Anticoagulative effects of the inhaled low molecular weight heparin certoparin in healthy subjects

Inhalation of heparin results in local antiinflammatory and antifibrotic effects and an inhibition of blood coagulation. A number of experimental and clinical studies demonstrated that inhalant administration of heparin or low molecular weight heparin (LMWH) is a feasible and save tool for anticoagulative treatment. However, heparin and LMWH differ in respect to their molecular weight, pulmonary absorption, and principle of their anticoagulative pattern. In our study we investigated the anticoagulative effect of different doses of the LMWH certoparin after inhalation (3000 IU-9000 IU) and subcutaneous injection (3000 IU) in healthy individuals in a cross-over design. Inhalations were performed using a new device allowing inhalations with optimized and standardized breathing patterns. The anticoagulative effect was determined by measurement of the anti-factor-Xa (anti-FXa) activity. Lung function parameters were measured before and after drug inhalation. Analysis of the anti-FXa activity as a function of the time after administration revealed values of the area under the curve (AUC) of 5.70+/-1.58 U.hour/ml and 8.43+/-1.31 U.hour/ml (mean+/-SD) with interindividual coefficients of variation of 28% and 13% after injection of 3000 IU and inhalation of 9000 IU, respectively. The AUC after inhalation of 9000 IU was significantly higher (P=0.0007) compared with subcutaneous injection of 3000 IU. In consequence, in order to obtain plasma anti-FXa activities of above 0.2 U/ml, which is considered sufficient for prophylaxis of venous thrombosis, 9000 IU LMWH have to be inhaled. Compared with the subcutaneous administration, the action of certoparin is longer after inhalation than after injection. Apparently, the drug is released rapidly according to a two-compartment kinetics, and its anticoagulant activity lasts over a long time without a marked plasma peak after administration. In detail, an elevation of plasma anti-FXa activity is achieved for 12 hours to 24 hours without a distinct peak shortly after inhalation. Inhalation of LMWH does not result in any changes in lung function or other side effects. The administration of LMWH by inhalation bears the following: the non-invasive route of drug application, the low interindividual variability of the anticoagulative effect, and a long-time pharmacological effect. These properties suggest that controlled inhalation of heparin is an attractive alternative to subcutaneous administration.

Inhalation of tobramycin in patients with cystic fibrosis: comparison of two methods

Inhalant tobramycin is established in the treatment of cystic fibrosis patients. Conventional nebulizers require a large amount of the expensive compound, because only a small fraction is deposited in the targeted lung region. In contrast, techniques based on controlled inhalation allow a high and reproducible deposition of the drug in specific lung regions. In our study we compared the efficiency of two techniques based on conventional and controlled inhalation in 16 cystic fibrosis patients aged 13-39 years. Inhalations with the doses of tobramycin of 300 mg and 150 mg were performed twice daily for three days. The efficiency of the drug deposition was measured by the determination of its serum concentration 1 h after the end of the inhalation. The mean FEV1 value in our patients was 61% of predicted, range 36%-116%. There were no differences in tobramycin serum concentrations among the three study days in both methods (controlled inhalation: 0.983 +/-0.381(+/-SD) mg/l, 1.119+/-0.448 mg/l, 1.194+/-0.568 mg/l; conventional inhalation: 1.075+/-0.798 mg/l, 1.294 0.839 mg/l and 1.269+/-0.767 mg/l, on Day 1, Day 2, and Day 3, respectively). Even though the drug amount was double in the conventional technique, there was no significant difference in its overall serum concentration from the three study days (conventional inhalation: 1.210+/-0.783 mg/l, controlled inhalation: 1.092+/-0.461 mg/l). In addition, the coefficient of variation and the required inhalation time were shorter in controlled inhalation than in conventional inhalation (42% vs. 65% and 7-8 min vs. 20 min, respectively). Our data suggest that controlled inhalation can significantly reduce the amount of a drug required for therapy, the inhalation time required for drug deposition, and the variability of pulmonary dosage. It seems probable that controlled inhalation can improve the antibiotic prevention of pulmonary infection.

Aerosol-derived airway morphometry (ADAM) in patients with lung emphysema diagnosed by computed tomography--reproducibility, diagnostic information and modelling

Gravitational deposition of monodisperse particles can be used to determine effective airway diameter (EAD). The aim of our study was to assess intraindividual variability of EAD in healthy subjects and patients with emphysema, to compare EAD in patients with different degree and type of emphysema, and to evaluate whether parametric or model analysis would improve the results. EAD was measured vs volumetric lung depth (LD) in 11 healthy subjects (FEV subset1 107%pred) and 41 patients with emphysema (FEV subset1 60%pred; 8/9/24 mild/moderate/severe, 18/7/16 centriacinar/panacinar/bullous according to HRCT). Repeated measurements in LDs of 6-30% showed coefficients of variation of 7.0-10.4% in healthy subjects and 8.3-11.9% in emphysema. Average EAD in 10-16% LD was increased in emphysema, in particular moderate and severe (p<0.05, each). The slope of EAD in 10-16% LD differed between healthy subjects and emphysema, especially bullous and centriacinar. Patients with severe emphysema also showed a different slope compared to mild emphysema and controls. The parameters of the power function used for data fitting also showed differences between controls and emphysema, as well as between centriacinar vs panacinar and bullous emphysema. In a three-compartment lung model only the diameter of the intermediate compartment was enlarged in emphysema. We conclude that in using aerosol-derived airway morphometry, reproducibility of repeated measurements is acceptable. Average values and slopes of the EAD curve, as well as a power function for data fitting, were sensitive in the detection of type and severity of emphysema. In contrast, application of a lung model did not improve the results.

Vergleich der unspezifischen bronchialen Provokation mit Methacholin unter kontrollierter und freier Inhalation

Using controlled breathing patterns during inhalation of drugs is characterized by a high dose reproducibility which may be of advantage for bronchial provocation testing. In this study 30 healthy subjects with an anamnesis of atopy underwent in a randomized cross-over design bronchial provocation testing with methacholine either with the Viasys-Jäger-APS system or with controlled inhalations (AKITA-System) (controlled inhalation volume and flow). Measured was the frequency of positive test results. Positive test results were defined by a 20 % decline of FEV (1) or a 100 % increase of specific airway resistance (sRaw). There were no significant differences in the prevalence of positive test results obtained with both techniques: APS-FEV (1) : 8, AKITA-FEV (1) : 9; APS-sRaw: 18, AKITA-sRaw: 17. More subjects showed a 100 % increase of sRaw as compared to a 20 % decrease of FEV (1), which may be interesting in order to understand differences in the diagnostic information given by both parameters. However, there were some discrepancies: only in 25 of 30 cases (sRaw: 21 of 30 cases) the results (positive or negative) agreed between both techniques. Although the two techniques for bronchial provocation test showed some discrepancies, these data suggest that controlled inhalations may be an alternative to the APS-system.

Pharmacokinetic of inhaled low molecular weight heparin

7209

Background: Treatment with Heparin and low molecular weight (LMW) Heparin is frequently used in oncology settings. Usually, these drugs are delivered by subcutaneous (s.c.) administration. Since 1963, the clinical relevance of inhalation of unfractionated as well as LMW-Heparin has been investigated in various studies with over 500 subjects. In this study, a single inhalation of the LMW-Heparin Certoparin (Mono-Embolex, Novartis) was investigated in 10 healthy subjects. The goal was to assess the pharmacokinetic behavior. Inhalations were performed using a novel inhalation system, which allows an accurate dosing in the lungs by controlling patient’s breathing pattern (AKITA). Lung deposition is about 85% of the emitted dose. Methods: 10 non-smoking healthy subjects participated in this study. Inhalation of 9000 IU of LMW-Heparin was compared to 3000 IU s.c. administration to achieve factor-Xa-activity in the plasma of 0.2 to 0.3 U/ml. Intravenous blood samples were taken 0.25, 0.5, 1, 2, 4, 6, 24, 48 hrs after administration. Factor-Xa-activity in plasma was assessed using the Berichrom assay (Dade Behring, Marburg, Germany). Results: Inhalation of LMW-Heparin was well tolerated and did not result in any side effects or changes in lung function. The maximum anti-Xa-activity in the plasma was 0.3 U/ml for the s.c. administration of Certoparin and 0.32 U/ml after inhalation of 9000 IU. However, pharmacokinetics was considerably different. Inhaled LMW-Heparin resulted in a prolonged anti-Xa-activity. After 6 (24) hours, the anti-Xa-activity after s.c. administration was down at 0.16 U/ml (0.10) and after inhalation at 0.30 (0.18) U/ml. Even after 48 hrs, the anti-Xa-activity after inhalation was significantly higher than the baseline value. Comparing area under the curve (AUC), bioavailability for the inhalation was 9.4 U · h/ml ± 14% compared to 5.7 U · h/ml ± 27% after s.c. administration. Conclusions: These results suggest that with controlled inhalation, this administration route is an attractive alternative to s.c. administration, with the result of longer bioavailability and less variability. A once daily administration is possible. Inhalation therapy with these kind of systems might also be useful with different anticancer agents, which cannot be administered orally.

[Table: see text]

[Six-minute-walking-test with and without oxygen in patients with COPD: comparison of walking distance and oxygen saturation in varying forms of application]

BACKGROUND

Patients afflicted with COPD and respiratory Failure often experience a decrease of oxygen saturation (SaO (2)) under physical strain. The aim of our study was to find out which changes occur in walking distance and SaO (2) under the application of Oxygen (O (2)) 2 l/min continous flow, under demand (D) and under normal air (RL) when performing the Six-Minute-Walking-Test (6MWT) and further, in which way do the 10 patients of the shortest walking distance group (group I) differ from the eo patients with the longest walking distance (group II) concerning the starter 6 MWT (under CF).

METHOD AND PATIENTS

27 patients undertook a 6MWT three days in a row with CF, D and (RL), 6 minutes before (phase I), during (phase II) and after (phase III) the 6MWT oxygen was applied in CF (day I), D (day II) and RL (day III), the mean oxygen saturation in each phase was measured and the change (DeltaSaO (2)) during and after the 6MWT was calculated. Additionally we measured the DeltaSaO (2) between start and middle, as well as between middle and end of each phase. In close proximity to the tests FEV (1) and pO (2) was determined.

RESULTS

In the total of all test persons there was no significant difference in the walking distance tetween the 3 forms of application. There was, however, a highly significant decrease of the oxygen saturation. The decrease in the two forms of oxygen application did not differ significantly. The decrease of SaO (2) under strain and the consecutive rise under rest occurred within the first 3 minutes of each phase. Patients of group II were often able to increase their walking distance under RL, whereas patients of group I decreased their walking distance further. In group II FEV (1) abs. was significantly higher, but FEV (1) % debit and pO (2) did not differ significantly between both groups.

CONCLUSIONS

Patients with a long walking distance showed a marked learning effect even under RL, they presented a higher FEV (1), but not an increased pO (2). The phase of resaturation after the end of strain is short. Oxygen application through a demand valve with a flow rate of 2 l/min is not inferior to a continuous flow. In more than half of all patients the SaO (2) fell below 90 % under both forms of oxygen application, in conclusion the flow rate should be increased in these cases.

Optimum peripheral drug deposition in patients with cystic fibrosis

In order to identify the optimum particle size and breathing pattern for high peripheral deposition of inhaled drugs in patients with cystic fibrosis, regional deposition in these patients was studied systematically as a function of particle size, inhalation volume and flow rate. Regional deposition was assessed using the single-breath regional deposition technique in which the concentration profile of inhaled and exhaled non-radioactive, monodisperse test particles is analyzed. Using this technique particle deposition within the functional dead space volume and peripherally can be assessed. Regional deposition was measured in 12 patients with cystic fibrosis using 2, 3, 4, and 5.5 microm particles, inhalation volumes of 500, 1000, 1500, and 2000 cm(3), and inhalation flow rates of 100, 250, 500, and 750 cm(3)/sec. Peripheral deposition was highest when 2-3-microm particles were inhaled with air-flow rates of 250-500 cm(3)/sec. With these parameters peripheral deposition increased with increasing inhalation volume and reached values of about 60% of the total drug inhaled. It has been shown that high peripheral drug deposition can be achieved in patients with CF when inhalations are performed using an optimized combination of particle size and breathing pattern.

Quantitative computed tomography and aerosol morphometry in COPD and alpha1-antitrypsin deficiency

Relative area of emphysema below -910 Hounsfield units (RA-910) and 15th percentile density (PD15) are quantitative computed tomography (CT) parameters used in the diagnosis of emphysema. New concepts for noninvasive diagnosis of emphysema are aerosol-derived airway morphometry, which measures effective airspace dimensions (EAD) and aerosol bolus dispersion (ABD). Quantitative CT, ABD and EAD were compared in 20 smokers with chronic obstructive pulmonary disease (COPD) and 22 patients with alpha1-antitrypsin deficiency (AAD) with a similar degree of airway obstruction and reduced diffusion capacity. In both groups, there was a significant correlation between RA-910 and PD15 and pulmonary function tests (PFTs). A significant correlation was also found between EAD, RA-910 and PD15 in the study population as a whole. Upon separation into two groups, the significance disappeared for the smokers with COPD and strengthened for those with AAD, where EAD correlated significantly with RA-910 and PD15. ABD was similar in the two groups and did not correlate with PFT and quantitative CT in either group. In conclusion, based on quantitative computed tomography and aerosol-derived airway morphometry, emphysema was significantly more severe in patients with alpha1-antitrypsin deficiency compared with patients with usual emphysema, despite similar measures of pulmonary function tests.