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Biomedical subjects

J A Izquierdo

Publications and source records attributed to J A Izquierdo.

At least 19 recordsLinked to original sources

Incidence of sexual dysfunction associated with antidepressant agents: a prospective multicenter study of 1022 outpatients. Spanish Working Group for the Study of Psychotropic-Related Sexual Dysfunction.

BACKGROUND: Antidepressants, especially selective serotonin reuptake inhibitors (SSRIs), venlafaxine, and clomipramine, are frequently associated with sexual dysfunction. Other antidepressants (nefazodone, mirtazapine, bupropion, amineptine, and moclobemide) with different mechanisms of action seem to have fewer sexual side effects. The incidence of sexual dysfunction is underestimated, and the use of a specific questionnaire is needed. METHOD: The authors analyzed the incidence of antidepressant-related sexual dysfunction in a multicenter, prospective, open-label study carried out by the Spanish Working Group for the Study of Psychotropic-Related Sexual Dysfunction. The group collected data from April 1995 to February 2000 on patients with previously normal sexual function who were being treated with antidepressants alone or antidepressants plus benzodiazepines. One thousand twenty-two outpatients (610 women, 412 men; mean age = 39.8 +/- 11.3 years) were interviewed using the Psychotropic-Related Sexual Dysfunction Questionnaire, which includes questions about libido, orgasm, ejaculation, erectile function, and general sexual satisfaction. RESULTS: The overall incidence of sexual dysfunction was 59.1% (604/1022) when all antidepressants were considered as a whole. There were relevant differences when the incidence of any type of sexual dysfunction was compared among different drugs: fluoxetine, 57.7% (161/279); sertraline, 62.9% (100/159); fluvoxamine, 62.3% (48/77); paroxetine, 70.7% (147/208); citalopram, 72.7% (48/66); venlafaxine, 67.3% (37/55); mirtazapine, 24.4% (12/49); nefazodone, 8% (4/50); amineptine, 6.9% (2/29); and moclobemide, 3.9% (1/26). Men had a higher frequency of sexual dysfunction (62.4%) than women (56.9%), although women had higher severity. About 40% of patients showed low tolerance of their sexual dysfunction. CONCLUSION: The incidence of sexual dysfunction with SSRIs and venlafaxine is high, ranging from 58% to 73%, as compared with serotonin-2 (5-HT2) blockers (nefazodone and mirtazapine), moclobemide, and amineptine.

Adolescent↗

SSRI-induced sexual dysfunction: fluoxetine, paroxetine, sertraline, and fluvoxamine in a prospective, multicenter, and descriptive clinical study of 344 patients.

The authors analyzed the incidence of sexual dysfunction (SD) with different selective serotonin reuptake inhibitors (SSRIs; fluoxetine, fluvoxamine, paroxetine, and sertraline) and hence the qualitative and quantitative changes in SD throughout time in a prospective and multicenter study. Outpatients (192 women and 152 men; age = 39.6 +/- 11.4 years) under treatment with SSRIs were interviewed with an SD questionnaire designed for this purpose by the authors and that included questions about the following: decreased libido, delayed orgasm or anorgasmia, delayed ejaculation, inability to ejaculate, impotence, and general sexual satisfaction. Patients with the following criteria were included: normal sexual function before SSRI intake, exclusive treatment with SSRIs or treatment associated with benzodiazepines, previous heterosexual or self-erotic current sexual practices. Excluded were patients with previous sexual dysfunction, association of SSRIs with neuroleptics, recent hormone intake, and significant medical illnesses. There was a significant increase in the incidence of SD when physicians asked the patients direct questions (58%) versus when SD was spontaneously reported (14%). There were some significant differences among different SSRIs: paroxetine provoked more delay of orgasm or ejaculation and more impotence than fluvoxamine, fluoxetine and sertraline (chi 2, p < .05). Only 24.5% of the patients had a good tolerance of their sexual dysfunction. Twelve male patients who suffered from premature ejaculation before the treatment preferred to maintain delayed ejaculation, and their sexual satisfaction, and that of their partners, clearly improved. Sexual dysfunction was positively correlated with dose. Patients experienced substantial improvement in sexual function when the dose was diminished or the drug was withdrawn. Men showed more incidence of sexual dysfunction than women, but women's sexual dysfunction was more intense than men's. In only 5.8% of patients, the dysfunction disappeared completely within 6 months, but 81.4% showed no improvement at all by the end of this period. Twelve of 15 patients experienced total improvement when the treatment was changed to moclobemide (450-600 mg/day), and 3 of 5 patients improved when treatment was changed to amineptine (200 mg/day).

1-Naphthylamine↗

Parametrization by non-linear regression and bayesian estimation of bentazepam in a multiple dosage regimen in humans.

The plasma levels of bentazepam were determined by an HPLC technique in a total of 10 patients receiving the drug orally in pill form who were on a dosage regimen with the drug administered every 8, 12 or 24 h. Blood samples were taken three times following the administration of the first and last dose and at times, immediately after the administration of intermediate doses. The parameters corresponding to a one-compartment kinetic model were calculated in each patient by using all the data on plasma levels still corresponding to different administrations by non-linear regression and applying programs with homoscedastic, heteroscedastic and bayesian estimation. The absorption constant had mean values of 2.33, 2.18 and 2.75 h-1. The elimination constant proved to be equal to 0.10, 0.09 and 0.22 h-1 while for the apparent distribution volume mean values of 1.89, 2.89 and 0.80 l/kg were found with each of the estimation programs employed, respectively. The values found for each of the kinetic parameters and with each of the programs were subjected to the non-parametric Kruskal-Wallis test with a view to detecting the presence or absence of statistically significant differences. The discrimination of the program that yielded the best fit was performed by linear regression between the values found for the plasma calculations and those calculated theoretically at the same time with each of the programs.

Adult↗

Presence of 5-hydroxy-indolacetic acid in Diloboderus abderus larvae without monoamine-oxidase-like activity.

The authors confirmed the presence of monoamines and 5-hydroxy-indolacetic acid (5-HIAA) in the cephalic region of Diloboderus abderus larvae employing a high pressure liquid chromatography (HPLC) with electrochemical detector. An anticholinesterase insecticide produced an increase in the serotonin and 5-HIAA endogenous levels, and did not modify the catecholamines. Monoamine-oxidase activity was undetectable with a radioactive method using 3H-tyramine as substrate.

Animals↗

Antistress and antifatigue properties of Panax ginseng: comparison with piracetam.

The antistress and antifatigue properties of a Chinese ginseng preparation were tested on Swiss albino mice, exposed to various experimental models of stress, and were compared with those of piracetam. Both ginseng and piracetam were administered chronically in drinking water for 16-18 days as well as acutely, by injection, 30-60 min prior to the experiments. Reactivity of the mice, loss in body weight, amount of faeces, length of endurance and incidence of mortality were graded and measured. Both piracetam and ginseng treatment provided good protection against electroshock stress when compared to the untreated mice; fighting scores, incidence of tonic convulsion and mortality were significantly less in the treated groups. In the heat stress experiments, both piracetam and ginseng provided significant protection to the treated mice against exposure to heat. In the fatigue stress of forced swim test, ginseng treatment provided effective adaptation to fatigue and increased endurance in both male and female mice; piracetam showed some antifatigue effects on the male mice only. In the locomotor activity tests, ginseng did not depress motility, while piracetam did so in the later part of the tests. These results are discussed in the light of the antistress properties of the drugs as reported in the literature.

Adaptation, Psychological↗

Effect of caffeine on the memory of the mouse.

Albino mice were injected i.p. with caffeine (27.9 mg/kg) 10 min pre-trial. The mice had no trial retention (300-s period) after 24 h. This result suggests that caffeine, at this dose, would upset some mechanism involved in memory processes. No correlation is observed between serotonin (5-HT) increase and caffeine's effect on retention.

Animals↗

Effect on rats and mice of a diet with low tryptophan content (maize flour).

Female Wistar rats when crowded together become aggressive if fed a diet with low tryptophan (Trp) content (maize, flour, Mf). When isolated during 30 days and fed Mf they show a decrease of weight, of total plasma Trp, and of Trp and 5-hydroxytryptamine (5-HT) in brain stem, but 5-hydroxyindolacetic acid (5-HIAA) of the same cerebral area does not change. These results partially agree with other authors observations. Mice isolated during 47 days and fed with Mf do not show any significant weight variation, the hypermotility of isolated mice on normal diet persists, but 5-HT and 5-HIAA significantly decreases in total brain, an effect that has been observed by another author. The effect on 5-HIAA does not depend on the diet, either balanced or with low Trp content.

Aggression↗

Pre-trial cocaine and performance in rat.

Cocaine injected pre-trial (10 mg/kg i.p.) improves performance in naive and high-performance (HP) and low-performance (LP) trained rats. When the effect of cocaine is removed, the number of conditioned responses decreases and equals that of drugless sessions. Cocaine favors only performance, not retention.

Animals↗