RESUMO
In the present multicentre, open-label, prospective, phase III study, we evaluated the real-world effectiveness and ease of use of nasal glucagon (NG) in the treatment of moderate/severe hypoglycaemic events (HEs) in adults with type 1 diabetes (T1D). Patients and caregivers were taught how to use NG (3 mg) to treat moderate/severe HEs, record the time taken to awaken or return to normal status, and measure blood glucose (BG) levels over time. Questionnaires were used to collect information about adverse events and ease of use of NG. In the efficacy analysis population, 69 patients experienced 157 HEs. In 95.7% patients, HEs resolved within 30 minutes of NG administration. In all the 12 severe HEs, patients awakened or returned to normal status within 15 minutes of NG administration without additional external medical help. Most caregivers reported that NG was easy to use. Most adverse events were local and of low to moderate severity. In this study, a single, 3-mg dose of NG demonstrated real-life effectiveness in treating moderate and severe HEs in adults with T1D. NG was well tolerated and easy to use.
Assuntos
Diabetes Mellitus Tipo 1/tratamento farmacológico , Glucagon/administração & dosagem , Hipoglicemia/tratamento farmacológico , Hipoglicemiantes/efeitos adversos , Insulina/efeitos adversos , Administração Intranasal , Adulto , Glicemia/análise , Automonitorização da Glicemia , Cuidadores , Feminino , Glucagon/uso terapêutico , Conhecimentos, Atitudes e Prática em Saúde , Humanos , Hipoglicemia/sangue , Hipoglicemia/induzido quimicamente , Hipoglicemia/fisiopatologia , Hipoglicemiantes/uso terapêutico , Insulina/uso terapêutico , Perda de Seguimento , Masculino , Pessoa de Meia-Idade , Pacientes Desistentes do Tratamento , Educação de Pacientes como Assunto , Autorrelato , Índice de Gravidade de Doença , Síncope/etiologia , Síncope/prevenção & controle , Fatores de TempoRESUMO
OBJECTIVE: This multicenter, open-label study was designed to evaluate real-world effectiveness and ease of use of nasal glucagon (NG) in treating moderate or severe hypoglycemic events in children and adolescents with type 1 diabetes (T1D). METHODS: Caregivers were trained to administer NG (3 mg) to the child/adolescent with T1D during spontaneous, symptomatic moderate or severe hypoglycemic events, observe treatment response (defined as awakening or returning to normal status within 30 minutes), and measure blood glucose (BG) levels every 15 minutes. Data regarding adverse events and ease of use were solicited using questionnaires. RESULTS: The analysis population included 14 patients who experienced 33 moderate hypoglycemic events with neuroglycopenic symptoms and BG level ≤70 mg/dL. Patients returned to normal status within 30 minutes of NG administration in all 33 events. Mean BG levels increased from 55.5 mg/dL (range 42-70 mg/dL) at baseline to 113.7 mg/dL (range 79-173 mg/dL) within 15 minutes of NG administration. In most hypoglycemic events (93.9%), caregivers reported that NG administration was easy or very easy; they could administer NG within 30 seconds in 60.6% of events. There were no serious adverse events. CONCLUSIONS: A single 3-mg dose of NG was effective in treating moderate, symptomatic, hypoglycemic events in children and adolescents with T1D in a real-world setting. It was easy-to-use and reasonably well tolerated. NG shows promise as an effective, needle-free, and user-friendly alternative to injectable glucagon.
Assuntos
Diabetes Mellitus Tipo 1/complicações , Glucagon/administração & dosagem , Hormônios/administração & dosagem , Hipoglicemia/tratamento farmacológico , Administração Intranasal , Adolescente , Cuidadores/psicologia , Criança , Diabetes Mellitus Tipo 1/tratamento farmacológico , Feminino , Humanos , Hipoglicemia/induzido quimicamente , Insulina/efeitos adversos , Masculino , Estudos Prospectivos , Resultado do TratamentoRESUMO
BACKGROUND: During severe hypoglycemic episodes, people with diabetes depend on others to help with treatment. We compared needle-free nasal glucagon and commercially available injectable glucagon for ease of use by caregivers of people with diabetes and by others in treating simulated episodes of severe hypoglycemia. METHODS: Sixteen instructed caregivers and 15 noninstructed acquaintances administered nasal and injectable glucagon to manikins, simulating unconscious people with diabetes during severe hypoglycemia episodes. RESULTS: With nasal glucagon, 15 caregivers (94%) and 14 acquaintances (93%) administered a full dose (mean time 0.27 and 0.44 min, respectively). One caregiver and one acquaintance did not administer nasal glucagon because they did not fully depress the plunger on the device. Two caregivers deliberately administered both insulin and nasal glucagon, believing that insulin would also help the patient. With injectable glucagon, eight caregivers (50%) injected glucagon (mean time 1.89 min), but only two (13%) administered the full dose. Three acquaintances (20%) injected a partial dose of injectable glucagon (mean time 2.40 min); none gave a full dose. Errors included injecting diluent only, bending the needle, and injecting with an empty syringe. Two caregivers and one acquaintance injected insulin because they confused insulin with injectable glucagon. CONCLUSIONS: More than 90% of participants delivered full doses of nasal glucagon, while 13% and 0% of caregivers and acquaintances delivered full doses of injectable glucagon, indicating that nasal glucagon is easier for nonmedically trained people to administer. Thus, nasal glucagon has the potential to substantially improve treatment for patients experiencing a life-threatening episode of severe hypoglycemia.
Assuntos
Glicemia , Diabetes Mellitus Tipo 1/sangue , Glucagon/uso terapêutico , Hipoglicemia/tratamento farmacológico , Administração Intranasal , Cuidadores , Glucagon/administração & dosagem , Humanos , Hipoglicemia/sangue , Injeções , ManequinsAssuntos
Diabetes Mellitus Tipo 1 , Glucagon , Adulto , Glicemia , Humanos , Hipoglicemia , InsulinaRESUMO
OBJECTIVE: Treatment of severe hypoglycemia outside of the hospital setting is limited to intramuscular glucagon requiring reconstitution prior to injection. The current study examined the safety and dose-response relationships of a needle-free intranasal glucagon preparation in youth aged 4 to <17 years. RESEARCH DESIGN AND METHODS: A total of 48 youth with type 1 diabetes completed the study at seven clinical centers. Participants in the two youngest cohorts (4 to <8 and 8 to <12 years old) were randomly assigned to receive either 2 or 3 mg intranasal glucagon in two separate sessions or to receive a single, weight-based dose of intramuscular glucagon. Participants aged 12 to <17 years received 1 mg intramuscular glucagon in one session and 3 mg intranasal glucagon in the other session. Glucagon was given after glucose was lowered to <80 mg/dL (mean nadir ranged between 67 and 75 mg/dL). RESULTS: All 24 intramuscular and 58 of the 59 intranasal doses produced a ≥25 mg/dL rise in glucose from nadir within 20 min of dosing. Times to peak plasma glucose and glucagon levels were similar under both intramuscular and intranasal conditions. Transient nausea occurred in 67% of intramuscular sessions versus 42% of intranasal sessions (P = 0.05); the efficacy and safety of the 2- and 3-mg intranasal doses were similar in the youngest cohorts. CONCLUSIONS: Results of this phase 1, pharmacokinetic, and pharmacodynamic study support the potential efficacy of a needle-free glucagon nasal powder delivery system for treatment of hypoglycemia in youth with type 1 diabetes. Given the similar frequency and transient nature of adverse effects of the 2- and 3-mg intranasal doses in the two youngest cohorts, a single 3-mg intranasal dose appears to be appropriate for use across the entire 4- to <17-year age range.
Assuntos
Administração Intranasal , Diabetes Mellitus Tipo 1/tratamento farmacológico , Glucagon/administração & dosagem , Adolescente , Glicemia/metabolismo , Criança , Pré-Escolar , Estudos de Coortes , Estudos Cross-Over , Relação Dose-Resposta a Droga , Método Duplo-Cego , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos/prevenção & controle , Feminino , Glucagon/efeitos adversos , Humanos , Hipoglicemia/sangue , Hipoglicemia/tratamento farmacológico , Injeções Intramusculares , Insulina/sangue , Insulina/uso terapêutico , Masculino , Náusea/etiologia , Náusea/prevenção & controle , PósRESUMO
OBJECTIVE: Treatment of severe hypoglycemia with loss of consciousness or seizure outside of the hospital setting is presently limited to intramuscular glucagon requiring reconstitution immediately prior to injection, a process prone to error or omission. A needle-free intranasal glucagon preparation was compared with intramuscular glucagon for treatment of insulin-induced hypoglycemia. RESEARCH DESIGN AND METHODS: At eight clinical centers, a randomized crossover noninferiority trial was conducted involving 75 adults with type 1 diabetes (mean age, 33 ± 12 years; median diabetes duration, 18 years) to compare intranasal (3 mg) versus intramuscular (1 mg) glucagon for treatment of hypoglycemia induced by intravenous insulin. Success was defined as an increase in plasma glucose to ≥70 mg/dL or ≥20 mg/dL from the glucose nadir within 30 min after receiving glucagon. RESULTS: Mean plasma glucose at time of glucagon administration was 48 ± 8 and 49 ± 8 mg/dL at the intranasal and intramuscular visits, respectively. Success criteria were met at all but one intranasal visit and at all intramuscular visits (98.7% vs. 100%; difference 1.3%, upper end of 1-sided 97.5% CI 4.0%). Mean time to success was 16 min for intranasal and 13 min for intramuscular (P < 0.001). Head/facial discomfort was reported during 25% of intranasal and 9% of intramuscular dosing visits; nausea (with or without vomiting) occurred with 35% and 38% of visits, respectively. CONCLUSIONS: Intranasal glucagon was highly effective in treating insulin-induced hypoglycemia in adults with type 1 diabetes. Although the trial was conducted in a controlled setting, the results are applicable to real-world management of severe hypoglycemia, which occurs owing to excessive therapeutic insulin relative to the impaired or absent endogenous glucagon response.
Assuntos
Diabetes Mellitus Tipo 1/tratamento farmacológico , Glucagon/administração & dosagem , Hormônios/uso terapêutico , Administração Intranasal , Adulto , Glicemia/efeitos dos fármacos , Estudos Cross-Over , Diabetes Mellitus Tipo 1/sangue , Feminino , Humanos , Hipoglicemia/induzido quimicamente , Insulina/uso terapêutico , Masculino , Pessoa de Meia-Idade , Adulto JovemRESUMO
The pathophysiology of urinary incontinence due to spaying remains unknown. Incontinent bitches can be treated successfully with depot preparations of GnRH-analogues and there are differences in plasma gonadotropin levels between continent and incontinent spayed bitches. It is therefore assumed that the supraordinated hormones, GnRH, FSH, and/or LH, have an effect on the urodynamic parameters. In this study, the potential influence of these hormones on the lower urinary tract was investigated by measuring urethral pressure profiles and cystometry. Simultaneously, plasma concentrations in 10 spayed Beagle bitches were determined 5 weeks prior to and 8 weeks after treatment with the GnRH analogue leuprolide. Within 1 week of GnRH analogue administration, plasma FSH and LH levels decreased from 72.5 and 7.7 to 7.75 and 0.72ng/mL, respectively. These plasma gonadotropin levels correspond with those of intact bitches during anoestrus. Urethral pressure profiles indicated that the treatment had no significant effect on maximum urethral closure pressure, functional and total length of the urethra, or area of the closure pressure curve. The data obtained by cystometry regarding mean bladder threshold volume showed a significant increase from 109 to 172mL. The improvement in bladder function after the application of GnRH-application is presumably a direct effect of the GnRH as a relationship between the plasma gonadotropin levels and the urodynamic parameters could not demonstrated.
Assuntos
Doenças do Cão/sangue , Cães/fisiologia , Hormônio Liberador de Gonadotropina/farmacologia , Uretra/fisiologia , Incontinência Urinária/veterinária , Animais , Doenças do Cão/tratamento farmacológico , Doenças do Cão/etiologia , Cães/sangue , Feminino , Hormônio Foliculoestimulante/sangue , Hormônio Liberador de Gonadotropina/análogos & derivados , Leuprolida/farmacologia , Hormônio Luteinizante/sangue , Ovariectomia/efeitos adversos , Ovariectomia/veterinária , Pressão , Incontinência Urinária/sangue , Incontinência Urinária/tratamento farmacológico , Incontinência Urinária/etiologiaRESUMO
In 23 bitches with urinary incontinence due to spaying, the effect of treatment with a long-acting formulation of leuprolide acetate on frequency of incontinence, plasma gonadotropin levels and urodynamic parameters was evaluated. In addition, the clinical effect was compared with that of treatment with alpha-adrenergics. Before treatment, the dogs' incontinent episodes occurred, on average, 4 times per day on up to 6 days per week. In the pre-trial after therapy with phenylpropanolamine (n=23) the episodes of incontinence decreased by 92%, in the double-blind study 5 weeks after GnRH-analogue (n=11) by 71%; and by 28% after the placebo (n=12). By the end of the study, nine of twenty-two leuprolide treated bitches responded completely to treatment and were continent for periods lasting 70-575 days after treatment. In another 10 dogs, response to therapy was partial and the frequency of incontinence was reduced by at least 50%. After therapy with placebo, one bitch had no episodes of incontinence for 412 days. Treatment with the GnRH-analogue significantly decreased the plasma gonadotropin levels but there was no correlation between the effect on gonadotropin levels and response to treatment. Treatment with leuprolide or placebo had no effect on urethral closure pressure regardless of the response to treatment. The hypothesis that the change of the plasma gonadotropin levels after spaying is the cause of reduced urethral closure function was not supported by the results of this study. A possible direct effect of GnRH-analogues on the bladder is discussed. Long acting GnRH analogues appear to be a well-tolerated alternative for urinary incontinence treatment, but they appear to be less effective than the alpha-adrenergics.
Assuntos
Doenças do Cão/tratamento farmacológico , Hormônio Liberador de Gonadotropina/uso terapêutico , Leuprolida/uso terapêutico , Incontinência Urinária/veterinária , Animais , Doenças do Cão/etiologia , Cães , Método Duplo-Cego , Feminino , Hormônio Foliculoestimulante/sangue , Hormônio Liberador de Gonadotropina/análogos & derivados , Hormônio Luteinizante/sangue , Ovariectomia/efeitos adversos , Ovariectomia/veterinária , Fatores de Tempo , Resultado do Tratamento , Incontinência Urinária/tratamento farmacológico , Incontinência Urinária/etiologiaRESUMO
OBJECTIVE: To evaluate the clinical and endocrine responses of ferrets with adrenocortical disease (ACD) to treatment with a slow-release implant of deslorelin acetate. ANIMALS: 15 ferrets with ACD. PROCEDURE: Ferrets were treated SC with a single slow-release, 3-mg implant of deslorelin acetate. Plasma estradiol, androstenedione, and 17-hydroxyprogesterone concentrations were measured before and after treatment and at relapse of clinical signs; at that time, the adrenal glands were grossly or ultrasonographically measured and affected glands that were surgically removed were examined histologically. RESULTS: Compared with findings before deslorelin treatment, vulvar swelling, pruritus, sexual behaviors, and aggression were significantly decreased or eliminated within 14 days of implantation; hair regrowth was evident 4 to 6 weeks after treatment. Within 1 month of treatment, plasma hormone concentrations significantly decreased and remained decreased until clinical relapse. Mean time to recurrence of clinical signs was 13.7 +/- 3.5 months (range, 8.5 to 20.5 months). In 5 ferrets, large palpable tumors developed within 2 months of clinical relapse; 3 of these ferrets were euthanatized because of adrenal gland tumor metastasis to the liver or tumor necrosis. CONCLUSIONS AND CLINICAL RELEVANCE: In ferrets with ACD, a slow-release deslorelin implant appears promising as a treatment to temporarily eliminate clinical signs and decrease plasma steroid hormone concentrations. Deslorelin may not decrease adrenal tumor growth in some treated ferrets. Deslorelin implants may be useful in the long-term management of hormone-induced sequelae in ferrets with ACD and in treatment of animals that are considered at surgical or anesthetic risk.
Assuntos
Doenças do Córtex Suprarrenal/veterinária , Furões , Pamoato de Triptorrelina/análogos & derivados , Pamoato de Triptorrelina/administração & dosagem , Doenças do Córtex Suprarrenal/tratamento farmacológico , Envelhecimento , Animais , Implantes de Medicamento/uso terapêutico , Feminino , Furões/sangue , Furões/fisiologia , Hormônios Esteroides Gonadais/sangue , Masculino , Recidiva , Pamoato de Triptorrelina/efeitos adversos , Pamoato de Triptorrelina/uso terapêuticoRESUMO
A novel controlled release formulation has been developed with PEGylated human insulin encapsulated in PLGA microspheres that produces multi-day release in vivo. The insulin is specifically PEGylated at the amino terminus of the B chain with a relatively low molecular weight PEG (5000 Da). Insulin with this modification retains full biological activity, but has a limited serum half-life, making encapsulation necessary for sustained release beyond a few hours. PEGylated insulin can be co-dissolved with PLGA in methylene chloride and microspheres made by a single o/w emulsion process. Insulin conformation and biological activity are preserved after PEGylation and PLGA encapsulation. The monolithic microspheres have inherently low burst release, an important safety feature for an extended release injectable insulin product. In PBS at 37 degrees C, formulations with a drug content of approximately 14% show very low (< 1%) initial release of insulin over one day and near zero order drug release after a lag of 3-4 days. In animal studies, PEG-insulin microspheres administered subcutaneously as a single injection produced < 1% release of insulin in the first day but then lowered the serum glucose levels of diabetic rats to values < 200 mg/dL for approximately 9 days. When doses were given at 7-day intervals, steady state drug levels were achieved after only 2 doses. PEG-insulin PLGA microparticles show promise as a once-weekly dosed, sustained release basal insulin formulation.
Assuntos
Diabetes Mellitus Experimental/tratamento farmacológico , Glicolatos/química , Hipoglicemiantes , Insulina de Ação Prolongada , Polietilenoglicóis/química , Animais , Dicroísmo Circular , Preparações de Ação Retardada , Humanos , Hipoglicemiantes/química , Hipoglicemiantes/farmacocinética , Hipoglicemiantes/uso terapêutico , Insulina de Ação Prolongada/química , Insulina de Ação Prolongada/farmacocinética , Insulina de Ação Prolongada/uso terapêutico , Ácido Láctico , Masculino , Microesferas , Peso Molecular , Tamanho da Partícula , Ácido Poliglicólico , Copolímero de Ácido Poliláctico e Ácido Poliglicólico , Ratos , Ratos Sprague-Dawley , SolubilidadeRESUMO
To determine whether the height of the plasma gonadotropin levels after spaying is associated with urinary incontinence, the concentrations of plasma follicle stimulating hormone (FSH) and luteinizing hormone (LH) were determined once in 191 intact and 308 spayed bitches. The bitches were grouped according to their risk for urinary incontinence and the medians of their respective gonadotropin levels were compared. For intact anestrous bitches, the FSH- and LH-plasma concentrations were 5.2 (4, 8) ng/mL (median (Q1, Q3)) and 0.5 (0.5-0.5) ng/mL, respectively. In the first year after spaying, the gonadotropin concentrations rose significantly, then stabilised at a level around 10 times those of intact bitches (FSH 62.5 (44, 91) ng/mL; LH 6.1(4, 11) ng/mL). The plasma gonadotropin concentrations of long-term spayed (>12 months) continent bitches (n=209) were higher (FSH 66.8 (46, 104) ng/mL; LH 6.5 (4, 11) ng/mL) than in spayed incontinent bitches (n=60) (FSH 51.5 (38, 74) ng/mL; LH 5.5 (3, 8) ng/mL), the latter also had a higher body weight. Multiple regression analysis showed that the FSH-plasma concentration and not the body weight was decisive for the occurrence of urinary incontinence. The results of this study suggest that levels of gonadotropins are associated, directly or indirectly in the pathophysiology of urinary incontinence after spaying.
Assuntos
Doenças do Cão/sangue , Hormônio Foliculoestimulante/sangue , Hormônio Luteinizante/sangue , Incontinência Urinária/veterinária , Animais , Peso Corporal , Cães , Feminino , Modelos Logísticos , Ovariectomia/veterinária , Fatores de Risco , Maturidade Sexual , Especificidade da Espécie , Fatores de Tempo , Incontinência Urinária/sangueRESUMO
Urinary incontinence due to acquired urethral sphincter incompetence is a common side effect of spaying, for which the underlying cause remains unknown. Spaying not only results in a significant reduction in the urethral closure pressure within 1 year but also in an increase in the plasma gonadotropin concentrations. To investigate the possible link between the post-ovariectomy changes in plasma gonadotropins and in urethral closure pressure, gonadotropin and urodynamic measurements were performed in 10 Beagle bitches before and for a period of 1 year after spaying. Plasma gonadotropin concentrations rose quickly after ovariectomy and peak levels were seen within 3-5 weeks, followed by a sharp drop until week 10. A steady increase was observed subsequently until week 42, when a plateau was reached. One year after spaying, the mean FSH concentration was 75.3 +/- 32.1 ng/ml, a 17-fold increase, and the LH was 8.3 +/- 3.8 ng/ml, an eightfold increase over the pre-spaying values. Ten months after spaying, the mean urethral closure pressure (9.7 cm H2O) was significantly reduced when compared to the mean pre-operative value of 15.4 cm H2O. However, there was no clear relationship between the gonadotropin concentrations and the urethral closure pressure. From these results it seems unlikely that chronically elevated gonadotropins are the underlying cause for reduced urethral closure pressure after spaying resulting in urinary incontinence.
Assuntos
Cães/fisiologia , Gonadotropinas/sangue , Ovariectomia/veterinária , Uretra/fisiologia , Animais , Doenças do Cão/etiologia , Feminino , Hormônio Foliculoestimulante/sangue , Cinética , Hormônio Luteinizante/sangue , Ovariectomia/efeitos adversos , Pressão , Incontinência Urinária/etiologia , Incontinência Urinária/veterináriaRESUMO
OBJECTIVE: To evaluate the potential utility of poly(D,L-lactic-co-glycolic)acid (PLGA) as a long-acting biodegradable drug delivery matrix for ivermectin used in the prevention of heartworm disease in dogs. ANIMALS: 30 adult female dogs. PROCEDURE: Microparticle formulations containing 25 weight percent (wt%), 35 wt%, and 50 wt% ivermectin were prepared by an oil-in-water emulsion technique with solvent extraction into excess water. A fourth formulation, consisting of a mixture of 15 wt% and 50 wt% ivermectin microparticles, was blended in a 1:1 ratio to result in a 32.5 wt% ivermectin formulation. Formulations were administered once on Day 0 to groups of 6 dogs at a dose of 0.5 mg of ivermectin/kg, s.c. Half of the dogs in each treatment group and 3 untreated control dogs were infected with Dirofilaria immitis larvae 121 and 170 days after treatment. Six months after infection, dogs were euthanatized and necropsies were performed. Pharmacokinetics and efficacy were investigated. RESULTS: Analysis of pharmacokinetic data revealed sustained release of ivermectin during at least 287 days in 3 distinct phases: a small initial peak, followed by release of drug through diffusion, and polymer degradation. Untreated control dogs were all infected with heartworms. Heartworms were not found in any of the dogs in the ivermectin-PLGA treated groups. Adverse clinical signs were not observed. CONCLUSIONS AND CLINICAL RELEVANCE: All formulations were 100% effective in preventing development of adult heartworms. Results indicate that PLGA microparticles are a promising drug delivery matrix for use with ivermectin for the prevention of heartworm disease for at least 6 months after treatment.
Assuntos
Dirofilaria , Dirofilariose/tratamento farmacológico , Doenças do Cão/prevenção & controle , Filaricidas/uso terapêutico , Ivermectina/uso terapêutico , Ácido Láctico/uso terapêutico , Ácido Poliglicólico/uso terapêutico , Polímeros/uso terapêutico , Animais , Cromatografia Líquida de Alta Pressão , Dirofilariose/prevenção & controle , Doenças do Cão/parasitologia , Cães , Relação Dose-Resposta a Droga , Portadores de Fármacos/uso terapêutico , Avaliação de Medicamentos , Ivermectina/sangue , Ivermectina/farmacocinética , Tamanho da Partícula , Copolímero de Ácido Poliláctico e Ácido Poliglicólico , Fatores de TempoRESUMO
Previous in vivo studies indicate that 2-hydroxyestradiol (2OHE) attenuates cardiovascular and renal diseases. In vitro studies suggest that the biological effects of 2OHE are mediated by 2-methoxyestradiol (2MEOE) after methylation of 2OHE by catechol-O-methyltransferase (COMT). This study tested the hypothesis that in vivo 2OHE is a prodrug of 2MEOE. We administered to male rats i.v. boluses of either 2OHE or 2MEOE and measured plasma levels of 2OHE and 2MEOE by gas chromatography-mass spectrometry at various time points after drug administration. After administration of 2OHE, plasma levels of 2OHE declined extremely rapidly [t(1/2(1)) = 0.94 min and t(1/2(2)) = 10.2 min] becoming undetectable after 45 min. Concomitant with the disappearance of 2OHE, 2MEOE occurred and then declined [t(1/2(1)) = 7.9 min and t(1/2(2)) = 24.9 min]. The peak concentration and total exposure (area under the curve) for 2OHE were much lower than for 2MEOE. 2OHE had a much higher plasma clearance (CL) and volume of distribution (V(d)) compared with 2MEOE (2OHE: CL = 1215 ml min(-1) kg(-1) and V(d) = 17,875 ml/kg; 2MEOE: CL = 50 ml min(-1) kg(-1) and V(d) = 1760 ml/kg). After administration of 2MEOE, plasma levels of 2MEOE declined [t(1/2(1)) = 2.5 min and t(1/2(2)) = 20.2 min] with a plasma CL of 50 ml min(-1) kg(-1) and a V(d) of 1500 ml/kg. We could not detect 2OHE in plasma from rats receiving 2MEOE. We conclude that the conversion of 2OHE to 2MEOE is so efficient that in terms of 2MEOE exposure, administration of 2OHE is bioequivalent to administration of 2MEOE itself.