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1.
Clin Pharmacol Ther ; 81(1): 69-75, 2007 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-17186001

RESUMO

Limited data are available about the effect of steady-state lopinavir and ritonavir (LPV/r) on bupropion pharmacokinetics. As patients may benefit by using these two agents in combination, this study determined the extent and direction of this drug-drug interaction. Twelve healthy volunteers received a single 100 mg dose of sustained-release bupropion before and after 2 weeks of treatment with LPV/r 400 mg/100 mg twice daily. Pharmacokinetics profiles were determined on days 1 and 30 for bupropion and hydroxybupropion and days 29 and 30 for LPV/r. LPV/r administration significantly decreased bupropion maximum plasma concentration (C(max)) by 57% (90% confidence interval (CI), 38-76%; P<0.01) and area under the curve (AUC) infinity by 57% (90% CI, 32-83%; P<0.01). Hydroxybupropion C(max) and AUC infinity decreased by 31% (90% CI, 7-55%; P<0.01) and by 50% (90% CI, 34-65%; P<0.01), respectively. No significant changes in the pharmacokinetics of LPV/r were found following administration of a single dose of bupropion. Concurrent use of LPV/r and bupropion resulted in decreased exposure to bupropion and its active metabolite hydroxybupropion that may necessitate as much as a 100% dose increase of bupropion. A probable mechanism for this interaction is the concurrent induction of cytochrome P450 2B6 and UDP-glucuronosyltransferase enzymes. LPV/r exposure is unaffected by a single dose of bupropion.


Assuntos
Antidepressivos de Segunda Geração/farmacocinética , Bupropiona/farmacocinética , Inibidores da Protease de HIV/farmacologia , Pirimidinonas/farmacologia , Ritonavir/farmacologia , Adulto , Antidepressivos de Segunda Geração/sangue , Área Sob a Curva , Bupropiona/análogos & derivados , Bupropiona/sangue , Antagonismo de Drogas , Combinação de Medicamentos , Feminino , Inibidores da Protease de HIV/administração & dosagem , Meia-Vida , Humanos , Lopinavir , Masculino , Taxa de Depuração Metabólica , Pirimidinonas/administração & dosagem , Ritonavir/administração & dosagem
2.
J Clin Oncol ; 7(8): 1142-9, 1989 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-2787840

RESUMO

Nausea and vomiting are commonly recognized side effects of chemotherapy. However, the incidence and duration of these effects have not been systematically studied in a large outpatient oncology population. This survey was conducted over two consecutive 6-week periods in the adult oncology clinics of two university teaching hospitals. The objectives were: (1) to document the incidence and duration of chemotherapy-induced nausea and vomiting; (2) to identify variables that influence nausea and vomiting; and (3) to describe patterns of antiemetic prescribing and compliance. One hundred thirty-eight completed patient-maintained diaries were returned (70% response rate). Anticipatory nausea and vomiting were reported by 9.4% and 6.5% of patients, respectively. Fifty percent and 27% of patients reported nausea and vomiting, respectively, on the day chemotherapy was administered (day 1: acute nausea and vomiting phase). Percentages fell to 22% and 11% by day three and 14% and 2.5% on day 5. Of patients who reported nausea and vomiting during the five-day period, 52% and 33% experienced nausea and vomiting, respectively, during the delayed period only (days 2 through 5: delayed emesis phase). Emetogenicity of chemotherapy significantly influenced incidence and duration of those symptoms. Sixty-seven percent of patients reported taking antiemetics on one or more days during the survey period. Of patients who reported antiemetic use, 92% reported antiemetics on day 1, 51% on day 3, and 31% on day 5. At-home antiemetic use was related to the emetogenicity of chemotherapy received. Patients who receive moderate to strong emetogens as defined in this report should receive antiemetic therapy for a minimum of three days. Increasing the dose of antiemetic prescribed both in the clinic and at home may be of benefit.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Náusea/epidemiologia , Vômito/epidemiologia , Adulto , Antieméticos/administração & dosagem , Antieméticos/uso terapêutico , Protocolos de Quimioterapia Combinada Antineoplásica/classificação , Estudos de Coortes , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Náusea/induzido quimicamente , Náusea/prevenção & controle , Pacientes Ambulatoriais , Cooperação do Paciente , Autoadministração , Fatores de Tempo , Vômito/induzido quimicamente , Vômito/prevenção & controle
3.
J Clin Oncol ; 16(4): 1380-7, 1998 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-9552041

RESUMO

PURPOSE: To evaluate the quality of life (QOL) of breast cancer patients who survived 2 to 5 years following initiation of adjuvant cytotoxic and/or hormonal therapy and to characterize relationships between QOL and patient physical symptoms, sexual function, and preferences regarding adjuvant treatment. PATIENTS AND METHODS: Eighty-six patients who had completed systemic adjuvant therapy for early-stage breast cancer between 1988 and 1991 were surveyed by written questionnaire and telephone interview. Sociodemographic information was obtained for each patient, and patients were asked to complete the Functional Living Index-Cancer (FLIC), the Symptom Distress Scale (SDS), the Medical Outcomes Study (MOS) Short Form 36 (SF-36), a series of questions regarding sexual function, and a survey about preferences for adjuvant therapy in relation to possible benefit. RESULTS: The mean FLIC score among all patients was 138.3 (+/- 12.2), which suggests a high level of QOL. The reported frequency of moderate to severe symptoms was generally low (ie, < 15%), with fatigue (31.4%), insomnia (23.3%), and local numbness at the site of surgery (22.1%) occurring with greatest frequency. Patients reported a wide range of sexual difficulties. Preference assessment showed that more than 65% of patients were willing to undergo 6 months of chemotherapy for a 5% increase in likelihood of cancer cure. CONCLUSION: Self-rated QOL in breast cancer patients 2 to 5 years following adjuvant therapy was generally favorable. Less than one third of patients reported moderate to severe symptoms. Selected aspects of sexual function appeared to be compromised. The majority of patients indicated a willingness to accept 6 months of chemotherapy for small to modest potential benefit.


Assuntos
Neoplasias da Mama/tratamento farmacológico , Quimioterapia Adjuvante/psicologia , Qualidade de Vida , Adulto , Idoso , Idoso de 80 Anos ou mais , Atitude Frente a Saúde , Neoplasias da Mama/psicologia , Feminino , Humanos , Pessoa de Meia-Idade , Sexualidade , Inquéritos e Questionários
4.
J Clin Oncol ; 15(1): 103-9, 1997 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-8996130

RESUMO

PURPOSE: To propose a classification of the acute emetogenicity of antineoplastic chemotherapy agents, and to develop an algorithm to define the emetogenicity of combination chemotherapy regimens. METHODS: A Medline search was conducted to identify (1) clinical trials that used chemotherapy as single-agent therapy, and (2) major reviews of antiemetic therapy. The search was limited to patients who received commonly used doses of chemotherapy agents, primarily by short (< 3 hours) intravenous infusions. Based on review of this information and our collective clinical experience, we assigned chemotherapy agents to one of five emetogenic levels by consensus. A preliminary algorithm to determine the emetogenicity of combination chemotherapy regimens was then designed by consensus. A final algorithm was developed after we analyzed a data base composed of patients treated on the placebo arms of four randomized antiemetic trials. RESULTS: Chemotherapy agents were divided into five levels: level 1 (< 10% of patients experience acute [< or = 24 hours after chemotherapy] emesis without antiemetic prophylaxis); level 2 (10% to 30%); level 3 (30% to 60%); level 4 (60% to 90%); and level 5 (> 90%). For combinations, the emetogenic level was determined by identifying the most emetogenic agent in the combination and then assessing the relative contribution of the other agents. The following rules apply: (1) level 1 agents do not contribute to the emetogenic level of a combination; (2) adding > or = one level 2 agent increases the emetogenicity of the combination by one level greater than the most emetogenic agent in the combination; and (3) adding level 3 or 4 agents increases the emetogenicity of the combination by one level per agent. CONCLUSION: The proposed classification schema provides a practical means to determine the emetogenic potential of individual chemotherapy agents and combination regimens during the 24 hours after administration. This system can serve as a framework for the development of antiemetic guidelines.


Assuntos
Algoritmos , Antineoplásicos/efeitos adversos , Antineoplásicos/classificação , Náusea/induzido quimicamente , Vômito/induzido quimicamente , Doença Aguda , Antineoplásicos/administração & dosagem , Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/classificação , Ensaios Clínicos como Assunto , Feminino , Humanos , Masculino , Ensaios Clínicos Controlados Aleatórios como Assunto
5.
J Clin Oncol ; 17(10): 3333-55, 1999 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-10506637

RESUMO

PURPOSE: Because toxicities associated with chemotherapy and radiotherapy can adversely affect short- and long-term patient quality of life, can limit the dose and duration of treatment, and may be life-threatening, specific agents designed to ameliorate or eliminate certain chemotherapy and radiotherapy toxicities have been developed. Variability in interpretation of the available data pertaining to the efficacy of the three United States Food and Drug Administration-approved agents that have potential chemotherapy- and radiotherapy-protectant activity-dexrazoxane, mesna, and amifostine-and questions about the role of these protectant agents in cancer care led to concern about the appropriate use of these agents. The American Society of Clinical Oncology sought to establish evidence-based, clinical practice guidelines for the use of dexrazoxane, mesna, and amifostine in patients who are not enrolled on clinical treatment trials. METHODS: A multidisciplinary Expert Panel reviewed the clinical data regarding the activity of dexrazoxane, mesna, and amifostine. A computerized literature search was performed using MEDLINE. In addition to reports collected by individual Panel members, all articles published in the English-speaking literature from June 1997 through December 1998 were collected for review by the Panel chairpersons, and appropriate articles were distributed to the entire Panel for review. Guidelines for use, levels of evidence, and grades of recommendation were reviewed and approved by the Panel. Outcomes considered in evaluating the benefit of a chemotherapy- or radiotherapy-protectant agent included amelioration of short- and long-term chemotherapy- or radiotherapy-related toxicities, risk of tumor protection by the agent, toxicity of the protectant agent itself, quality of life, and economic impact. To the extent that these data were available, the Panel placed the greatest value on lesser toxicity that did not carry a concomitant risk of tumor protection. RESULTS AND CONCLUSION: Mesna: (1) Mesna, dosed as detailed in these guidelines, is recommended to decrease the incidence of standard-dose ifosfamide-associated urothelial toxicity. (2) There is insufficient evidence on which to base a guideline for the use of mesna to prevent urothelial toxicity with ifosfamide doses that exceed 2.5 g/m(2)/d. (3) Either mesna or forced saline diuresis is recommended to decrease the incidence of urothelial toxicity associated with high-dose cyclophosphamide use in the stem-cell transplantation setting. Dexrazoxane: (1) The use of dexrazoxane is not routinely recommended for patients with metastatic breast cancer who receive initial doxorubicin-based chemotherapy. (2) The use of dexrazoxane may be considered for patients with metastatic breast cancer who have received a cumulative dosage of 300 mg/m(2) or greater of doxorubicin in the metastatic setting and who may benefit from continued doxorubicin-containing therapy. (3) The use of dexrazoxane in the adjuvant setting is not recommended outside of a clinical trial. (4) The use of dexrazoxane can be considered in adult patients who have received more than 300 mg/m(2) of doxorubicin-based therapy for tumors other than breast cancer, although caution should be used in settings in which doxorubicin-based therapy has been shown to improve survival because of concerns of tumor protection by dexrazoxane. (5) There is insufficient evidence to make a guideline for the use of dexrazoxane in the treatment of pediatric malignancies, with epirubicin-based regimens, or with high-dose anthracycline-containing regimens. Similarly, there is insufficient evidence on which to base a guideline for the use of dexrazoxane in patients with cardiac risk factors or underlying cardiac disease. (6) Patients receiving dexrazoxane should continue to be monitored for cardiac toxicity. Amifostine: (1) Amifostine may be considered for the reduction of nephrotoxicity in patients receiving cisplatin-based chemoth


Assuntos
Amifostina/uso terapêutico , Fármacos Cardiovasculares/uso terapêutico , Mesna/uso terapêutico , Substâncias Protetoras/uso terapêutico , Protetores contra Radiação/uso terapêutico , Razoxano/uso terapêutico , Adulto , Antineoplásicos/efeitos adversos , Humanos , Neoplasias/tratamento farmacológico , Neoplasias/radioterapia , Radioterapia/efeitos adversos
6.
Clin Pharmacol Ther ; 55(6): 638-48, 1994 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-8004880

RESUMO

OBJECTIVE: To evaluate the pharmacokinetics and pharmacodynamics of recombinant activated factor VII (rFVIIa). METHODS: Single-dose pharmacokinetics of three dose levels (17.5, 35, and 70 micrograms/kg) of rFVIIa were investigated in 15 patients with hemophilia with severe factor VIII or factor IX deficiency (with or without inhibitors) while they were in the nonbleeding state and during bleeding episodes. Factor VII clotting activity (FVII:C) was determined 5 minutes before and at 10, 20, and 50 minutes and 2, 4, 6, 8, 12, and 24 hours after rFVIIa administration. Model-independent pharmacokinetic analysis of FVII:C plasma concentration-time data included determination of plasma clearance, mean residence time, and volume of distribution. rFVIIa recovery was determined from the plasma FVII:C observed 10 minutes after administration. Pharmacodynamic assessments of prothrombin time, activated partial thromboplastic time, and Factor X values obtained concurrently with FVII:C samples were performed. RESULTS: Sufficient data to allow pharmacokinetic parameter calculation were available for 25 nonbleeding episodes in 11 patients (17.5 micrograms/kg, n = 8; 35 micrograms/kg, n = 9; 70 micrograms/kg, n = 8) and for five bleeding episodes in three patients (17.5 micrograms/kg, n = 2; 35 micrograms/kg, n = 2; 35 micrograms/kg, n = 1). Recovery was calculated during 27 nonbleeding and 17 bleeding episodes. rFVIIa distribution volume is two to three times that of plasma. Median clearance was low--31.0 ml/hr.kg in nonbleeding episodes and 32.5 mg/hr.kg in bleeding episodes. In nonbleeding episodes, median mean residence time was 3.44 hours and median half-life was 2.89 hours. In bleeding episodes, the elimination rate appears to be higher, with a median mean residence time of 2.97 hours and a median half-life of 2.30 hours. Recovery was 45.6% during nonbleeding conditions and 43.5% during bleeding episodes (p = 0.0006); it was statistically lower with the highest dose level than with the 17.5 and 35 micrograms/kg doses (p = 0.007). A significant statistical relationship was observed between values of the prothrombin time and activated partial thromboplastin time, and values of FVII:C with use of maximum effect model. CONCLUSIONS: The pharmacokinetics of rFVIIa are linear in the dose range evaluated. The results suggest potential value of prothrombin time determination in the monitoring of rFVIIa therapy.


Assuntos
Fator VIIa/farmacologia , Hemofilia A/sangue , Hemofilia B/sangue , Hemorragia/sangue , Adolescente , Adulto , Análise de Variância , Esquema de Medicação , Fator VIIa/administração & dosagem , Fator VIIa/farmacocinética , Hemofilia A/complicações , Hemofilia A/tratamento farmacológico , Hemofilia B/complicações , Hemofilia B/tratamento farmacológico , Hemorragia/tratamento farmacológico , Hemorragia/etiologia , Humanos , Injeções Intravenosas , Masculino , Pessoa de Meia-Idade , Proteínas Recombinantes/administração & dosagem , Proteínas Recombinantes/farmacocinética , Proteínas Recombinantes/farmacologia
7.
Clin Pharmacol Ther ; 68(4): 356-66, 2000 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11061575

RESUMO

PURPOSE: The aims of these experiments were to determine the effect of a therapeutic regimen of dexamethasone on cytochrome P4503A4 (CYP3A4) activity in healthy volunteers; and the concentration-effect relationship between dexamethasone and CYP3A4 activity in primary human hepatocyte cultures. METHODS: The effect of dexamethasone (8 mg administered by mouth two times a day for 5 days) on CYP3A4 activity in 12 healthy volunteers was assessed with the erythromycin breath test and urinary ratio of dextromethorphan to 3-methoxymorphinan. Concentration-effect of dexamethasone on CYP3A4-dependent testosterone 6-beta-hydroxylation was determined in human hepatocytes treated with 2 to 250 micromol/L dexamethasone. RESULTS: The percent of erythromycin metabolized per hour increased from 2.20% +/- 0.60% (mean +/- SD) at baseline to 2.67% +/- 0.55% on day 5 of dexamethasone (mean increase in hepatic CYP3A4 activity 25.7% +/- 24.6%; P = .004). The mean urinary ratio of dextromethorphan to 3-methoxymorphinan was 28 (4.8 to 109) and 7 (1 to 23) at baseline and on day 5 of dexamethasone (mean decrease = 49%; P = .06). Substantial intersubject variability was observed in the extent of CYP3A4 induction. The extent of CYP3A4 induction was inversely correlated with baseline erythromycin breath test (r2 = 0.58). In hepatocytes, dexamethasone 2 to 250 micromol/L resulted in an average 1.7-fold to 6.9-fold increase in CYP3A4 activity, respectively. The extent of CYP3A4 induction with dexamethasone in hepatocyte preparations was inversely correlated with baseline activity (r2 = 0.59). CONCLUSIONS: These data demonstrate that dexamethasone at doses used clinically increased CYP3A4 activity with extensive intersubject variability and that the extent of CYP3A4 induction was, in part, predicted by the baseline activity of CYP3A4 in both healthy volunteers and human hepatocyte cultures.


Assuntos
Sistema Enzimático do Citocromo P-450/biossíntese , Dexametasona/farmacologia , Dextrometorfano/análogos & derivados , Glucocorticoides/farmacologia , Hepatócitos/efeitos dos fármacos , Hepatócitos/enzimologia , Oxigenases de Função Mista/biossíntese , Administração Oral , Adulto , Anti-Inflamatórios/farmacologia , Testes Respiratórios/métodos , Células Cultivadas , Citocromo P-450 CYP3A , Dexametasona/administração & dosagem , Dexametasona/sangue , Dextrometorfano/urina , Relação Dose-Resposta a Droga , Esquema de Medicação , Indução Enzimática/efeitos dos fármacos , Eritromicina/análise , Feminino , Glucocorticoides/administração & dosagem , Glucocorticoides/sangue , Humanos , Hidroxilação/efeitos dos fármacos , Técnicas In Vitro , Masculino , Valor Preditivo dos Testes , Valores de Referência , Testosterona/metabolismo
8.
J Thromb Haemost ; 2(10): 1745-51, 2004 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-15456485

RESUMO

BACKGROUND: Anticoagulants are often given for extended periods of time to patients at high risk for venous thromboembolism, such as after orthopedic surgery. Daily subcutaneous (sc) injections can be inconvenient to the patient. A long-acting anticoagulant requiring less frequent dosing could make treatment more acceptable. Thrombomodulin is a natural anticoagulant that activates protein C, which leads to inactivation of factor (F)Va and FVIIIa and decreased thrombin formation. Recombinant human thrombomodulin is a novel anticoagulant with a long half-life in animal models. METHODS AND RESULTS: This phase I study examined pharmacokinetics, pharmacodynamics, and safety of recombinant human soluble thrombomodulin (ART-123) after administration of doses between 0.02 and 0.06 mg kg(-1) body weight intravenously (iv), and between 0.02 and 0.45 mg kg(-1) sc in 55 healthy volunteers. The plasma half-life was 2-3 days after sc injection of various single doses. Plasma ART-123 levels estimated to be needed for prevention of thrombus formation in humans were maintained for at least 6 days after single sc injection of 0.30 and 0.45 mg kg(-1) ART-123. Antithrombotic activity with these doses was demonstrated by achieving prothrombinase inhibition of more than 80% for more than 6 days after administration. No major bleeding occurred. Pharmacodynamic modeling revealed that adequate antithrombotic ART-123 levels can be achieved for 6 days with one dose of 0.45 mg kg(-1) ART-123, and for 12 days with 2 doses of 0.30 mg kg(-1), given 5 days apart. CONCLUSIONS: Recombinant human soluble thrombomodulin (ART-123) has a long half-life after sc injection and is well tolerated, making it a suitable agent to be tested in clinical thromboprophylaxis trials.


Assuntos
Proteínas Recombinantes/administração & dosagem , Proteínas Recombinantes/farmacocinética , Trombomodulina/administração & dosagem , Adulto , Idoso , Anticoagulantes/efeitos adversos , Anticoagulantes/farmacocinética , Anticoagulantes/uso terapêutico , Coagulação Sanguínea/efeitos dos fármacos , Testes de Coagulação Sanguínea , Relação Dose-Resposta a Droga , Feminino , Meia-Vida , Humanos , Injeções Subcutâneas , Masculino , Pessoa de Meia-Idade , Farmacocinética , Proteínas Recombinantes/efeitos adversos , Proteínas Recombinantes/uso terapêutico , Solubilidade , Tromboplastina/antagonistas & inibidores
9.
Thromb Haemost ; 77(5): 944-8, 1997 May.
Artigo em Inglês | MEDLINE | ID: mdl-9184407

RESUMO

Current therapy for hemophilia B requires large intravenous doses of factor IX (F.IX) given in the clinic or at home. Although home therapy is possible for many patients, it is often complicated by factors such as the lack of good venous access. Very little is known about extravascular routes for administering proteins like F.IX (57 kD) or other vitamin K-dependent procoagulant factors into the circulation. Questions about the absorption rate from extravascular administration as well as plasma recovery and bioavailability have arisen recently with the growing availability of highly purified procoagulant proteins and increased interest in gene therapy of hemophilia B. Therefore, a group of studies were undertaken to determine the absorption rate, plasma recovery, and bioavailability of high purity, human plasma-derived F.IX concentrates administered via extravascular routes in hemophilia B dogs and in one human hemophilia B subject. Five hemophilia B dogs were given human F.IX via either a subcutaneous (s.c.), intramuscular (i.m.), intraperitoneal (i.p.) or intravenous (i.v.) route. In a subsequent study, a single SC administration of human F.IX was compared to an identical i.v. dose of F.IX in the human hemophilia B subject. All extravascular routes of F.IX administration in both the canine and human gave lower levels of circulating plasma F.IX than the i.v. route, however all routes resulted in measurable F.IX activity. Of the extravascular routes, the i.m. injection in the canine resulted in a bioavailability of 82.8%, while the s.c. injection resulted in a bioavailability of 63.5%. F.IX reached the plasma compartment by all extravascular routes used, confirming that F.IX can be absorbed extravascularly. The duration of measurable F.IX activity following extravascular administration is prolonged beyond that typically seen with i.v. administration. These data show that significant levels of F.IX may be obtained via s.c. injection in canine and human hemophilia B subjects and further highlight the potential of extravascular routes of administration for future experimental and clinical uses of F.IX and other procoagulant proteins.


Assuntos
Doenças do Cão , Fator IX/uso terapêutico , Hemofilia B/terapia , Hemofilia B/veterinária , Animais , Disponibilidade Biológica , Cães , Fator IX/administração & dosagem , Fator IX/farmacocinética , Meia-Vida , Humanos , Injeções Intramusculares , Injeções Intraperitoneais , Injeções Intravenosas , Taxa de Depuração Metabólica , Fatores de Tempo
10.
J Clin Pharmacol ; 41(7): 723-31, 2001 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-11452704

RESUMO

Gender-based differences in cytochrome P450 (CYP) activity may occur due to endogenous hormonal fluctuations with the menstrual cycle, which are altered by oral contraceptives. This study assessed the average activity and within-subject variability in CYP3A4 and CYP2D6 in men, women taking Triphasil, and regularly menstruating women not receiving oral contraceptives. Thirty-three healthy volunteers participated in this 28-day pilot study (12 women receiving Triphasil) (OCs), 11 regularly menstruating women not on exogenous progesterone or estrogen (no OCs), and 10 men. CYP3A4 and CYP2D6 activities were phenotyped with dextromethorphan (DM) on study days 7, 14, 21, and 28 using urinary ratios of DM:3-methoxymorphinan (3MM) and DM:dextrorphan (DX), respectively. Serial blood concentrations of estrogen and progesterone and menstrual diaries were used to determine menstrual phase in both groups of women. Average urinary DM:3MM and DM:DX in the 28 extensive metabolizers of CYP2D6 did not differ between the three study populations (p = 0.86 and 0.93, respectively). Post hoc power analysis indicated that more than 1000 subjects would be needed for 80% power (alpha = 0.05) to detect a +/- 15% difference from the population mean in the urinary ratios of dextromethorphan and its metabolites 3MM and DX. Variability in CYP3A4 and CYP2D6 activity, characterized by intrasubject standard deviation, also did not differ. The varying doses of levonorgesterol and ethinyl estradiol in Triphasil, fluctuations in estrogen and progesterone, and menstrual phase did not influence CYP3A4 or CYP2D6 activity. It was concluded that CYP3A4 and CYP2D6 activity and intrasubject variability were not different in the three study populations, and thus a clinically important difference between men, women on Triphasil, and women not receiving oral contraceptives is unlikely. High inter- and intrasubject variability in DM:3MM and DM:DX were clearly demonstrated and limit the use of dextromethorphan to phenotype endogenous CYP3A4 and CYP2D6 activity.


Assuntos
Anticoncepcionais Orais Combinados/farmacologia , Citocromo P-450 CYP2D6/metabolismo , Sistema Enzimático do Citocromo P-450/metabolismo , Dextrometorfano/metabolismo , Combinação Etinil Estradiol e Norgestrel/farmacologia , Antagonistas de Aminoácidos Excitatórios/metabolismo , Menstruação/metabolismo , Oxigenases de Função Mista/metabolismo , Adulto , Análise de Variância , Citocromo P-450 CYP2D6/genética , Citocromo P-450 CYP3A , Sistema Enzimático do Citocromo P-450/genética , Dextrometorfano/urina , Antagonistas de Aminoácidos Excitatórios/urina , Feminino , Humanos , Masculino , Oxigenases de Função Mista/genética , Fenótipo , Projetos Piloto , Caracteres Sexuais
11.
Cancer Chemother Pharmacol ; 47(5): 373-9, 2001 May.
Artigo em Inglês | MEDLINE | ID: mdl-11391850

RESUMO

PURPOSE: Carboplatin is frequently dosed to achieve a desired area under the plasma concentration-time curve (AUC) by using the Calvert or Chatelut equations to estimate carboplatin clearance. Accurate determination of glomerular filtration rate (GFR) is necessary to correctly calculate carboplatin clearance using the Calvert equation. In clinical practice, the Cockcroft-Gault formula is frequently used to estimate GFR, but this practice has been reported to under- and overestimate carboplatin clearance. The purpose of this trial was to compare determinations of carboplatin clearance using the Chatelut equation and four separate GFR determinations, including 99mTc-DTPA, the Cockcroft-Gault formula, a 24-h urine collection and a 2-h urine collection. METHODS: Carboplatin clearance was estimated in 21 previously untreated extensive-stage small-cell lung cancer patients. GFR was determined using 99mTc-DTPA, the Cockcroft-Gault formula, 24-h urine collection and 2-h urine collection. Serum and urine creatinine concentrations were measured using enzymatic assays. The carboplatin clearance was then calculated by individually adding 25 to the four GFR determinations based on the Calvert equation, which states that carboplatin clearance equals GFR + 25 (nonrenal clearance). The carboplatin clearance was also estimated using the Chatelut equation. The five determinations of carboplatin clearance were compared using Friedman's test and post-hoc Wilcoxon signed rank tests. Precision and bias for each carboplatin clearance determination were calculated assuming that 99mTc-DTPA provided the most accurate measure of GFR. RESULTS: A statistically significant difference was found between the five methods of estimating carboplatin clearance (P < 0.001). No difference was found between carboplatin clearance calculated using 99mTc-DTPA and the Chatelut equation, the Cockcroft-Gault formula or the 2-h urine collection. The Chatelut equation provided more precision and less bias than the 2-h urine collection (median precision 20% and 30%, median bias -1% and -18%, respectively). CONCLUSION: Compared to 99mTc-DTPA, the Chatelut equation more accurately estimates carboplatin clearance than the Cockcroft-Gault formula, the 2-h urine collection and the 24-h urine collection. The greater negative bias found for the latter three estimates of carboplatin clearance could result in underdosing of carboplatin.


Assuntos
Antineoplásicos/farmacocinética , Carboplatina/farmacocinética , Creatinina/metabolismo , Taxa de Filtração Glomerular , Adulto , Idoso , Antineoplásicos/administração & dosagem , Antineoplásicos/uso terapêutico , Antineoplásicos/urina , Área Sob a Curva , Carboplatina/administração & dosagem , Carboplatina/uso terapêutico , Carboplatina/urina , Carcinoma de Células Pequenas/tratamento farmacológico , Feminino , Humanos , Neoplasias Pulmonares/tratamento farmacológico , Masculino , Pessoa de Meia-Idade , Pentetato de Tecnécio Tc 99m
12.
Pharmacotherapy ; 12(4): 346-52, 1992.
Artigo em Inglês | MEDLINE | ID: mdl-1518733

RESUMO

Quality of life (QOL) has transcended from an implicit concern to an explicit measurement in oncology. In contemporary clinical research, QOL can now often be identified and objectively measured in health as well as in illness. The major domains which comprise QOL in patients with cancer include symptoms and side effects, social function, physical function, and psychological status. One of the preferred methods for measuring QOL consists of self-administered questionnaires. A number of instruments have been developed which vary in features such as type of domains included, number of items, response options, specificity for disease type, and psychometric assessments. The role of QOL assessment is becoming increasingly important in clinical oncology.


Assuntos
Oncologia , Neoplasias/psicologia , Qualidade de Vida , Atividades Cotidianas , Ensaios Clínicos como Assunto , Nível de Saúde , Humanos , Testes Psicológicos , Psicometria , Inquéritos e Questionários
13.
Pharmacotherapy ; 17(4): 822-6, 1997.
Artigo em Inglês | MEDLINE | ID: mdl-9250565

RESUMO

Thrombotic and hemorrhagic events may result from high circulating concentrations of platelets (> 1,000,000/mm3), and measures to reduce the platelet count are indicated in symptomatic or extreme thrombocytosis. The platelet count can be decreased quickly by plasmapheresis, but the effect is transient. Patients with thrombocytosis secondary to a myeloproliferative disease, such as chronic myelogenous leukemia (CML), frequently require more sustained suppression of the platelet count. Hydroxyurea, busulfan, and interferon are used to maintain a lower platelet count but are occasionally ineffective or intolerable. An alternative to these therapies is anagrelide, a quinazolin derivative that was approved by the Food and Drug Administration in March 1997. Because current dosing guidelines for anagrelide are scarce, the dosing method of the Anagrelide Study Group that published the largest study to date on the drug's efficacy in thrombocytosis was followed. Two unexpected episodes of anagrelide-induced thrombocytopenia occurred despite following these dosing methods. This prompted a critical evaluation of the pharmacodynamic response and the appropriateness of anagrelide dosage recommendations. A case of thrombocytosis treated with anagrelide in a patient with CML is described.


Assuntos
Inibidores da Agregação Plaquetária/efeitos adversos , Quinazolinas/efeitos adversos , Trombocitopenia/induzido quimicamente , Adulto , Ensaios Clínicos como Assunto , Esquema de Medicação , Feminino , Humanos , Leucemia Mielogênica Crônica BCR-ABL Positiva/tratamento farmacológico , Quinazolinas/administração & dosagem
14.
Pharmacotherapy ; 16(5): 961-4, 1996.
Artigo em Inglês | MEDLINE | ID: mdl-8888094

RESUMO

Placement of a urethral catheter has been recommended to ensure adequate methotrexate elimination in patients with a neobladder; however, the need for this and its impact on methotrexate elimination have not been determined. A 53-year-old man with a cecal continent urinary diversion received intravenous methotrexate 30 mg/m2 on two occasions, with and without urethral catheter drainage of the neobladder. Serum methotrexate concentrations declined at a rate that resulted in 24- and 48-hour values falling below the accepted toxic concentration threshold of 5-50 mumol/L, and 0.05 mumol/L, respectively. In this man, who received low-dose methotrexate, catheterization of the neobladder did not alter methotrexate elimination sufficiently to justify its cost, risk, and inconvenience.


Assuntos
Antimetabólitos Antineoplásicos/sangue , Metotrexato/sangue , Cateterismo Urinário , Coletores de Urina , Antimetabólitos Antineoplásicos/farmacocinética , Antimetabólitos Antineoplásicos/uso terapêutico , Carcinoma de Células de Transição/tratamento farmacológico , Humanos , Neoplasias Hepáticas/tratamento farmacológico , Neoplasias Hepáticas/secundário , Masculino , Metotrexato/farmacocinética , Metotrexato/uso terapêutico , Pessoa de Meia-Idade , Neoplasias da Bexiga Urinária/tratamento farmacológico
15.
Pharmacotherapy ; 14(2): 224-8, 1994.
Artigo em Inglês | MEDLINE | ID: mdl-8197044

RESUMO

STUDY OBJECTIVE: To compare prothrombin time (PT), activated partial thromboplastin time (aPTT), and factor VII values in concurrent blood samples obtained by direct venipuncture and from a peripheral venous catheter. DESIGN: Concurrent samples obtained from catheters and by direct venipuncture were studied. In a separate crossover bioequivalence assessment of DNA-derived factor VIIa (rFVIIa) from two different batches, sample results of each technique were compared. SETTING: University hospital clinical research unit. PATIENTS: Six patients with hemophilia A under nonbleeding conditions. INTERVENTIONS: The patients received a single dose of rFVIIa 70 micrograms/kg administered by intravenous push over 2 minutes. Concurrent blood samples were collected at 2, 3, 4, 6, 8, 10, and 12 hours after rFVIIa administration. Catheter blood samples were drawn from a three-way stopcock attached to an 18-gauge peripheral venous catheter in the patient's forearm and connected to an intravenous solution of 5% dextrose with half normal saline maintained at a rate of 30 ml/hour. Venipuncture samples were drawn from the opposite arm. MEASUREMENTS AND MAIN RESULTS: The PT and aPTT values were determined by using a BBL Fibrometer (PT) and a Coagamate X-2 with automated aPTT reagent. Blood samples were analyzed for factor VII concentration using the Novo Clot assay. The mean venipuncture-obtained PT (8.9 +/- 1.0 sec) and aPTT (48.7 +/- 13.6 sec) values were numerically equivalent to mean catheter-derived PT (9.0 +/- 1.0 sec) and aPTT (48.3 +/- 12.5 sec) results, as were mean venipuncture and catheter-obtained FVII:C values. CONCLUSIONS: The PT and aPTT values determined after venipuncture and through the peripheral catheter were not statistically different (p > 0.05) when compared by paired or unpaired analysis. Similarly, values of FVII:C measured after venipuncture were statistically equivalent to those after sampling through the peripheral catheter. All six patients preferred the catheter method of blood collection over venipuncture.


Assuntos
Coleta de Amostras Sanguíneas/métodos , Fator VII/análise , Hemofilia A/sangue , Tempo de Tromboplastina Parcial , Tempo de Protrombina , Adulto , Sangria , Cateterismo Venoso Central , Hospitais Universitários , Humanos , Masculino
16.
J Pain Symptom Manage ; 5(4): 262-4, 1990 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-2384706

RESUMO

Pentostatin (2'-deoxycoformycin) is a unique antineoplastic agent that has proven valuable in the treatment of a number of lymphoid malignancies. Dose-limiting toxicities observed in clinical trials include central nervous system (CNS) effects and acute renal failure. Information regarding the incidence, duration, and severity of nausea and vomiting from published reports is conflicting and insufficient to provide recommendations for optimal supportive measures. We report the results of a phase I study where pentostatin was associated with a 20% incidence of vomiting following courses one and two (pentostatin alone). The third course of pentostatin administered concurrently with alpha interferon resulted in a 29% incidence of vomiting and by course four had increased to 50%. Grade of severity was similarly increased, and nausea and vomiting was the dose-limiting toxicity in 6 of 15 patients. Forty-two percent of all episodes of vomiting were delayed in onset (onset 24 hr after drug administration) and in over 80% of cases persisted for greater than 48 hr in duration. Potential mechanisms that may account for these findings, as well as recommendations regarding antiemetic therapy are provided.


Assuntos
Interferon Tipo I/efeitos adversos , Linfoma/tratamento farmacológico , Pentostatina/efeitos adversos , Vômito/induzido quimicamente , Adulto , Idoso , Quimioterapia Combinada , Humanos , Incidência , Interferon Tipo I/administração & dosagem , Interferon Tipo I/uso terapêutico , Pessoa de Meia-Idade , Pentostatina/administração & dosagem , Pentostatina/uso terapêutico , Vômito/epidemiologia
17.
J Pain Symptom Manage ; 19(4): 295-308, 2000 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-10799796

RESUMO

Few data are available that address the cost of postoperative pain management, although such knowledge would enhance our understanding of caregiver choices related to direct medical costs, such as type, frequency, and route of medication. This article describes the cost of postoperative pain medications before and after an educational program provided to nurses, pharmacists, and physicians in six community hospitals. Medication costs were calculated by averaging across all brands the average wholesale price of the most common dose administered in the sample for each medication. The median cost of postoperative pain medication across all days, all surgeries, was $9.46. Calculating the cost of acute postoperative pain medication suggested that cost over stay is highly influenced by the use of a few expensive medications. The relationship of medication cost to length of stay (LOS), function, and pain intensity is discussed.


Assuntos
Analgésicos/economia , Analgésicos/uso terapêutico , Dor Pós-Operatória/tratamento farmacológico , Dor Pós-Operatória/economia , Doença Aguda , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
18.
J Pain Symptom Manage ; 17(4): 277-87, 1999 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-10203880

RESUMO

The United States Agency for Health Care Policy and Research (AHCPR) Acute Pain Management Guidelines were written to provide a scientific basis for practice. Educational programs designed to promote use of the guidelines may change practice in community hospitals. This article describes the development and implementation of an education program for nurses, physicians, and pharmacists in six community hospitals. Program content addressing the use of continuous quality improvement (CQI) teams, detailed pain histories, application of algorithms and dose calculation is described; direct and indirect outcome measures are reviewed. Six months after the program, all three experimental sites reported use of the AHCPR Guidelines in practice. Nurses reported that assessment and documentation of patients' duration of pain were perceived to be the most important caregiver behaviors providing benefit to patients: Across all respondents' reports of regularly performed activities, the activity performed by the largest proportion was assessing and documenting pain using a 0-10 rating scale.


Assuntos
Educação Médica Continuada , Educação Continuada em Enfermagem , Educação Continuada em Farmácia , Dor Pós-Operatória/psicologia , Dor Pós-Operatória/terapia , Doença Aguda , Hospitais Comunitários , Humanos , Avaliação de Resultados em Cuidados de Saúde , Educação de Pacientes como Assunto , Garantia da Qualidade dos Cuidados de Saúde , Estados Unidos
19.
J Pain Symptom Manage ; 15(5): 275-84, 1998 May.
Artigo em Inglês | MEDLINE | ID: mdl-9654832

RESUMO

It is widely believed that patients' reluctance to report pain and adhere to treatment recommendations are significant barriers to cancer pain control. However, few investigators have examined barriers to cancer pain management from the cancer patient's perspective. Ambulatory patients with cancer who had experienced cancer-related pain in the previous month or were currently taking analgesics for cancer pain control were asked to participate in this study. Information regarding (a) pain assessment, (b) pain medication use, (c) concerns and barriers to compliance, (d) communication patterns regarding pain and pain control, and (e) demographics were collected during a 10-min structured interview. Approximately 20% of patients with a current cancer diagnosis who were approached reported that they had experienced pain or taken analgesic drugs during the preceding month. Eighty-eight percent of these patients ranked their pain as five or greater (scale, 0-10), and 81% reported impaired function due to pain. Major barriers to effective treatment included forgetfulness, the belief that pain should be tolerated, concerns about side effects, and fear and disdain of dependence, addiction, and tolerance. One-third of patients felt that their pain could not be better controlled than it currently was. Patients reported frequent communication regarding pain and pain control with physicians (52%), nurses (41%), and pharmacists (17%). The low pain prevalence, coupled with high pain intensity and associated dysfunction, appears to be a reflection of patient's unwillingness to report pain of mild to moderate intensity. In addition to previously recognized factors, stoicism and fatalism represent significant barriers to cancer pain control.


Assuntos
Analgesia Controlada pelo Paciente , Pesquisas sobre Atenção à Saúde , Neoplasias/complicações , Dor/tratamento farmacológico , Assistência Centrada no Paciente/métodos , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
20.
Life Sci ; 46(10): 699-705, 1990.
Artigo em Inglês | MEDLINE | ID: mdl-2314191

RESUMO

Cisplatin-containing chemotherapy regimens are known to produce intense nausea and vomiting. Angiotensin II (AII) and vasopressin (AVP) have been shown to have emetic properties. The role of these two peptides on cisplatin-induced vomiting was investigated in beagle dogs. Cisplatin (2 mg/kg, IV over 5 min) produced consistent emesis in all dogs after a mean latency time of 144 +/- 4 min. Serum Angiotensin Converting Enzyme (ACE) and plasma AII levels did not significantly change 3 hr after cisplatin administration (at the time of nausea and emesis) in control animals. AVP levels rose from 0.3 pg/ml to 7.5 pg/ml 3 hrs after cisplatin. Complete inhibition of ACE with enalapril (given at 3 mg/kg p.o., 3 hrs prior to cisplatin) reduced AII levels by 70%, but failed to significantly modify the increase in AVP levels (7.2 +/- 2.2 pg/ml), the latency time to emesis (149 +/- 2 min) and the number of emetic episodes induced by cisplatin. These results suggest that AII does not mediate cisplatin-induced emesis, nor does it mediate the increase in AVP observed at the time of emesis. We propose that AVP may be a good marker for nausea and emesis, and that increases in AVP may be neurally-mediated. The large increase in circulating AVP may represent a desirable water conservation response in anticipation of fluid losses induced by vomiting.


Assuntos
Angiotensina II/fisiologia , Arginina Vasopressina/fisiologia , Cisplatino/efeitos adversos , Vômito/induzido quimicamente , Angiotensina II/antagonistas & inibidores , Angiotensina II/sangue , Animais , Arginina Vasopressina/sangue , Cães , Enalapril/farmacologia , Masculino
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