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Biomedical subjects

M G Gelder

Publications and source records attributed to M G Gelder.

12 recordsLinked to original sources

Plasma fluphenazine levels by radioimmunoassay in schizophrenic patients treated with depot injections of fluphenazine decanoate.

1 Using a radioimmunoassay, plasma fluphenazine (FPZ) concentrations were examined in 33 schizophrenic patients during 38 intervals between injections of FPZ decanoate. Doses ranged from 12.5 to 150 mg and intervals from 1 to 5 weeks. At least three blood samples were taken between injections from each subject; also in 26 subjects additional samples were taken during the first 24 h post-injection. 2 FPZ was measurable in all plasma samples. 3 Each injection was followed by a rapid rise in plasma FPZ concentration to a maximum at 1-8 h. The height of this peak varied considerably. Within the next 12-36 h plasma FPZ fell to a level slightly above that found before injection and then remained stable until the next injection, thus confirming the steady release of FPZ from the depot over this period. 4 For the group, dose and mean plasma FPZ levels correlated strongly. 5 Despite this, there was a four-fold variation in plasma FPZ concentration among subjects receiving the same dose. 6 The FPZ level on the last day of an interval between injections was a satisfactory estimate of the mean FPZ level for the interval. 7 In one subject examined in this way, a positive correlation was found (r = 0.76) between plasma FPZ (by radioimmunoassay) and plasma prolactin levels.

Adult

Clinical significance of plasma chlorpromazine levels. II. Plasma levels of the drug, some of its metabolites and prolactin in patients receiving long-term phenothiazine treatment.

Plasma levels of chlorpromazine (CPZ), 3 of its metabolites and prolactin were measured repeatedly in 18 chronic schizophrenic patients. The patients were studied while on chronic phenothiazine medication (chlorpromazine in 8, other phenothiazines in 10), during 4-6 weeks on placebo and during 6-12 weeks of CPZ treatment. The findings were compared with those obtained during acute CPZ treatment in patients who had received similar CPZ doses but no previous long-term phenothiazine medication. Plasma CPZ levels were similar in the chronic and the acute groups and so was their relation to dose. In neither group was therapeutic effect related to plasma CPZ level. In these chronic patients, in contrast to findings during acute CPZ treatment, neither prolactin level nor the appearance of parkinsonian symptoms was related to plasma drug level. In the chronic group both these effects were less pronounced during the period on CPZ which followed the placebo than were the corresponding effects during CPZ treatment in the acute group. Since plasma CPZ levels of the two groups were similar, these differences may be due to an acquired tolerance of the nervous system to some of the antidopaminergic effects of the drug.

Adult

Clinical significance of plasma chlorpromazine levels. I. Plasma levels of the drug, some of its metabolites and prolactin during acute treatment.

Seventeen acute psychotic patients were studied in the course of chlorpromazine (CPZ) treatment. Blood samples were taken weekly both before and two hours after the morning CPZ dose. Plasma levels of CPZ, CPZ sulphoxide (CPZ SO) monodesmethylated CPZ (NOR1CPZ) and 7-hydroxy CPZ (7OH CPZ) were estimated by gas chromatography. Plasma prolactin, luteinizing hormone, testosterone and oestrogens were measured by radioimmunoassay. Six of the seven patients who showed no clinical improvement had plasma CPZ levels equal to or higher than those of patients who improved. 'Non-responders' has a greater proportion of CPZ SO in pre-dosage samples. The occurrence of parkinsonian side effects was associated with a mean plasma CPZ of greater than 50 ng/ml and a mean plasma prolactin of greater than 30 ng/ml two hours after dosage. The elevation of prolactin preceded the onset of parkinsonian symptoms by 1-2 weeks. There was a significant positive correlation between mean plasma prolactin and mean plasma CPZ levels. The prolactin response may prove a useful index of the central antidopaminergic effect of neuroleptic drugs.

Acute Disease

Hormonal changes and mood in the puerperium.

This investigation is an attempt to test the common supposition that postpartum emotional disturbance is related to hormone changes. A group of 27 normal pregnant women were assessed three times before delivery and sixteen times in the six weeks following delivery. During the first two interviews baseline data on personality and other personal variables were obtained. On each occasion blood was taken and three measures of clinical status and mood were completed. Plasma LH, FSH, total oestrogen and progesterone results are presented in detail and the results of prolactin assays mentioned more briefly. An attempt to correlate hormone findings and clinical findings is described. This failed to produce any strong evidence that hormones are related to mood at this time, although hormone changes were correlated weakly with a few specific symptoms. Some of the unexpected clinical findings and technical difficulties of the study are discussed, with special reference to possible further research in this area.

Affective Symptoms

Imaginal flooding and exposure to real phobic situations: treatment outcome with agoraphobic patients.

Each of thirty-six female agoraphobic out-patients were treated by one of three methods: 8 sessions of imaginal flooding followed by 8 sessions of practice in the real situation; 16 sessions of combined flooding and practice; or 16 sessions of practice alone. Three therapists treated equal numbers of patients in each group, and there was some evidence that patients' response varied according to the therapist seen, irrespective of treatment group. There were no significant differences between treatment groups after 8 sessions, 16 sessions or on six-month follow-up. It is concluded that there are no long-term differences between the effects of treatments involving exposure to either imaginal or real phobic situations or to a combination of both, provided that patients are encouraged to practise between sessions.

Agoraphobia

Imaginal flooding and exposure to real phobic situations: changes during treatment.

This paper reports the results of measures taken during treatment in the study of imaginal flooding and exposure to real phobic situations previously described by Mathews, Johnston, Lancashire, Munby, Shaw and Gelder (1976). On weekly measures of change of similar reduction in phobic behaviour in all treatments was found, confirming the previous findings. Differences in therapist effectiveness were also confirmed. On measures of the immediate effects of treatment, exposure to the phobic situation had consistent positive effects, imaginal flooding had little or no detectable effect. It is proposed that the treatments studied differ in their immediate effects on phobic behaviour but also have the common effect of facilitating counterphobic behaviour outside the treatment situation, and that this is the main agent of therapeutic change.

Anxiety

Correlation between plasma levels of prolactin and chlorpromazine in psychiatric patients.

Plasma levels of chlorpromazine (CPZ) and prolactin were measured repeatedly in 14 psychiatric patients throughout CPZ treatment. Mean prolactin level was elevated in 11 subjects (all six women and five of eight men). Mean plasma prolactin correlated significantly with mean plasma CPZ but not with the dose of the drug. Only patients with mean plasma prolactin above 35 ng/ml developed Parkinsonian side-effects.

Administration, Oral