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Biomedical subjects

J Kanto

Publications and source records attributed to J Kanto.

At least 19 recordsLinked to original sources
PubMed1992

Dexmedetomidine reduces intraocular pressure, intubation responses and anaesthetic requirements in patients undergoing ophthalmic surgery.

We studied the effects of a single i.v. dose of dexmedetomidine, a highly selective and specific alpha 2 adrenoceptor agonist, on intraocular pressure (IOP), haemodynamic and sympathoadrenal responses to laryngoscopy and tracheal intubation, and on anaesthetic requirements in ophthalmic surgery. Thirty ASA I-II patients undergoing cataract surgery were allocated randomly to receive either dexmedetomidine 0.6 microgram kg-1 or saline placebo i.v. 10 min before induction of anaesthesia in a double-blind design. After dexmedetomidine there was a 34% (95% confidence interval (CI) 27-43%) reduction in IOP (P less than 0.001) and 62% (CI 57-68%) decrease in plasma noradrenaline concentrations (P less than 0.001). After intubation, maximum heart rate was 18% (CI 3-33%, P = 0.036) and the maximum IOP 27% (CI 11-43%, P = 0.005) less in the dexmedetomidine group compared with the patients treated with placebo. Within 10 min after intubation, maximum systolic and diastolic arterial pressures were also significantly (P = 0.013 and P = 0.020) smaller in the dexmedetomidine group. The induction dose of thiopentone was smaller (23% (CI 20-26%) P = 0.012), and the use of isoflurane or fentanyl supplements during anaesthesia was less frequent in the dexmedetomidine group. The patients premedicated with dexmedetomidine recovered faster from anaesthesia (P = 0.042). These results suggest that dexmedetomidine may be a useful anaesthetic adjunct in ophthalmic surgery.

Adolescent↗
PubMed1992

Diazepam and atropine as premedicants: no discrimination by monoamine metabolite and catecholamine measurements in cerebrospinal fluid and plasma.

The relationships between self-reported assessments of the quality of the preoperative night's sleep, preoperative anxiety, and several biochemical and physiological indicators of stress reaction were investigated in pregnant women at term receiving no premedication (n = 15), a placebo tablet (n = 15), diazepam 5 mg p.o. (n = 15), or atropine 0.01 mg/kg i.m. (n = 15), in connection with spinal analgesia for elective caesarean section. In the patients receiving no premedication, the subjective estimate of the quality of the preoperative night's sleep was negatively associated with concentrations of noradrenaline (NA) and its metabolite, 3-methoxy-4-hydroxyphenylglycol (MHPG) in CSF, and with plasma adrenaline. The anxiolytic effect of diazepam was reflected as significantly lower plasma levels of another metabolite of NA, 3,4-dihydroxyphenylglycol (DHPG). Placebo and diazepam, and to a lesser extent atropine, confounded the statistical relationships between the clinical and biochemical responses found in the patients with no premedication. On the whole, the biochemical monoamine measurements were of little use in determining the clinical effects of different kinds of premedicants.

3,4-Dihydroxyphenylacetic Acid↗
PubMed1992

Comparison of propofol infusion and isoflurane for maintenance of anesthesia for dentistry in mentally retarded patients.

A continuous infusion of propofol following an induction dose of 2 mg/kg was compared with thiopental/isoflurane for the induction and maintenance of anesthesia in 20 mentally retarded outpatients undergoing routine dental procedures. The infusion rate of propofol and the concentration of isoflurane were adjusted to maintain the heart rate and blood pressure within +/- 25% of the baseline values. Postoperative wakefulness was assessed using a 100-mm visual analogue scale at the time of extubation and at 5, 10, 15, 30, 60, 90, and 120 min after extubation. Both agents provided adequate anesthesia for the treatment, and no major adverse reactions occurred. Recovery was more complete during the first hour after extubation in the propofol group, and these patients were discharged earlier.

Adolescent↗
PubMed1992

Hypotensive anesthesia for middle ear surgery: a comparison of propofol infusion and isoflurane.

An infusion of propofol (2,6-diisopropylphenol) was compared with isoflurane to induce hypotension for middle ear surgery. Forty patients (ASA physical status I-II, 16-55 years) scheduled for elective surgery were included in an open randomized study. The pharmacokinetics of propofol infusion were also studied in 6 patients. Both agents produced controlled hypotension (MAP reduction of 30% from the baseline values) with an acceptable visibility of the surgical field. No major complications occurred. The mean total dose of propofol infusion was 6.4 +/- 2.7 mg/kg and the mean concentration of isoflurane was 0.9 +/- 0.4%. Considerable interindividual pharmacokinetic variability was found and propofol was extensively distributed and rapidly cleared from the body after the infusion. Propofol infusion may be a new alternative as a hypotensive agent in middle ear surgery.

Adolescent↗
PubMed1979

Long-term nitrazepam treatment in psychiatric out-patients with insomnia.

Psychiatric patients (N = 26) were treated chronically (from 1 week to 12 years) with nitrazepam, because of insomnia. The patients gave their subjective estimations of the effects and side effects of nitrazepam. The concentrations of nitrazepam in the plasma were measured by 63Ni-EC-gas-liquid chromatography. The pharmacokinetics of nitrazepam were compared between the psychiatric patients and healthy volunteers (N = 11). The steady-state concentrations and the half-life of nitrazepam in the psychiatric patients were comparable to those of the healthy volunteers. The subjective hypnotic effect of nitrazepam was mostly good or satisfactory and remained unchanged during long-term treatment. Only a few, mild side effects were reported. Nitrazepam does not seem to cause enzyme induction with lowered plasma levels and may therefore be of special value in the treatment of chronic insomnia.

Adult↗
PubMed1979

Human pharmacokinetics of nitrazepam: effect of age and diseases.

Plasma concentrations of nitrazepam were measured by gas-liquid chromatography in: young healthy volunteers, in geriatric and psychiatric patients and in epileptic children. The disposition of nitrazepam was described in terms of a two-compartment open model. After a single oral dose of nitrazepam 5 mg the most prominent differences between the experimental groups were in the beta-phase half-life mean 29 h in the young volunteers and 40 h in geriatric patients , and in the apparent volume of distribution during the beta-phase of 2.4 vs 4.8 1/kg. Total plasma clearance and the average steady state concentration in both groups were equal. The plasma level rose at a rate proportional to the beta-phase half-life, and so, they were achieved more rapidly in the young than in the old subjects (3.5 vs 7.5 d). No change in steady-state level or in the half-life of nitrazepam were found during long term treatment, which indicates lack of enzyme induction or inhibition. In 95% of the epileptic children with a good to fair clinical response, the plasma concentration of nitrazepam was 40-180 ng/ml (mean 114 ng/ml). As all of the patients were on combined antiepileptic therapy, no attempt was made to correlate plasma level with therapeutic response.

Adolescent↗
PubMed1979

Flunitrazepam versus placebo premedication for minor surgery.

The clinical effects of oral flunitrazepam (2 mg on the night before operation followed by 2 mg on the morning of operation) and placebo as premedicants were tested in a double-blind study in 81 gynaecological patients. The separate or total concentrations of flunitrazepam and its demethylated metabolite in plasma (measured by gas chromatography) were correlated with the clinical effects of flunitrapam premedication, assessed both sugjectively and objectively. In most parameters tested (sleep on the night before operation, sedation, apprehension, headache, pulse rate), there was a positive, significant difference between the flunitrazepam group (n = 44) and the placebo group (n = 37). No significant difference was found between the two groups in emetic effect, excitement, systolic blood pressure increase, and vene-puncture, but the patients receiving flunitrazepam felt significantly more dizziness. The temperature of the left forefinger before, during and after the anaesthesia did not vary significantly between the two groups. There was no correlation between the plasma concentration of flunitrazepam and its demethylated metabolite (separate or total concentrations) and any of the parameters tested before induction of anaesthesia. Flunitrazepam is a new oral premedicant with prominent sedative and anxiolytic actions. When the drug is given as a sedative on the night before operation, followed by a second dose on the morning of operation, the beneficial effects last for at least 8 hours after the second dose.

Adult↗
PubMed1979

A comparative study on the clinical effects of oxazepam and diazepam: Relationship between plasma level and effect.

The clinical effects of oxazepam and diazepam as oral premedicants were tested in a double-blind study of 60 children and 50 adults. The gas chromatographically measured concentrations of the active unconjugated forms of oxazepam and diazepam in the plasma were correlated to their clinical effects, as assessed both subjectively and objectively (sleep, sedation, apprehension, excitement, dizziness, emetic effect, headache, increase or decrease in systolic blood pressure, increase in pulse rate, venepuncture). No significant difference in the effects of these two benzodiazepine derivatives were observed, nor was there any obvious relationship between the plasma concentration and clinical effect.

Adult↗
PubMed1979

Erythromycin levels in serum during treatment with erythromycin stearate and base.

The serum concentrations of erythromycin during treatment with erythromycin stearate and erythromycin base were compared in a randomised cross-over study with 21 hospital patients. No statistically significant differences between the brands were found in the serum erythromycin levels at any time or in the areas under the serum level-time curve.

Administration, Oral↗
PubMed1979

Labetalol as a hypotensive agent in otological operations.

The usefulness of labetalol, a new combined alpha and beta adrenoceptor antagonist as a hypotensive agent in otological operations was studied in 18 otherwise healthy patients. After a single 1.0 mg/kg i.v. dose the maximum decrease in systolic (18%) and diastolic (8%) blood pressure occured between 5 to 15 minutes (mean 11 min), and the pretreatment blood pressure values were reached in 15 to 55 min (mean 26 min). Similarly, after a single 2.0 mg/kg i.v. dose the maximum blood pressure decrease (32%/20%) was observed in 5 to 40 minutes (mean 23.5 min) lasting 30 to 95 minutes (mean 60.1 min). Generally, a moderate decrease in blood pressure without a concomitant increase in heart rate or excessive hypotension was found.

Adrenergic alpha-Antagonists↗
PubMed1979

Absorption of sustained-release and plain papaverine in man.

The concentrations of papaverine in the plasma of healthy volunteers were determined by a GLC-method both after single and repeated oral doses of plain and sustained-release drug formulation. In both experiments the AUC-value after the sustained-release drug form was significantly lower than after the plain papaverine and no maintenance of plasma levels for 12 hours after the sustained-release drug form was observed. Our work demonstrates that the systemic availability or papaverine can be markedly affected by product formulation.

Adult↗
PubMed1979

Plasma lidocaine concentrations after different methods of releasing the tourniquet during intravenous regional anaesthesia.

Different methods of tourniquet release have been proposed to decrease the concentrations of local anaesthetic released into the systemic circulation at the end of intravenous regional anaesthesia. The effect of releasing the tourniquet intermittently with 5 seconds (group I) and 30 seconds (group II) deflation periods or at once (group III) was studied in 25 adult patients after intravenous regional anaesthesia with 40 ml of 0.5% lidocaine. The venous plasma lidocaine concentrations from the contralateral arm were measured by gas chromatography. There was no leakage of lidocaine from the occluded arm into the systemic circulation. The mean maximum plasma lidocaine concentration in group I 1.99 +/- 1.45 (SD) microgram/ml, in group II 1.33 +/- 0.54 microgram/ml and in group III 1.56 +/- 0.88 microgram/ml (P greater than 0.05) was below the toxic concentrations reported in the literature. There were subjective complaints such as dizziness and ringing in the ears in 4 out of the 7 patients in group I, in 2 out of the 9 patients in group II and in one of the 9 patients in group III (P greater than 0.05). There was no correlation between the duration of tourniquet time (range 12-87 minutes) and the maximum plasma lidocaine concentration. The intermittent release of the tourniquet did not decrease the venous plasma lidocaine concentrations in the contralateral arm; neither did comparing the lidocaine pharmacokinetics in 5 patients of group II after tourniquet release and in the 5 healthy volunteers after a single 100 mg intravenous lidocaine injection reveal any differences.

Adult↗
PubMed1979

Oral oxazepam as a premedicant in minor surgery.

The clinical effects of oral oxazepam and placebo as premedicants were tested in a double-blind study in 40 gynaecological patients. The gas chromatographically measured concentrations of the active, unconjugated forms of oxazepam in the plasma were correlated with the clinical effects of oxazepam, assessed both subjectively and objectively. The insertion of an intravenous cannula was significantly more difficult (p less than 0.001) in the placebo premedicated group. However, there was no significant difference between the two groups in the cutaneous temperature of the left forefinger. Of the eleven parameters tested there was a significant difference between the oxazepam and placebo group in the quality of sleep on the night before operation (p less than 0.05) and in the degree of preoperative sedation (p less than 0.01). The combined results of the eleven parameters of the oxazepam group also differed positively significantly from the placebo group (p less than 0.01). There was no obvious relationship between the plasma concentration and clinical effect of oxazepam.

Abortion, Spontaneous↗
PubMed1978

Dihydroergotamine: pharmacokinetics and usefulness in spinal anaesthesia.

In a double-blind study, 0.5 mg of dihydroergotamine or the same volume of placebo was used to prevent hypotension caused by spinal anaesthesia. The plasma concentrations of dihydroergotamine were determined by a new radioimmunoassay developed for ergot alkaloids, and pharmacokinetic calculations were based on the equation of a two-compartment open model. No significant changes were observed in the heart rates of the two patient groups. In Group I, which received dihydroergotamine, significant increased in both systolic and diastolic blood pressures were measured after drug administration, and, compared to the base-line measurements before spinal anaesthesia, no significant decreases in systolic or diastolic blood pressures were recorded. In contrast to Group I, there was a significant decrease in both systolic and diastolic blood pressures in the placebo Group II during spinal anaesthesia. There were no significant differences, however, in the temperature of the great toe between Groups I and II. Dihydroergotamine disappeared quickly from plasma, with a mean alpha-phase half-life of 1.35 min, which explained its rapid effect on blood pressure. Beta-phase half-life (mean 23.20 min), the volume of distribution at beta-phase (mean 0.25 I/kg), and the total plasma clearance (mean 1562.8 ml/min) indicate rapid elimination of the drug from the body.

Aged↗
PubMed1978

Urinary electrolyte profiles after amiloride, hydrochlorthiazide and the combination.

Acute effects of amiloride (5 mg) (A), hydrochlorthiazide (50 mg) (H) and the combination (50 + 5 mg) (HA) on urinary electrolyte excretion and pH of ten healthy volunteers--taking placebo five times and twice randomly A and HA and once H--were studied during one day. Amiloride showed a natriuretic effect, which in combination was additive to that of hydrochlorthiazide, but the excretion of water did not increase significantly after A. The urinary excretion of potassium decreased with amiloride below normal levels and was at the level of placebo after the combination (HA). There was a striking linear correlation between urinary sodium and potassium with all the drugs, although showing with A a higher potassium retention during high sodium excretion. Urinary pH rose after A and HA during the first 8 hours, but this effect was not seen, however, after H. No significant differences in the effect of the two brands of A (Medamor and Puritrid) on the urinary electrolyte excretion and pH, nor in those of the two brands of HA (Moduretic and Amitrid) were found. Similarly, the plasma concentrations of hydrochlorthiazide, determined gas chromatographically, were equal after Moduretic and Amitrid tablets. The systemic availability of H was faster in the combination of HA than alone. In the AUC value of H, however, there was no significant difference between HA and H tablets.

Adolescent↗
PubMed1978

The effect of sublingually administered nitroglycerin on the contraction of the human gallbladder.

Nitroglycerin (0.5 mg) was administered sublingually either before (n = 10) or after (n = 10) a standard contraction meal (200 ml of cream) during oral cholecystography. In both groups the standard contraction meal caused a significant contraction of the gallbladder. Nitroglycerin had no significant dilatation effect; hence its benefit during an acute attack of pain in a patient with gallstones seems to be questionable.

Adolescent↗