• Title/Summary/Keyword: biological half life

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Drug Interaction of Nalidixic Acid and Probenecid in Rabbits (Nalidixic Acid와 Probenecid의 약물 상호 작용)

  • 최준식
    • YAKHAK HOEJI
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    • v.27 no.2
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    • pp.133-138
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    • 1983
  • The interaction between nalidixic acid and probenecid was studied pharmacokinetically in rabbits. The blood level and the area under the concentration curve(AUC) of nalidixic acid administered orally in dose of 100mg/kg was elevated by the coadministration of probenecid. Probenecid inhibited both the urinary excretion and the biliary excretion of nalidixic acid. Therefore, biological half-life of nalidixic acid was prolonged by the coadministrarion of probenecid. It was considered that the coadmini-stration of probenecid is more desirable than the single administration of nalidixic acid for the therapeutic effect.

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Pharmacokinetics of Acetaminophen in Rabbits with Experimental Renal Failure (실험적 신장장해 가토에서 아세트아미노펜의 약물동태학적 연구)

  • 최준식;이종기
    • YAKHAK HOEJI
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    • v.29 no.4
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    • pp.216-219
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    • 1985
  • The phormacokinetics of acetaminophen were investigated in rabbits with folate-induced renal failure. The blood level, the area under the blood concentraction curve(AUC) and the biological half-life were increased significantly, and the urinary excretion was decreased significantly as compared with those of normal rabbits. Serum creatinine concentration and AUC, creatinine clearance and renal clearance have linear relationship respectively. Dosage regimen of acetaminophen was considered to be adjusted in renal failure.

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Poor Sleep Quality and Its Effect on Quality of Life in the Elderly with Late Life Depression (노년기 우울증 환자의 수면의 질 저하가 삶의 질에 미치는 영향)

  • Choe, Jin Yeong;Park, Joon Hyuk
    • Korean Journal of Biological Psychiatry
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    • v.21 no.2
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    • pp.74-80
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    • 2014
  • Objectives More than half of the elders suffer from chronic sleep disturbances. Moreover, sleep disturbances are more prevalent in patients with depressive disorder than in community dwelling elderly. In this study, we aim to estimate the risk factors of poor sleep quality and its effect on quality of life in patients with late life depression. Methods This study included 159 depressive patients aged 65 years or older who completed Pittsburgh Sleep Quality Index (PSQI). A global PSQI score of 5 or greater indicates a poor sleeper. Structural diagnostic interviews were performed using the Korean version of Mini International Neuropsychiatric Interview (MINI). Depression was evaluated by the Korean form of Geriatric Depression Scale (KGDS). Global cognition was assessed by Mini-Mental State Examination in the Korean version of the Consortium to Establish a Registry for Alzheimer's Disease assessment packet. Quality of life was evaluated by the Korean version of Short-Form 36-Item Health Survey (SF-36). Results The frequencies of poor sleepers were 90.5% in major depressive disorder, 71.8% in minor depressive disorder, 47.1% in subsyndromal depressive disorder, and 73.0% in all types of depressive disorders. Multivariate logistic regression analysis indicated that female [odds ratio (OR) = 2.83, 95% confidence interval (CI) = 1.20-6.67] and higher KGDS score (OR = 1.13, 95% CI = 1.05-1.21) were risk factors of poor sleep quality in patients with late life depression. In the analysis of ANCOVA adjusted for age, gender, education and KGDS score, the mean scores of vitality mental health and mental component summary of SF-36 were lower in poor sleepers than in good sleepers. Conclusions Poor sleepers among patients with late life depression are very common and are associated with female and higher KGDS scores. Poor sleep quality causes a significant negative effect on mental health quality. So researchers and clinicians should be more vigilant in the evaluation and treatment of sleep disturbances in patients with late life depression.

Residue Patterns and Biological Half-lives of Pyridalyl and Fluopicolide in Watermelon (수박 중 및 Pyridalyl 및 Fluopicolide의 잔류 특성 및 생물학적 반감기 산출)

  • Park, Ji-Su;Yang, Seung-Hyun;Choi, Hoon
    • Korean Journal of Environmental Agriculture
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    • v.36 no.1
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    • pp.50-56
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    • 2017
  • BACKGROUND: The present study was carried out to identify the residue patterns of insecticide pyridalyl and fungicide fluopicolide in watermelon and calculate the biological half-lives for establishing the pre-harvest residue limits (PHRLs). METHODSANDRESULTS:The watermelon samples for residue analysis were harvested 7 times during 0~10 days (Field 1) and 0~20 days (Field 2) after treatment of pesticides on watermelon in two different fields at the recommended dose, respectively. The residue analysis was conducted with HPLC/UVD. The method limit of quantitation (MLOQ) were set at 0.05 and 0.02 mg/kg, respectively, and overall mean recoveries were 81.2~90.5% for pyridalyl and fluopicolide. The residues in sample were stable for 43~47 days. The initial residue amount in field 1 and 2 were 0.12~0.16 mg/kg for pyridalyl and 0.23~0.24 mg/kg for fluopicolide, which were below maximum residue limit (MRL). The biological half-lives in field 1 and 2 were 26.9 and 17.9 days for pyridalyl and 16.6 and 94.2 days for fluopicolide, respectively. CONCLUSION: The PHRL for watermelon were estimated as 0.21 and 1.03 mg/kg for pyridalyl and flopicolide at 10 days before harvesting. The residue patterns of pyridalyl and fluopicolide were characterized by a very slow decrease of residue levels in watermelon.

Quantitation of abamectin by HPTLC and its pharmacokinetics after intramuscular injection in pigs (돼지에서 근육주사한 Abamectin에 대한 HPTLC 분석 및 약물동태학)

  • Park, Seung-chun;Yun, Hyo-in
    • Korean Journal of Veterinary Research
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    • v.40 no.1
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    • pp.35-41
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    • 2000
  • We established a new method to analyze abamectin using HPTLC (high performance thin layer chromatography) in order to obtain its pharmacokinetic profiles in pigs. Recovery of abamectin in pig serum after fluorescence derivatization was $80.01{\pm}3.82%$ at 0.1ppm and $83.67{\pm}3.63%$ at 10ppm, respectively. Detection reproducibility in terms of coefficient variation (c.v.) was 3.09% and 2.74% (intra-day), and 3.71% and 51.7%(inter-day), for 0.1 and 10ppm, respectively. Pharmacokinetics of abamectin was studied in five Yorkshire-Landrace mixed bred male pigs ($35.0{\pm}2.7kg$) administered intramuscularly 0.3mg/kg b.w. Pharmacokinetic profiles of abamectin in pigs were described by the 1-compartment open model with first-order absorption and first-order elimination. AUC (area under the curve) was $262.65{\pm}16.44ng{\cdot}day/ml$ and the biological elimination half-life ($t_{1/2},\;k_e$) was $5.28{\pm}0.84$ days, indicating somewhat high bioavailability and long half-life by the intramuscular route. We suggest intramucular injection of abamectin could be also used in place of the recommended route of its subcutaneous administration so far.

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A Study for Establishment of High Dose Radioiodine Therapy Patients' Release Standard

  • Park, Hoon-Hee;Kim, Hyun-Soo;Dong, Kyung-Rae
    • Korean Journal of Digital Imaging in Medicine
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    • v.13 no.4
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    • pp.153-156
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    • 2011
  • This study, which is proceeded in the department of nuclear medicine, aims at preventing unnecessary radiation exposure to the patients and the people near the patients by understanding and presenting the realities about the isolating period for the high dose radioiodine patients after total thyroidectomy in the 7 general hospitals in metropolitan area. Theoretically, the physical half-life of the high dose radioiodine is 8 days. Radioiodine lower than 100 mCi usually is eliminated all in 2 days 1 night considering the biological half-life and the amount of excreting radioiodine The hospitalization standard of the patients treated with high-dose radioiodine therapy has been established according to the fact above. Investigation of the data and questionnaire from the hospital have proven that some hospitals didn't even measure the acceptable dose because of the faith in the vague data. Besides, the some of those inevitably let the readmitting patients exceeding the acceptable dose be in the general ward, not in the isolation ward, because the number of the isolation rooms is relatively smaller than the patients. Thus, we want to contribute that patients understand the realities and the hospitals consider the relevant problem actively so that the problem will be settled by this journal.

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Synthesis and Evaluation of a Ligand Targeting the Somatostatin Receptor for Drug Delivery to Tumor Cell (암세포 내로의 약물 전달 증진 목적의 신규 소마토스타틴 수용체 타겟리간드 합성 및 평가)

  • Choi, SunJu;Hong, YoungDon;Lee, SoYoung;Jung, SungHee
    • Journal of Radiation Industry
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    • v.9 no.4
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    • pp.193-198
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    • 2015
  • Most of targeted therapies block the action of certain enzymes, proteins, or other molecules involved in the growth and spread of cancer cells to produce its cytotoxic effect. Either small molecule drugs or monoclonal antibodies are mostly used in targeted therapies. Unfortunately, targeted therapy has a certain degree of unwanted side effect like other cytotoxicity inducing chemotherapies. To overcome and to reduce unwanted side effects during a cancer therapy, recently radiopeptide therapies has got the worlds' attraction for the tumor targeting modalities due to its beneficial effect on less side effect compared to cytotoxic chemotherapies. Among radiopeptide therapies, $^{177}Lu$-DOTATATE is a major modality as an effective one invented so far in treating neuroendocrine tumor (NET) and it has been in clinical trials at least one decade. Although it does have rather effective therapeutic effect on NET, it has less effective in rather large solid tumor. There are many ways to improve or increase therapeutic effect of radiopeptide are a finding the potent small molecules to target the tumor site selectively, or a labeling with radioisotope of emitting high energy, or an improving its biological half-life by introducing different moieties to increase lipophilicity. Present study was focus to increase a biological half-life of radio somatostatin which will target the somatostatin receptor by altering the bifunctional chelator (BFCA) by introducing lipophilic moiety to the somatostatin, which would make the labeled peptide stay longer in the tumor site and thus it can intensify the therapeutic effect on tumor cell itself and around tissues.

Biopharmaceutical studies on copper(II) chelates of sulfanilamide derivatives (Sulfanilamide유도체의 동(II)착화합물에 대한 생물약제학적 연구)

  • 김재백
    • YAKHAK HOEJI
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    • v.15 no.2
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    • pp.41-52
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    • 1971
  • Cu(II) chelates of several sulfanilamide derivatives (Sulfa-Cu) were prepared and their effects on solubility, absorptivity in intestinal lumen, biding tendency with serum protein and erythrocytes, concentration in rabbit blood, and acetylation rate were studied in comparison with their free ligand forms. For solubility concerned, the partition coefficients of Sulfa-Cu are decreased as following order: Sulfadimethoxine Copper chelate (SDM-Cu), Sulfamethoxypyridazine Copper chelate (SD-Cu), Sulfamerazine Copper chelate (SM-Cu), Sulfaisoxazole Copper chelate (SIX-Cu). The partition coefficients of SDM-Cu and ST-Cu were much greater than those of ligands. this phenomenone acounts for the rapid absorption of SDM-Cu and ST-Cu in the rat small intestine (in situ). The Sulfa-Cu were absorbed at the intestinal lumen of a rat in the rate of first order and there was no difference between long acting sulfa drugs and their Cu0chelates in biological half lives. In binding experiments, sulfa-Cu binded with serum protein in lower ratio than their ligands except SIX-Cu. On other hand, acetylation rates of sulfa-Cu were higher than those of free sulfa drugs and the acetylation rate were higher than those of free sulfa drugs and powder. In a experiment on Sulfa-Cu concentration in rabbit blood, the half lives of SD-Cu, SIX-cu, ST-Cu, and SM-Cu were longer than those of their ligands. Above all, the half life of SD-Cu appeared to be approximately 3.5 times logner than that of corresponding ligand, SD. When absorption of sulfa drugs or sulfa-Cu at the small intestinal lumen of a rat and the concentration in rabbit blood after absorption were compared, it was found that there was not always conrrelated.

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Dissipation Pattern of Fungicides Boscalid and Pyraclostrobin in Jujube (대추 중 살균제 boscalid와 pyraclostrobin의 잔류 소실 특성)

  • Jo, Hyeong-Wook;Sohn, Sang-Hyun;Kim, Kyoung-Jin;Hwang, Gi-Jun;Jo, Beom-Haeng;Gil, Seok-Ju;Kwon, Chan-Hyeok;Moon, Joon-Kwan
    • The Korean Journal of Pesticide Science
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    • v.21 no.1
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    • pp.17-25
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    • 2017
  • Dissipation pattern and biological half-lives of fungicides boscalid and pyraclostrobin were calculated on jujube. The pesticides were sprayed on jujube in two different field at the standard rate, respectively. The raw agricultural commodities were harvested at 0 (2 hr), 1, 3, 5, 7, 10 and 14 days after treatment, and analyzed by HPLC/DAD. The method limit of quantification (MLOQ) was $0.02mg\;kg^{-1}$ for boscalid and pyraclostrobin. The recovery ranged 101.8~109.3% with below 5% of CV (Coefficient of variation) for boscalid and 104.2~115.4% with below 5% of CV for pyraclostrobin. An average initial deposit at field 1 and field 2 samples were observed 0.40 and $0.48mg\;kg^{-1}$ for boscalid and, 0.76 and $0.57mg\;kg^{-1}$ for pyraclostrobin, respectively. The biological half-lives of field 1 and field 2 were 11.0 and 13.2 day for boscalid, and 6.1 and 12.7 days for pyraclostrobin.