Ana Serrano

University of the Andes (Venezuela), Mérida, Mérida, Venezuela

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Publications (11)24.82 Total impact

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    ABSTRACT: Constipation occurs in 25-60% of the subjects during administration of the antipsychotic drug (AP) clozapine (CLZ). We used a colonic transit diagnostic test that quantifies in a single abdominal X-ray the number of silver O-ring markers out of 25 units ingested five days before. The quantity of markers is directly proportional to the degree of gastrointestinal hypomotility, and elimination of over 80% of the markers is considered normal. The test was applied to three groups of AP-treated subjects for at least three consecutive months: CLZ alone (n=45), CLZ+Other APs (n=28), and Other APs (n=64). The number of remaining markers at day 5 (mean±S.D.) was significantly higher in the CLZ alone (10.8±10.6) and in the CLZ+Other APs (9.7±9.7) groups than in the Other AP group (4.5±6.7), Kruskal-Wallis test: p=0.004. No significant associations were found between the number of markers, age, AP dose and treatment duration. All subjects who passed <80% of markers - which approximately corresponds to the 60th percentile of marker elimination - showed a scattered marker distribution along the colon, thus suggesting colon inertia. In subjects with hypomotility, 38.5% of the CLZ group, 25% of the CLZ+Other APs group, and 25% of the Other APs group were negative for the Rome III clinical criteria of constipation, thus showing objective, not subjective, hypomotility. This study objectively confirms significant gastrointestinal hypomotility associated with CLZ administration. Copyright © 2015 Elsevier B.V. All rights reserved.
    Schizophrenia Research 05/2015; 166(1-3). DOI:10.1016/j.schres.2015.05.025 · 3.92 Impact Factor
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    ABSTRACT: Evidence points to a high prevalence of metabolic dysfunction in bipolar disorder (BD), but few studies have evaluated the relatives of subjects with BD. We conducted a cross-sectional study in an extended family of patients with BD type I. The available relatives of the same family were interviewed (DSM-IV-R) and assessed in fasting conditions for body mass index, constituent variables of the metabolic syndrome (MS), leptin levels, insulin resistance index, and single nucleotide polymorphisms (SNPs) for the leptin receptor and promoter and PPAR-γ2 genes. The frequency of MS was compared with that recorded in the local general population. Ninety-three relatives of three adults with BD were evaluated (30 aged < 18 years, 63 aged > 18 years). The frequency of MS was similar to that of the general population. Significantly higher frequencies of abnormal glucose, total and low density cholesterol (LDL-c) levels (all p < 0.05), waist circumference (p = 0.057), and leptin and insulin resistance values (in adults only) were observed in the family. Adults with the QQ genotype of the leptin receptor displayed higher LDL-c levels than carriers of the R allele. The associations among BD consanguinity, familial hypercholesterolemia, and leptin receptor SNPs reported herein should be replicated and extended in other pedigrees.
    Revista Brasileira de Psiquiatria 02/2015; DOI:10.1590/1516-4446-2014-1425 · 1.77 Impact Factor
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    ABSTRACT: Background: The antipsychotic drug (APD) clozapine (CLZ) is under-prescribed because of concerns about its safety. We evaluated in separate protocols the frequency of cardiomyopathy and hyponatraemia, which are adverse drug effects, where few comparative studies are available. Methods: Cross-sectional studies in subjects treated for at least 3 consecutive months with the same drug were conducted. Cardiomyopathy: Patients undergoing treatment either with CLZ (n = 125) or with other typical or atypical APDs (n = 59) were examined by a cardiologist who also recorded echocardiograms and electrocardiograms in order to diagnose cardiomyopathy. Hyponatraemia: Fasting sodium levels were assessed in patients receiving any of the following treatments: CLZ (n = 88), other atypical APDs (n = 61), typical APDs (n = 23), typical + atypical APDs (n = 11), and other drugs/drug-free (n = 36). Results: Cardiomyopathy: No case of cardiomyopathy was detected. The frequency of abnormal ventricular ejection fraction (< 55%) was similar in both treatment groups (p = 1). Hyponatraemia: The frequency of hyponatraemia (percentage; 95% CI) was: CLZ (3.4%; -0.7, 7.1); other atypical APDs (4.9%; -0.5, 10.3); typical APDs (26.1%; 8.2, 44.0); typical + atypical APDs (9.1%; -7.8, 26.0); other drugs/drug-free (0%). None of the CLZ hyponatraemia subjects were on monotherapy. Conclusions: Our results are at odds with previous studies of CLZ-associated cardiomyopathy. However, they must be compared to further cross-sectional or prospective studies because most published data come from either case reports or pharmacovigilance systems. The frequency of hyponatraemia during CLZ administration was similar to that observed with other atypical APDs, and it was significantly lower than that recorded with typical agents. These results, along with numerous case reports on the effects of CLZ in patients with polydipsia and water intoxication, point to a safe or even positive profile of CLZ on electrolytic regulation.
    Australian and New Zealand Journal of Psychiatry 08/2013; 48(2). DOI:10.1177/0004867413502089 · 3.41 Impact Factor
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    ABSTRACT: Background and Objectives: The authors assessed the effectiveness of olanzapine as an adjunctive treatment in migraine status. Methods: Randomized, double-blind, placebo-controlled study. Subjects consecutively admitted to a day program of tertiary referral (97 % women; age: 35.8 ± 11.8 yrs.) were assigned to olanzapine (n = 14, 5-10 mg/day) or placebo (n = 17), added to the standard neurological treatment during 4 days. Primary measures were the change in pain and the return to regular daily activities. Secondary and safety measures were the magnitude of sedation, constipation and glucose level changes. Results: No significant differences were observed in the overall analysis of the primary measures. However, change in pain significantly correlated with age in the olanzapine group (p = 0.03). In the > 40 year-old group, olanzapine (n = 5) displayed a significantly higher reduction in pain than placebo (n = 4) at days 1 (p = 0.048) and 3 (p = 0.045). No significant differences were observed in the change of serum glucose levels. Conclusions: Olanzapine was well tolerated and sedation was welcomed by most subjects. The positive effect in subjects aged > 40 years awaits replication.
    European Journal of Psychiatry 12/2012; 26(4):260-265. DOI:10.4321/S0213-61632012000400005 · 0.46 Impact Factor

  • Investigación clínica 06/2012; 53(1):38-51. · 0.47 Impact Factor
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    ABSTRACT: The authors quantified the prevalence of migraine in subjects with mental disorders, first-degree relatives and the adult general population (GP) in Mérida, Venezuela. After validation, a modified, short version of the Lipton's diagnostic scale was administered to consecutively admitted in- and out-patients (n = 1059), their first-degree relatives (n = 445) and a probabilistic sample of the GP (n = 516). In the GP, the frequency of migraine (percentage and 95% confidence interval) was 14.9 (11.8-17.9). The migraine frequencies were (percentage and odd ratio probability against the GP: bipolar disorder (15.7%, p = 0.5), schizophrenia (8.3%, p = 0.08), depression and dysthimia (24.4%, p = 0.2), anxiety disorders (10.0%, p = 0.02), personality disorders (11.4%, p = 0.15), all other disorders (15.5%, p = 0.4), relatives of bipolar patients (4.4%, p < 0.001), relatives of schizophrenia patients (3.5%, p = 0.003), and relatives of patients with all other mental disorders (12.8%, p = 0.4). Migraine was more common in women (p < 0.001), and the bipolar patients presented the highest female to male ratio (8:1). A high variability was observed in migraine prevalence among the diagnostic categories, but it was particularly high in subjects with affective disorders, mainly in women, who thus deserve special attention from clinicians.
    Investigación clínica 03/2012; 53(1):38-51. · 0.47 Impact Factor
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    ABSTRACT: Few studies on the association between atypical antipsychotic drug (AAP) administration and metabolic dysfunction have concurrently evaluated the general population (GP), other psychotropic drug treatments and drug-free psychiatric patients. We assessed the frequency of the metabolic syndrome (MS) according to the National Cholesterol Education Program criteria (NCEP) and its constituting variables in a GP sample (n=271) and in patients receiving, for at least three consecutive months, antiepileptic drugs (n=93), olanzapine (n=162), clozapine (n=105), typical antipsychotics (n=117), other AAP (n=58), other psychotropic drugs (n=185), and drug-free individuals (n=636). Subjects were clinically classified as schizophrenia, bipolar or other axis I disorders (DSM-IV-RT), and as first-degree relatives of each diagnostic group. The MS was detected in 26.6% of the GP (95% confidence interval: 21.5-31.8). No diagnostic or treatment group had a significantly higher age-adjusted frequency than the GP (p>0.05). Treatment duration did not significantly affect the results. However, significant differences were observed in the frequency of abnormal MS constituting variables in comparison to the GP. For example, schizophrenia patients and their relatives, bipolar subjects and olanzapine- and clozapine-treated patients had higher abnormal waist circumference values. In addition, bipolar patients and their relatives and subjects treated with olanzapine and other AAPs had higher frequencies of abnormal glucose levels. Neither schizophrenia nor bipolar patients in the diagnostic categories nor the olanzapine or the clozapine groups displayed higher proportions of abnormal triglycerides, high density cholesterol or blood pressure levels than the GP. While we did not demonstrate an increased frequency of the MS in AAP-treated subjects, our results confirm that specific metabolic variables must be monitored in psychiatric patients. Besides they stress the importance, in epidemiological studies, of concurrently comparing the figures recorded in AAP-treated patients with those obtained in the local GP, other drug treatment groups and drug-free subjects when referring to the magnitude of the metabolic effects of specific antipsychotic agents.
    Schizophrenia Research 11/2010; 126(1-3):93-102. DOI:10.1016/j.schres.2010.10.014 · 3.92 Impact Factor
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    ABSTRACT: Leptin dysregulation has been implicated in the body weight gain and metabolic dysfunction observed with the second generation antipsychotic drugs (SGAD) olanzapine and clozapine. This study quantified the frequency of subjects with abnormal correlation between leptin and the body mass index controlling for gender (defined as being out of the upper or lower 95% confidence interval in the regression line when combining each group with the drug-free subjects) after prolonged treatment with olanzapine (n=126), clozapine (n=62), first generation antiypsychotics (n=91), other SGAD (n=22), other psychotropic drugs (n=65) and drug-free subjects (n=229). None of the analysis was significant (p>0.05). In fact, in 17 out of 20 comparisons, the drug-free group had numerically higher frequencies of outliers than the corresponding treatment group. There were 28 outliers (4.7% of the total sample). In agreement with previous studies, cross-sectional analysis did not report gross alterations in serum leptin levels during olanzapine or clozapine administration. Longitudinal studies should focus on leptin regulation early on treatment, on the frequency of abnormal leptin receptor sensitivity and/or specific polymorphisms in the leptin allele and on several confounding factors in order to design personalized preventive and therapeutic measures.
    Schizophrenia Research 10/2008; 106(2-3):315-9. DOI:10.1016/j.schres.2008.08.031 · 3.92 Impact Factor
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    ABSTRACT: Excessive body weight gain (BWG) is a clinically relevant side effect of olanzapine administration. The primary objective of this study was to assess whether metformin prevents or reverses BWG in patients with schizophrenia or bipolar disorder under olanzapine administration. Secondarily we evaluated diverse metabolic variables. Eighty patients taking olanzapine (5-20 mg daily for more than 4 consecutive months) were randomly allocated to metformin (n=40; 850 to 2550 mg daily) or placebo (n=40) group in a 12-week double-blind protocol. Waist circumference (WC) body weight (BW), body mass index (BMI) fasting glucose, glycated hemoglobin (Hb1c), insulin, an insulin resistance index (HOMA-IR) lipids, leptin, c-reactive protein, fibrinogen, cortisol and the growth hormone (GH) were evaluated at baseline and at week 12 of treatment. The metformin group lost 1.4+/-3.2 kg (p=0.01) and tended to decrease its leptin levels, whereas the placebo group maintained a stable weight: -0.18+/-2.8 kg (p=0.7). The HOMA-IR significantly increased after placebo (p=0.006) and did not change after metformin (p=0.8). No ostensible differences were observed in the other variables, even though metformin did not improve the lipid profile and the Hb1c levels. Metformin may safely assist olanzapine-treated patients in body weight and carbohydrate metabolism control.
    Schizophrenia Research 08/2007; 93(1-3):99-108. DOI:10.1016/j.schres.2007.03.029 · 3.92 Impact Factor
  • Article: P2-187

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    ABSTRACT: To assess whether metformin prevents body weight gain (BWG) and metabolic dysfunction in patients with schizophrenia who are treated with olanzapine. Forty patients taking olanzapine (10 mg daily) were randomly allocated to a metformin (n = 20; 850 to 1700 mg daily) or placebo (n = 20) group in a 14-week double-blind study. Waist circumference (WC), BWG, body mass index (BMI) fasting glucose, insulin, and lipids were evaluated at baseline and at Weeks 7 and 14 of treatment. At Week 14, BWG (kg) was similar in the metformin group (5.5 kg) and the placebo group (6.3 kg), P = 0.4. There were no differences between the changes in BMI, WC, glucose, insulin, insulin resistance index (HOMA-IR), and plasma lipid levels observed in the treatment group and the placebo group; however, glucose levels decreased significantly after metformin administration (P = 0.02). The HOMA-IR decreased significantly in both groups, but 3 subjects from the placebo group developed fasting glucose levels greater than 5 mmol/L. After taking metformin, triglyceride levels increased, but the cholesterol profile improved significantly. Metformin did not prevent olanzapine-induced BWG. While some lipid parameters worsened during placebo, the HOMA-IR improved in both the placebo and the metformin groups. Carbohydrate metabolism impairment was not systematically observed during short-term olanzapine administration.
    Canadian journal of psychiatry. Revue canadienne de psychiatrie 04/2006; 51(3):192-6. · 2.55 Impact Factor