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Biomedical subjects

H Allonen

Publications and source records attributed to H Allonen.

At least 55 records · Page 3Linked to original sources
PubMed1981

Interaction between proxyphylline and salbutamol.

Salbutamol increased significantly the bronchodilating effect of proxyphylline both in experimental animals and in asthmatic patients. In guinea pigs (modified Konzett-Rössler method) the reduction in response to metacholine caused by increasing doses of proxyphylline and salbutamol significantly exceeded that of either drug alone. In a double-blind, randomized cross-over study conducted on 3 consecutive days, asthmatic patients received 500 mg proxyphylline orally three times daily. On the 2nd or 3rd day a significantly greater improvement in the peak expiratory flow was found after the combination of proxyphylline and salbutamol (3 mg p.o.) in comparison with proxyphylline and placebo. Salbutamol had no significant effect on the plasma concentrations of proxyphylline, which varied between 14 and 22 microgram/ml. The combination of oral proxyphylline and salbutamol is clinically useful in increasing drug response without increased adverse effects.

Adolescent↗
PubMed1981

Pharmacokinetics of labetalol in healthy volunteers.

The pharmacokinetics of labetalol, a combined alpha- and beta-receptor blocking agent, were studied in eight healthy volunteers. After intravenous injections (n = 4) of 1.5 mg/kg, the drug was rapidly distributed (mean T 1/2 = 4.9 min) and quite rapidly eliminated (mean T 1/2 = 4.9 hrs). The mean total plasma clearance value was 24.80 ml/min/kg. The values for Vdc (mean 1.1 l/kg) and Vdss (mean 9.41 l/kg) indicate extensive extravascular distribution of labetalol. The systemic availability was about 18%. There was a significant correlation between the calculated drug concentrations in the hypothetical compartment 2 and the percentage decreases in blood pressure after the intravenous injection. After a single 200 mg oral dose (solution, non-coated and coated tablets), the tablet formulation had no significant effect on the gastrointestinal absorption. After repeated oral doses of 200 mg twice daily (n = 4), no accumulation in plasma was observed.

Administration, Oral↗
PubMed1981

Pharmacokinetics of dihydroergotamine in healthy volunteers and in neurological patients after a single intravenous injection.

The pharmacokinetics of dihydroergotamine (DHE) was studied in healthy volunteers (n = 6) and in neurological patients (n = 12). After a single 1.0 mg intravenous injection (n = 5) DHE quickly disappeared (T 1/2 beta = 32.9 min, Vdss = 0.33 liter/kg, Cltot = 1055.7 ml/min). In saliva (dose 1.0 mg, n =6) and cerebrospinal fluid (dose 0.5 mg, n =12) there were no measurable amounts of DHE after a single i.v. dose. The 32-h cumulative urinary excretion was 0.02-0.04% of the 1.0 mg intravenous dose. In one subject renal (0.18 ml/min) and extrarenal (692.9 ml/min) clearance of DHE was calculated. According to our results DHe is probably eliminated mainly by hepatic metabolism. The pharmacokinetic properties of DHE indicate a fast clinical response without a cumulative action.

Adult↗
PubMed1980

Two-year rates for Nova T and Copper T in a comparative study.

A random assignment comparative study between Nova T and Copper T 200 after two years of use revealed that the Nova T resulted in a significantly lower pregnancy rate than the Copper T. The study was performed simultaneously in Denmark, Sweden and Finland. The pregnancy rate in Nova T users was lower than in Copper T users in every country and in every age and parity group. There was no clinic effect in the pregnancy rate of Nova T users. The other termination rates of these two devices were not significantly different. The first segment continuation rates at two years of postmenstrual insertions were 64.7 for Nova T and 65.5 for Copper T 200. It seems that Nova T is an improved copper-releasing IUD.

Actuarial Analysis↗
PubMed1980

The pharmacokinetics of dihydroergotamine in the beagle dog after a single intravenous injection and after a continuous intravenous infusion.

The pharmacokinetics of dihydroergotamine (DHE) was studied in 6 beagles after a single 2.0 mg intravenous dose and after a continuous intravenous infusion (dose 2.0 mg, infusion time 51 min.=2.8-3.5 micrograms/min./kg). The concentrations of DHE in the plasma during 6 hours were determined by a radioimmunoassay. The mean alpha-phase T1/2 was 0.92 min. and 5.93 min., the mean beta-phase T1/2 was 104.42 min. and 115.79 min., and the mean plasma clearance value 202.88 ml/min. and 234.79 ml/min. after a single intravenous injection a continuous infusion administration, respectively. Similarly, the Vdc - values were 0.121/kg and significantly from each other. The simulated concentrations of DHE in the peripheral compartment increased rapidly explaining its fast effect on the vasculature in clinical use.

Animals↗
PubMed1980

Combined alpha- and beta-blockade with labetalol in post-open heart surgery hypertension. Reversal of hemodynamic deterioration with glucagon.

The hemodynamic effects of intravenous labetalol (a combined alpha- and beta-blocking agent) were studied in 11 patients during early post-open heart surgery hypertension. With a mean dosage of 15 mg, labetalol reduced both systemic arterial pressures and the heart rate by an average of 21 percent (p < .001). The patients failed to compensate for the decline in pressure and pulse rate by elevation of their stroke volume, and even the cardiac index (CI) was severely depressed (from 2.30 to 1.67 L/min/m2, ie, 27 percent; p < .001). Neither left ventricular filling pressure nor vascular resistance was affected by labetalol early after open heart surgery. In four patients, 3 mg of glucagon after administration of labetalol elevated pulmonary arterial pressures and increased the CI by 16 percent. Two patients were observed on the preoperative day, and their response to labetalol was similar to that described in earlier studies: during blood pressure decline, CI was slightly augmented, and the systemic vascular resistance was greatly reduced (26 percent). The results indicate that after open heart surgery, patients are highly sensitive to the beta-blocking effects of labetalol, and although labetalol can greatly reduce myocardial oxygen consumption, it cannot be recommended for the treatment of post-open heart surgery hypertension.

Adult↗
PubMed1980

The use of labetalol as a moderate hypotensive agent in otological operations--plasma concentrations after intravenous administration.

The usefulness of labetalol, a combined alpha and beta adrenoceptor antagonist, as a moderate hypotensive agent during combination anaesthesia in otological operations was studied. These preliminary results show that an intravenous dose of 2.0 mg/kg of body weight of labetalol causes a moderate decrease in blood pressure without a concomitant increase in heart rate or excessive hypotension. The half-life of the elimination phase of labetalol in plasma varied between 3.9 and 6.3 hours. A direct relationship between the intravenous dose of the drug (0.5, 1.0 and 2.0 mg/kg i.v.) and the increase in the AUC value was observed. No correlation was found between the decrease in either the systolic or diastolic blood pressure and the plasma level of labetalol. This new type of antagonist may possess advantages over other current hypotensive drugs, i.e lack of tachycardia and excessive hypotension.

Adult↗
PubMed1979

Combined and national experience of postmenstrual IUD insertions of Nova-T and Copper-T in a randomized study.

A randomized comparative study between Nova-T and Copper-T-200 was performed simultaneously in Denmark, Finland and Sweden. The results of 741 postmenstrual insertions with Nova-T and 780 with Copper-T are reported. The pregnancy rate of Nova-T was lower in every age and parity group. The pregnancy rate of Copper-T-200 varied in participating countries, whereas the pregnancy rate of Nova-T was equally low in every country. The termination rate because of expulsion with Nova-T was less affected by age and parity than that of Copper-T. Significant differences in the continuation rates with the same device were found between countries. Removals because of infection showed that women below 25 years of age had a high risk for infection regardless of parity.

Adolescent↗
PubMed1979

Pharmacokinetics of nitrazepam in saliva and serum after a single oral dose.

The pharmacokinetics of nitrazepam in saliva and serum was studied in 12 healthy volunteers after a single administration of a 5 mg nitrazepam tablet. The binding of nitrazepam to plasma proteins was determined 4 hours after the administration by ultracentrifugation. The analysis of nitrazepam concentrations was performed by 63Ni-EC-GLC. The pharmacokinetic parameters were evaluated manually or by AUTOAN-program in serum, and manually in saliva. The concentrations of nitrazepam in serum and saliva correlated significantly (r = 0.472, P less than 0.001, n = 97). The ratio saliva: serum was, however, time dependent. The protein free fraction in serum was significantly higher (P less than 0.01) than the salivary concentration at the same time (4 hours after administration). The peak concentrations in serum and saliva were 40.7 and 1.9 ng/ml (P less than 0.001) and the times to reach the peak maximum 2.4 and 2.5 hours, respectively (difference not significant). The mean half-life of nitrazepam in serum was 30.5 hrs and in saliva 39.9 hrs, the difference being significant at P less than 0.05. The distribution phase parameters, poorly described before, were calculated. The clinical value of nitrazepam analysis in saliva seems to be negligible.

Administration, Oral↗
PubMed1979

Alpha- and beta-adrenoceptor blocking properties of labetalol in renin release.

The effect of labetalol, an alpha- and beta-adrenergic receptor blocking antihypertensive, on plasma renin activity (PRA) and the hemodynamics of healthy volunteers at rest and during an ergometric exercise test was studied. Oral doses of 200 and 400 mg labetalol were tested against a placebo in a crossover manner. The labetalol plasma concentrations were determined. Systolic and diastolic blood pressures in the supine position decreased after 400 mg labetalol as did the response of the heart rate to exercise. The lower dose decreased the resting heart rate, but had no effect on the heart rate during exercise. The ergometric exercise induced an increase in PRA which was partly inhibited after 200 mg labetalol in a manner similar to that induced by beta-blockers in our earlier studies. After 400 mg labetalol PRA was already increased at one hour at sitting rest and this higher basal level was maintained for four hours. After this higher dose of labetalol the reaction of PRA to exercise was not significantly inhibited. In renin release the vasodilating alpha-blockade thus dominated the beta-blocking property of labetalol at the dose which decreased the blood pressure.

Adrenergic alpha-Antagonists↗
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

Antihypertensive effect and plasma levels of labetalol. A comparison with propranolol and dihydrallazine.

Seventeen outpatients suffering from essential hypertension were treated in a double-blind cross-over study with labetalol or with a combination of propranolol and dihydrallazine. The doses were increased depending on the response during the six week treatment periods. Both treatments reduced the blood pressure significantly as compared to the placebo, and the combination more than labetalol with the doses used, apparently because of a higher degree of the beta-blockade. Positive linear correlations were found between the dose of labetalol and the concentration in plasma as well as the concentration of labetalol in plasma and the decrease of standing blood pressures.

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↗