PubMed Health⌕ Search

Biomedical subjects

S Kaojarern

Publications and source records attributed to S Kaojarern.

At least 19 recordsLinked to original sources
PubMed2004

Non-occupational lead and cadmium exposure and blood pressure in Thai men.

In this study, the effects of low level exposure to lead and cadmium on blood pressure among 212 men have been examined. The mean age was 41 years (range 34-53). The means of systolic and diastolic blood pressure were 126 (range 94-159) and 78 (range 58-117) mmHg, respectively. Blood lead concentration ranged from 144.31 to 779.34 etamol/L with a geometric mean (GM) of 363.11 etamol/L. Blood cadmium levels ranged from 1.33-37.81 etamol/L with GM of 8.09 etamol/L. For stepwise regression analysis, an increase in systolic blood pressure was significantly predictive by an increasing blood lead (p<0.001) whereas blood cadmium showed no significant correlation with blood pressure. Body mass index and alcohol consumption also contributed to both systolic and diastolic blood pressure. These findings also supported our proposal concerning the association between blood lead and blood pressure.

Adult↗
PubMed1999

Comparative bioavailability of paracetamol.

Prescribing brand name versus generic drugs continues to be a controversial issue. The harmful effects of nonequivalence result from either too little or too much drug reaching the patient which will cause either failure of treatment or adverse drug reactions. On the other hand, if physicians prescribe higher priced original drugs instead of therapeutically equivalent lower cost generic drugs to their patients, the patients then have to pay for the added cost. This study was designed to compare the bioavailability of paracetamol of a generic versus original drug. The original brand (Tylenol, Cilag) which was assigned as the reference standard against another generic formulation (Sara, Thai Nakorn Patana). Ten healthy male volunteers aged 20 to 45 years participated in this study. The study was conducted as a cross-over experimental design. The dose was 2 tablets of 500 mg. In conclusion, based on the concentration-time curve and pharmacokinetic analysis there were no statistically significant differences between T1/2 absorption and Cmax. Although AUC of Sara was marginally statistically greater than Tylenol, this magnitude of difference probably has no clinical significance. All these parameters are within the accepted 20 per cent difference, indicating these products are bioequivalent.

Acetaminophen↗
PubMed1998

Lead exposure and accumulation in healthy Thais: assessed by lead levels, EDTA mobilization and heme synthesis-related parameters.

Lead is one of the pollutants which is of public concern. The magnitude of lead contamination in Thai people is of interest. The objective of this study was to evaluate the lead status in normal healthy volunteers. Normal volunteers were included. The blood for lead level, Zinc protoporphyrin (ZPP), delta-aminolevulinic acid dehydratase (ALA-D) activity, and baseline urine for lead, delta-aminolevulinic acid (ALA) and coproporphyrinogen III (CP3) were collected. The EDTA mobilization test was done. 24 hour urine after administration of the drug was collected for lead analysis. Thirty volunteers were included in the study. All were men whose average age was 32.5 +/- 6.9 years. The mean lead level was 5.95 +/- 2.01 micrograms/dL and 5.83 +/- 2.32 micrograms/L in urine. The 24 hour urine lead contents before and after EDTA administration were significantly different (11.11 +/- 6.72 and 16.05 +/- 9.51 micrograms respectively). Blood ALA-D activity was 251.6 +/- 80.4 unit/ml of RBC. Urine ALA and CP3 were 0.56 +/- 1.2 mg/L and 22.17 +/- 23.9 micrograms/L respectively. All were in the normal ranges. All parameters suggested that the healthy Thai volunteers had an acceptable magnitude of lead exposure and accumulation.

Adult↗
PubMed1997

Single oral loading dose of phenytoin: a pharmacokinetics study.

In order to determine the optimal single oral loading dose of phenytoin in patients with seizures, a two part study of phenytoin pharmacokinetics was conducted. In the first part, 15 mg/kg of phenytoin was given orally as a single dose to 19 normal medical volunteers with informed consent. Serum concentrations of phenytoin reached the therapeutic level (10 micrograms/ml) with an average of 2.62 +/- 1.25 h. The peak concentrations at 7.26 +/- 4.77 h was 11.95 +/- 2.8 micrograms/ml. The oral loading doses, calculated from a model incorporating a first order of absorption and Michaelis-Menten elimination kinetics to yield the target phenytoin serum concentration of 15 micrograms/ml were 18.7 mg/kg in males and 24.8 mg/kg in females. The larger dose for females is probably required due to the higher total apparent volume of distribution in females than in males. In the second part, seven male and seven female patients with seizures with informed consent received these calculated dosage regimens. For these patients, a single oral loading dose of phenytoin rapidly produced therapeutic concentration (10 micrograms/ml) within an average of 2.04 +/- 0.44 h in males and 2.35 +/- 1.6 h in females with minimal side-effects. For males, the peak concentration at 9.71 +/- 5.94 h was 23.89 +/- 5.46 micrograms/ml and that for females was 21.46 +/- 5.08 micrograms/ml at 7.71 +/- 3.73 h, respectively. Oral loading dose of phenytoin is safe, effective and can be considered in patients who need prompt control of seizures within a few hours, particularly in those areas where medical facilities are limited. It may also replace the intravenous route of phenytoin when the intravenous route is contraindicated.

Administration, Oral↗
PubMed1997

Comparative study of bioavailability and clinical efficacy of carbamazepine in epileptic patients.

OBJECTIVE: To compare the bioavailability of three generic brands of carbamazepine tablets with that of a proprietary brand in adult patients with epilepsy. DESIGN: A double-blind, randomized, three-phase crossover study. SETTING: A psychiatric facility. PARTICIPANTS: Eighteen patients with epilepsy who had taken carbamazepine at least 5 months before entering the study. MAIN OUTCOME MEASURES: Ten blood specimens from each patient were collected at steady-state. Plasma concentration of carbamazepine was analyzed for pharmacokinetic parameters such as maximum plasma concentration (Cmax), mean time to reach maximum concentration (tmax), and mean AUC. RESULTS: There were no statistically significant differences in these parameters among four brands of carbamazepine. However, when comparing the 90% CI of AUC of three generic brands with that of the proprietary brand, the AUC of two generic brands lay within a range of 80% to 120%. The effects of gender and each brand of carbamazepine on these pharmacokinetic parameters were also analyzed. Breakthrough seizures occurred even though the plasma concentration of carbamazepine was therapeutic. CONCLUSIONS: The bioavailability of two generic brands of carbamazepine tablets (Carmapine and Carzepine) and the proprietary brand (Tegretol) were equivalent in this sample of adult patients with epilepsy.

Adolescent↗
PubMed1996

Risk factors between analgesic use and chronic nephropathy in Thailand.

Analgesic abuse is common in Thailand. Heavy use of analgesic may also increase risk of chronic nephropathy. However, the extent of this risk remains unclear. We carried out a case-control study in three referral hospitals. A total of 84 patients with newly diagnosed of chronic tubulointerstitial nephritis were enrolled as cases. Two control groups were randomly selected, 192 from hospitalized patients who had no renal disease and serum creatinine below 1.2 mg/dl and 166 from relatives of friends visiting the hospitals. Both cases and controls were interviewed by a standardized pre-coded questionnaire to obtain histories of analgesic use before diagnosis of renal disease. On multiple logistic regression analysis, patients whose estimated lifetime use of acetaminophen of 1,000 g or more had an increased risk of chronic nephropathy compared with non-users, the odds ratio (OR) was 5.9 (95% confidence interval (CI) 1.3-25.6, hospital controls) and OR = 5.8 (95% CI 1.04-31.9, visitor controls). Also, uses of aspirin showed a similar relationship. Patients who used aspirin 1,000 g or more per lifetime had higher risk of chronic nephropathy when compared to non-users, the odds ratio were 7.1 (95% CI 2.0-25.8, hospital controls) and 20.4 (95% CI 2.4-174.2) for visitor controls. These data indicate that analgesic abuse increased risk of chronic nephropathy in Thailand.

Acetaminophen↗
PubMed1995

Gastric emptying in acute uncomplicated falciparum malaria.

Gastric emptying by paracetamol absorption test was performed in 22 patients with uncomplicated falciparum malaria. There was no significant difference in the time to reach the maximum plasma paracetamol concentration (Tmax) and the maximum plasma paracetamol concentration (Cmax) of the patients during acute illness and convalescence. We concluded that gastric emptying was not altered in acute uncomplicated falciparum malaria.

Acetaminophen↗
PubMed1992

Effect of lung irradiation on mice following paraquat intoxication.

To determine the effect of lung irradiation in mice with paraquat poisoning and whether irradiation could prevent lung destruction, we found the the lethal dose for 50 percent survival (LD50) in 50 mice (Swiss strain) was 25 mg/kg of body weight. The first control group comprised 15 mice and their lungs were irradiated with 200 rad for seven days. There was no death within six weeks. The lungs at autopsy appeared mildly congested. The control group comprised 15 mice. They were injected with 25 mg/kg of paraquat. Six died within three days. The experimental group included 14 mice injected with paraquat and with lung irradiation. Eight died within three days (p greater than 0.5). The pathologic findings in the experimental group revealed lung congestion and fibrosis that was more pronounced than in the group that received only paraquat. We conclude that radiotherapy is not effective in amelioration of paraquat-induced lung damage in mice.

Animals↗
PubMed1992

Acute cyanide poisoning: a case report with toxicokinetic study.

Cyanide poisoning is a life threatening condition. But specific antidotes exist and can be easily prepared from available substances in hospital. Administration of antidotes will produce methemoglobin, which itself causes hypoxia. Nitrite induced methemoglobin can be extremely dangerous and even lethal. Before administering the antidotes, the diagnosis should be confirmed. Nitrite should not be given if the poisoning is mild or diagnosis is uncertain, to avoid excessive methemoglobin, dosage of sodium nitrite must be adjusted according to hemoglobin level (Table 1). Usage of sodium nitrite and sodium thiosulfate in the recommended doses are safe and effective for cyanide poisoning.

Acute Disease↗
PubMed1992

Original versus generic piroxicams, their cost-effective evaluation in rheumatoid arthritis (RA) patients.

This was a 12 week double-blind cross over study of 14 patients with rheumatoid arthritis on the cost-effectiveness of different priced piroxicams. All three drugs affected a significant improvement over baseline measurements in most of the clinical parameters assessed with statistical comparable efficacy. Pharmacokinetic analysis also showed similar properties except for the time to reach maximum concentration which was in favor of drug A. This property may be advantageous in treating acute conditions such as gouty attacks. However, in chronic disease like rheumatoid arthritis, there was no significant difference in pharmacologic and clinical efficacy among the three different piroxicams marketed in Thailand.

Adult↗
PubMed1991

Effect of steroids on cerebrospinal fluid penetration of antituberculous drugs in tuberculous meningitis.

Sixteen patients with oral isoniazid, pyrazinamide, rifampin, and intramuscular streptomycin for tuberculous meningitis were studied. The concentrations of isoniazid, pyrazinamide, rifampin, and streptomycin in cerebrospinal fluid (CSF) obtained 3 hours after administration were 2.40, 34.78, 0.29, and 3.78 micrograms/ml, respectively. The CSF concentrations of isoniazid and pyrazinamide were well above the minimum inhibitory concentration for Mycobacterium tuberculosis. Concentrations of rifampin and streptomycin were above the minimal inhibitory concentration initially but declined below the minimal inhibitory concentration at later times. The CSF penetration of isoniazid, pyrazinamide, rifampin, and streptomycin was about 89%, 91%, 5%, and 20%, respectively. In eight patients who received antituberculous drugs in combination with steroids, the mean CSF and serum concentrations, as well as CSF/serum ratios at various intervals of treatment, were not statistically different (p greater than 0.05) from those of the eight patients who did not receive steroids.

Adult↗
PubMed1991

Predicting outcomes in paraquat poisonings.

The purpose of this study was to analyze the factors in patients with paraquat poisoning at admission which were able to predict the chance of survival. From January 1983 to September 1988, 24 patients were admitted to Ramathibodi Hospital because of paraquat poisoning. Nine were male and 15 were female, aged 29.9 +/- 18 y (range from 12 to 73 y). The amount of paraquat ingested was 57.4 +/- 107.9 ml. Patients were treated with Fuller's Earth and forced diuresis. The serum paraquat levels obtained in 15 patients were 0.17 +/- 0.34 ug/ml at 24.7 +/- 6.6 h after ingestion. Seventeen patients (71%) died. A prediction rule was developed by discriminant analysis and multiple logistic linear regression to predict outcome in paraquat poisoning. Age, amount of paraquat ingested, and white blood cell count at admission were identified as positively correlated with mortality. The discriminant function which classified the patients into the expired group if the function was negative, and vice versa, was 0.027 age + 0.022 ingested amount + 0.0002 WBC - 4.06. The model was validated by the jackknife method and prospectively. Seventy-nine percent of patients in the study group were classified correctly when using the jackknife method. Prospectively, The prediction rule correctly classified all 9 newly admitted paraquat poisoning patients. We conclude that age, ingested amount, and white blood cell count at admission are prognostically significant in paraquat poisoning. The prediction rule based on the above prognostic factors can appropriately forecast outcome in paraquat-poisoned patients.

Adolescent↗
PubMed1990

The blood/cerebrospinal fluid partitioning of pyrazinamide: a study during the course of treatment of tuberculous meningitis.

Concentrations of pyrazinamide were measured in serum and cerebrospinal fluid (CSF) of 17 adult patients with tuberculous meningitis up to six months after starting treatment. Pyrazinamide penetrated excellently into the CSF and mean concentrations at various intervals up to six months of treatment were consistently above that required for inhibition of the growth of Mycobacterium tuberculosis. The blood/CSF partitioning of pyrazinamide does not change as the patients recover from the meningitis.

Adolescent↗
PubMed1990

Bioavailability and pharmacokinetics of furosemide marketed in Thailand.

Thirteen different brands of 40 mg furosemide tablets available in Thailand were evaluated. In vitro studies revealed that all products met the requirement of United States Pharmacopoeia XX for weight variation, per cent labeled amount, and disintegration time. However, there were only 4 brands that passed the dissolution test specification. The original brand (brand A) and the three local brands (brand B, C and D) with differences in dissolution characteristics were selected for bioavailability study. Relative bioavailability of 40 mg furosemide tablets were performed on eight healthy Thai males using a crossover design. Plasma furosemide concentrations were determined by high-performance liquid chromatographic method. Clinical response to these tablets were also studied by determination of urine output and electrolyte excretion. Individual plasma data was analyzed according to one-compartment open model using the PCNONLIN computer program. The elimination half-life of furosemide was 1.27 hours. The mean individual peak plasma levels ranged from 0.61-1.12 micrograms/ml and the time required to reach the peak ranged from 1.63-2.00 hours. There were no statistically significant differences in parameters studied between the original and the local brands (p greater than 0.05). The relative bioavailability of furosemide with respect to brand A were 70.29, 113.41, and 94.93 per cent for brand B, C and D, respectively. There was no relationship between in vitro and in vivo characteristics. Clinical response, in terms of diuresis and electrolyte excretion, e.g., sodium, chloride and potassium, between four brands of furosemide tablets were also not significantly different (p greater than 0.05), indicating that the four brands are clinically equivalent.

Adult↗
PubMed1989

Dosing regimen of gentamicin during intermittent peritoneal dialysis.

The peritoneal clearance of gentamicin was studied in 11 chronic uremic patients who undergoing intermittent peritoneal dialysis. Gentamicin was significantly removed by peritoneal dialysis with a clearance value of 9.75 +/- 3.78 ml/min. The serum half life was 14.08 +/- 3.57 hr, a value significantly less than that of non dialysed end stage renal disease patients. The mean apparent volume of distribution of the drug in these patients was about 27% of body weight. The derived value for gentamicin peritoneal clearance and volume of distribution can be used to calculate maintenance dose during intermittent peritoneal dialysis. In order to achieve the peak level of 8 micrograms/ml, supplementary dose compensated for the loss during peritoneal dialysis is approximately 40% of loading dose 0.8 mg/kg every 12 hours.

Gentamicins↗
PubMed1989

Pharmacokinetics of amikacin in hematologic malignancies.

The pharmacokinetics of amikacin in 10 patients with hematologic malignancies and 1 patient with aplastic anemia were investigated. At an administered dose of 7 mg/kg of body weight, a volume of distribution of 0.4 liters/kg, an elimination half-life of 3.0 h, and a total body clearance of 2.1 ml/min per kg, amikacin achieved a peak level in blood of 21 micrograms/ml. Results of the study revealed that there was a marked increase in volume of distribution of amikacin in these patients compared with normal.

Adult↗
PubMed1989

Comparative bioavailability of praziquantel tablets.

Six different brands of 600 mg praziquantel tablets were evaluated. In vitro studies demonstrated that all but one of the products met the British Pharmacopoeia 1980 disintegration time specifications. The comparative bioavailability of four of the internationally available brands of praziquantel tablets were then studied in eight healthy volunteers using a crossover design. Serum praziquantel levels were determined by high-performance liquid chromatography. Individual serum profiles were analyzed for pharmacokinetic parameters such as maximum serum concentration, time to reach maximum, and area under the curve. Following administration of praziquantel 40 mg/kg po, the mean peak serum concentrations and the time to reach the peak ranged from 1.007 to 1.625 micrograms/ml and from 1.72 to 2.81 hours, respectively. The elimination half-life of praziquantel was 1.15 (0.94-1.25) hours. Differences greater than 20 percent (p less than 0.05) were noted for these parameters between the original brand and the generic formulations. The relative bioavailabilities of the generic praziquantel formulations, with respect to the original brand, were 91.25, 80.95, and 69.86 percent. This is due to the failure of disintegration and subsequently poor dissolution. The effect of 30 percent reduction of bioavailability may lead to unacceptably high rates of treatment failure.

Adult↗