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Biomedical subjects

S Sundberg

Publications and source records attributed to S Sundberg.

At least 55 records · Page 3Linked to original sources
PubMed1986

Pharmacokinetics of slow-release diltiazem and its effect on atrioventricular conduction in healthy volunteers.

The pharmacokinetics and effect of a slow-release and a conventional diltiazem tablet on atrioventricular conduction were compared in a randomized cross-over study after a single dose and at steady state in 12 healthy volunteers. The time to peak concentration was significantly delayed after the slow-release as compared to the conventional tablet, both after a single dose (2.7 vs. 0.9 h) and at steady-state (1.9 vs. 0.9 h). The peak concentration was also significantly reduced. There was no marked loss in bioavailability with the slow-release formulation. The maximal fluctuations in serum diltiazem at steady-state for the slow-release tablet were markedly less than after the conventional tablet (62 vs 87%). The PQ-interval was longer after the conventional tablet as compared to the slow-release tablet (both in doses of 120 mg) after a single dose (187 vs 163 ms) and at steady-state (197 vs 174 ms). The maximal prolongation was seen 1 h after intake of the drug. Heart rate was decreased only by 6-9 beats/min, irrespective of the dose. Slow-release diltiazem appears to have many advantages over a conventional tablet.

Adult↗
PubMed1986

Sustained release verapamil in hypertension. Results from a noninvasive ambulatory blood pressure monitoring and a clinical study.

The antihypertensive effect of a new sustained-release matrix formulation of verapamil 200 mg was investigated in a dose-response study in patients with mild to moderate essential hypertension. Noninvasive ambulatory blood pressure measurements were recorded over 24 h in 6 patients with diastolic blood pressure greater than or equal to 100 mmHg. The patients received sustained-release verapamil 200 mg once daily and twice daily in a randomized order. Each medication period lasted 2 weeks. Verapamil 200 mg twice daily had a better antihypertensive effect than the same dose once daily. After a 6-week placebo period 27 patients with a diastolic blood pressure greater than or equal to 100 mmHg were included in a double-blind clinical trial. The patients received sustained release verapamil 200 mg once daily and twice daily in a randomized crossover manner. Each medication period lasted 6 weeks, with an intervening 6-week placebo period. A diastolic blood pressure of less than or equal to 95 mmHg was achieved in 6 patients with the once-daily regimen and in 14 with the twice-daily regimen. The mean fall in diastolic blood pressure was 4 and 9 mmHg, respectively (p less than 0.05). We conclude that sustained-release verapamil 200 mg once daily gives a satisfactory blood pressure response only in a minority of patients, while 200 mg twice daily has a significantly better antihypertensive effect. Both doses were well tolerated.

Adult↗
PubMed1986

Drug- and temperature-induced changes in peripheral circulation measured by laser-Doppler flowmetry and digital-pulse plethysmography.

We measured the effects of a new transdermal nitroglycerin patch (25 mg, 10 cm2) applied for 24 h, norphenephrine (6 mg), prazosin (1 mg) as well as local heat and cold provocation on blood pressure, heart rate, skin blood flow (measured by laser-Doppler flowmetry, L-D) and peripheral arterial resistance (assessed by digital pulse plethysmography, D-P) in 15 healthy volunteers (aged 21-31 years). Heat provocation induced a three-fold increase in skin blood flow in the hand (p less than 0.001) and cold provocation a decrease in flow (p less than 0.05) of about 20%. Forehead skin blood flow did not change. Peripheral arterial resistance showed less consistent changes during the provocation tests. Prazosin increased the forehead skin blood flow (p less than 0.01) and decreased peripheral arterial resistance, while norphenephrine showed an opposite effect. Transdermal nitroglycerin induced an increase of 25% in forehead skin blood flow (p less than 0.05) which persisted for 24 h and a decrease in peripheral arterial resistance (p less than 0.02), but this effect was evident up to 8 h only. We conclude that (1) local heat and cold provocation mainly affected skin blood flow, (2) vasodilative and vasoconstrictive drugs showed marked changes in peripheral arterial resistance, but at different points in time from subject to subject, and (3) transdermal nitroglycerin patches induced haemodynamic changes persisting for up to 8-24 h.

2-Hydroxyphenethylamine↗
PubMed1986

Comparison of ketanserin and pindolol in hypertension.

The antihypertensive effects of ketanserin (40 mg twice daily) and pindolol (5 mg twice daily) as monotherapy were compared in a crossover, double-blind trial in 17 patients with essential hypertension. Both ketanserin and pindolol decreased supine systolic and diastolic blood pressure significantly (P less than 0.01 for systolic and P less than 0.001 for diastolic) when evaluated at the end of the 2-month treatment periods. There was no significant difference between the two drugs. No significant changes in heart rate were observed on either drug. Both drugs were well tolerated.

Adult↗
PubMed1984

Effect of hydroxyethyl starch and dextran on plasma volume and blood hemostasis and coagulation.

Six healthy male subjects were given in a crossover fashion medium molecular weight (HES 125) and low molecular weight (HES 40) hydroxyethyl starch, dextran, and balanced salt solution by intravenous infusion. The plasma volumes were determined using labeled albumin and plasma protein measurements. Three properties of factor VIII protein complex and indices of blood coagulation and hemostasis were measured before and after the infusions. Both the salt solution and HES 40 increased plasma volume, but their effect wore off within 3 hours. Dextran and HES 125 increased plasma volume significantly (P less than 0.001) more than the salt solution did, and the expansion was maintained for 24 hours. Plasma volume increases (dextran and HES 125) were associated with high nonglucose carbohydrate levels in plasma and low levels in urine. No or slight increases in plasma volumes (HES 40), on the other hand, were associated with low and high carbohydrate levels in plasma and urine, respectively. Serum alpha-amylase activity increased significantly after both HES preparations as compared to salt solution. Dextran and HES 125 decreased all the three values of factor VIII, these decreases being maximal 3 to 6 hours after administration and highest (about 25 per cent) for F VIII R:Ag and F VIII R:cof. It is concluded that HES 125 and dextran are equally effective plasma expanders.

Adult↗
PubMed1984

Effects of flunarizine and pentoxifylline on walking distance and blood rheology in claudication.

Thirty-one patients, mean age 60 years (range 45-80 years), with a typical history and objective symptoms of intermittent claudication with a reported maximal walking distance less than 500 m, were included in a cross-over study. After a one month's run-in period on placebo, the patients were randomized into two groups: one group started with flunarizine (5 mg t.i.d.) and the other with pentoxifylline (400 mg t.i.d.). The treatment lasted 3 months, whereafter the medications were changed. The trial followed a double-blind design. The median of the maximal walking distance was 255 m after the placebo period, increasing significantly (p less than 0.01) during both medication periods: by 43% and 18% during flunarizine and pentoxifylline, respectively. No changes were recorded in the ankle systolic blood pressure ratio ( ASBP -ratio) after placebo or either medication period. Red cell rigidity (Pmax), which was initially elevated, decreased significantly (p less than 0.05) during both medication periods, but there were no significant differences between the two drugs. No changes were found in whole blood or plasma viscosity. We conclude that the decrease in red cell rigidity may have contributed to the increased walking distance.

Aged↗
PubMed1984

Acute effects and long-term variations in skin blood flow measured with laser Doppler flowmetry.

Skin blood flow of 30 healthy volunteers (age 17-58 years) was measured at a number of sites and in different ways using laser Doppler flowmetry (Periflux) to establish reference values. The interindividual and spatial variations were great. The long-term variation in skin blood flow was studied in five subjects from the above group, both at 2-h intervals on the same day and on five different days within 2-3 weeks. No significant variation between the values recorded at different times was observed. Forehead was the best measurement site showing the lowest coefficient of variation (CV) of 20-21%, all mean values recorded at different times falling within the 95% confidence limits of the reference values. Forearm skin blood flow was also followed in another 12 healthy volunteers (age 21-24 years) after administration of 0.5 mg of sublingual nitroglycerin. A rapid and transient increase of about 40% in blood flow, which peaked at 3-4 min was observed (P less than 0.05). It is concluded that laser Doppler flowmetry is very sensitive in measuring acute changes in skin blood flow, and may also be applicable in long-term studies on factors affecting microcirculatory flow.

Adolescent↗
PubMed1984

Lorcainide in the prophylaxis of ventricular arrhythmias in acute myocardial infarction.

Lorcainide, a new class I antiarrhythmic agent, was administered intravenously to eight patients with acute myocardial infarction for 24 hours, and thereafter given by mouth, 200 mg daily for ten days. Ten control infarction patients were given lidocaine 3 mg/min during the first 24 hours and the oral betablocking agent, pindolol, for the following ten days. The two groups were comparable with respect to age, sex, onset-admission interval, and site and size of infarction. Ventricular premature beats were monitored with a 24-hour continuous ECG recording on days 1, 6 and 10. Complex ventricular premature beats were common during the first 24 hours of infarction; their occurrence and severity were similar in both groups, as judged by the Lown grading system. The plasma levels of lorcainide after the 24-hour infusion ranged 72-144 ng/ml (mean 95 ng/ml). On the sixth day, 12 hours after previous oral dose, lorcainide plasma levels ranged 11-82 ng/ml (mean 42 ng/ml). No major adverse effects were noticed, mild insomnia being the most disturbing reaction. It is concluded that lorcainide is an acceptable alternative to lidocaine in the treatment of ventricular arrhythmias in the acute stage of myocardial infarction. It has the advantage of being effective by oral route, too.

Administration, Oral↗
PubMed1984

Impairment of captopril bioavailability by concomitant food and antacid intake.

Single oral doses of captopril (50 mg) were given in a randomized cross-over study to 10 healthy volunteers after fasting, after a standardized breakfast (440 kcal; 1804 kJ) or with 50 ml of an antacid suspension. Blood and urine samples were analyzed by gas chromatography. The peak captopril concentrations attained were 701 +/- 81 ng/ml (mean +/- s.e.m.) after fasting, 351 +/- 56 ng/ml with an antacid (p less than 0.05) and 140 +/- 14 ng/ml after a meal (p less than 0.01). The peak concentrations were reached in 0.5, 0.9 and 1.5 h (p less than 0.01), and the areas under the blood concentration-time curves were 782 +/- 86, 456 +/- 60 (p less than 0.05) and 344 +/- 47 ng X h/ml (p less than 0.01), respectively. The relative bioavailability of captopril was 0.66 and 0.48 with antacid and after food, respectively. The deleterious effect of food - but not that of antacid - was reflected as a delayed hypotensive activity of captopril.

Adult↗
PubMed1984

The effects of physical training and flunarizine on walking capacity in intermittent claudication.

The clinical significance of drugs improving red cell deformability is not confirmed. We established the effect of physical training alone and combined with flunarizine on intermittent claudication. Twelve patients aged 48-73 years were included in the study. Pain-free walking distance on treadmill, ankle/arm pressure ratio and transcutaneous oxygen tension were measured. Walking distance increased significantly (p less than 0.05) by 130% from 75 m to 173 m during the first year when the patients were on programmed physical training. Ankle/arm pressure ratio also increased significantly (p less than 0.05) from 0.46 to 0.55 during this period. The increase in walking distance ceased when the programmed physical training was discontinued for 6 months. During the following double-blind, cross-over medication period the patients were given flunarizine 5 mg b.i.d. and placebos in randomized order for 3 months each. They also continued the same programmed physical training as during the first year. Walking distance increased, albeit not significantly, with time to 392 m after the second medication period. There was no difference, however, between flunarizine and placebo. Ankle/arm pressure ratio was of the same magnitude as at the beginning of the trial. Oxygen tension measurements did not give consistent results. We conclude that programmed physical training increased walking distance as a function of time. Flunarizine had no effect on the performance of patients with intermittent claudication.

Aged↗
PubMed1983

Nitroglycerin ointment effective for seven hours in severe angina pectoris.

The efficacy and tolerability of nitroglycerin (NTG) ointment were studied in 80 male patients with severe angina pectoris. Two symptom-limited exercise tests were performed on successive days after application of an ointment containing 15 mg NTG or a placebo (P) ointment. The patients were assigned to 4 groups. The study was conducted in a double-blind, cross-over manner. The total amount of work performed was higher in all groups on NTG (46-70%) compared to P ointment. The difference was statistically significant (p less than 0.001) at all points of time from 0.5 to 7 hours. The ST segment depression in ECG at the end of the exercise test was slightly greater on P than on NTG, but the difference was statistically significant only in the 3-hour group (p less than 0.01). The frequencies of headache and dizziness were 35% and 16%, respectively, on NTG. Eight patients (10%) reported that headache was severe enough to prevent regular use of NTG ointment. NTG ointment is effective, has a long duration of action and is relatively well tolerated by patients with severe angina pectoris.

Angina Pectoris↗
PubMed1983

Astemizole in the treatment of hay fever.

A double-blind parallel trial of astemizole, pheniramine and placebo was carried out in 51 patients with hay fever. Astemizole is a new potent H1-antihistamine with long duration of action but devoid of central activity. Evaluation criteria were daily symptom- and side effect score cards, daily nasal peak flow measurements, clinical examination and blood tests. Control of nasal symptoms was significantly better with both antihistamines than with placebo. Tiredness and anticholinergic side effects were less common in the astemizole group than in the pheniramine group. No significant changes in the "safety evaluation" blood tests were observed.

Adolescent↗
PubMed1983

Suitability of plasma expanders in patients receiving low-dose heparin for prevention of venous thrombosis after surgery.

Patients (132) receiving low-dose heparin for the prevention of venous thrombosis after surgery were given in random order in addition to standard fluid therapy, a 500 ml infusion of balanced salt solution and glucose, 4% gelatine, 6% dextran, or 6% hydroxyethyl starch (mean molecular weight 40,000 or 125,000) after induction of anaesthesia. Variables of blood coagulation and haemostasis were measured before and after the operation, and peroperative bleeding tendency and postoperative bleeding complications were subjectively evaluated by the surgeon. None of the treatments significantly decreased platelet count or increased capillary bleeding time when compared to values before operation. The peroperative bleeding tendency was similar after each infusion (moderately-to-markedly increased in 18-32% of the patients). None of the patients given balanced salt solution and glucose only had postoperative bleeding complications, whereas 8-18% of patients given plasma expanders presented with such complications (plasma expanders vs no plasma expanders P less than 0.05). The results suggest that administration of gelatine, dextran or hydroxyethyl starch should be avoided in patients receiving low-dose heparin treatment for surgery.

Anesthesia↗
PubMed1983

A five-year follow-up study on cardiorespiratory function in adolescent elite endurance runners.

It is not known whether the superior cardiorespiratory function in adolescent athletes is attributed to the effects of training or to genetic disposition. We re-examined 6 elite endurance runners and 7 boys with ordinary physical activity 5-6 years after the first examination. At the age of 14 years the two groups did not differ as regards height, weight, percent body fat and lean body mass (LBM). The runners had slightly superior cardiorespiratory characteristics but, with the exception of lower resting and maximal heart rates (HR) in the runners, the differences were not statistically significant. At the age of 19-20 years the runners had significantly higher maximal oxygen uptake (VO2 max) per kg body weight (74 vs. 61 ml/min/kg), VO2 max/LBM (85 vs. 74 ml/min/kg LBM), calculated work at a heart rate of 170 beats/min (W170) per kg body weight (3.9 vs. 2.7 W/kg), W170/LBM (4.5 vs. 3.3 W/kg LBM), larger relative heart volume (HV) (472 vs. 369 ml/m2) and lower resting HR (52 vs. 68 beats/min) than the controls. The runners also displayed greater increases in the growth-corrected percentage changes in cardiorespiratory variables, but the differences did not reach statistical significance. We conclude that the relative VO2 max, W170 and HV values in the runners had increased as a result of a prolonged endurance training.

Adolescent↗
PubMed1983

Lung volume and exercise ventilation in blind and normal boys and girls.

Lung volume at rest and ventilation during maximal exercise on a bicycle ergometer were measured in 180 children. The material comprised 12 blind boys and 11 blind girls (8-14 years) as well as 82 normal boys and 75 normal girls (8-17 years). Forced vital capacity (FVC) per height did not differ significantly between blind and normal children of either sex. Forced expiratory volume in one second (FEV1.0) as a percentage of FVC was very similar in all four groups. Maximal expiratory volume (VE max) was significantly (p less than 0.01) higher in normal than in blind children of both sexes. Tidal volume during maximal work (VT max) as a percentage of FVC (VT max/FVC%) was not age dependent and showed no sex differences. It was significantly (p less than 0.001) higher in normal than in blind children of both sexes. In conclusion, it seems as if a low level of habitual physical activity does not influence lung volume (FVC), while the bellow function of the lungs during maximal work (VE max, VT max/FVC%) is inferior in blind, sedetary children.

Adolescent↗
PubMed1983

Resting- and postexercise-ECG findings in an adult Lapp population.

Resting electrocardiograms were recorded in 412 and postexercise-ECGs in 186 Lapp men and women over the age of 40. Abnormalities in the resting-ECG suggestive of old myocardial infarction by the Minnesota code were found in 7% of the men and in 1% of the women. ST-depression compatible with myocardial ischaemia in the resting-ECG were found in 3% of men aged 40-49 years and in 5% of women of the same age; and increased with age up to 11% and 24% in men and women, respectively, over the age of 60. Postexercise ST-depressions of "ischemic type" were found in 18% of the men and in 13% of the women, but there was no clear age dependence. The frequency of high amplitude R-waves of the left type was high compared with most normal populations, especially in men (29%). These prevalences were very similar to those previously reported in a Finnish population.

Adult↗
PubMed1982

Resting ECG in athletic and non-athletic adolescent boys: correlations with heart volume and cardiorespiratory fitness.

Resting ECG was recorded in 59 endurance trained athletic and 81 non-athletic boys aged 10-17 years and the findings were correlated with heart volume and cardiorespiratory fitness. The two groups were physically similar, but the athletes had significantly higher maximal oxygen uptake and the 15-17-year-old athletes had larger heart volumes. ECG findings were rather similar in both groups, the major differences being a lower heart rate in the athletes than in the controls (71 vs 82 beats/min) and a longer PQ interval (0.151 vs. 0.140 s) and a greater sum of SV2 and RV4 (59 vs. 50 mm) in the 15-17-year-old athletes. In the controls no correlation existed between precordial voltage criteria for ventricular hypertrophy and heart volume or between heart volume and cardiorespiratory fitness. Contrary to this, in the athletes both SV2 + RV5 and SV2 + RV4 correlated significantly (r about 0.40) with relative heart volume, and relative heart volume with both maximal oxygen uptake per kg (r = 0.41) and calculated work at heart rate 170 beats/min expressed per kg (r = 0.61). Our findings seem to indicate that as a consequence of endurance training the high level of cardiorespiratory fitness becomes related to a large heart volume. It is obvious that ECG changes due to relative vagal dominance develop earlier in the adolescent athletes than those attributable to anatomical changes.

Adolescent↗