis, painful osteoporosis, post-operative conditions, and extra-articular rheumatism and could represent a first step towards multi-factorial therapeutic management of these diseases.

[Diclofenac/orphenadrine infusion therapy in patients with active arthrosis]. / Diclofenac/Orphenadrin-Infusionstherapie bei Patienten mit aktivierten Arthrosen.

This study investigated the efficacy and safety of a diclofenac/orphenadrin infusion in 21 female and 1 male patients with clinically and radiologically diagnosed inflammatory osteoarthritis of the big joints, especially the knee and hip joints. The patients received 1 infusion per day over 2 h for 10 days. Efficacy and safety were assessed by measuring the subjective pain intensity at rest and during exercise on a visual analogue scale and on an ordinal rating scale before and after every infusion. The patients were interviewed daily for possible side effects. After the 10-days treatment course a 5% reduction of pain at rest and a 37.5% reduction of pain during exercise was observed. Subjective pain intensity was reduced by an average of 32.5%. In most cases relief was noticeable after the 4th infusion. 9 patients rated the medication safety as "very good", 11 patients as "good". A total of 12 patients reported mainly mild side effects such as vertigo, dry mouth, and temporarily reduced visual acuity. Based on its rapid onset of action and its efficacy, it can be stated that the investigated diclofenac/orphenadrin infusion is a valuable extension of the therapeutic methods in patients with inflammatory osteoarthritis.

[Atypical acute dystonia]. / Atypisk akut dystoni.

Acute dystonia is a common adverse effect following anti-psychotic medication, which mainly appears shortly after beginning treatment or increasing the dosage. Laryngeal dysfunction may carely occur as part of the picture of acute dystonia and, if so, usually with dyspnoea. We describe a case of acute dystonia with atypical onset without relation to changes in dosage and with laryngeal involvement with aphonia, but without dyspnoea.

Impaired cognitive shifting in parkinsonian patients on anticholinergic therapy.

In this study we established that cognitive shifting, an ability that is known to be affected in PD, is more impaired in PD patients, treated with anticholinergics, than in de novo patients. Eleven PD patients on anticholinergic monotherapy were compared with 30 de novo patients. The groups did not differ with respect to age, duration and severity of PD, and depression, nor with respect to general intelligence or attention. We assessed cognitive shifting with three different card-sorting tests. The patients on anticholinergics showed a poorer performance on all card-sorting tests than the de novo patients did. The patients on anticholinergics needed significantly more trials in two card-sorting tests and discovered significantly less categories in total. There was also a significant difference in memory performance, but memory performance did not correlate with any score on the card-sorting tests. This indicates that the performance on card-sorting tests and the memory performance were independent.