Safety of long-term clozapine administration. Frequency of cardiomyopathy and hyponatraemia: two cross-sectional, naturalistic studies.

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.

Metformin as an adjunctive treatment to control body weight and metabolic dysfunction during olanzapine administration: a multicentric, double-blind, placebo-controlled trial.

BACKGROUND: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: Metformin may safely assist olanzapine-treated patients in body weight and carbohydrate metabolism control.

Colonic transit diagnostic test shows significant gastrointestinal hypomotility in clozapine-treated patients in comparison with subjects treated with other antipsychotics.

BACKGROUND: Constipation occurs in 25-60% of the subjects during administration of the antipsychotic drug (AP) clozapine (CLZ). METHODS: 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). RESULTS: 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. CONCLUSIONS: This study objectively confirms significant gastrointestinal hypomotility associated with CLZ administration.

The metabolic syndrome and its constituting variables in atypical antipsychotic-treated subjects: comparison with other drug treatments, drug-free psychiatric patients, first-degree relatives and the general population in Venezuela.

BACKGROUND: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.

Polymorphisms of the LEP- and LEPR genes, metabolic profile after prolonged clozapine administration and response to the antidiabetic metformin.

BACKGROUND: The role of leptin in atypical antipsychotic-induced metabolic dysfunction was explored by assessing the anthropometric and metabolic profile and the response to metformin (MET) of clozapine- (CLZ) treated schizophrenia patients according to their single nucleotide polymorphisms (SNPs) in the leptin promoter (LEP2548/GA) and leptin receptor (LEPR Q223R) genes. METHODS: Phase 1. Body mass index (BMI), waist circumference, serum glucose, HbA1C, lipids, leptin, cortisol, insulin resistance index (HOMA-IR), metabolic syndrome and the frequencies of SNPs were assessed in 56 CLZ-treated patients (78.6% males). Phase 2. Fifty two phase 1 subjects were randomly assigned to MET XR (n=23) (1000 mg/day) or placebo (n=29) for 14 weeks. Changes in anthropometric and biochemical variables were compared between the SNPs. RESULTS: Phase 1. The QQ group displayed the lowest triglyceride levels (p<0.05). No other significant difference was observed. Phase 2. Change in anthropometric variables did not differ between the genotypes in any treatment group. After MET, glucose levels significantly increased in the GG group (p<0.05), whereas the HOMA-IR and the low density cholesterol significantly decreased in the QQ- but not in the (QR+RR) group (p<0.05). No differences were observed after placebo. CONCLUSIONS: BW response to CLZ was not related to LEP- and LEPR-SNPs. The GG and (QR+RR) genotypes showed an unexpectedly opposite and blunted response to MET administration respectively.

Extended release metformin for metabolic control assistance during prolonged clozapine administration: a 14 week, double-blind, parallel group, placebo-controlled study.

BACKGROUND: Clozapine is the most effective agent in treatment-resistant schizophrenia. However, it is frequently associated with excessive body weight (BW) gain, type 2 diabetes mellitus and hyperlipidemia. The antidiabetic metformin (MET) has proved effective to assist in BW control during olanzapine administration. Therefore, we aimed to test whether MET may improve the metabolic profile in patients under prolonged clozapine administration. METHODS: In a double-blind, parallel group protocol, 61 patients (94.4% with schizophrenia) receiving clozapine (196.8+/-132 mg daily, range: 25-500) for more than 3 consecutive months (86.5+/-40.6 months, range: 4-168) were randomly allocated to extended release MET (n=31; 500 to 1000 mg daily) or placebo (n=30) group for 14 weeks. The BW, the body mass index, waist circumference, serum glucose, insulin, lipids, glycated hemoglobin (HBA1c), leptin and cortisol, and the HOMA-IR index were assessed at baseline, and weeks 7 and 14. RESULTS: MET was well tolerated and the mental state was not impaired during the study. The protocol was completed by all the placebo subjects and by 24 MET-treated patients. In a complete analysis at week 14, without including data of the 7 dropouts, the MET group lost -1.87+/-2.9 kg, whereas the placebo group had a stable BW: 0.16+/-2.9 kg, p=0.01 for the between group comparisons (effect size: 0.70). Leptin levels also tended to decrease after MET (p=0.08). Insulin and the triglyceride-HDL-C ratio significantly decreased (p<0.05, effect size 0.59 and 1.99 respectively) and the HDL-C significantly increased (p=0.001, effect size 0.95) after MET. CONCLUSIONS: MET improves metabolic control during prolonged clozapine administration.