Biomedical subjects

R L Elton

Publications and source records attributed to R L Elton.

16 recordsLinked to original sources

PubMed1986

Bromocriptine: long-term low-dose therapy in Parkinson's disease.

Low-dose bromocriptine therapy (average dose 14.5 mg/day at 2 years) produced significant improvement in 25 of 39 parkinsonian patients. Bradykinesia was less in de novo subjects; tremor and rigidity improved most in the levodopa subjects. Five of six patients improved after a low-dose bromocriptine drug "holiday." After the addition of bromocriptine any reductions in levodopa dosage were small, with repeated cuts made gradually over months preventing the deterioration commonly seen with larger sudden reductions in levodopa dosage. Five patients withdrew because of intolerable adverse effects, two because of worsening response. Adverse effects were mild and generally dose dependent, and in some patients they disappeared without reduction in continuing bromocriptine therapy. Eighty percent of those who tolerated bromocriptine maintained response over 2 years. Bromocriptine did not induce dyskinesia, the wearing-off response, or the on-off phenomenon in de novo subjects and was used as a first choice drug in these parkinsonian patients. Best results were obtained from a combination of bromocriptine and levodopa.

Adult↗

PubMed1985

Bromocriptine as primary therapy for prolactin-secreting macroadenomas: results of a prospective multicenter study.

To assess the effectiveness of bromocriptine in reducing the size of PRL-secreting macroadenomas with extrasellar extension, we conducted a prospective multicenter trial in patients without prior radiotherapy, applying a standard protocol of treatment and tumor size evaluation. Basal serum PRL levels [1441 +/- 417 (+/- SEM) ng/ml for women; 3451 +/- 1111 ng/ml for men] fell in all patients and to 11% or less of basal values in all patients but 1. Normal PRL levels were reached in 18 of the 27 patients. In 13 patients (46%), tumor size was reduced by greater than 50%, in 5 patients (18%) by about 50%, and in 9 patients (36%) by approximately 10-25%. The extent of tumor size reduction did not correlate with basal PRL, nadir PRL, percent fall in PRL, or whether PRL levels reached normal. However, a reduction in PRL levels always preceded any detectable change in tumor size. In 19 patients, reduction in tumor size was evident by 6 weeks, but in the other 8, such reduction was not noted until the 6 month evaluation. In the 4 patients in whom bromocriptine was discontinued at the end of 1 yr, tumor reexpansion occurred in 3. Visual fields improved in 9 of the 10 patients in whom they were abnormal. Because of the excellent results found in most of the patients in this series, we suggest that therapy with bromocriptine should be considered as initial management for patients with PRL-secreting macroadenomas.

Adenoma↗

PubMed1985

Low dosages of bromocriptine added to levodopa in Parkinson's disease.

Thirty-six patients with Parkinson's disease, on levodopa, were admitted to a double-blind, parallel, 40-week study of adjunct bromocriptine in dosages increased by 2.5 mg every 4 weeks. A 37% improvement of the mean neurologic deficit score was obtained at the maximal daily dosage of 20 mg. Improvement was greatest in patients with mild disease. The wearing-off effect, off-dose abnormal involuntary movements, and leg pains, associated with levodopa, improved in over 70% of patients at an average dosage of 13 mg. Only 15% of patients had adverse reactions severe enough to necessitate discontinuance of the drug. Abnormalities of mental state were less severe than expected, but two patients had exacerbations of angina pectoris.

Adult↗

PubMed1984

Mesulergine, a new dopamine agonist: effects on anterior pituitary function and kinetics.

We investigated the effects of single doses of mesulergine on basal and thyrotropin-releasing hormone (TRH)-stimulated serum levels of several anterior pituitary hormones in healthy men and defined its kinetics. We also compared the effects on serum prolactin (PRL) levels of three doses (0.1, 0.35, and 0.5 mg) of mesulergine to those in response to 2.5 mg bromocriptine. Secretory rates of PRL before the first dose of TRH were not affected by any dose of mesulergine or bromocriptine. TRH-stimulated PRL secretion was not altered by 0.1 mg mesulergine but was blunted by both the 0.35- and 0.5-mg doses at 10 A.M. and 1 P.M. Bromocriptine inhibited TRH-stimulated PRL secretion at 10 A.M. and 8 P.M. When analyzed as the 8 A.M. to 8 P.M. and the 8 P.M. to 9 A.M. (day 2) intervals, PRL secretion was not changed by 0.1 or 0.35 mg mesulergine but was suppressed during both periods by the 0.5-mg dose. A dose-response relationship was evident, however, between mesulergine and PRL secretion during both the 8 A.M. to 8 P.M. (R2 = 0.27) and the 8 P.M. to 9 A.M. (day 2; R2 = 0.18) intervals. Bromocriptine lowered PRL secretion during both intervals. Secretory rates of growth hormone during these intervals were not affected by 0.1 mg or 0.35 mg mesulergine but were increased during both intervals by the 0.5-mg dose. Neither the secretory rates of thyrotropin in response to TRH nor those of cortisol, luteinizing hormone, or follicle-stimulating hormone were changed by 0.1 or 0.35 mg mesulergine.(ABSTRACT TRUNCATED AT 250 WORDS)

Absorption↗

PubMed1982

Bromocriptine: low-dose therapy in Parkinson disease.

In a double-blind trial with a placebo phase, low-dose bromocriptine therapy (average dose, 15 mg per day) produced a significant improvement in 25 idiopathic parkinsonian patients. Tremor and bradykinesia were equally and significantly improved in both the levodopa-treated and the de novo patients. Rigidity was most improved in the levodopa-treated subjects. Age was not a factor in determining the dose of bromocriptine or the degree of improvement. Adverse effects occurred in 30% but were mild and dose-dependent. Four subjects, unable to tolerate initial doses of bromocriptine, withdrew from the trial. A low initial dose (1 mg per day) and slow escalation in dosage produced an optimal, though delayed improvement. Low-dose bromocriptine therapy is effective, does not induce significant dyskinesia nor on-off phenomenon, and is probably an alternative to levodopa as a drug of first choice in Parkinson disease.

Aged↗

PubMed1979