Biomedical subjects

C E Pfeifle

Publications and source records attributed to C E Pfeifle.

25 records · Page 2Linked to original sources

PubMed1983

Clinical pharmacokinetics of intraarterial cisplatin in humans.

The pharmacokinetics of intraarterially administered cisplatin (DDP) were studied in three patients with large hepatic tumors, and one patient with a fibrous histiocytoma in the thigh, using an assay sensitive to only those forms of non-protein bound DDP capable of reacting with the nucleophilic ligand diethyldithiocarbamate. Each patient received continuous intravenous and intraarterial infusions at various dose rates, with and without concurrent infusion of the neutralizing agent sodium thiosulfate. Steady-state DDP concentrations were achieved within two hours, and the mean (+/- SEM) plasma clearance at infusion rates of 5-15 mg/m2 per hour was 345 +/- 45 mL/m2 per minute. Apparent plasma clearance did not vary significantly with route of infusion. Based on the plasma clearance, predicted values for the relative advantage of an intraarterial infusion (Rt) were less than two for hepatic infusion; observed values averaged 1.9 +/- 0.5 (+/- SEM). The infusion of thiosulfate did not significantly increase plasma clearance. The mean (+/- SEM) extraction ratio for hepatic infusions was 0.24 +/- 0.09, and for infusion of the peripheral soft tissue sarcoma it was 0.27 +/- 0.03. These data indicate that from the point of view of both the tumor and the systemic circulation there is only a limited pharmacologic advantage for intraarterial infusion of DDP into organs with plasma flows of greater than 350 mL/m2 per minute.

Adult↗

PubMed1983

Phase I trial of cytarabine and hydroxyurea.

A combination of hydroxyurea (HU) and cytarabine (ara-C) can overcome ara-C resistance in vitro. To determine the pattern of toxicity of this combination, 22 patients with refractory leukemia and lymphoma were treated for 5 days with ara-C (100 mg/m2/day by constant infusion) and escalating doses of HU (0.375-1.77 g/m2 every 6 hours). Hematologic toxicity was severe even at the lowest HU dose level. Skin and mucosal toxic effects were frequent but not dose-limiting. No novel types of toxic effects were observed.

Adolescent↗

PubMed1983

Intraperitoneal cis-diamminedichloroplatinum with systemic thiosulfate protection.

The toxicity and pharmacokinetics of cis-diamminedichloroplatinum (cisplatin) (90 mg/sq m) administered as a single 4-hr peritoneal dialysis, with or without concurrent i.v. infusion of sodium thiosulfate, 0.43 or 2.13 g/sq m/hr for 12 hr, were studied on 20 courses of treatment. When given without thiosulfate, the toxicity of cisplatin was systemic rather than local, and the peritoneal cavity/plasma ratio of the area under the curve was 12. Addition of i.v. thiosulfate significantly reduced the nephrotoxicity. The concentration of cisplatin in the peritoneal cavity was sufficiently greater than that in the plasma to prevent thiosulfate, which equilibrated into the cavity, from interfering with the antitumor activity of cisplatin in the peritoneum. This study demonstrates a pharmacokinetic advantage of i.p. chemotherapy with cisplatin.

Adult↗

PubMed1982

Modulation of the cellular pharmacology and clinical toxicity of 1-beta-D-arabinofuranosylcytosine.

The effect of thymidine (dThd) and hydroxyurea (HU) on the cellular metabolism of 1-beta-D-arabinofuranosylcytosine (Ara-C) was investigated in the human promyelocytic cell line HL-60. Both dThd and HU increased the cellular uptake and rate of formation of Ara-CTP. Measurement of ribo- and deoxyribonucleotide triphosphate pools implicated a reduction of the dCTP as the mechanism of this effect. dThd and HU had opposite effects on the incorporation of Ara-C into DNA per unit time, but both enhanced the incorporation of Ara-C per unit of newly synthesized DNA. In a Phase I trial Ara-C was given by continuous infusion for five days at 100 mg/m2, and HU by mouth every six hours with dose escalation from 0.375 to 1.78 g/m2 every six hours. Myelosuppression was the dose-limiting toxicity; the major nonhematologic toxicity was skin rash. To date responses have been observed in chronic myelogenous leukemia in blast crisis and diffuse histiocytic lymphoma.

Arabinofuranosylcytosine Triphosphate↗

PubMed1982

Comprehensive pharmaceutical services for a state correctional facility.

A contractual model for comprehensive pharmaceutical services involving a major medical center pharmacy, a university, and a state department of corrections is described. Project goals and methods for the provision of services are described. These include areas of formulary development, inventory management, drug distribution, on-site placement of pharmacy operations, and educational development. Impact of the program was assessed over a 30-month period. Development of policies and procedures for drug use in a correctional setting enabled implementation of a strict patient population-specific drug formulary. Procedural changes resulted in an 83% decrease in on-site drug inventories and a 62% decrease in quarterly drug expenditures. A one-time saving of more than $26,500 resulted from the decrease in on-site inventory, and an annual saving of $44,000 is projected for decreased drug expenditures. All but five controlled substances were removed from the formulary, and only 13 nonprescription items remained in the formulary. An educational course on health care in correctional settings provided exposure for pharmacy students to this new area of institutional practice. The contractual model proved both cost-effective and functional for the department of corrections.

Education, Pharmacy↗

PubMed1981

Phenytoin sodium solubility in three intravenous solutions.

The solubility of phenytoin sodium injection of two manufacturer's was studied in three intravenous fluids, 0.9% sodium chloride, lactated Ringer's, and four manufacturers 5% dextrose injections. Phenytoin sodium for injection was added to 250 ml of an intravenous fluid to give calculated initial concentrations of 0.40, 0.98, 2.38, and 4.55 mg/ml. The pH of each solution was determined before and after the addition of phenytoin. Visual examination and nephelometric measurements for crystals were performed at various times between 5 and 1440 minutes after mixing. Phenytoin concentration was determined by spectrophotometry at these times; nephelometric measurements were done on unfiltered samples. The concentration of phenytoin declined rapidly in all dextrose solutions but at different rates for each brand. A greater stability was demonstrated when phenytoin was diluted in 0.9% sodium chloride and lactated Ringer's injections. Mean concentrations in excess of 95% of initial concentration were maintained for eight hours in those fluids. The two brands of phenytoin sodium injection did not differ consistently with respect to solubility. Crystals were observed in all dextrose solutions; nephelometric measurements indicated crystals were present in all solutions. The pH of all solutions increased sharply upon addition of phenytoin sodium injection. It is concluded that 0.9% sodium chloride and lactated Ringer's injections are suitable diluents for the intravenous administration of phenytoin. Factors other than pH and cosolvent concentration may affect phenytoin stability in dextrose solutions.

Drug Stability↗

PubMedDate not supplied

Chiropractic in The Netherlands: a survey of Dutch chiropractors.

BACKGROUND: In the Netherlands, there is increasing public and political interest in chiropractic treatment. There is, however, very little descriptive information available in the Netherlands on the chiropractic profession. Therefore, a survey was conducted among all Dutch chiropractors. METHODS: A questionnaire was sent to all members of the Netherlands' Chiropractors Association (n = 59). It contained questions on (postgraduate) education, practice management, diagnostics (including radiology use), treatment, interprofessional cooperation and referral. RESULTS: The response was 88%. Chiropractic is growing rapidly: the number of chiropractors has doubled in five years. Chiropractors primarily treat back and neck pain, with an average of 8 treatments. Conventional orthopedic and neurological examination along with motion palpation are the cornerstones of physical examination. The respondents stressed the importance of direct access to radiography and specialized (hospital) diagnostics. Fifty-eight percent of the chiropractors have their own X-ray equipment. The most frequent reason for taking new X-rays was the absence of cooperation with radiology departments. Self-referral is the largest source of patients. The referral rate to other health care professionals is low. CONCLUSIONS: The number of chiropractors is growing rapidly. They have an exceptional position in the Dutch health care system. Access to X-ray and more specialized diagnostics are presently the most important political issues.

Chiropractic↗