Exercise and Plasma Concentrations of (R)- and (S)-Propranolol During Long-Term Treatment with (R,S)-Propranolol

1996 ◽  
Vol 59 (2) ◽  
pp. 202-202
Author(s):  
K. Stoschitzky ◽  
M. Schumacher ◽  
W. Klein ◽  
W. Lindner
Keyword(s):  
Plasma Concentrations ◽  
Term Treatment ◽  
Long Term Treatment

Changes in imatinib plasma trough level during long-term treatment of patients with advanced gastrointestinal stromal tumors.

2011 ◽  
Vol 29 (4_suppl) ◽  
pp. 306-306
Author(s):  
Y. Kang ◽  
C. Yoo ◽  
B. Ryoo ◽  
H. Chang ◽  
J. Lee ◽  
...  
Keyword(s):  
Plasma Level ◽  
Gastrointestinal Stromal Tumors ◽  
Plasma Concentrations ◽  
Term Treatment ◽  
Albumin Concentration ◽  
Stromal Tumors ◽  
Long Term Treatment ◽  
The Mean ◽  
Median Interval

306 Background: Pharmacokinetic study in patients with gastrointestinal stromal tumors (GISTs) suggested that plasma concentrations of imatinib decrease following long-term exposure. We therefore measured changes in imatinib plasma trough levels (Cmin) after long-term exposure. Methods: Between November 2009 and May 2010, follow-up (FU) imatinib Cmin was measured in 65 patients who received the same dose of imatinib for at least 9 months after a previous baseline (BL) measurement. Total 244 blood samples were obtained (127 at BL and 117 at FU) and plasma level was measured by liquid chromatography-tandem mass spectrometry. Results: Median patient age was 54 years (range, 28–76 years) and 42 (64.6%) patients were male. Sixty-one (93.8%) patients were treated with 400 mg/day imatinib and 4 (6.2%) with 300 mg/day. The median interval from initiation of imatinib to BL test was 6.4 months (range, 0.5–66.6 months), and the median interval between BL and FU test was 13.1 months (range, 9.6–18.4 months). The mean ± standard deviation imatinib Cmin was significantly higher at FU than at BL (1442 ± 693 ng/mL vs 1221 ± 624 ng/mL, p<0.001). The mean inter- and intra-subject variabilities were 49.2% and 25.5%, respectively, at BL, and 44.2% and 20.4%, respectively, at FU. Multivariate analysis showed a significant correlation between the ratio of FU to BL imatinib Cmin and that of albumin (r=-0.397, p=0.001). In per-sample analysis, imatinib Cmin was significantly correlated with age, hemoglobin, albumin, creatinine clearance, previous major gastrectomy and time between initiation of imatinib and plasma level tests. Conclusions: Steady-state imatinib Cmin did not decrease but remained stable in most GIST patients during long-term treatment. Changes in imatinib Cmin were associated with changes in albumin concentration. Monitoring of imatinib Cmin only for concerns about time-dependent decreases in imatinib exposure is not necessary. [Table: see text]

scholarly journals Systemic and presystemic conversion of carbamazepine to carbamazepine-10,11-epoxide during long term treatment

2006 ◽  
Vol 12 (1) ◽  
pp. 13-16 ◽  
Author(s):  
Pietro Fagiolino ◽  
Marta Vázquez ◽  
Ivette Olano ◽  
Aurora Delfino
Keyword(s):  
Plasma Concentrations ◽  
Chronic Administration ◽  
Hplc Method ◽  
Term Treatment ◽  
Published Data ◽  
Long Term Treatment ◽  
Important Pathway ◽  
Kinetics Of ◽  
Dose Dependent

INTRODUCTION: Carbamazepine (CBZ) undergoes biotransformation, being CYP3A4 the major cytocrome P450 (CYP) enzyme catalyzing the carbamazepine-10,11-epoxide (EPOX) formation, which is quantitatively the most important pathway in CBZ metabolism. There is evidence of dose-dependent elimination of this drug due to its autoinduction capacity. Moreover, published data showed an incomplete bioavailability of CBZ since its absorption increases when grapefruit juice was administered. Both CYP3A4 and MRP2 (located in the enterocyte) are autoinduced during long term use of CBZ. As the other enzymes involved in CBZ metabolism are negligible in the gut, presystemic biotransformation through CYP3A4 could be responsible for the bioavailability of the drug as well as EPOX formation. OBJECTIVE: The purpose of our study was to assess the importance of presystemic formation of EPOX during the autoinduction of CBZ versus the daily administered dose. PATIENTS AND METHODS: 40 adults (average age: 28 years) and 29 children (average age: 9 years) receiving CBZ as monotherapy were included in the study. CBZ and EPOX plasma concentrations were analyzed by a previous validated HPLC method. RESULTS AND CONCLUSION: The results obtained confirmed the metabolic induction after chronic administration and provided new elements to suggest a strong contribution of dose-dependent bioavailability in the non linear kinetics of CBZ.

Long-term negative feedback effects of oestrogen and progesterone on the pituitary gland of the long-term ovariectomized ewe

1989 ◽  
Vol 120 (2) ◽  
pp. 207-214 ◽  
Author(s):  
I. J. Clarke ◽  
J. T. Cummins ◽  
M. E. Crowder ◽  
T. M. Nett
Keyword(s):  
Plasma Concentrations ◽  
Pulse Amplitude ◽  
Pituitary Surgery ◽  
Pulse Frequency ◽  
Term Treatment ◽  
Gnrh Receptors ◽  
Long Term Treatment ◽  
Group 3 ◽  
Group 2

ABSTRACT The effects of long-term treatment with physiological doses of oestradiol or oestradiol plus progesterone on plasma gonadotrophin levels and pituitary content of LH and gonadotrophin-releasing hormone (GnRH) receptors were studied in ovariectomized–hypothalamo-pituitary disconnected ewes given 250 ng pulses of GnRH every 2 h (i.v.). A pilot experiment showed that 3 cm long Silastic implants (s.c.) reduced both LH pulse frequency and pulse amplitude in long-term (> 6 months) ovariectomized ewes. The main experiment was conducted over 3 weeks in ovariectomized–hypothalamo-pituitary disconnected ewes that had received pulsatile GnRH replacement for 1 week after pituitary surgery. Group 1 (n = 5) received GnRH pulses alone throughout the study. Group 2 (n = 6) received oestradiol in week 2 and oestradiol plus progesterone in week 3 and in group 3 (n = 6) the steroid treatments were reversed. Oestradiol reduced (P < 0·05) the mean (± s.e.m.) amplitude of LH in pulses in group 2 (from 8·2 ± 1·6 to 5·0 ± 0·5 μg/l) and group 3 (from 11·6 ± 1·2 to 9·3 ±1·0 μg/l); an additional effect of progesterone was seen in group 2 but not group 3. The amplitudes of the LH pulses did not change in the control ewes. Plasma concentrations of FSH were reduced by approximately 50% by the oestradiol treatments with no additional effects of progesterone. There was no effect of steroidal treatment on pituitary content of LH or pituitary levels of GnRH receptors. We conclude that long-term oestradiol treatment, with or without progesterone, reduces plasma amplitudes of LH pulses by a direct pituitary effect, but the magnitude of this effect was less than that observed on GnRH secretion in short-term ovariectomized ewes in an earlier study. The reduction in plasma LH pulse amplitude is not due to a direct pituitary effect of these steroids on GnRH receptor number. Journal of Endocrinology (1989) 120, 207–214

scholarly journals Long term treatment with theophylline increases malonyl dialdehyde plasma concentrations.

Thorax ◽  
1984 ◽  
Vol 39 (2) ◽  
pp. 137-139 ◽  
Author(s):  
P Godard ◽  
J Chaintreuil ◽  
J Bensadoun ◽  
G Parelon ◽  
A C de Paulet ◽  
...  
Keyword(s):  
Plasma Concentrations ◽  
Term Treatment ◽  
Long Term Treatment ◽  
Malonyl Dialdehyde

Anti-Hypertensive Effect of Metoprolol in Spontaneously Hypertensive Rats

1976 ◽  
Vol 51 (s3) ◽  
pp. 443s-445s
Author(s):  
B. Ljung ◽  
B. Åblad ◽  
L. Drews ◽  
E. Fellenius ◽  
A. Kjellstedt ◽  
...  
Keyword(s):  
Spontaneously Hypertensive Rats ◽  
Plasma Concentrations ◽  
Term Treatment ◽  
Hypertensive Rats ◽  
Spontaneously Hypertensive ◽  
Arterial Blood ◽  
Long Term Treatment ◽  
Portal Veins

1. Oral and intravenous administration of metoprolol to adult spontaneously hypertensive rats (SHR) with established hypertension lowered arterial blood pressure within 4 days of treatment. 2. Steady-state plasma concentrations of metoprolol were similar to those of patients during antihypertensive treatment with this drug. 3. The neuroeffector function of portal veins of SHR treated orally for 14 days or intravenously for 4 days was not impaired when studied in vitro. This is in contrast to previous findings after long-term treatment. 4. It is concluded that the anti-hypertensive effect of metoprolol in SHR in many respects resembles that observed in patients. It is suggested that impairment of vasomotor nerve control may contribute to the anti-hypertensive effect of β-adrenoreceptor antagonists.

Effects of long-term treatment with LH on induction of cyclic ovarian activity in seasonally anoestrous ewes

1984 ◽  
Vol 100 (1) ◽  
pp. 67-73 ◽  
Author(s):  
K. P. McNatty ◽  
N. Hudson ◽  
M. Gibb ◽  
K. Ball ◽  
J. Fannin ◽  
...  
Keyword(s):  
Plasma Concentrations ◽  
Term Treatment ◽  
Oestrous Cycle ◽  
Ovarian Activity ◽  
Cyclic Activity ◽  
Long Term Treatment ◽  
Term Administration ◽  
Term Maintenance

ABSTRACT The aim of the present study was to establish whether cyclic ovarian activity could be induced and then maintained in anoestrous Romney ewes by the long-term administration of regular intravenous pulses of LH (10 μg ovine LH i.v. once every 1 or 2 h for 29–91 days). The LH pulse regimen was designed to generate plasma profiles of LH that were comparable to those experienced during the luteal and follicular phases of the oestrous cycle. The results showed that the LH treatments were capable of inducing cyclic ovarian activity, as assessed from the concentrations of progesterone in plasma, but that the treatments were inadequate for sustaining cyclic activity beyond two consecutive progestational phases. After 35–56 days of treatment, the plasma concentrations of FSH declined significantly (P <0·05) relative to those in the untreated animals. These data suggest that FSH supplementation as well as LH might be required for the long-term maintenance of cyclic ovarian activity in seasonally anoestrous ewes. J. Endocr. (1984) 100, 67–73

Hypnotherapy is effective in the long-term treatment of functional dyspepsia

2001 ◽  
Vol 120 (5) ◽  
pp. A115-A115 ◽  
Author(s):  
E CALVERT ◽  
L HOUGHTON ◽  
P COOPER ◽  
P WHORWELL
Keyword(s):  
Functional Dyspepsia ◽  
Term Treatment ◽  
Long Term Treatment
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