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Biomedical subjects

J Walden

Publications and source records attributed to J Walden.

At least 73 records · Page 4Linked to original sources
PubMed1996

Acute brain syndrome after tapering off clozapine in clozapine-lithium combination.

1. This is a report of a patient who developed an acute organic psychosis due to neurotoxicity of lithium several days after tapering off a long-lasting clozapine therapy. 2. The organic brain syndrome with initial illusionary misperceptions, a confusional state and a lapse into a pre-coma developed three days after the end of clozapine therapy and seven days after the beginning of haloperidol addition. 3. Possible pharmacokinetic and pharmacodynamic factors responsible for the severe neurotoxicity of lithium after withdrawal of clozapine and addition of haloperidol are discussed.

Adult↗
PubMed1996

An acute psychotic disorder caused by pefloxacin: a case report.

1. The patient, a 59 year old woman, developed a state of acute excitation several hours after the administration of 400 mg of the fluorquinolone pefloxacin in combination with 1000 mg paracetamol. Nine days later, after a total dosage of pefloxacin of 800 mg, she was admitted to our hospital with a psychotic disorder. 2. There was a full remission of symptoms after treatment with perazine up to a dosage of 500 mg/day. 3. Three years ago, the patient had developed a manic state under a medication with corticosteroids. 4. So far, the mechanism of--in this case--long-lasting central nervous side effects of fluorquinolones is not known. In patients with increased vulnerability of the CNS or in advanced age the application of fluorquinolones should be considered critically, in particular in combination with non-steroidal anti-inflammatory drugs.

Female↗
PubMed1996

Combined treatment with lithium and nimodipine in a bipolar I manic syndrome.

1. The benefit of a combined treatment with the calcium antagonist nimodipine and lithium in a bipolar I disorder (currently manic, DSM IV 296.44, ICD 10 F 31.1) was explored and documented in a longitudinal single case study. 2. Nimodipine (270 mg/d) was added to lithium (900 mg/d), substituting for previously administered neuroleptics, in an up to then unsatisfactorily treated manic patient. 3. A clear-cut improvement in the patient's condition was achieved within a fortnight, and lasted over the continuation period of this drug regimen. This combined treatment was discontinued after eight weeks and lithium alone was then administered. Within three months another manic episode appeared. 4. Side-effects and changes of lithium blood levels were not observed during the combined treatment with nimodipine and lithium. 5. Further research on the benefits of adding a calcium antagonist, instead of neuroleptics, to lithium therapy for bipolar manic disorder patients who do not respond sufficiently to lithium is recommended. In addition, the benefits of a long term prophylaxis of nimodipine alone or in combination with lithium should be evaluated in those bipolar patients who still show a high relapse frequency on lithium alone.

Adult↗
PubMed1996

Addition of lamotrigine to valproate may enhance efficacy in the treatment of bipolar affective disorder.

The new antiepileptic lamotrigine has been shown to be effective in the treatment of focal epilepsies with or without secondary generalization and has also been suggested to be efficacious in the treatment and prophylaxis of affective disorders. Therefore, we analyzed its possible benefit in a patient with refractory bipolar affective disorder. Lamotrigine (up to 150 mg/d) was added to valproate (2700 mg/d), substituting previously administered neuroleptics. A considerable improvement of the patient's condition was achieved several days after the beginning of lamotrigine co-administration, and lasted over the total follow-up period of more than one year. The plasma concentrations after total remission were in the range of 1.9 to 6.2 mg/l for lamotrigine and 57.1 to 95.2 mg/l for valproate. This positive action of lamotrigine is discussed in the context of the drug's elementary effects on sodium and calcium channels.

Adult↗
PubMed1996

[Phase prevention in bipolar affective disorder with nimodipine. A case report].

A 56-year-old female patient had a history of more than 10 years' duration of a bipolar affective disorder manifest mainly as depressive episodes. These episodes used to occur once or twice each year, frequently leading to hospital admission. On average, the episodes lasted for about 2 months, and they tended to be followed by brief periods of hypomania. Only once, in 1986, did a manic episode make hospitalization necessary. Attempted prophylaxis with lithium at therapeutic plasma levels did not prove effective. Treatment with carbamazepine was discontinued because of leukopenia. The most recent stay in hospital became necessary because of a depressive episode that lasted for 5 months and did not respond to therapy. On admission the patient's score on the Hamilton depression scale was 23. When the calcium antagonist nimodipine was given at a dosage quickly escalated to 360 mg daily, the patient could be discharged in a state of complete remission after 26 days. For the first time in many years she has been emotionally stable for almost 1 year with single agent nimodipine therapy at 180 mg daily.

Bipolar Disorder↗
PubMed1995

Improvement in exercise capacity of candidates awaiting heart transplantation.

OBJECTIVES: This study determined the frequency of improvement in peak oxygen uptake and its role in reevaluation of candidates awaiting heart transplantation. BACKGROUND: Ambulatory candidates for transplantation usually wait > 6 months to undergo the procedure, and during this period symptoms may lessen, and peak oxygen uptake may improve. Whereas initial transplant candidacy is based increasingly on objective criteria, there are no established guidelines for reevaluation to determine who can leave the active waiting list. METHODS: All ambulatory transplant candidates with initial peak oxygen uptake < 14 ml/kg per min were identified. Of 107 such patients listed, 68 survived without early deterioration or transplantation to undergo repeat exercise. A strategy of reevaluation using specific clinical criteria and exercise performance was tested to determine whether patients with improved oxygen uptake could safely be followed without transplantation. RESULTS: In 38 of the 68 patients, peak oxygen uptake increased by > or = 2 ml/kg per min to a level > or = 12 ml/kg per min after 6 +/- 5 months, together with an increase in anaerobic threshold, peak oxygen pulse and exercise heart rate reserve and a decrease in heart rate at rest. Increased peak oxygen uptake was accompanied by stable clinical status without congestion in 31 of 38 patients, and these 31 were taken off the active waiting list. At 2 years, their actuarial survival rate was 100%, and the survival rate without relisting for transplantation was 85%. CONCLUSION: Reevaluation of exercise capacity and clinical status allowed removal of 31 (29%) of 107 ambulatory transplant candidates from the waiting list with excellent early survival despite low peak oxygen uptake on initial testing. The ability to increase peak oxygen uptake, particularly with increased peak oxygen pulse, may indicate improved prognosis as well as functional capacity and, in combination with stable clinical status, may be an indication to defer transplantation in favor of more compromised candidates.

Adolescent↗
PubMed1995

Effects of the serotonin-1A agonists buspirone and ipsapirone on field potentials in the hippocampus slice: comparison with carbamzepine and verapamil.

The serotonin-1A agonists buspirone (BU) and ipsapirone (IPSA) have been demonstrated to exert antidepressant and anxiolytic effects. Since some antidepressant drugs and the antiepileptic substance carbamazepine have calcium antagonistic properties, the interaction of BU and IPSA with carbamazepine and the organic calcium channel blocker verapamil was analyzed in the low Mg2+ induced model epilepsy which has been shown to be suppressed specifically by organic calcium antagonists. BU and IPSA reduced the frequency of occurrence of low magnesium induced field potentials in CA1 and CA3 areas of the hippocampus slice preparation (guinea pigs) in a dose dependent manner. The subthreshold concentrations which yielded no effect were 5 mumol/l for BU and IPSA, 10 mumol/l for carbamazepine and 2 mumol/l for verapamil. Combinations of these subthreshold concentrations elicited a reduction in the repetition rate of field potentials. The results indicate that BU and IPSA behave additively with verapamil and carbamazepine, which may be due to a common action on the same subtype of calcium channels. It may be assumed that besides their action on 5-HT1A receptors BU and IPSA may also have calcium antagonistic properties.

Animals↗
PubMed1995

Effects of carbamazepine on membrane properties of rat sensory spinal ganglion cells in vitro.

The present study aimed to examine effects of the antiepileptic drug carbamazepine (CBZ) on membrane properties. Therefore, effects of CBZ on voltage-dependent ion channels were investigated in rat sensory spinal ganglion cells in primary cultures. (i) Membrane potentials and action potentials were recorded by sharp microelectrodes: CBZ reduced neuronal excitability without changing the resting membrane potential, and suppressed tetrodotoxin (TTX)-resistant components of action potentials which were blocked by cobalt and hence were interpreted as Ca2+ spikes. The rising phase and peak amplitude of TTX-sensitive components of action potentials, however, were hardly altered. (ii) Voltage-dependent inward and outward currents were elicited in the whole-cell configuration of the patch clamp technique. CBZ reduced (presumably L-type) Ca2+ currents. In some cells Ca2+ currents partly recovered during washing with control saline. The effects on Na+ and K+ currents were not uniform and often insignificant. The present study indicates that CBZ has calcium-antagonistic properties.

Action Potentials↗
PubMed1995

[Value of old and new anticonvulsants in treatment of psychiatric diseases].

Besides the classical application in the treatment of different forms of epilepsies antiepileptic drugs are also used for the therapy of psychic diseases. In the present review the elementary mechanisms of action, pharmacology, indications as well as side effects of antiepileptic drugs are described. Successively, the wide used drugs carbamazepine, valproate, phenytoin and ethosuximide and of new substances which have been launched or will be launched in the near future in Germany such as lamotrigine, vigabatrin, gabapentin and oxcarbazepine, are initially presented with regard to epilepsies, and thereafter in the context of prophylaxis and treatment of psychic diseases. Several uncontrolled and controlled clinical studies indicating the efficacy of carbamazepine and valproate in the treatment of the acute manic syndrome and the prophylaxis of bipolar affective disorders have been presented. An effect on the acute depressive syndrome is, however, uncertain. Because of the strong side effects of lithium and the non-response to lithium in some patients, antiepileptic drugs are an important alternative in treating affective disorders.

Anticonvulsants↗
PubMed1995

Clinical findings with nimodipine in dementia: test of the calcium hypothesis.

Calcium toxicity seems to be involved in ischemic brain lesions like in vascular dementia and possibly in primary degenerative dementia of Alzheimer's type. The calcium channel blocker nimodipine readily passes the blood-brain barrier and may thus serve as a pharmacologic probe to test the hypothesis of calcium toxicity. Although nimodipine proved to be superior to placebo in a considerable amount of studies in dementia the concept of calcium toxicity cannot be accepted as established. This is due to some methodological flaws in the clinical trials as well as the limited effect size. Moreover, bridging to other findings especially in Alzheimer-type dementia like amyloid deposition and the relationship to apolipoprotein-E isotypes is still far from complete.

Alzheimer Disease↗
PubMed1994

Carbamazepine as adjunct or alternative to lithium in the prophylaxis of recurrent affective disorders.

Patients with affective disorder insufficiently responding to prophylactic lithium present a major problem to maintenance pharmacotherapy. The present retrospective study tested the efficacy of carbamazepine in 73 such patients. The patients who were switched from lithium to carbamazepine monotherapy had additional benefit, but not those switched to combined lithium plus carbamazepine. This failure to replicate a number of recent pilot studies showing synergistic effects of lithium and carbamazepine may however have been due to a heterogeneity concerning the combined effects of some negative response predictors, although none of these was significant in itself. Nevertheless, synergism cannot be taken as guaranteed. Prospective controlled trials are needed.

Adult↗
PubMed1993

Effects of valproate on early and late potassium currents of single neurons.

The effects of valproate sodium (VPA) on potassium currents were tested in identified neurons of the snail Helix pomatia. VPA was extracellularly and intracellularly applied. VPA (i) had no effects on the current-voltage relation of the early potassium outward current (IA), (ii) shifted the steady state inactivation function of IA to more positive potentials, (iii) increased the amplitude of the late potassium outward currents. It is suggested that the extrasynaptic effects on potassium currents markedly contribute to the antiepileptic and antimanic effects of VPA.

Animals↗
PubMed1993

Calcium-antagonistic effects of carbamazepine in epilepsies and affective psychoses.

Carbamazepine (CBZ) is known to have beneficial effects in the treatment of epilepsies and in the prophylaxis of affective disorders. Since increased transmembrane calcium fluxes and intracellular calcium concentrations play a key role in the generation of epilepsies and possibly also in the development of these psychiatric disorders the effects of CBZ on epileptic discharges (elicited by caffeine, penicillin and low Mg2+) in CA3 neurons of hippocampal slices were compared with those of the organic calcium antagonist verapamil and found to be almost the same.

Animals↗
PubMed1993

Effects of carbamazepine on action potentials and calcium currents in rat spinal ganglion cells in vitro.

The effects of carbamazepine (CBZ) on action potentials and calcium currents in cultured rat sensory spinal ganglion cells were investigated. CBZ was found to reversibly suppress the calcium-dependent components of action potentials and to reduce the amplitude of the after-hyperpolarizations, while the rising phase and the peak amplitude were hardly changed. Furthermore, CBZ caused a marked reduction in the calcium currents, which in some cells was reversible. The present findings confirm that CBZ has calcium-antagonistic properties.

Action Potentials↗
PubMed1992

Calcium antagonistic effects of carbamazepine as a mechanism of action in neuropsychiatric disorders: studies in calcium dependent model epilepsies.

Carbamazepine (CBZ) is used in neurology for the treatment of epilepsies and trigeminal neuralgia and in psychiatry for the prophylactic treatment of affective and schizoaffective psychoses. Since a common mechanism of epilepsies and affective psychoses might be increased intracellular calcium ion levels, CBZ action was analyzed in penicillin, caffeine and low Mg2+ induced model epilepsies which have been shown to be suppressed specifically by organic calcium antagonists. In CA3 and CA1 areas of hippocampal slice preparations of guinea pigs CBZ reduced paroxysmal depolarizations and extracellular field potentials (EFP) in a typical time and concentration dependent manner as it is known from calcium antagonists. Furthermore, subthreshold concentrations of the organic calcium antagonist verapamil intensified the action of CBZ. NMDA induced increases of the discharge rate of EFP were, however, unaffected by CBZ.

Animals↗
PubMed1992

[Importance of calcium ions and calcium antagonists in affective psychoses].

Apart from the eminent changes in the neurotransmitter systems of the central nervous system, a disturbance of the calcium ion concentration may be of significance in the pathophysiology of affective psychoses. The present paper deals with the contribution of calcium ions in the generation of affective psychoses and discusses the calcium antagonism as a new strategy in the treatment of the disease. The following topics will be described: 1. Disturbances of calcium metabolism in affective psychoses, 2. a comparison of lithium and carbamazepine effects, 3. clinical studies with organic calcium channel blockers in affective psychoses and 4. the role of calcium ions in affective psychoses.

Affective Disorders, Psychotic↗
PubMed1992

Epileptogenesis: contributions of calcium ions and antiepileptic calcium antagonists.

The results demonstrate that organic calcium antagonists are able to reduce epileptic activity at the level of single neurons and of neuronal populations. This holds true also for human cortical tissue. Among other observations already published this justifies the hope that calcium antagonistic agents might be useful in the treatment of human epilepsies (28).

Animals↗