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L C Pennypacker

Publications and source records attributed to L C Pennypacker.

4 recordsLinked to original sources

Efficacy and adverse effects of clozapine in four elderly psychotic patients.

BACKGROUND: Clozapine is an atypical antipsychotic agent that is effective in refractory schizophrenic patients. Older patients may have various psychotic manifestations that may not be responsive to typical neuroleptic therapy. There may also be patient-specific factors--declines in reserve capacity and homeostasis, and age-related changes in the pharmacokinetics and pharmacodynamics of drugs--in older patients that increase their susceptibility to the side effects of psychotropic medications. While clozapine has few extrapyramidal side effects, it has other side effects that may be problematic in the older population. METHOD: In our geropsychiatric unit, clozapine was prescribed for four patients over the age of 65 years. All patients were either experiencing psychotic symptoms refractory to other antipsychotic medications or had relative contraindications to a typical neuroleptic. Two of the four were chronic schizophrenics, and three of the four also presented with dementia. RESULTS: Two of the four patients did eventually receive relief of psychotic symptoms from clozapine. All four experienced events after initiation of clozapine therapy, which included falls (2 patients), symptomatic bradycardia (2 patients), and delirium (1 patient). All these adverse effects occurred on doses ranging from 6.25 to 37.50 mg/day, and the three patients with moderate-to-severe dementia experienced these severe adverse effects after administration of the first dose. CONCLUSION: Clozapine may be a useful drug for older patients with psychotic symptoms; however, at current dosage recommendations, adverse events may occur, especially on first dose. Well-designed studies need to be performed to assess the effectiveness and dosage ranges for this population.

Accidental Falls

High prevalence of cobalamin deficiency in elderly outpatients.

OBJECTIVE: To measure the prevalence of cobalamin (vitamin B12) deficiency in geriatric outpatients as documented by both low serum cobalamin levels and elevations of serum methylmalonic acid and homocysteine and to determine the response to cobalamin treatment. DESIGN: Prospective study screening elderly subjects for cobalamin deficiency using radiodilution cobalamin assays as well as stable isotope dilution gas chromatography-mass spectrometry methylmalonic acid and homocysteine assays. In patients with serum cobalamin levels < or = 300 pg/mL, the response to cobalamin treatment in the group with levels of methylmalonic acid and/or homocysteine > 3 standard deviations (SD) above the mean for normals was compared with that of those without such elevations. SETTING: Outpatient geriatric clinics at the VA Medical Center and University Health Sciences Center, Denver, CO. PATIENTS: One-hundred and fifty-two consecutive outpatients, ages 65 to 99, were screened. Twenty-nine subjects with serum cobalamin levels < or = 300 pg/mL were prospectively evaluated and treated with cobalamin. MAIN OUTCOME MEASURES: Cobalamin, methylmalonic acid, homocysteine, complete blood counts, neurologic examination, and neuropsychological testing. RESULTS: The prevalence of cobalamin deficiency as defined by a serum cobalamin level < or = 300 pg/mL and levels of serum methylmalonic acid and/or homocysteine elevated to > 3 SD was 14.5% of the screened outpatients. A similar proportion of patients with low normal serum cobalamin levels (between 201 and 300 pg/mL) demonstrated elevated metabolites > 3 SD (56%) compared with patients with low serum cobalamin levels (< or = 200 pg/mL) (62%). Cobalamin therapy caused a marked fall or complete correction of the elevated methylmalonic acid and homocysteine levels in each patient who was treated prospectively. Results for complete blood count, lactate dehydrogenase, bilirubin, baseline neurologic score, and baseline neuropsychologic scores did not differ in the group of patients with elevated metabolites compared with those with normal metabolites. The mean red cell volume fell significantly in the patients with elevated metabolites after 6 months of cobalamin treatment. One patient with elevated metabolites had marked improvement in his neurologic abnormalities after 6 months of cobalamin treatment. CONCLUSION: There was a high (14.5%) prevalence of cobalamin deficiency as demonstrated by elevations in serum methylmalonic acid and homocysteine in addition to low or low normal serum cobalamin levels in elderly outpatients. The serum cobalamin level was insensitive for screening since similar numbers of patients with low normal serum cobalamin levels of 201-300 pg/mL compared with patients with low cobalamin levels (< or = 200 pg/mL) had markedly elevated metabolites which fell with cobalamin treatment. Additional studies will be required to define the full clinical benefit from treatment with Cbl in elderly subjects.

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