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T Van Putten

Publications and source records attributed to T Van Putten.

At least 37 records · Page 2Linked to original sources
PubMed1990

Therapeutic monitoring of steady-state plasma levels of the N4'-oxide metabolite of fluphenazine in chronically treated schizophrenic patients determined by a specific and sensitive radioimmunoassay.

Highly specific and sensitive antisera for fluphenazine-N4'-oxide (FLUNO) were obtained from New Zealand white rabbits immunized with a bovine serum albumin conjugate of 7-(3-carboxypropionyl)propchlorperazine-N4'-oxide. One of the antisera was used to develop a radioimmunoassay (RIA) procedure that enabled for the first time the determination of steady-state plasma levels of FLUNO, an active metabolite, in patients treated with oral or intramuscular (i.m.) fluphenazine (FLU). This method has sufficient sensitivity to quantitate accurately 20 pg of FLUNO in 200 microliters of plasma extract with a coefficient of variation of less than 8%. The antiserum had negligible cross-reactivity (less than 2%) with FLU and its major metabolites such as FLU sulfoxide, 7-hydroxy-FLU, and N-deshydroxyethyl-FLU. To confirm that the developed RIA procedure specifically quantitated FLUNO, FLUNO was selectively reduced to FLU by sodium dithionite in plasma samples from patients. A good correlation (r2 = 0.9646) was observed between the total FLU level and the sum of FLU and FLU equivalent to FLUNO determined separately in the same plasma. The steady-state plasma concentrations of FLUNO in patients receiving a daily oral dose of 5 to 20 mg of FLU dihydrochloride ranged from 13 to 378% of that of FLU, whereas this value ranged from 10 to 214% in plasma samples from patients treated with a biweekly intramuscular (i.m.) dose of 5 mg of FLU decanoate.

Administration, Oral↗
PubMed1990

Fluphenazine plasma levels and clinical response.

We monitored fluphenazine plasma levels in 39 schizophrenic patients who participated in a 2-year double-blind comparison of 5 mg and 25 mg of fluphenazine decanoate (FD) administered every 14 days. We investigated the relationship between log-transformed plasma levels at 3, 6, and 9 months and subsequent psychotic exacerbations with logistic regression and survival analysis. Using logistic regression, the relationship was nonsignificant at 3 months (chi-square = .21, df = 1, p = .65), but significant at 6 months (chi-square = 4.38, df = 1, p = .04) and 9 months (chi-square = 8.98, df = 1, p = .003). Using survival analysis with fluphenazine levels as a covariate (Cox models), we also found significant relationships between the fluphenazine plasma level and the risk of exacerbations at 6 months (chi-square = 3.77, df = 1, p = .052) and 9 months (chi-square = 12.21, df = 1, p = .0005), but not at three months (chi-square = 0.87, df = 1, p = .65). These findings suggest that the measurement of fluphenazine plasma levels may be helpful in decision-making about the dosage of FD.

Adult↗
PubMed1989

Pharmacokinetics of long-acting injectable neuroleptic drugs: clinical implications.

The authors review the literature regarding the pharmacokinetics of long-acting injectable neuroleptic drugs (LINS). There are important differences between LINS and oral neuroleptics that affect their pharmacokinetics. By avoiding first pass metabolism in gut and liver, LINS result in lower circulating concentrations of metabolites than are found after oral administration. In addition, LINS take more time to reach a stable steady state than their oral counterparts. The clinical significance of these pharmacokinetic properties is discussed. The authors recommend that when patients are being changed from oral neuroleptics to LINS, that this conversion be done gradually over several months.

Antipsychotic Agents↗
PubMed1989

Plasma levels of parent drug and metabolites in patients receiving oral and depot fluphenazine.

We evaluated the metabolism of fluphenazine (FLU) in patients treated with either the oral form of FLU or with fluphenazine decanoate (FD). Samples for both patient populations were analyzed using four different radioimmunoassays developed in our laboratories for fluphenazine, fluphenazine sulfoxide (FS), 7-hydroxy fluphenazine (7OHFLU), and fluphenazine N-oxide (FLUNO). In patients receiving oral FLU the levels of FS and 7OHFLU were significantly higher than levels of FLU. In patients receiving FD, the levels of metabolites were significantly lower than FLU levels. This supports the view that drug metabolism is likely to be a more important factor for patients treated with an oral as opposed to a depot phenothiazine neuroleptic.

Delayed-Action Preparations↗
PubMed1989

Anticholinergic effects on memory: benztropine versus amantadine.

To evaluate anticholinergic effects on cognition and other functions, we studied 60 healthy volunteers in a double-blind crossover trial of two antiparkinsonian agents, benztropine and amantadine. Benztropine 4 mg/day, but not amantadine 200 mg/day, impaired free recall and perception of time, and subjects' perception of their own memory impairment was significantly greater with benztropine. Side effects in general were worse with benztropine, particularly such anticholinergic effects as dry mouth and blurred vision, and benztropine decreased measured salivary flow to a significantly greater degree than amantadine. Our findings support the hypothesis that drugs that decrease cholinergic transmission impair storage of new information into long-term memory, but have little effect on retrieval from memory or on tasks involving only immediate memory. Clinically, anticholinergic agents can levy a considerable burden on memory and time perception.

Adolescent↗
PubMed1988

Differential effect of low and conventional doses of fluphenazine on schizophrenic outpatients with good or poor information-processing abilities.

Thirty-six stabilized schizophrenic outpatients were randomly assigned to receive either 5 or 25 mg of fluphenazine decanoate biweekly and were followed up for two years. The best and worst outcomes were found in groups with good or poor information-processing abilities (as measured by a partial-report span-of-apprehension task) given the same 25-mg dose of fluphenazine decanoate. The 86% two-year survival rate of the patients with poor span performance was considerably better, while the 44% one-year and the 21% two-year survival rates of patients with good span performance were considerably lower than previously reported survival rates for schizophrenic patients receiving a conventional dose of fluphenazine. The significant correlations in a patient's span performance for periods up to one year were consistent with the hypothesis that this task taps processes associated with vulnerability to schizophrenic disorder.

Adult↗
PubMed1988

Propranolol as a primary treatment of neuroleptic-induced akathisia.

We conducted a randomized, double-blind clinical trial of propranolol versus placebo as a single treatment of neuroleptic-induced akathisia in eleven schizophrenic patients. Neither propranolol nor placebo treated patients showed a significant improvement in akathisia. While propranolol may be useful as an adjunct to anticholinergic medication in the treatment of neuroleptic-induced akathisia, propranolol does not appear to be effective within 48 hours as a primary treatment in a select group of schizophrenic patients.

Adult↗
PubMed1987

Low- and conventional-dose maintenance therapy with fluphenazine decanoate. Two-year outcome.

We evaluated the effectiveness and the side effects of what we defined as low (5-mg) and conventional (25-mg) doses of fluphenazine decanoate administered every two weeks in a double-blind comparison. Subjects were 66 patients who fulfilled DSM-III criteria for schizophrenic disorder. Evaluation of the survival with each dose revealed no significant difference at one year, but significantly better survival was seen with the 25-mg dose (64%) than the 5-mg dose (31%) at two years. There was no significant difference in survival when the clinician was permitted to make a dosage adjustment up to 10 mg in the low-dose group and 50 mg in the higher-dose group when the patient demonstrated evidence of a symptomatic exacerbation. Patients assigned to the higher dose appeared to feel more uncomfortable during the early months of the study, as indicated by significantly higher scores on subscales of the Hopkins Symptom Checklist-90R and higher side effect scores for retardation and akathisia. Implications for clinical practice are discussed.

Adult↗
PubMed1987

The sulfoxidation of fluphenazine in schizophrenic patients maintained on fluphenazine decanoate.

Highly sensitive radioimmunoassays were applied to study the sulfoxidation of fluphenazine in 30 schizophrenic patients maintained on either 5 mg or 25 mg fluphenazine decanoate by intramuscular injection every 14 days over a period of 6 months. The presence of the sulfoxide metabolite was detected in all but one of the patients, such that 97% of the 340 plasma samples analysed contained the metabolite. Interpatient variations in plasma levels of fluphenazine, fluphenazine sulfoxide, and in drug to metabolite plasma level ratios were several fold higher than the corresponding intrapatient variations at both dosages. There were statistically significant tendencies for mean plasma fluphenazine levels to rise and mean plasma sulfoxide levels to fall over the 6-month period of study among patients on the high dose, consistent with our previously reported observation that it takes 3-6 months to establish a steady state of fluphenazine with this dosage regimen. By contrast, there were no statistically significant changes in mean plasma levels of either fluphenazine or its sulfoxide in patients on the low dose. Nevertheless, there was a significant rise in fluphenazine to fluphenazine sulfoxide mean plasma level ratios in both dosage groups. It is difficult to assess the significance of the changes in the drug to metabolite ratios with time, since there are no kinetic data on the phase II metabolism (conjugation) of fluphenazine or fluphenazine sulfoxide. This study shows that sulfoxidation is an important major pathway in the metabolism of intramuscularly-administered fluphenazine, and implies that metabolic sites other than gut wall are also involved in the process.

Fluphenazine↗
PubMed1987

Behavioral toxicity of antipsychotic drugs.

Extrapyramidal symptoms cause much misery, often go undiagnosed, and can interfere with treatment and rehabilitation. Akinesia is a behavioral state of diminished motoric and psychic spontaneity that is difficult to distinguish from the negative symptoms of schizophrenia. The most useful clinical correlates of akinesia are a subjective sense of sedation and excessive sleeping. Akinesia interferes with social adjustment and may manifest as "postpsychotic depression." The subjective restlessness of akathisia is usually accompanied by telltale foot movements: rocking from foot to foot while standing or walking on the spot. Akathisia is strongly associated with depression and dysphoric responses to neuroleptics and has even been linked to suicidal and homicidal behavior in extreme cases.

Antipsychotic Agents↗
PubMed1987

The efficacy of piquindone, a new atypical neuroleptic, in the treatment of the positive and negative symptoms of schizophrenia.

Piquindone (RO22-1319), a new "atypical" neuroleptic, was administered for 2 weeks to 37 schizophrenic patients, and the effects of treatment were examined in a double-blind, placebo-controlled trial. "Atypical" neuroleptics are those that block animal behaviors that model antipsychotic actions in humans at doses lower than those necessary to block animal behaviors that model extrapyramidal actions. Our results demonstrate that piquindone led to moderate but significant improvements in the positive symptoms of schizophrenia and to improvements in negative symptoms just below the level of statistical significance. This supports the notion that neuroleptics categorized as "atypical" in preclinical experiments may prove to be clinically efficacious in humans. In addition, our anecdotal observations were that piquindone caused minimal extrapyramidal symptoms. This is consistent with the preclinical data and suggests that atypical neuroleptics may be associated with fewer extrapyramidal side effects in humans than conventional neuroleptics. However, this must be substantiated by further research.

Adult↗