The Care Coordinator's Tasks During the Implementation of an Integrated Care Pathway for Older Patients: A Qualitative Study Based on the French National "Health Pathway of Seniors for Preserved Autonomy" Pilot Program.

Background: Although integrated care and care coordination are known to be beneficial for older adults' population, the specific tasks of a Care Coordinator (CC) for integrated care pathways for this population have not been studied in detail. Setting & Subjects: The French national pilot program PAERPA provided an integrated care pathway for older adults. In North France, a CC was recruited to support patients and professionals. Objectives: (i) To analyse the CC's tasks in an integrated care pathway for older patients, and (ii) to record perceptions on the CC's tasks among the participating general practitioners (GP) and community pharmacists. Design & Methods: Qualitative, two-phase study: (i) Task analysis of the CC's tasks, to compare the planned and actual tasks; (ii) semi-structured interviews among GPs and community pharmacists involved in the pathway. Results: (i) The task analysis showed that the CC's actual tasks differed from planned tasks. The CC was only meant to be involved in the early stages of the process; actually, the CC undertook more or even unforeseen tasks in coordination, communication, and administrative support throughout the care pathways. (ii) The 28 interviewed healthcare professionals considered the CC's tasks to be essential to the success of pathways. They appreciated the CC's administrative support. However, CC's tasks related to interprofessional communication, and patient and family information, were controversially perceived among GPs and pharmacists. Conclusions: The CC's tasks in an integrated care pathway for older adults showed that the CC's overall workload was greater than expected and appreciated by healthcare professionals.

[Assessment of general practitioners' knowledge of inhalers]. / Évaluation des connaissances des médecins généralistes sur les inhalateurs. Les médecins généralistes savent-ils utiliser les inhalateurs qu'ils prescrivent dans le traitement de l'asthme ?

INTRODUCTION: Inhaled drug delivery is the cornerstone treatment for asthma. General practitioners (GPs) have a key role for educating patient about how to use their inhalers. The purpose of this study was to find out whether GPs know how to use the inhalers they usually prescribe. METHOD: This was a descriptive and analytical cross-sectional study among GPs from the Paris metropolitan area. GPs had to choose the inhalers they usually prescribe and then demonstrate their use. The technique of use was assessed using a scale specific to each type of inhaler. Overall success was defined by the use of prescribed inhalers without critical errors. RESULTS: Thirty-seven GPs were recruited between July 2018 and July 2019. Nineteen GPs (51.4%) were able to use the inhalers they prescribed without critical errors. The success rate without critical error was better with the pressurized metered dose inhalers with spacer than with other inhalers. The overall success rate was better among GPs who had previously used an inhaler on a personal basis (OR 7.58 95%CI [1.86, 37.02]) or who had prescribed only one type of inhaler (OR 4,8 95%CI [1.21, 22.41]). CONCLUSION: Half of the GPs in our study did not know how to use the inhalers they prescribe and therefore may have difficulty educating their patients.

Bivalve δ15N isoscapes provide a baseline for urban nitrogen footprint at the edge of a World Heritage coral reef.

Eutrophication is a major threat to world's coral reefs. Here, we mapped the distribution of the anthropogenic nitrogen footprint around Nouméa, a coastal city surrounded by 15,743 km2 of UNESCO listed reefs. We measured the δ15N signature of 348 long-lived benthic bivalves from 12 species at 27 sites and interpolated these to generate a δ15N isoscape. We evaluated the influence of water residence times on nitrogen enrichment and predicted an eutrophication risk at the UNESCO core area. Nitrogen isoscapes revealed a strong spatial gradient (4.3 to 11.7‰) from the outer lagoon to three highly exposed bays of Nouméa. Several protected reefs would benefit from an improved management of wastewater outputs, while one bay in the UNESCO core area may suffer a high eutrophication risk in the future. Our study reinforces the usefulness of using benthic animals to characterize the anthropogenic N-footprint and provide a necessary baseline for both ecologists and policy makers.

Mercury contamination level and speciation inventory in Lakes Titicaca & Uru-Uru (Bolivia): Current status and future trends.

Aquatic ecosystems of the Bolivian Altiplano (∼3800 m a.s.l.) are characterized by extreme hydro-climatic constrains (e.g., high UV-radiations and low oxygen) and are under the pressure of increasing anthropogenic activities, unregulated mining, agricultural and urban development. We report here a complete inventory of mercury (Hg) levels and speciation in the water column, atmosphere, sediment and key sentinel organisms (i.e., plankton, fish and birds) of two endorheic Lakes of the same watershed differing with respect to their size, eutrophication and contamination levels. Total Hg (THg) and monomethylmercury (MMHg) concentrations in filtered water and sediment of Lake Titicaca are in the lowest range of reported levels in other large lakes worldwide. Downstream, Hg levels are 3-10 times higher in the shallow eutrophic Lake Uru-Uru than in Lake Titicaca due to high Hg inputs from the surrounding mining region. High percentages of MMHg were found in the filtered and unfiltered water rising up from <1 to ∼50% THg from the oligo/hetero-trophic Lake Titicaca to the eutrophic Lake Uru-Uru. Such high %MMHg is explained by a high in situ MMHg production in relation to the sulfate rich substrate, the low oxygen levels of the water column, and the stabilization of MMHg due to abundant ligands present in these alkaline waters. Differences in MMHg concentrations in water and sediments compartments between Lake Titicaca and Uru-Uru were found to mirror the offset in MMHg levels that also exist in their respective food webs. This suggests that in situ MMHg baseline production is likely the main factor controlling MMHg levels in fish species consumed by the local population. Finally, the increase of anthropogenic pressure in Lake Titicaca may probably enhance eutrophication processes which favor MMHg production and thus accumulation in water and biota.

Pharmacokinetics of ornidazole in patients with severe liver cirrhosis.

Pharmacokinetics of ornidazole, a nitroimidazole derivative, was studied after intravenous injection in 10 patients with severe alcoholic cirrhosis and 10 healthy volunteers. Plasma concentrations of ornidazole and its two major hydroxylated metabolites, M1 (alpha-(chloromethyl)-2-hydroxymethyl-5-nitroimidazole-1-ethanol) and M4 (3-(2-methyl-5-nitroimidazole 1-yl) 1,2 propane diol), were measured by HPLC. The t1/2 of ornidazole was 14.1 +/- 0.5 hours for normal subjects and 21.9 +/- 2.9 hours for patients with cirrhosis. Mean plasma clearance was 50.6 +/- 2.1 ml/min in control subjects and 34.9 +/- 4.9 ml/min in patients, whereas apparent V SS was not modified in hepatic insufficiency. In healthy volunteers, M1 and M4 levels are well below levels of the parent drug; in cirrhosis both metabolites accumulate in plasma as a result of decreased elimination. Hepatic cirrhosis prolongs ornidazole elimination, and to avoid cumulation the interval between repeated doses could be doubled.

Effects of ticlopidine, a new platelet aggregation inhibitor in man.

Ticlopidine is a new platelet aggregation inhibitor. The effect of this drug was studied on 55 subjects, healthy volunteers and hospitalized patients. The action requires 24 to 48 hr to appear, and lasts more than 3 days. A dose-effect relationship was studied with oral daily doses ranging from 250 to 1,000 mg during 1 wk; it showed a 50% inhibition on adenosine diphosphate (ADP)-induced aggregation at 2 muM concentration on an oral daily dose of 450 mg. No action was found on collagen-induced aggregation, and a mild effect was observed on platelet adhesiveness. Clinical tolerance was assessed in patients given ticlopidine in oral doses up to 500 mg/day during several weeks, showing no overt side effects and no change in the safety parameters.

Clinical tolerance and profile of cytokine induction in healthy volunteers following the simultaneous administration of ifn-alpha and the synthetic immunomodulator murabutide.

As the therapeutic use of interferon-alpha (IFN-alpha) is limited by a dose-dependent toxicity and variable efficacy, ways of improving the therapeutic index of the cytokine are being sought. Murabutide (N-acetyl muramyl-L-alanyl-D-glutamine-O-n-butyl-ester) (ISTAC Biotechnology, Lille, France) is a safe synthetic and clinically acceptable immunomodulator that enhances the biologic activities of IFN-alpha in different experimental models. We evaluated in healthy human volunteers tolerance of the coadministration of Murabutide with increasing doses of IFN-alpha. The simultaneous administration of the two drugs was well tolerated without any increased or prohibiting toxicity, and all recipients experienced side effects that were similar to those observed after the administration of IFN-alpha alone. We also profiled the serum levels of cytokines induced following coinjection of the two drugs. We mostly detected an induction of anti-inflammatory cytokines and of human immunodeficiency virus type 1 (HIV-1)-suppressive beta-chemokines, in the absence of release of key proinflammatory cytokines. Therefore, the simultaneous administration of Murabutide and IFN-alpha is well tolerated and does not lead to increased toxicity. In addition, the selectivity in the profile of cytokines and chemokines induced following the coadministration of Murabutide and IFN-alpha points to the potential use of this combination in the treatment of inflammatory diseases and chronic viral infections.

A possible method to control prolongations of bleeding time under antiplatelet therapy with ticlopidine.

The interactions of oral and i.v. administrations of corticosteroids with the effects of ticlopidine were studied, in a search for an antidote for possible excessive prolongations of bleeding time induced by antiaggregating agents. Indeed, the results show that an i.v. injection of methylprednisolone or an oral treatment with prednisolone counteract the prolongation of bleeding time but do not interfere with the inhibition of platelet aggregation brought about by ticlopidine. This could be ascribed to a vasoconstrictive effect of corticosteroids, possibly through reduction of vascular prostacyclin release. If this mode of action was confirmed, this useful finding would essentially apply to ticlopidine, but not to cyclooxygenase inhibitors such as aspirin which, by themselves, abolish prostacyclin production.

Comparison of the pharmacokinetic profiles of three low molecular mass heparins--dalteparin, enoxaparin and nadroparin--administered subcutaneously in healthy volunteers (doses for prevention of thromboembolism).

The present trial was designed to comparatively investigate the pharmacokinetic profile and evaluate the apparent bioavailability pattern of three already marketed low molecular mass heparins (LMMHs): dalteparin (Fragmin), nadroparin (Fraxiparin), and enoxaparin (Lovenox) given by subcutaneous route. The study was carried out in 20 healthy young volunteers given, according to a cross over design, a single subcutaneous injection of the doses recommended for the prophylaxis of deep vein thrombosis (commercial preparations, prefilled syringes): dalteparin 2,500 IU (= 2,500 IU anti-Xa), nadroparin 7,500 ICU (= 3,075 IU anti-Xa), enoxaparin 20 mg (= 2,000 IU anti-Xa) and enoxaparin 40 mg (= 4,000 IU anti-Xa). Of the markers used, activated partial thromboplastin time (APTT), thrombin clotting time (TCT), Heptest, anti-thrombin (aIIa) activity and anti-Xa (aXa) activity, the most pertinent parameter (from a biodynamic viewpoint) is plasma aXa activity. We demonstrated that dalteparin, nadroparin and enoxaparin exhibit statistically significantly different pharmacokinetic and overall disposition patterns. Normalized to the same injected dose (1,000 IU aXa), the relative actual amount of plasma anti-Xa activity generated by enoxaparin is 1.48 times greater (p < 0.001) than that of nadroparin and 2.28 times greater (p < 0.001) than that of dalteparin while the plasma amount induced by nadroparin is 1.54 times greater (p < 0.001) than that of dalteparin. The apparent total body clearance of enoxaparin doses (CL/F = 16.7 +/- 5.5 and 13.8 +/- 3.2 ml/min) is significantly smaller than those of nadroparin (CL/F = 21.4 +/- 7.0 ml/min; p < 0.01) and dalteparin (CL/F = 33.3 +/- 11.8 ml/min; p < 0.001) while dalteparin apparent clearance is about 1.5-fold greater (p < 0.001) than that of nadroparin. These LMMHs also differ by their renal excretion pattern: more fragments exhibiting an anti-Xa activity are recovered in urine following enoxaparin doses (6.4 and 8.7% of the dose, respectively) than following nadroparin (3.9%) and dalteparin (3.4%) injection. These differences in the disposition profiles explain why the apparent elimination half life t1/2 values of the LMMHs compared here are different: dalteparin: 2.8 h; nadroparin: 3.7 h; and enoxaparin: 4.1 h. Whether or not these differences may contribute to explain the different safety/efficacy balance of each of these antithrombotic medications remains to be discussed and needs further studies.

The influence of food on the bioavailability of a slow release theophylline preparation.

Food-induced changes in the absorption of Theostat 300, a controlled release formulation of theophylline, have been studied in healthy volunteers. This open, randomised, 3-way, single-dose study involved 12 volunteers who received the drug either while fasting, or with a standardised low-fat (10g), or high-fat (60g) breakfast. Each subject was studied over a 3-week period, with 3 separate days of oral treatment and a 7-day washout period between treatments. The results showed no differences in AUC0-24 and tmax values between the 3 kinds of diet. The only differences observed concerned absorption. Food intake increased Cmax values by 20%. The steady-state peak concentration obtained by means of simulated plasma levels was not influenced by food intake. This slight food-drug interaction of Theostat 300 seemed to be of no clinical significance.

Pharmacokinetics of nicorandil.

This report presents the findings of some studies on single intravenous and oral dosing performed in healthy volunteers to determine the pharmacokinetics and preliminary metabolism of nicorandil, a new vasodilator acting via increase of both membrane potassium conductance and intracellular cyclic guanosine monophosphate in vascular smooth muscle. Nicorandil (5 to 40 mg) is rapidly and completely absorbed after oral administration. Absolute bioavailability is 75 +/- 23% (mean +/- standard deviation) indicating that no significant hepatic first-pass effect exists; peak plasma levels occur within 0.30 to 1.0 hours after dosing. Maximal concentration and area under the plasma concentration time curve of the parent drug are linearly related to a dose range of 5 to 40 mg, which covers the therapeutic regimen proposed for the treatment of patients with angina pectoris. The apparent distribution volume is about 1.4 liters/kg and the plasma concentrations decline according to 2 different processes: (1) a rapid elimination phase (apparent t1/2 beta congruent to 1 hour) that involves about 96% of the dose found in plasma, and a slower phase between the eighth and twenty-fourth hour that could be the consequence of the vascular affinity of the compound. Nicorandil is weakly bound to human plasma proteins (free fraction greater than 75%) and its mean residence time is close to 1.25 hour. Both in animals and in humans, preliminary metabolic studies show that the main biotransformation pathways are denitration and then introduction into the nicotinamide metabolism. However, unchanged nicorandil and denitrated metabolite excreted into the urine represent only about 1 and 4% of the dose, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Comparative bioavailability study of cefixime administered as tablets or aqueous solution.

The relative bioavailability of cefixime was studied in 24 healthy male volunteers, with each subject receiving a single 400mg dose of cefixime administered as an aqueous solution, a 400mg tablet and two 200mg tablets, in a randomised crossover sequence. Serum and urine samples were analysed using high-performance liquid chromatography. Peak cefixime levels were achieved 3 hours after administration of the solution vs 4 hours for the 2 tablet formulations; however, the extent of absorption was only slightly improved with the solution (by 14 and 7% compared with the 1 x 400 and 2 x 200mg tablets, respectively). The 400mg and 2 x 200mg tablets were found to be bioequivalent. The pharmacokinetic profile of the 400mg cefixime tablet (mean maximum plasma concentrations of 4.4 mg/L at 4 hours, area under the concentration-time curve of 34.4 mg/L.h, and apparent terminal elimination half-life of 3.7 hours) supports the clinical evaluation of a 400mg once-daily dosage regimen for cefixime.

EEG profile of intravenous zolpidem in healthy volunteers.

Zolpidem is an imidazopyridine which binds specifically to the omega 1 receptor. Zolpidem demonstrated potent hypnotic activity at a dose of 10 mg. Pharmacodynamics and pharmacokinetics of zolpidem were studied after daytime administration in a randomised, double-blind, placebo-controlled, cross-over trial. Single doses of zolpidem (10 mg IV as a 3-min infusion and 20 mg orally) and placebo were firstly tested in 12 healthy young male volunteers. Two other doses (5 mg IV and orally) were then evaluated in 6 out of these 12 subjects. EEG (4 leads = Fp2-T4, Fp1-T3, T4-02 and T3-01), and Stanford Sleepiness Scale (SSS) were measured up to 5 h postdosing. Blood samples were also collected up to 24 h. The time course of the hypnotic activity of zolpidem, assessed by the score obtained on SSS, showed a similar profile whatever the route or the dose administered: slightly earlier onset after IV but sedative scores were reached at 30 min and the effect peaked between 1 and 1.5 h and lasted 4 h in both conditions. The EEG profile of zolpidem was characterised by a decrease of alpha activity and an increase in delta and in beta activity. The effect on beta activity was marked within the first hour and then disappeared. The time course of delta and alpha activities indicated a rapid onset (10 min after IV, 30 min after oral route) and a duration of 3-4 h. The amplitude of these relative EEG changes and their duration were independent of the route of administration and the dose administered. AUC and Cmax increased proportionally to the administered dose and elimination half life (2h), clearance and volume of distribution did not change according to the dose or the route of administration.(ABSTRACT TRUNCATED AT 250 WORDS)

Pharmacokinetics of sparfloxacin in humans after single oral administration at doses of 200, 400, 600, and 800 mg.

The pharmacokinetics of sparfloxacin at oral doses of 200, 400, 600, and 800 mg were studied in 12 healthy volunteers in a randomized double-blind crossover study. Each dose administration was separated by a 1-week washout period. Plasma and urine samples were collected up to 120 hours postdosing, for determination of free and total (free plus glucurono-conjugated) sparfloxacin levels by high-performance liquid chromatography assay and ultraviolet detection. Mean Cmax values ranged from 705 +/- 158 to 1966 +/- 620 ng/mL for the 200 to 800 mg doses, at median tmax ranging from 4 to 5 hours. A slight decrease of sparfloxacin bioavailability with increasing dose was observed because AUC was 87% to 88% of the expected area when the dose was doubled. The elimination half-life values were constant over the dose range (with values ranging from 18 to 21 hours) as well as the renal clearance. The metabolic ratio conjugated/free drug was not modified by increasing dose.

Clinical pharmacology of flurbiprofen: a novel inhibitor of platelet aggregation.

Studies are reviewed of the inhibitory effect of flurbiprofen, given in doses ranging from 50 mg to 200 mg per day for 1 week, on platelet aggregation measured by biological tests (adenosine diphosphate and collagen methods). Flurbiprofen at doses of 50 mg and 100 mg daily had a peak time of action of between 1 and 2 hours, the effects usually disappearing after 24 hours, and 100 mg flurbiprofen caused a similar decrease in platelet aggregation to 1 g aspirin daily. In a clinical study of 72 patients with chronic glomerulonephritis treated with doses of flurbiprofen up to 200 daily there was a significant correlation between the parameters of aggregation measured and treatment, and between proteinuria and adenosine disphosphate aggregation when the flurbiprofen dose did not exceed 100 mg daily.

Improved delivery of ipratropium bromide using Respimat (a new soft mist inhaler) compared with a conventional metered dose inhaler: cumulative dose response study in patients with COPD.

Respimat (RMT) is a reusable, propellant-free, soft mist inhaler (SMI), a novel device for inhalation therapy. We conducted a three-period cross-over study to evaluate the safety and efficacy of cumulative doses of ipratropium bromide inhaled from RMT (Two dose levels) or from a pressurized metered dose inhaler (MDI), in 36 patients with chronic obstructive pulmonary disease (COPD). The bronchodilator effect of ipratropium bromide was greater when administered via RMT (10 or 20 microg per puff, given double-blind within device, to total doses of 160 or 320 microg) than via MDI (20 microg per puff, total dose 320 microg). The bronchodilator effects of the 160 and 320 microg doses delivered via RMT were similar. Cumulative ipratropium bromide doses of 320 microg given via MDI or RMT and 160 microg given via RMT produced similar safety profiles. Between 45 min after the first drug inhalation and 45 min after the final dose, greater bronchodilatory effect was obtained from half the cumulative dose of ipratropium (RMT 10 microg per puff) when compared with the MDI (20 microg per puff). Therefore, ipratropium bromide delivered by RMT is as safe as, and can be more effective than, the MDI on acute administration in patients with COPD.

Comparison of two estradiol transdermal systems (Oesclim 50 and Estraderm TTS 50). II. Local skin tolerability.

OBJECTIVES: The objectives were to compare the local skin tolerability of a matrix-type estradiol transdermal system, Oesclim 50, with that of the reservoir-type system, Estraderm TTS 50. METHODS: Two randomised studies were performed. In the first study, the modified Draize-Shelanski-Jordan method of sensitization was used in an open, parallel-group trial to compare the cutaneous tolerability of repeated applications of Oesclim 50 with that of Estraderm TTS 50 in 24 healthy postmenopausal women. The second study was an open, randomised, parallel-group, multi-centre clinical trial involving 283 healthy menopausal women. A total of 143 women were allocated to treatment with Oesclim 50 and 140 to Estraderm TTS 50. The treatment duration was four months. RESULTS: The first study showed that the treatments, Oesclim 50 and Estraderm TTS 50, had no sensitizing potential and did not induce allergic reactions. In the second study, 4.2% of applications in the Oesclim group provoked reactions compared with 9.5% in the Estraderm group (P < 0.001). Thirty-seven patients (25.9%) treated with Oesclim and 55 patients (39.9%) receiving Estraderm experienced one or more reactions (P < 0.05). Redness and itching were the most frequent types of application site reaction in both treatment groups. The durations of the reactions were significantly shorter in the Oesclim group (P < 0.01), with a higher percentage of durations of less than 1 h and a lower percentage of durations of over 48 h than in the Estraderm TTS 50 group. None of the reactions in the Oesclim group led to premature removal of the patch, compared with 11 (3.4%) in the Estraderm group (P < 0.05). The number of patients who discontinued treatment due to application site reactions was one (0.7%) in the Oesclim group and seven (5.1%) in the Estraderm group (P < 0.05). Efficacy and general safety were comparable in the two treatment groups. CONCLUSIONS: In the first study, neither Oesclim nor Estraderm induced allergic reactions. In the second study, the local skin tolerability of Oesclim was significantly better than that of Estraderm, in terms of the number, duration and severity of the application site reactions.

Pharmacokinetics of 2-(alpha-thenoylthio)-propionylglycine (TTPG) in healthy volunteers--an oral dose-proportionality investigation.

The dose linearity of 2-(alpha-thenoylthio)-propionylglycine (TTPG) pharmacokinetics after a single oral administration at three different TTPG doses (180, 540 and 1080 mg) was evaluated in 12 healthy volunteers according to an open, randomized, cross-over study with a 1-week wash-out period between each administration. The duration of the study, for each subject, was 4 weeks. Plasma concentration and urinary excretion of TTPG and its two systemic metabolites, namely propionylglycine (tiopronin) and thiophenecarboxylic acid (TCA) were assayed by a previously well validated HPLC method. Due to differences in the physical and chemical properties of these compounds, two assays were needed, one to measure TTPG and TCA as such, and one to measure derivatized tiopronin. Both used UV detection. TTPG, tiopronin and TCA were quickly detected in plasma, suggesting that the drug administered is rapidly absorbed and biotransformed, in part, in the systemic circulation into the two metabolites noted above. Time-to-peak for all three analytes showed a trend to increase with increasing doses of TTPG, being: 0.42, 0.40 and 0.67 h (P < 0.01) with TTPG; 0.53, 0.47 and 0.73 h (P < 0.05) with TCA; and 1.33, 2.13 and 2.58 h (P < 0.01) with tiopronin. Cmax showed the opposite behaviour with values (ng ml-1) normalized to the dose of 540 mg: 1235, 905 and 513 (P < 0.001) with TTPG; 888, 547 and 383 (P < 0.001) with TCA; and 7290, 6950 and 5170 (P < 0.01) with tiopronin.(ABSTRACT TRUNCATED AT 250 WORDS)

Pharmacokinetics and metabolism of diltiazem in man.

Dilitazem, a coronary vasodilating agent, after oral administration of four different doses, was well and rapidly absorbed. The pharmacokinetics of the drug followed a two-compartment model, with a rapid distribution and an elimination with a half-life of 4-7 hours. After chronic treatment the pharmacokinetic parameters were practically unchanged and therefore no accumulation of the drug was observed. The comparison between capsule and tablet preparations showed that both forms had a similar bioavailability. Diltiazem was extensively metabilized and only a few percent of the drug was found in urine. Several metabolites, also present as conjugates, have been identified by means of gas chromatography-mass spectrometry.

The interactions of ticlopidine and aspirin in normal subjects.

This trial was performed on 24 health volunteers in order to study the possible interactions between aspirin and ticlopidine. The results confirm the inhibitory activity of aspirin on collagen-induced aggregation and that of ticlopidine on ADP-induced aggregation. If aspirin does not modify the inhibitory effect of ticlopidine on ADP-induced aggregation, ticlopidine on the other hand potentiates the effect of aspirin on collagen-induced aggregation.