Evaluation of reflex cold provocation by laser Doppler flowmetry in clinically healthy subjects with a history of cold hands.

The aim of the present study was to investigate capillary blood flow and the reaction to cold provocation by means of laser Doppler flowmetry (LDF) and measurement of skin temperature at the fingertip of 39 healthy subjects who had a history of cold hands and feet but were free of any clinically significant vasospastic symptoms. A group of 39 sex- and age-matched healthy subjects without such complaints served as the control. The anamnestic complaints about cold hands and feet could be substantiated by the presence of a lower baseline skin perfusion and temperature. However, the maintenance of the normal range of reagibility to a reflex contractile stimulus with an unaltered potential to recover distinctly separates these subjects from patients with Raynaud's disease.

[Weaning of young smokers using a transdermal nicotine patch]. / Entwöhnung junger Raucher mit Hilfe eines transdermalen Nikotinpflasters.

To assess efficacy and tolerance of a transdermal nicotine system (TNS) as adjuvant to tobacco withdrawal, 112 young, nicotine-dependent cigarette smokers were treated for nine weeks with TNS (n = 56) or placebo (n = 56). Initial doses of nicotine (21 or 14 mg/24 h) were based on previous smoking habits and stepwise reduced to 7 mg/24 h if abstinence was achieved during medication. After treatment, 39.3% of the TNS users were abstinent versus 19.6% on placebo (p less than 0.05). The craving for cigarettes diminished steadily, but not more significantly on TNS medication. Tenseness, difficulty in concentration and feelings of hunger were consistently and in part significantly lessened in the TNS group. The other withdrawal symptoms were not influenced by TNS treatment. Nine-month follow-up cotinine-verified abstinence rates were 12.5% in the TNS and 3.6% in the placebo group (n. s.). Transient mild or moderate erythema at the application site appeared in 20% of the TNS and 6.3% of the placebo group, and 7.1% of the TNS users dropped out because of severe localized erythema. Other mild, transient, systemic side effects reported by 33.9% of the TNS and 26.8% of the placebo users (n. s.) did not lead to drop-outs.

[Laser Doppler flow measurement of the finger during cold provocation: results in 140 patients with healthy blood vessels]. / Laser-Doppler Fluxmessung am Finger während Kälteprovokation: Ergebnisse bei 140 Gefässgesunden.

Flow patterns of the cutaneous circulation of the third left finger was studied before and after standardized cold challenge in 140 healthy subjects by means of Laser-Doppler flowmetry. Flow behaviour showed no statistical differences regarding to age, sex and day time. Nevertheless, the results may serve only to a limited extent as a reference in the evaluation of individual test results for everyday angiological diagnosis since the interindividual variability of the flux values is considerable. However, the present data obtained from a relatively large normal population are suitable as a reference basis for scientific investigations using groups of healthy subjects or patients.

The use of transdermal nicotine in smoking cessation.

The transdermal administration of nicotine by means of a transdermal nicotine system (TNS) affords a novel way of nicotine replacement to alleviate smoking cessation. The plasma levels of nicotine maintained with the TNS are in the range of the footpoint concentrations observed in smokers. The efficacy of the TNS was investigated in two placebo-controlled double-blind smoking cessation programs with minimal contact and minimal psychological support. A total of 311 smokers were treated for 3 months or 9 weeks. The abstinence rates at the end of the treatment and weaning periods were almost doubled in the TNS groups (36% and 39%) as compared to the placebo groups (23% and 20%) with a significant difference for both studies (p less than 0.05). These data suggest that the TNS can also improve the smoking cessation rates under the conditions of general medical advice, making it suitable for use outside of specialized smoking cessation centers.

Pharmacokinetics and bioavailability of nicotine in healthy volunteers following single and repeated administration of different doses of transdermal nicotine systems.

Healthy nicotine-dependent smokers were applied different doses of transdermal nicotine systems (TNS) during single and repeated administrations. Plasma and urine nicotine and cotinine concentrations were determined by high performance liquid chromatography (HPLC). After single application of TNS, the maximal concentration (Cmax) and area under curve (AUC) of nicotine in plasma as well as the amount of nicotine excreted in urine were linearly related to the dose. The stable urinary cotinine excretion was not influenced by the amount of nicotine delivered by the TNS. The relevant 24 h plasma nicotine concentration reached after TNS application compares well with the plasma nicotine footpoints--not the peaks--observed in moderate to heavy cigarette smokers. A comparison between different nicotine doses from different TNS allowed to conclude to the functionality of the systems as regards pharmacokinetics and bioavailability. One or two hours after removal of the systems, there was a very slow decline of the nicotine concentrations. After repeated application of TNS, there was evidence for only a very limited nicotine accumulation in plasma (+14%) or in urine (+9%) over 10 days. The steady-state of nicotine was reached within 4 days. The continuous delivery of nicotine over 24 h resulted in an early morning plasma concentration which probably decreases or prevents the craving for the first cigarette.

Human pharmacological investigations of a transdermal nicotine system.

To define the pharmacological properties of a newly developed transdermal nicotine system (TNS) designed to facilitate abstention from smoking, three human pharmacology studies were performed in healthy, nicotine-dependent smokers. The first study, in which cigarette smoking served as the standard mode of nicotine intake, was carried out to evaluate the most suitable non-invasive methods for detecting the pharmacodynamic effects of nicotine and to provide a baseline for comparisons with the results of the subsequent studies to assess the effects of single and repeated applications of the TNS. The pharmacodynamic changes induced by smoking were generally most pronounced after the first cigarette following 10 hours' abstinence. The most sensitive parameters were heart rate, which increased, stroke volume measured by impedance cardiography, which decreased, cutaneous blood flow measured by Laser Doppler flowmetry and skin temperature, which diminished to a statistically significant extent after each cigarette. Increases in blood pressure were not very pronounced. Plasma catecholamines were consistently elevated after each cigarette, but the changes were not statistically significant. Compared with those induced by cigarette smoking, the cardiovascular effect seen after either a single application of the TNS (10, 20 and 40 mg/24 h) or repeated application of a TNS delivering 14 mg nicotine/24 h were minor. A slight increase in blood pressure was detectable only on the first day of application and had disappeared after 10 days' repetitive application, suggesting the development of partial tolerance. Heart rate was slightly increased by 3-7% and stroke volume decreased by 5-12% on the tenth day of TNS application.(ABSTRACT TRUNCATED AT 250 WORDS)