Prediction of haloperidol steady-state levels in plasma after a single test dose

Because of large interindividual variabilities in the pharmacokinetics of haloperidol (HPDL), empirically adjusting the dose to achieve steady-state levels in plasma (Css) is a time-consuming process. We report a method to individualize dose to achieve a desired Css from an observed drug level 24 hours after a single 15-mg test dose of HPDL. Drug-free schizophrenic and schizo-affective patients were blindly and randomly assigned to achieve a low (< 5 ng/ml), medium (10-18 ng/ml), or high (> 25 ng/ml) Css range of HPDL. On day 1 of the study, each patient received an oral "test" dose of HPDL (15 mg), and blood was drawn 24 hours later to determine drug levels in plasma (C24h). The first 34 patients (group I) were then maintained empirically on 2, 5 to 8, or 10 to 15 mg twice daily of oral HPDL concentrate for 5 days to achieve a low, medium, or high Css range, respectively. For the next 58 patients (group II), the dose of HPDL to achieve the assigned Css range was computed by using C24h in a prediction formula. Application of the C24h correctly predicted the maintenance dose required to achieve the Css in 73.2% of the cases. Further, there was a highly significant correlation (R2 = 0.877, p < 0.0001) between the predicted dose and the actual dose required to achieve the targeted Css range. On the basis of these results, we have formulated a nomogram to help predict the maintenance dose required to achieve low, medium, or high HPDL targeted ranges at various C24h values.

Haloperidol plasma concentrations in Taiwanese psychiatric patients

Haloperidol and reduced haloperidol are interconverted. The plasma concentrations of these two butyrophenones have been suggested to be important factors in determining the clinical effect of haloperidol treatment. The steady-state plasma concentrations of haloperidol and reduced haloperidol were measured in 322 Taiwanese schizophrenic patients using high performance liquid chromatography. The daily doses of haloperidol varied from 5 to 200 mg (mean +/- SD, 35.3 +/- 34.6 mg). There was a positive correlation between plasma concentrations and doses, following the equation: haloperidol concentration (ng/mL) = 0.88 x dose (mg/day)-1.66. However, the interpatient variation in haloperidol concentrations was up to ten-fold even in patients receiving the same dose (20 mg/day, n = 88). The expected values were about 10% to 50% higher than those reported in Caucasian patients. The plasma reduced haloperidol concentrations were significantly lower than, and correlated with, those of haloperidol in patients with haloperidol levels lower than 25 ng/mL. However, once haloperidol exceeded 25 ng/mL, reduced haloperidol levels rapidly elevated and appeared significantly higher than haloperidol levels. While haloperidol could reach its steady state in about 1 week, reduced haloperidol needed at least 4 weeks to do so. Haloperidol doses of less than 30 mg/day and plasma concentrations lower than 25 ng/mL are recommended for most Chinese patients.

Plasma haloperidol levels and clinical effects in schizophrenia and schizoaffective disorder

BACKGROUND

Plasma haloperidol levels between 5 and 11 ng/mL may be clinically optimal for acutely exacerbated schizophrenia, but the evidence for this therapeutic window has been inconsistent.

METHODS

Haloperidol was administered in a double-blind manner during two consecutive 3-week experimental periods to 65 patients with acutely exacerbated schizophrenia or schizoaffective disorder. Two plasma levels were targeted: "low" (2 ng/mL) and "moderate" (10 ng/mL). The subjects were randomly assigned to four treatment sequences (low-low, low-moderate, moderate-moderate, or moderate-low).

RESULTS

In the first 3 weeks, the antipsychotic efficacy of haloperidol increased with plasma levels up to approximately 12 ng/mL. In the second 3 weeks, decrease of plasma levels reduced negative symptoms.

CONCLUSION

For most patients, plasma levels not exceeding 12 ng/mL yield the best results in the first 3 weeks of treatment. Subsequent lowering of the plasma levels may improve negative symptoms.

The hypothalamic-pituitary-thyroid axis in patients maintained on lithium prophylaxis for years: high triiodothyronine serum concentrations are correlated to the prophylactic efficacy

Serum concentrations of thyrotropine (TSH), thyroxine (T4), free T4 (fT4), triiodothyronine (T3) and reverse T3 (rT3) were measured 4 x during a 12-month period in 28 patients with major depressive disorder maintained on lithium prophylaxis for 4-23 years (mean = 11.8). The course of illness was carefully monitored and documented for all patients throughout a 3.5-year period. All hormones were also measured in 41 healthy controls matched for age and gender. Patients on lithium had normal serum concentrations of TSH, T4, fT4 and T3 only the levels of rT3 were elevated. The efficacy of the lithium prophylaxis was significantly correlated to the serum concentrations of T3, i.e., the higher the patients' serum levels of T3, the shorter was the overall duration of recurrences of depression within the 3.5-year period. We conclude that: (1) thyrotropine and the thyroid hormones, which are often abnormal during the first weeks or months of lithium treatment, returned to normal when lithium prophylaxis was maintained for years; (2) a possible explanation for the higher T3-serum concentrations in responders might be that lithium interacts with thyroid hormone metabolism in the CNS, leading to enhanced T3 concentrations in the tissue and to a secondary increase in the serum concentrations of T3.

Relation of leukocyte counts during clozapine treatment to serum concentrations of clozapine and metabolites

OBJECTIVE

This study was done to test the hypothesis that serum concentration of norclozapine is a risk factor for leukopenia during treatment with clozapine.

METHOD

Maximum decreases in leukocyte counts in 44 unselected patients treated with clozapine were determined and then correlated with drug doses and serum concentrations of clozapine, norclozapine, and clozapine-N-oxide.

RESULTS

White cell and granulocyte counts decreased by up to 60%-73%, but there were no positive correlations between these decrements and drug dose, drug level, ratio of drug level to drug dose, or ratio of norclozapine level to clozapine level, nor were the decreases related to age or gender.

CONCLUSIONS

While these results do not suggest in vivo hemotoxicity of norclozapine, further study of patients with clinically significant leukopenia is required.

The psychotropic effects of inhibitors of steroid biosynthesis in depressed patients refractory to treatment

Twenty patients, diagnosed as suffering from treatment-resistant major depression, were treated with one or more drugs that decrease corticosteroid biosynthesis. Nine were psychotic, 11 nonpsychotic. Seventeen completed the treatment (8 psychotic, 9 nonpsychotic); 13 responded (5 psychotic, 8 nonpsychotic; 11 responded completely (i.e., a drop in the Hamilton Depression Scale of at least 50%, to < or = 15), and 2 responded partially. The mean age of the responders (45.2 +/- 12.6 years) did not differ significantly from that of the nonresponders (48.7 +/- 12/3). Data were analyzed in the following categories; (1) the presence or absence of psychosis, (2) response or nonresponse to treatment, and (3) the drug(s) used (aminoglutethimide, ketoconazole, or a combination of either of these with metyrapone). The patients improved over time on the Hamilton Depression Scale independent of the medication used. Responders demonstrated improvement in mood, insomnia, anxiety, diurnal variation, paranoia and obsessive compulsiveness. Nonpsychotics responded better than psychotics.

Plasma clozapine levels and clinical response for treatment-refractory schizophrenic patients

OBJECTIVE

The purpose of this study was to determine if plasma clozapine levels were associated with treatment response.

METHOD

To examine this question, neuroleptic nonresponsive patients with schizophrenia or schizoaffective disorder were given clozapine, which was titrated to 500 mg/day by day 14 of treatment, and the dose was held fixed at least through day 21. Subsequently, clozapine doses were adjusted as clinically indicated, up to a maximum of 900 mg/day. Plasma clozapine levels were obtained at weeks 3 and 6, and standard clinical ratings (Brief Psychiatric Rating Scale [BPRS] and Clinical Global Impression) were done at baseline and at weeks 3 and 6.

RESULTS

Data from 45 subjects were analyzed. There were no correlations between plasma clozapine levels and change in BPRS scores at treatment weeks 3 and 6. However, when the subjects were classified as responders or nonresponders, therapeutic response was associated with clozapine blood levels above 350 ng/ml.

CONCLUSIONS

This study suggest that clozapine blood levels are correlated with clinical response.

Assessment of the central dopaminergic index of plasma HVA in schizophrenia

Under fasting conditions, the dopamine (DA) metabolite homovanillic acid (HVA) in plasma originates mainly from central DA neurons or from central and peripheral noradrenergic (NA) neurons. The latter source contributes, in addition to HVA, the norepinephrine metabolites, for example, 3-methoxy-4-hydroxyphenylglycol (MHPG). It has been shown in primates that the association between HVA and MHPG in plasma or urine under varying rates of NA metabolism can be used to obtain an estimate of the central DA neuronal contribution of HVA to plasma or urine. This estimate is called the central dopaminergic index (CDI). Two studies presented here examine the applicability of this model in schizophrenia patients. The results were consistent with the proposed model and suggested that only about 30 percent of the total plasma HVA concentrations in our patients were derived from central DA neurons. A convenient modification of this model is proposed for future studies. Since the CDI of plasma HVA is not likely to be confounded by NA activity, this tool may prove useful in disentangling the roles played by the DA and NA systems in schizophrenia.

Lithium response and genetics of affective disorders

The authors have carried out an investigation of psychiatric morbidity in families of patients who responded and failed to respond to long-term lithium treatment. The study included 121 probands with RDC primary affective disorders and 903 first-degree relatives and spouses. Seventy-one probands were responders and 50 were nonresponders to long-term lithium treatment. Extended to 20 years, the follow-up of patients and their families provided substantial information relevant for the diagnosis and reliable assessment of lithium response. The diagnoses were based on all available information, SADS-L interviews and RDC criteria. The principal statistical methods were survival analysis and Cox regression analysis. The results revealed a significantly higher frequency of bipolar disorder in the relatives of lithium responders (3.8% vs. 0%). Schizophrenia was more common in the families of nonresponders (2.4% vs. 0.3%). There were no significant differences in the rates of other psychiatric disorders. Both family history and the proband's diagnosis contribute independently to predicting response to long-term lithium.

Hypocholesterolemia and affective disorders

The authors' specific aim was to assess hypocholesterolemia in 203 patients hospitalized because of affective disorders (depression, bipolar disorder, and schizoaffective disorder) compared with 1,595 self-referred subjects in an urban supermarket screening and with 11,864 subjects in the National Health and Nutrition Examination Survey II, a national probability sample. Low plasma cholesterol concentrations (< 160 mg/dL) were much more common in patients with affective disorders (20%) than in urban supermarket screenees (4%, P < or = 0.001) or in the National Health and Nutrition Examination Survey II subjects (10%, P < or = 0.001). When paired with supermarket screenees by age and sex, patients with affective disorders had much lower plasma total cholesterol (P < or = 0.0002), low-density lipoprotein cholesterol (P < or = 0.001), and high-density lipoprotein cholesterol (P < or = 0.0001), and higher triglyceride concentrations (P < or = 0.03). Neither the severity of the affective disorders nor severity-age interactions were associated with plasma cholesterol concentrations (P > 0.1); age and plasma cholesterol were positively associated (P = 0.01). None of the psychoactive drugs had a significant independent association with the patients' low-density lipoprotein cholesterol. Plasma cholesterol in patients hospitalized with affective disorders is shifted markedly downward toward hypocholesterolemic concentrations (< 160 mg/dL). There is no evidence that low plasma cholesterol could cause or worsen affective disorders.

Decrease of serum iron in acutely psychotic schizophrenic patients

Iron deficiency has been shown to effect the dopaminergic system. Iron deficient rats have low dopamine D2 receptor levels and modified dopamine-mediated behaviors, including reversal of circadian cycles of these behaviors. Abnormal iron deposits have been found in the brains of schizophrenics in CT and post mortum studies. We examined serum iron levels at 0800, 1700 and 2400 hours in 26 medication free schizophrenic patients in acute psychotic relapse and compared them to iron levels in a normal control group. The results show significant decreases in the iron levels at 1700 and 2400, and a non significant drop in the 0800 levels. A feedback mechanism involving iron and dopamine is proposed.

Effect of switching carbamazepine to oxcarbazepine on the plasma levels of neuroleptics. A case report

Carbamazepine was switched to its 10-keto analogue oxcarbazepine among six difficult-to-treat schizophrenic or organic psychotic patients using concomitantly haloperidol, chlorpromazine or clozapine. This change resulted within 2-4 weeks in the 50-200% increase in the plasma levels of these neuroleptics and the appearance of extrapyramidal symptoms. None of the patients showed any clinical deteriotation during the following 3-6 months. The results of this case report support the idea that in contrast with carbamazepine oxcarbazepine does not induce the hepatic microsomal enzyme systems regulating the inactivation of antipsychotic drugs.

Autoaggressive behavior is closely related to serotonin availability in schizoaffective disorder

Lowered serotonin turnover has been observed in impulsive hetero- and auto-aggressive behavior. Most notably the CSF 5-hydroxyindole acetic acid concentrations were decreased. However, data on CSF or blood serotonin are far from clear-cut, since similar levels in suicidal and non-suicidal patients have also been noted. Longitudinal studies of suicidal patients have revealed pronounced shifts in blood serotonin levels, whereas healthy subjects' blood serotonin levels remained stable. We investigated blood serotonin levels of female schizoaffective patients and healthy women to test whether the fluctuations correlated with changes in autoaggressive behavior. The patients were divided into three groups: nonsuicidal, acutely suicidal, and postsuicidal. Nonsuicidal and postsuicidal schizoaffective patients' and healthy women's blood serotonin levels were similar. Suicidal patients' blood serotonin levels were significantly lower than those of healthy subjects and postsuicidal patients. We interpret the serotonin augmentation after a suicide attempt as a psychobiological correlate of increased neurotransmitter function.

[Erythrocyte superoxide dismutase (eSOD) determination in positive moments of psychosis]

Dysregulation of free radical metabolism has been supposed to be involved in schizophrenia etiopathogeny. Recently, Wang et al. showed a red blood cell super oxide dismutase increase in positive schizophrenia (Crow's type I), but neither in negative schizophrenia (Crow's type II) nor in controls. The study included 28 in-patients suffering from acute positive psychosis who were compared with 15 controls. We confirmed the results of Wang. We found a significantly red blood cell Super oxide dismutase increase in positive psychosis, in comparison to negative psychosis and controls (p = 0.0001). This SOD increase was in relationship with the degree of clinical psychomotor excitement. After 21 days of neuroleptic treatment, SOD activity decreased and reached standard values. These results support the hypothesis of striking relationships between catecholaminergic hyper-metabolism and SOD increase, in positive psychosis. These could account for psychotic positive symptoms improvement with neuroleptic treatment, which blocks dopamine pathways.

Does the change of psychopathology during the placebo period predict the response to subsequent treatment with active medication

We examined whether deterioration in psychiatric symptoms during the placebo period predicted short-term response to subsequent treatment. Acutely exacerbated chronic schizophrenic or schizoaffective patients (n = 123) received placebo for 6.2 days on average. Afterwards, fixed haloperidol plasma levels were maintained for 6 weeks. Psychopathology was evaluated on the basis of the Brief Psychiatric Rating Scale (BPRS), which was administered weekly by trained raters. The global BPRS score at the beginning of the active treatment accounted for 11% of the end-point variance of the global BPRS score (p < 0.0002) and the change of psychopathology during the preceding placebo period explained additional 3.1% (p < 0.053) of it. The change in most of the BPRS factor scores contributed significantly to the prediction of the end-point BPRS score. The patients who had low scores on admission to the study and high scores at the end of the placebo period showed the greatest improvement. The results suggest that in addition to the baseline severity of psychopathology, the change of psychopathology that occurs during the pretreatment placebo period can partially account for treatment response.

[Determination of remoxipride in cadaver blood using high pressure liquid chromatography]

The suitability of high pressure liquid chromatography (HPLC) for determining remoxipride levels in cadaver blood was tested in a case of possible remoxipride intoxication. Level in our case was found to be lower than in cases of remoxipride poisoning described in the literature. The procedure developed for using HPLC to measure remoxipride levels in cadaver blood is described in detail. Using this method a distinction could be made between remoxipride and sulpiride.

[Suicide with prothipendyl]

The distribution of prothipendyl (Dominal) in two cases of fatal poisoning are reported. The highest concentration of prothipendyl were found in liver (1.2 g/kg to 1.8 g/kg) and kidney (0.6 g/kg). Prothipendyl concentrations in these organs far exceeded those in blood. In the first case we found a blood concentration 200 times over the therapeutic range. Prothipendyl was detected in all specimens tested including: lung, muscle and stomach. These results are in agreement with limited, previously reported data and indicate that more then 4 g of prothipendyl is fatal overdose. In this report the survival time and dose are discussed.

Nadolol for lithium tremor in the presence of liver damage

Lithium-induced tremor classically responds to treatment with propranolol. Since it is metabolized in the liver, propranolol may not be the drug of choice in those patients who have compromised liver function or who are recovering from prior liver diseases. Another nonselective beta-adrenergic blocker, nadolol, has no hepatic biotransformation. We present here the first case report of successful treatment of lithium-induced tremor with nadolol, which was selected because the patient had compromised liver function. The patient's liver function tests remained stable with the therapy.

Serum concentrations of clozapine and its major metabolites: effects of cotreatment with fluoxetine or valproate

Serum concentrations of clozapine, norclozapine, and clozapine-N-oxide were assayed in psychotic patients treated with clozapine alone (N = 17), clozapine with fluoxetine added (N = 6), or clozapine with valproic acid added (N = 11). Subjects were matched for age and other treatments, and concentrations were corrected for daily dose of clozapine (milligrams per kilogram of body weight). With valproic acid, there was a minor increase in total clozapine metabolites, which was even less with dose correction. Fluoxetine increased all clozapine analytes, in some cases to twice the levels in the subjects given only clozapine.

CSF and plasma MHPG, and CSF MHPG index: pretreatment levels in diagnostic groups and response to somatic treatments

The authors report a significant positive correlation between levels of 3-methoxy-4-hydroxyphenylglycol (MHPG) in cerebrospinal fluid (CSF) and plasma in drug-free affective disorder patients (major depression, mania, and schizoaffective disorder), but not in schizophrenia. Recent kinetic studies on the relationship between plasma and CSF MHPG discourage the interpretation of independent CSF MHPG levels without correction for the diffusion of MHPG across the blood-brain barrier. The authors therefore examine pretreatment CSF and plasma MHPG levels, and the CSF MHPG index (CSF MHPG corrected for by using simultaneously obtained plasma MHPG according to the method of Kopin et al. [1983]). No significant differences were found in these pretreatment MHPG measures among the four diagnostic groups. Changes in these MHPG indices, and their correlations with behavioral rating scores, are also examined with respect to response to the four major somatic therapies (neuroleptics, lithium, antidepressants, and electroconvulsive therapy).

Relation of plasma fluphenazine levels to treatment response and extrapyramidal side effects in first-episode schizophrenic patients

OBJECTIVE

The aim of this study was to determine the relation between plasma fluphenazine levels and clinical response in first-episode schizophrenic patients.

METHOD

Data from 36 first-episode schizophrenic or schizoaffective inpatients diagnosed according to the Research Diagnostic Criteria were evaluated. The patients received open, standardized treatment with fluphenazine, 20 mg/day, for at least 4 weeks. Psychopathology was assessed biweekly, and plasma fluphenazine levels were ascertained weekly. Patients were classified as responders or nonresponders, and correlations between their neuroleptic levels and ratings of psychopathologic and extrapyramidal symptoms were computed.

RESULTS

Plasma fluphenazine levels for weeks 1 through 4 were significantly correlated with each other but were not correlated with age, gender, diagnosis, or race. Mean neuroleptic levels (weeks 3 and 4) were not different between responders and nonresponders and were not correlated with measures of psychopathology or extrapyramidal symptoms.

CONCLUSIONS

These results do not indicate an association between plasma fluphenazine levels and response to treatment or extrapyramidal side effects in first-episode schizophrenia. The disparity between the results of this study and those of previous studies may be due to methodological differences or to a biologically based difference between first-episode and chronic patients.

Abnormal plasma levels of serine, methionine, and taurine in transient acute polymorphic psychosis

The present study explored the usefulness of plasma amino acid concentrations in discriminating a subgroup of patients with transient acute polymorphic psychoses characterized by psychosensory symptoms (APP+ patients). Levels of amino acids in the plasma of APP+ patients were compared with levels in psychiatric patients with other types of psychotic symptomatology and a healthy control group. Both the APP+ patients and patients with bipolar affective disorder had significantly lower plasma concentrations of serine compared with concentrations in the other groups studied. Since the plasma concentrations of taurine and methionine were also different in the APP+ patients, the ratio of taurine to the product of serine and methionine (the TSM ratio) was used in an attempt to increase the sensitivity in discriminating these patients. The TSM ratio in the APP+ patients was significantly higher than those in the other groups studied, except for the patients with bipolar affective disorder. It appears that the determination of serine and the TSM ratio in the plasma of psychotic patients may be a useful diagnostic validator in a group of patients with acute polymorphic psychoses.