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Biomedical subjects

R Horowski

Publications and source records attributed to R Horowski.

At least 37 records · Page 2Linked to original sources
PubMed1992

[The determination of cerebral dopamine (D2) receptor density by using 123I-IBZM-SPECT in Parkinson disease patients].

An alteration of the dopaminergic nigrostriatal system is believed to be the main pathogenetic factor of Parkinson's disease (PD). We report on our initial results on the determination of the post-synaptic dopamine-D2-receptor binding of 123I-IBZM in patients with PD. Drug-native patients showed a significantly higher IBZM binding in the basal ganglia as compared to patients on specific dopaminergic medication. Age, duration of the disease and the severity of the disease do not seem to influence the IBZM-receptor binding. We conclude that 123I-IBZM-SPECT is an extremely useful tool for the evaluation of the functional state of cerebral dopamine-D2-receptors.

Aged↗
PubMed1991

Antagonist effect of terguride in Parkinson's disease.

The effects of the partial dopamine agonist terguride (9,10 transdihydrolisuride; THDL) on striatal dopamine receptors were studied by its i.v. administration to 13 patients with Parkinson's disease. Patients were maintained in a steadily mobile state with abnormal involuntary movements by a constant i.v. infusion of levodopa. Terguride showed dopamine antagonist properties in nine patients. In two of these nine patients, a decrease in dyskinesia score was observed without a concomitant worsening of parkinsonian symptoms, whereas in the remaining seven, full parkinsonian akinesia followed THDL administration. The subsequent i.v. injection of the dopamine agonist lisuride reversed THDL-induced akinesia in these seven patients. In the remaining four patients, no clinically significant motor effects were observed. These results show dopamine antagonist activity of terguride in patients with Parkinson's disease treated with Levodopa. Further studies using a wider dose titration are required to evaluate the possible role of dopamine partial agonists in the therapy of levodopa-induced dyskinesias.

Adult↗
PubMed1991

Lisuride plus selegiline in the treatment of early Parkinson's disease.

We treated 20 early Parkinson's disease subjects with the dopamine agonist lisuride in combination with the MAO-B inhibitor selegiline (L-deprenyl). We started with lisuride alone for one month, then we added selegiline versus placebo to lisuride in double-blind conditions for 3 months; finally all patients received lisuride and selegiline for another 3 months. Lisuride alone (1.43 +/- 0.10 mg) significantly improved PD. When selegiline (10 mg/day) was added in the double-blind phase the mean lisuride dosage could be reduced by 22.8% without deterioration of the clinical effects, and the same occurred in the former placebo group when selegiline was added. The combination of both drugs was well tolerated. These data are of interest for the interpretation of the effects of selegiline.

Adult↗
PubMed1991

Can we differentiate symptomatic and neuroprotective effects in parkinsonism? The dopamine agonist lisuride delays the need for levodopa therapy to a similar extent as reported for deprenyl.

Delaying levodopa therapy by a drug currently is being perceived by patients and doctors as an indication for a beneficial effect on the progression of Parkinson's disease. We discuss this view critically and present results from a retrospective analysis of data of 185 consecutive patients treated with lisuride monotherapy which show a significant degree in postponing levodopa therapy. These clinical observations have indicated that the initiation of levodopa administration could be postponed in some 60% of patients for 1 year or more, whilst after several years most patients required levodopa as an addition or alternative treatment. Some patients (approximately 10%, 5 out of 66 at one center at Turku, and 12 out of 119 in an Italian multicenter study) did well on lisuride alone for greater than or equal to 5 years. Thus, the results for long-term lisuride monotherapy in the controlled prospective study by U.K. Rinne could be confirmed by the data from the various Italian centers with similar long-term experiences, with even more favourable results. Comparable results as obtained with deprenyl in the DATATOP study could be found with lisuride monotherapy patients. This demonstrates that symptomatic therapy with the dopamine agonists lisuride is able to postpone levodopa therapy to a similar extent as has been reported in the case of deprenyl. In the latter case, a favourable effect on the progression of the disease had been postulated. We compare published data on both drugs and conclude that the delay in levodopa therapy observed with both drugs is compatible with the assumption of a symptomatic or general activating effect, and that other criteria need to be used for studying the progression of a neurodegenerative disease.

Humans↗
PubMed1991

[A preclinical study of the organ distribution and radiation dosage of radioiodinated iodolisuride].

The distribution in rats of 125I-iodo-lisuride was studied. Three rats each were sacrificed at fixed intervals between 5 min and 24 h p.i., and the radioactivity was measured in isolated organs and parts of the body. The organ distribution and biexponential blood disappearance were similar to values for unlabeled lisuride. The radiation dose was estimated for man assuming a 123I label. The resulting doses were comparable to those from other radiopharmaceuticals in clinical use.

Animals↗
PubMed1990

[Terguride in hyperprolactinemia--experiences with 5 patients].

Hyperprolactinemia can successfully be treated by dopaminagonists such as bromocriptin or lisuride. About 10% of patients complain about side effects like orthostatic hypotension, nausea or vomiting, which may lead to discontinuation of treatment. We therefore conducted a study using terguride--a new dopaminagonist--in 5 patients with hyperprolactinemia and intolerable side effects under conventional treatment. Terguride is the transdihydroderivative of lisuride (Dopergin). We treated 5 patients, 2 men with macroprolactinoma and 3 women with microprolactinoma with terguride. The mean duration of treatment was 15.6 months (7-37 months). Patients were treated with up to 5 mg terguride daily. All 5 patients had a marked initial decrease of elevated prolactin levels 8 h after administration of 0.25 mg terguride orally. Three patients became normoprolactinemic after sufficient increase of the dose of terguride, 2 female patients with a microprolactinoma got eumenorrhoeic thereafter. The treatment with terguride was tolerated without side effects by all patients. There were no significant changes of the examined parameters of clinical chemistry nor the other pituitary hormones. Results of cranial computertomography did not change in 4 patients, one patient had tumor progression. Tergurid as a dopaminagonist is an effective inhibitor of prolactin with little side effects and thus a useful drug in the treatment of hyperprolactinemia.

Adult↗
PubMed1989

A study of the cardiopressor effects of lisuride in the treatment of parkinsonism and pathological aging brain.

In this study, the hemodynamic and neurochemical effects of lisuride, a dopamine agonist with serotoninergic properties, have been evaluated in de novo parkinsonian patients and in elderly subjects with mild cognitive impairment. Blood pressure (BP), heart rate (HR), and urinary catecholamine (CA) fluctuations throughout the 24-h cycle were monitored before and during lisuride therapy along with BP, HR, and plasma CA responses to the tilt-table test. Lisuride (1.2-2.4 mg/day) administered in an open-type 15-day study was capable of decreasing the urinary CA excretion and norepinephrine plasma levels in parkinsonian patients. In some cases, the cardiovascular response to standing was impaired. Lower doses of the drug (0.15 mg/day), administered to elderly patients in a double-blind parallel group vs. placebo study, did not induce any change in cardiopressor responses but decreased the 24-h urinary excretion of epinephrine. These results suggest the importance in both conditions of detecting early stages of alterations in cardiopressor homeostatic processes before therapy with DAergic drugs is initiated.

Aged↗
PubMed1988

Suppression of puerperal lactation by terguride. A double-blind study.

Clinical efficacy, prolactin (PRL)-lowering effect and tolerance of terguride (an 8-alpha-ergoline derived from Lisuride which acts as a partial dopaminergic agonist) were investigated in a double-blind study on inhibition of puerperal lactation using three different daily doses of the drug (0.25, 0.5 and 1.0 mg). With 0.5 and 1.0 daily therapeutical regimens PRL levels were suppressed in a dose-dependent manner and lactation was prevented. Terguride was highly well tolerated.

Clinical Trials as Topic↗
PubMed1986

Effect of terguride on prolactin levels in normal, puerperal and hyperprolactinaemic women.

Terguride, is an 8 - alpha - ergoline derived from lisuride, acts as a partial dopamine (DA) agonist. The effect and tolerance of terguride has been investigated by an acute administration of 0.2 mg p.o. to 8 normal women, 8 patients with hyperprolactinaemia and 8 women with puerperal hyperprolactinaemia. Prolactin (PRL) levels were markedly suppressed in all subjects, with no significant differences between the groups. Treatment for 5 days with terguride 0.4 mg/day or 0.8 mg/day was studied as an inhibitor of lactation. PRL levels were suppressed in a dose-related manner. No untoward side-effects were noted.

Adult↗
PubMed1986

Chronic treatment of pathological hyperprolactinemia and acromegaly with the new ergot derivative terguride.

The long term effectiveness and tolerance of terguride, a new ergot derivative, as initial therapy were evaluated in 20 patients with pathological hyperprolactinemia (PHP; group A) and 7 patients with acromegaly. We also studied 10 patients with PHP whose treatment was changed from bromocriptine or lisuride to terguride (group B). Terguride, given for at least 6 months in divided doses ranging from 0.25-1.50 mg/day to group A patients, resulted in normal (11 patients) or markedly reduced plasma PRL levels. Gonadal function was restored in all but 2 patients in this group, and the tumors shrank in 3 of 5 patients with a macroprolactinoma and in 1 of 3 patients with a microprolactinoma. In group B patients, positive effects of the previous treatment on PRL levels, gonadal function, and tumor growth were maintained by terguride. Terguride suppressed plasma GH levels below 50% of baseline in 4 of the 7 acromegalic patients. Two of the 27 patients initially treated with terguride complained of mild nausea and postural hypotension only after the first dose (0.25 mg) of the drug. No patient in group B had any side-effects during terguride, with the exception of 1 patient who was also intolerant to bromocriptine. We conclude that terguride is an effective well tolerated dopaminergic agent in PHP.

Acromegaly↗
PubMed1986

Rapid regression of macroprolactinomas by the new dopamine partial agonist terguride.

Two patients with macroprolactinomas were treated with the partial dopamine agonist, terguride. The prolactin (Prl) levels were lowered very effectively and in both cases the clinical symptoms improved markedly during the first days of treatment. Computerized tomography (CT) and magnetic resonance imaging (MRI) follow-up studies showed distinct tumour shrinkages which were first documented by MRI within 2 weeks of treatment. Tumour residues were, however, still demonstrable by MRI after more than one year respectively 3 months of therapy. In principal, results from both imaging techniques were comparable with the exception of the one year follow-up study of patient 1. In CT no residual tumour mass was visible whereas MRI showed only little reduction when compared to the 30th week scan. Throughout the treatment terguride was well tolerated without any side effects up to a maximal daily dosage of 3 mg given orally. Presumably the partial agonistic features of terguride contributed to the good tolerance of the treatment as compared to that of full dopamine agonists like bromocriptine of lisuride. Thus, these preliminary results indicate that terguride may be a beneficial alternative in the treatment of prolactinomas and other hyperprolactinaemic states.

Adenoma↗
PubMed1986

Dopamine agonists in the treatment of hyperprolactinemia. Comparison between bromocriptine and lisuride.

27 patients (12 women and 15 men) with hyperprolactinemia were treated with the dopamine agonists lisuride (Dopergin) and bromocriptine on a cross-over basis for 3-6 months. By this treatment, plasma prolactin levels were reduced by 83 and 87%, and normalization was achieved in 13 patients in the lisuride group (average dosage 1 mg/d) and in 15 patients in the bromocriptine group (average dosage 10 mg/d). Side effects, consisting of orthostatic hypotension, vomiting and nausea, occurred in 11 patients treated with lisuride and 13 patients treated with bromocriptine, and 2 patients in the lisuride group and one in the bromocriptine group stopped the medication for this reason. There was a good correlation in the doses of both drugs used. There was a tendency for the prolactin-lowering effect of lisuride to last longer upon cessation of therapy which might be related to the higher receptor affinity of both drugs. In general, however, the present results indicate that bromocriptine and lisuride are comparable in efficacy and side effects, but that individual patients respond better to one or the other drug.

Bromocriptine↗
PubMed1985

Effect of the new ergot derivative terguride on plasma PRL and GH levels in patients with pathological hyperprolactinemia or acromegaly.

Terguride, a derivative of lisuride, has been shown to possess a mixed dopaminergic-antidopaminergic activity in experimental models. We have studied the effects on PRL and GH levels of 0.2 mg po of terguride in 8 normal subjects, in 15 patients with pathological hyperprolactinemia (PHP) and in 17 patients with active acromegaly. In PHP, PRL levels were significantly reduced up to 300 min after terguride with a nadir (45 +/- 4.0% SE) significantly lower (p less than 0.05) than the one observed in the 8 normal subjects (72 +/- 3.5%). There was no significant difference in plasma PRL levels after 0.2 mg terguride or lisuride in 7 out of 15 patients tested with both drugs. Terguride did not significantly modify GH levels in PHP and in normals but when considering basal and peak (occurring between 60 and 150 min) GH values, a significant difference was found (p less than 0.01). Mean peak of GH did not differ significantly between PHP (5.0 +/- 1.1 ng/ml) and normals (6.8 +/- 1.7 ng/ml). Plasma GH levels of 17 acromegalics were not modified by 0.2 mg of terguride but were significantly reduced by 2.5 mg of bromocriptine. Terguride and bromocriptine reduced PRL levels in acromegalics (p less than 0.01) without any significant difference between the two drug. 0.2 mg terguride bid given for 15 days to 7 healthy volunteers significantly reduced both basal and sulpiride (25 mg im)-stimulated PRL levels. Side effects were observed only in 4 out of 47 subjects tested with terguride and in 8 out of 34 tested with bromocriptine.

Acromegaly↗