Pilot study of a CCKB antagonist in patients with panic disorder: preliminary findings

L-365,260 is a CCKB antagonist which has been shown to completely prevent CCK-4-induced symptoms of panic attack in single-dose (50 mg) placebo-controlled studies in patients with panic disorder. The present report is data from one site (n = 38) in a multicenter study (n = 88) designed to assess the preliminary efficacy and safety of L-365,260 in patients meeting DSM-III-R criteria for panic disorder, with or without agoraphobia. In order to participate, male and female patients were between 18-55 years of age and in good physical health. Following a one-week single-blind placebo lead-in, patients were randomized to 30 mg four times daily of L-365,260 (n = 18; 7 M, 11 F) or placebo (n = 20; 9 M, 11 F) for six weeks. At end of study, none of the efficacy measures, including the frequency of panic attacks, the Physician's Global Improvement Scale, and the Hamilton Rating Scale for Anxiety, were significantly improved over baseline values. L-365,260 was well-tolerated; the most common drug-related adverse events were headache and lightheadedness. Further testing of L-365,260 at higher dosages, or testing of other CCKB antagonists, is required to rule out the usefulness of this novel treatment approach.

[Tetrazepam in the treatment of acute cervical syndrome. Randomized double-blind pilot study comparing tetrazepam and placebo]

METHODS

In a double-blind study, 20 ambulatory patients with acute painful restriction of mobility of the cervical spine and overall marked impairment were treated for seven days with tetrazepam (150 mg or a lower dose from the third day onward) or placebo. Paracetamol was permitted in addition if required. Test criteria: The main criterion of efficacy was a summed score of three parameters: pain, restriction of mobility, and general impairment.

RESULTS

The difference between the groups was statistically highly significant (p = 0.005). Tolerability was adjudged to be "very good" for the placebo group, and, on average, "good" for the tetrazepam group.

[An experimental study of the pharmacokinetic mechanisms for the development of gidazepam tolerance]

It has been shown that the basis for the development of tolerance to the myorelaxant effect of gidazepam given long to rats is biotransformational changes followed by varying pharmacokinetic parameters: decreases in the AUC of gidazepam and its desalkyl metabolite in plasma, in brain in particular, redistribution of these substances between the plasma and brain of tolerant rats. Changes in pharmacokinetic parameters have no influence on their anxiolytic effects.

Open study of clobazam in refractory epilepsy

Clobazam is a 1,5-benzodiazepine reported to have a wide spectrum of antiepileptic activity and is associated with less neurotoxicity than the 1,4-benzodiazepines, nitrazepam and clonazepam. The effect of clobazam on seizure control and neurologic behavior was examined prospectively in 115 children (average age: 8.4 years) with intractable seizures. Eighteen children (16%) became seizure free and a further 35 (31%) demonstrated a greater than 90% decrease in seizure frequency. Tolerance to the antiepileptic effect of clobazam was observed in 30 of 79 children (38%) who demonstrated an initial improvement in seizure control. Complete tolerance was observed in 9 patients, partial tolerance in 9, and partial tolerance that responded to an increased dose of clobazam in 12. Seventy-two percent of patients reported improvement and 26% worsening in at least one parameter of neurologic function after beginning clobazam. The improvement in neurologic function correlated poorly with change in seizure control. Patients who discontinued 1,4-benzodiazepine (n = 37) had a greater improvement in attention span, alertness, balance, drooling, and mood compared to the remainder of the group. These data suggest that clobazam is effective in the treatment of children with a wide range of epilepsies and seizure types and support the clinical impression that clobazam is associated with less neurotoxicity than the 1,4-benzodiazepines.

Octreotide and cholecystokinin antagonist reduce edema in obstruction-induced acute pancreatitis

Obstruction-induced acute pancreatitis in rats is associated with increased plasma cholecystokinin (CCK) levels. Duodenal replacement of bile reduces severity of pancreatitis and limits CCK increase. We investigated the role of CCK in the pathogenesis of obstruction-induced acute pancreatitis by pretreating rats with the somatostatin analog octreotide and the CCK antagonist L-364,718. Octreotide inhibits duodenal CCK release, and L-364,718 competitively blocks CCK receptors. We studied 31 rats after (1) sham operation (n = 7), (2) bile and pancreatic duct obstruction (BPDO) (n = 12), (3) BPDO plus octreotide (20 micrograms/kg IP and then 5 micrograms/kg/hr IV) (n = 6), and (4) BPDO plus L-364,718 (1 mg/kg IP and then 0.25 mg/kg/hr IV) (n = 6). Rats were killed after 18 hours. Pancreas weight, acute pancreatitis histology score, and plasma amylase and CCK levels were determined. Octreotide and L-364,718 limited the increase in pancreas weight. Octreotide also limited the rise in plasma CCK levels. These findings suggest that CCK may play a role in the pathogenesis of obstruction-induced acute pancreatitis.

[New pharmacodynamic effects of gidazepam and befol in patients with cardiac arrhythmias]

The new Russian drugs gidazepam, a tranquilizer, and befol, an antidepressant, show not only their psychotropic action, but change cardiac electrophysiological function and produce antiarrhythmic effects, which allows them to be used in the treatment of various cardiac arrhythmias. The antiarrhythmic effect of the psychopharmacological agents is largely shown in patients with ventricular premature contraction and paroxysmal tachycardias in the presence of neurocirculatory dystonia, as well as with great deviations of the electrophysiological properties of the cardiac conduction system from the their mean values, by promoting their normalization. The antiarrhythmic effect of gidazepam is higher than that of befol in both patients with neurocirculatory dystonia and those with coronary heart disease.

Prevention of ethanol-induced gastric damage by the imidazobenzodiazepines Ro 15-4513 and Ro 15-3505 in rats

The protective effects of the imidazobenzodiazepines Ro 15-4513 and Ro 15-3505 against ethanol-induced gastric damage were investigated. Gastric lesions were induced in rats by the oral administration of 1 ml of absolute ethanol. Ro 15-4513 (2.5-10 mg/kg, IP) or Ro 15-3505 (5-20 mg/kg, IP), administered 30 min before ethanol, protected against ethanol-induced gastric damage. The protective effects of these compounds were blocked by the benzodiazepine antagonist, flumazenil (10 mg/kg, IP). These results present evidence for the involvement of the GABA-benzodiazepine receptor complex in the pathogenesis of ethanol-induced gastric damage.

Lack of effect of concomitant clobazam on interictal 123I-iomazenil SPECT

Single photon emission computed tomography (SPECT) is being increasingly used as an adjunctive technique in the localisation of epileptogenic foci prior to surgery. Fourteen patients (five male, nine female; mean age 31 years) with refractory complex partial seizures, all of whom had abnormal 99Tc HM-PAO SPECT scans, were imaged again using the benzodiazepine receptor ligand 123I-iomazenil. Eleven of these patients displayed the same abnormality on both scans. The magnitude of the deficit, however, was slightly greater (P < 0.05) on the iomazenil scan compared with the HM-PAO study. These 11 patients were then randomised into two groups. Group 1 (n = 7) received clobazam 20 mg/day for a minimum of 7 days before a second iomazenil study was performed. Patients in group 2 (n = 4) underwent a second iomazenil scan at the same time interval as those in group 1, but without the additional clobazam. The resultant scans were reported blind to treatment. There were no qualitative or quantitative differences between the first and second iomazenil studies in either group. Patients can be imaged using 123I-iomazenil without withdrawing clobazam therapy. From this preliminary study, there seems little advantage in using iomazenil in place of HM-PAO to delineate the extent of the zone of epileptogenesis. Whether iomazenil SPECT will prove to be more sensitive in identifying the site of the epileptic focus remains to be determined.

CCK/gastrin antagonists--clinical perspectives

There are (at least) two types of receptor for cholecystokinin (CCK)/gastrin peptides. Highly potent specific antagonists are available for both types. The CCKA-receptor mediates classical CCK-like effects on the gut. Antagonists given to man inhibit pancreatic enzyme secretion and generally shorten gastrointestinal transit times. Potential clinical indications include anorexia, gastro-paresis, pseudo-paresis, pseudo-obstruction, severe constipation and chronic pancreatitis. However gallbladder contraction is markedly inhibited and this led to gallstone formation in baboons. This will obviously have to be avoided if CCKA antagonists are to be used in man. CCKB-receptors mediate the effects of gastrin on the gut and the effects of CCK in the brain. They inhibit gastrin-stimulated acid secretion. If used in acid-peptic disease they might inhibit the trophic effects of gastrin on enterochromaffin cells. CCKB-antagonists can also inhibit the growth of some gastrin-dependent tumours, including certain human colonic cancer cell lines which produce gastrin. CCKB-antagonists have a potent anxiolytic-like effect in animals, and this effect might become their main clinical application.

[Therapeutic potential of Ro 5-3335. New active benzodiazepine in vitro against HIV-1 viruses resistant or non-resistant to AZT]

Ro 5-3335 is a new benzodiazepine highly active in vitro (IC50 = 0.1-1.0 microM [corrected]) against HIV-1 viruses of AIDS resistant or non-resistant to zidovudine (AZT). It is also active against HIV-2. Ro 5-3335 is original by its mechanism of action, acting on the trans-activation factor of transcription (TAT) and non on the reverse transcriptase. Such as, it could prevent proviral DNA to express in both evolutive and silent AIDS resistant or non-resistant to AZT or to other anti-reverse transcriptase series. In addition, in antagonizing extracellular TAT's actions, Ro 5-3335 could alleviate the syndrome commonly associated with AIDS as Kaposi's syndrome. In rodent test, Ro 5-3335 has no diazepam-like central effects and presents in comparison to AZT a more favorable therapeutic index. In dog, the elimination half-life, peak concentration and availability are 2 h, 0.8 microM and 85% respectively, after a 1 mg.kg-1 oral dose of Ro 5-3335. Theoretically, Ro 5-3335 and now its analogue Ro 24-7429 seem to possess all virtues to antagonize evolutive and latent AIDS. Its arrival is timely to cope with the ever increasing resistance phenomena, lengthy development of AIDS vaccines, exponential contamination of populations worldwide and last but not least possibly to impede evolutions of the disease. Ability to manipulate TAT-mediated activation of HIV-1 genes paves the ways to study conceivable corrections of abnormal gene expressions of neurotransmitters, hormones, oncogenes and key enzymes.

Do benzodiazepine ligands contribute to hepatic encephalopathy?

1. Levels of BZ receptor ligands are elevated in the brain of animal models of FHF and humans with FHF. Some of these ligands have agonist properties and some are known 1, 4-BZs which bind to the DS receptor. Much of the BZ receptor ligand activity in HE is unidentified and it is possible that some may bind to receptor subtypes other than the DS receptor. 2. Average levels of BZ receptor ligands in the brain in HE do not appear to be sufficient to augment GABAergic tone to a degree that would result in severe encephalopathy (i.e. coma). However, these ligands have a heterogeneous distribution in the brain and their neuroinhibitory effects may be potentiated by increased availability of GABA at GABAA receptors. Furthermore, that these ligands may contribute to HE is suggested by anecdotal reports of ameliorations of HE being induced in a majority of patients by the BZ receptor antagonist flumazenil. 3. The response of HE to flumazenil in humans is usually incomplete and in animal models may be modest. Potential explanations for these findings include pharmacokinetics, BZ receptor subtype specificity and higher levels of BZ receptor ligands in the brain in humans with HE than in animal models. 4. Certain BZ receptor ligands e.g. Ro 15-3505 and Ro 15-4513, that are structurally related to flumazenil, are more efficacious at ameliorating HE than flumazenil in animal models. These findings may be more dependent on differences in BZ receptor subtype specificity than differences in intrinsic activity. The properties of an ideal BZ receptor ligand for administration to a patient with HE would appear to be: (i) antagonist action at BZ receptors, (ii) no intrinsic activity apparent after a conventional pharmacologic dose, (iii) high specificity and affinity for BZ receptors, (iv) slow metabolism, and (v) absence of toxic effects. Promising ligands, such as Ro 15-3505, with weak partial inverse agonist actions and hence analeptic potential, require careful evaluation of their therapeutic index before clinical application. 5. BZ receptor ligands may be useful in the management of HE. Specifically, they may be given IV: (i) to reverse effects of exogenous BZs; (ii) to aid in the differential diagnosis of encephalopathy; (iii) to provide prognostic information; and (iv) to optimize brain function. They may also be given orally with the objective of reducing dietary protein intolerance in patients with chronic liver disease.

Flexor reflex for assessment of common interneurone activity in spasticity

The purpose of this investigation was to evaluate the alterations of flexor reflex parameters in spasticity and the possibilities to take advantage of them as a method for assessment of common interneurone activity. Clinical and electromyographical examinations were performed on 120 patients with spastic hemiparesis after stroke. The flexor reflex was obtained after supramaximal electrostimulation of the tibial nerve behind the ankle. The stimulus consisted of 50 msec train of 1 msec duration pulses given at 100 Hz. The reflex activity was recorded from the tibialis anterior muscle. As all patients were with hemiparesis the healthy side was used as a control. The patients were subdivided into four groups, each treated with different myorelaxants (Baclofen, Sirdalud, Myolastan and electroacupuncture). After about 25 days treatment the clinical and electromyographic examinations were repeated. The flexor reflex was recorded with two clearly distinguishable responses on the healthy, as well as on the spastic side. On the spastic side a reflex with prolonged latencies and durations, as well as with decreased amplitudes and thresholds of both reflex responses was found. On the spastic side the first reflex response had higher threshold than the second one, while on the healthy side it was vice versa. Moderate correlations were found between most of the reflex parameters. No correlations were found between the reflex parameters and the degree of spasticity. Only after Baclofen treatment all reflex parameters tended to normalized. After treatment with Myolastan, Sirdalud and electroacupuncture only the second response's duration shortened. In conclusion the flexor reflex is a sensitive method for assessment of altered common interneurone activity in spasticity.(ABSTRACT TRUNCATED AT 250 WORDS)

[Partial motor status epilepticus. Primary form provoked by eye closure]

We report the case of a young female patient with photosensitive primary epilepsy who presented partial motor status epilepticus provoked by the act of shutting the eyes. Clinical, EEG and neuroimage data are presented and discussed.

Relationship between benzodiazepine receptor occupancy and functional effects in vivo of four ligands of differing intrinsic efficacies

Agonists at the benzodiazepine receptor (BZR) produce their effects through potentiation of the inhibitory alpha-aminobutyric acid-mediated neurotransmission in the central nervous system via positive allosteric modulation of the gamma-aminobutyric acidA receptor. Agonists with high intrinsic efficacy are anticonvulsant, anxiolytic, muscle relaxant and sedative, whereas agonists with low intrinsic efficacy (partial agonists) are predominantly anticonvulsant and anxiolytic, but antagonize muscle relaxant and sedative effects of full agonists. The four BZR ligands triazolam, diazepam, Ro 19-8022 (a benzoquinolizinone) and bretazenil (Ro 16-6028, an imidazobenzodiazepinone) were pharmacologically characterized in various neurological and behavioral paradigms in mice: two anticonvulsant tests (prevention of audiogenic and pentylenetetrazol-induced seizures), a conflict test which reveals both anxiolytic and sedative properties and two tests which mainly measure motor impairment (rotarod and horizontal wire test). Although triazolam and diazepam elicited an effect in all tests, Ro 19-8022 and bretazenil exhibited anticonvulsant and anxiolytic properties, but virtually failed to induce motor impairment and severe sedation. In separate experiments, fractional BZR occupancy in vivo was assessed by inhibition of [3H]flumazenil binding and correlated with the pharmacological effects. Although diazepam and triazolam produced effects beginning at low to intermediate fractional BZR occupancy, Ro 19-8022 and bretazenil required a higher BZR occupancy to do so, in accordance with their partial agonistic character. With the two full agonists, anticonvulsant and anticonflict activities were elicited at a lower fractional BZR occupancy than muscle relaxant and sedative effects.(ABSTRACT TRUNCATED AT 250 WORDS)

[Comparative analysis of antiarrhythmic action and electrophysiological effects of a new benzodiazepine derivative gidazepam and ethacizin in arrhythmias of various genesis]

The antiarrhythmic and electrophysiological effects of the new benzodiazepine tranquilizer gidazepam versus ethacizin were examined in patients with cardiac arrhythmias. The antiarrhythmic effect of the agent was found during 24-day monitoring and simulated psychoemotional stress in 81% of patients with neurocirculatory dystonia and in 61% of patients with coronary heart disease. The antiarrhythmic effects developed with gidazepam-induced changes in electrophysiological properties of the cardiac conduction system. The preventive antiarrhythmic effect of gidazepam was demonstrated to be higher than that of ethacizin during stress in patients with arrhythmias of extra-ischemic genesis.

Effect of somatostatin analogue and cholecystokinin receptor antagonist on bile-induced acute canine pancreatitis

To determine whether a synthetic somatostatin analogue, octreotide, and a cholecystokinin receptor antagonist, L-364,718, may be beneficial in acute pancreatitis, 33 dogs were assigned to four groups. Each dog underwent laparotomy with injection of autologous bile into the dorsal pancreatic duct. Thirty minutes after the induction of pancreatitis, Group 1 received a subcutaneous injection of octreotide (200 micrograms/kg), Group 2 received an equal volume of the octreotide carrier, Group 3 received an hourly intravenous bolus of L-364,718 (60 micrograms/kg), and Group 4 received an equal volume of the L-364,718 carrier. Hemodynamic profiles, arterial blood gases, plasma glucose, and serum amylase were obtained before laparotomy, at bile injection, and at hourly intervals. The pancreas was removed after 8 hours for gross evaluation, measurement of water content, and histologic examination. A significant decrease in cardiac index and a significant increase in serum amylase and pancreatic edema occurred in all four groups 8 hours after the induction of pancreatitis (P less than 0.05), but there was no statistical difference between any group. Likewise, there was no difference in gross or histologic changes in the pancreas of any group. The somatostatin analogue, octreotide, and the cholecystokinin receptor antagonist, L-364,718, did not ameliorate the effects of severe, bile-induced pancreatitis in dogs.

[Comparative anti-arrhythmia effectiveness of activators of body stress-limiting systems in patients with arrhythmia]

The antiarrhythmic effects produced by activators of the body's stress-limiting systems were comparatively evaluated in patients with cardiac arrhythmias of ischemic and non-ischemic etiology. Acediprol, gidazepam, and befol were found to be beneficial in ventricular premature contraction when psychoemotional stress was simulated, as evidenced by 24-hour monitoring. The most pronounced protective therapeutical effect of the drugs was observed in patients with arrhythmias of extracoronary origin and in individuals with a marked arrhythmogenic effect of stress. Gidazepam was shown to suppress the provocative arrhythmogenic effect of the stress test.

A pilot clinical trial of the cholecystokinin receptor antagonist MK-329 in patients with advanced pancreatic cancer

MK-329 is a nonpeptidal, highly specific cholecystokinin (CCK) receptor antagonist, with affinity for pancreatic and gallbladder CCK receptors similar to CCK itself. MK-329 and its progenitor, asperlicin, can inhibit the growth of CCK receptor-positive human pancreatic cancer in athymic mice. Based on these activities and the ability of MK-329 to transiently increase food intake and enhance morphine analgesia in murine models, we conducted an open trial of MK-329 in 18 patients with advanced pancreatic cancer in whom the CCK receptor status of the tumors was unknown. Tumor response, pain control, and nutritional parameters (hunger rating, caloric intake, body weight, and anthropometrics) were serially assessed. The results of the study failed to demonstrate any impact of MK-329 on tumor progression, pain, or nutrition. Toxicity was mild and limited to nausea, vomiting, diarrhea, and abdominal cramps, with 17 of 18 patients able to tolerate treatment. While a role for MK-329 in the management of patients with advanced pancreatic cancer cannot be supported by the results of this trial, additional studies of this agent in patients with known CCK receptor-positive tumors, at escalated doses, and possibly in conjunction with other growth antagonists, appear warranted.

Tolerance to the anticonvulsant effects of clobazam in mice

Tolerance to the anticonvulsant effects of clobazam has been studied in three murine models of epilepsy: pentylenetetrazole- and N-methyl-D,L-aspartic acid-induced seizures and audiogenic-induced seizures in the DBA/2 strain. Tolerance occurred most rapidly in the pentylenetetrazole model but the development of tolerance could be reduced by increasing the dose interval. Tolerance to the protective effects of clobazam occurred more readily to the first tonic seizure than to the full tonic clonic seizure. The development of tolerance could not be attributed to smaller concentrations of clobazam in brain or to increasing concentrations of the metabolite. Although slower to develop, tolerance to clobazam did occur in the N-methyl-D,L-aspartate model. However, tolerance to the protection from the full tonic clonic seizure in DBA/2 mice could not be detected, even when the dose of clobazam was reduced to the smallest dose that acutely protected most of the mice. In contrast, the protection given by clobazam to the induction of the wild-run in DBA/2 mice, did exhibit tolerance. Studies on the mechanism of tolerance to the anticonvulsant activity of benzodiazepines must take account of the seizure model used and the dose and interval between doses.

[Chronic prostatodynia and psychosomatic care]

Depression is a regular accompaniment of all chronic painful conditions. A study was conducted to assess the effect of treatment of the depressive factor in patients with chronic prostatodynia. Effects were compared of psychosomatic therapy (psychotherapy, relaxation, etc.) alone in 9 patients (group I) and the same psychosomatic care plus treatment with amineptine and clobazam in 9 patients (group II). Results showed that 2 patients recovered and 3 were improved (62%) with 1 drop-out in group II, versus recovery and 2 improvements (42%) with 2 drop outs in group I. These findings are analyzed and discussed.

Mechanisms of tetrazepam action on spasticity

This investigation assessed the mechanisms of Tetrazepam action on spasticity using a battery of electromyographic methods. Thirty patients with post-stroke spastic hemiparesis treated with Tetrazepam took part in the investigation. A questionnaire for assessment of subjective improvement after treatment used a 5-point scale. The 5-point scales were used to assess muscle tone, muscle strength and tendon reflexes. A battery of electromyographic methods was used to analyse different mechanisms of spasticity: for alpha-motoneuron activity--the F-wave parameters; for gamma-motoneuron activity--the TA/H amplitude ratio; for presynaptic inhibition--the ratio of H-reflex maximal amplitudes before and after vibration on the Achilles tendon (Hvibr/Hmax); for common interneuron activity--the flexor reflex parameters. Our results revealed that Tetrazepam reduces tone in spastic muscles and has a slight effect on tendon hyperreflexia. It has no influence on muscle strength, Babinski sign and ankle clonus. Tetrazepam acts by decreasing motoneurone activity and increasing presynaptic inhibition.