A Possible Method to Control Prolongations of Bleeding Time under Antiplatelet Therapy with Ticlopidine

Efficacy of multimodal analgesia injection combined with corticosteroids after arthroscopic rotator cuff repair

INTRODUCTION

Although arthroscopic rotator cuff repair is minimally invasive, there is still considerable postoperative pain, especially during the first 48 hours. The present study assessed the short-term efficacy and safety of multimodal analgesic (MMA) injection associated to corticosteroids in arthroscopic rotator cuff tear surgery.

MATERIAL AND METHOD

A single-center prospective randomized study included 50 patients undergoing arthroscopic rotator cuff tear surgery. The study group received subacromial injection of a mixture of morphine, ropivacaine and methylprednisolone associated to intra-articular injection of morphine plus methylprednisolone; the control group received only isotonic saline. All patients had had 24 hours self-administered morphine associated to standard analgesia. Postoperative data were recorded at 30 minutes and 1, 2, 4, 6, 12, 18 and 24 hours: pain intensity, morphine intake and side effects, and also time to first morphine bolus and additional analgesic intake. Constant, ASES and SST functional scores were recorded at 3 months.

RESULTS

Postoperative pain was significantly less intense in the MMA group than in controls at 30 min, H1, H4, H6, H12, H18 and H24 (P<0.05). A rebound at D10 occurred in both groups. During the first 24 hours, MMA significantly reduced cumulative resort to morphine (P<0.05 at H1/2, P<0.001 at H1-24). Mean time to first bolus was significantly longer in the MMA group (71.6 vs. 33 min; P<0.05). The rate of opioid-related side effects was similar between groups. At last follow-up, functional scores were similar between groups. There were no cases of infection or delayed skin healing.

CONCLUSION

MMA associated to corticosteroids after arthroscopic rotator cuff tear surgery provided immediate benefit in terms of analgesia and morphine sparing, without apparent risk of infection. The practice is presently little known in France and deserves longer-term assessment, especially as regards functional rehabilitation and tendon healing.

LEVEL OF EVIDENCE

2.

Effects of periarticular steroid injection on knee function and the inflammatory response following Unicondylar Knee Arthroplasty

There is little information on the values of CRP and ESR as markers for inflammation in Unicondylar Knee Arthroplasty. The effect of periarticular steroid injection in post-operative pain relief and clinical recovery has not been well studied. Eighty-three consecutive patients undergoing primary UKAs were randomized to receive either an intra-operative periarticular injection with a local anaesthetic and adrenaline or with the addition of triamcinolone acetonide. CRP and ESR values, pain VAS and other scores, as well as clinical functional parameters, were obtained and analysed. Patients were assessed daily till discharge and up to 6 months post-operatively. Plasma CRP and ESR fluctuate after a UKA, with normalizing values indicating uneventful recovery. Periarticular steroid injections reduce post-operative pain and inflammation, and are clinically relevant as they improve short-term functional recovery and clinical parameters, resulting in better outcomes for patients without having major complications.

Peri-articular steroid injection improves the outcome after unicondylar knee replacement

We have performed a prospective double-blind, randomised controlled trial over two years to evaluate the efficacy and safety of an intra-operative peri-articular injection of triamcinolone acetonide in patients undergoing medial unicondylar knee replacement. We randomised 90 patients into two equal groups. The study group received an injection of triamcinolone acetonide, bupivacaine, and epinephrine into the peri-articular tissues at the end of the operation. The control group received the same injection mixture but without the addition of triamcinolone. The peri-operative analgesic regimen was standardised.

The study group reported a significant reduction in pain (p = 0.014 at 12 hours, p = 0.031 at 18 hours and p = 0.031 at 24 hours) and had a better range of movement (p = 0.023 at three months). There was no significant difference in the rate of infection and no incidence of tendon rupture in either group.

The addition of corticosteroid to the peri-articular injection after unicondylar knee replacement had both immediate and short-term benefits in terms of relief from pain, and rehabilitation with no increased risk of infection.

[Short-term tolerance of three days pulse methyprednisolone therapy: a prospective study in 146 patients]

AIM

To study the immediate tolerance of high-dose intravenous pulse steroids. PATIENTS ET METHOD: Prospective study over a six months period in 146 consecutive patients treated by three pulses of 250, 500 or 1000 mg/d methylprednisolone for various eye diseases. Daily monitoring including: standardized questionnaire, electrocardiogram, automated blood pressure measurements, fasting blood glucose and kaliemia.

RESULTS

One hundred and twenty-nine patients (88,4%) had one ore more side effect(s), mainly transient and of mild intensity, the first one being neuropsychological disturbances (insomnia in half the patients). Myocardial ischemia was observed in three patients (2,1%) with known coronary insufficiency or high cardiovascular risk, blood pressure levels of at least 180/110 mmHg were recorded in five hypertensive patients (3,4%), bradycardia occurred in 14 patients (9,7%), symptomatic in one. After the first pulse, we observed a mean 54+/-30% increase of fasting glucose (P <0,001), followed during the next pulses by a spontaneous slow return toward baseline values in non diabetic patients, contrasting with additional hyperglycemic effects in diabetics, and a mean 5,4+/-10,3% increase of kaliemia (P <0,001) staying unchanged during the next pulses, and suggesting a rapid potassium efflux from the cell as a direct effect of methylprednisolone.

CONCLUSION

Severe complications of pulse methylprednisolone, mainly cardiovascular, are strongly related to underlying comorbidities. Glucose monitoring is necessary only in diabetic patients. Potassium movements suggest a risk of hypokalicystia, of potential danger in patients with cardiac disease. A close clinical, blood pressure and electrocardiographic monitoring is needed during the whole treatment.

A randomized crossover comparative study of aspirin, cilostazol and clopidogrel in normal controls: analysis with quantitative bleeding time and platelet aggregation test

The effects of three antiplatelet drugs, aspirin, clopidogrel and cilostazol, were examined and compared using a quantitative bleeding time (QBT) test apparatus. In 12 healthy adult male subjects, a QBT test and platelet aggregation test were performed before and after medication. Cilostazol was found to be as effective as aspirin and clopidogrel in inhibiting platelet aggregation. Following the oral administration of aspirin and clopidogrel for 7 days, the bleeding time was significantly prolonged. In contrast, none of these QBT parameters were altered by the cilostazol treatment. This suggests that cilostazol has potent efficacy in inhibiting platelet aggregation without prolonging the bleeding time and changing the bleeding pattern.

The effects of platelet inhibitors on blood use in cardiac surgery

Platelet inhibition via glycoprotein (GP) IIb/IIIa receptor antagonists has greatly reduced the need for emergent cardiac surgery. However, this change has come at a cost to both the patient and the cardiac surgical team in terms of increased bleeding risk. Current guidelines for patients requiring coronary artery bypass surgery include: 1) cessation of GP IIb/IIIa inhibitor; 2) delay of surgery for up to 12 h if abciximab, tirofiban, or eptafibitide is used; 3) utilization of ultrafiltration via zero balance technique; 4) maintenance of standard heparin dosing despite elevated bleeding times; and 5) transfusion of platelets as needed, rather than prophylactically. These agents present cardiac surgery teams with increased risk during CABG, although overall risk may be diminished by the substantial benefits to patients with acute coronary syndromes and percutaneous interventions, i.e., reduced infarction rates and improved vessel patency. With judicious planning, urgent coronary artery bypass can be safely performed on patients who have been treated with GP IIb/IIIa receptor inhibitors.

Pharmacokinetics and pharmacodynamics of sibrafiban alone or in combination with ticlopidine and aspirin

AIMS

The purpose of this clinical study was to evaluate the effects of a ticlopidine/aspirin combination on the pharmacokinetics and pharmacodynamics of sibrafiban and the tolerability of the combination therapy

METHODS

Thirty-eight healthy male volunteers were randomized to receive one of the following treatments for 7 days: sibrafiban (n = 12), ticlopidine/aspirin (n = 12), or the combination treatment sibrafiban/ticlopidine/aspirin (n = 14). Concentrations of the active metabolite of sibrafiban, Ro 44-3888, in plasma and urine were determined by column-switching liquid chromatography combined with tandem mass spectrometry. The pharmacodynamics of sibrafiban and ticlopidine/aspirin were examined by measuring the inhibition of ADP- or collagen-induced platelet aggregation.

RESULTS

The addition of ticlopidine/aspirin to sibrafiban did not significantly alter the pharmacokinetic parameters of Ro 44-3888. the geometric mean ratio for AUC(0,12h) was 110 (95% CI 0.82, 1.22). Separately, sibrafiban and ticlopidine/aspirin inhibited ADP-and collagen-induced platelet aggregation and the effects of the two treatments were additive. For example, the average inhibition of ADP-induced platelet aggregation over 12 h was 42% in the sibrafiban treated group, 55% in the ticlopidine/aspirin group and 69% in the sibrafiban/ticlopidine group. The bleeding time was prolonged in the treatments with ticlopidine/aspirin (8.1 min) and sibrafiban/ticlopidine/aspirin (8. 6 min) compared with sibrafiban alone (3.5 min).

CONCLUSIONS

This study shows a significant pharmacodynamic interaction between sibrafiban and ticlopidine/aspirin. Consequently, the simultaneous administration of sibrafiban and ticlopidine/aspirin should be carefully monitored to ensure the patient's coverage with an antiplatelet drug without exposure to an excessive bleeding risk.

Ticlopidine and antiplatelet therapy

OBJECTIVE

To review the pharmacology, pharmacokinetics, clinical efficacy, and toxicity of ticlopidine. Comparisons with other antiplatelet agents are presented, with an emphasis on efficacy, and a recommendation is provided regarding ticlopidine's place in therapy.

DATA SOURCES

A MEDLINE literature retrieval of English-language journal articles from 1987 to January 1993 and references identified from bibliographies of review articles and clinical trials.

STUDY SELECTION

Randomized, blind, controlled studies of ticlopidine and other antiplatelet agents were preferentially selected.

DATA EXTRACTION

Clinical trials were reviewed in terms of study design, efficacy results, and toxicity.

DATA SYNTHESIS

Ticlopidine is a new antiplatelet agent with a distinct mechanism of action. In the largest trial of the drug for the prevention of stroke, it was found to be more effective than aspirin in reducing the risk of stroke or death. Clinical trials have also shown ticlopidine to decrease the rate of vascular death and myocardial infarction in patients with unstable angina, and to maintain venous graft patency after coronary artery bypass grafting. The use of ticlopidine in diabetic microangiopathy and peripheral vascular disease appears promising, but further studies are needed. Adverse reactions most commonly reported with ticlopidine are gastrointestinal complaints; the most severe reaction is transient neutropenia, which is seen in approximately 2.3 percent of patients and is severe in nearly 1 percent.

CONCLUSIONS

Ticlopidine is a reasonable alternative for use in preventing stroke among patients unable to take aspirin or those who do not benefit from aspirin therapy. Its use as first-line therapy is limited by its high cost and the occurrence of hematologic adverse effects.

Ticlopidine as a hemorrhagic risk factor in coronary surgery

We retrospectively reviewed the postoperative hemorrhagic risk in patients undergoing surgery for coronary revascularization who had received platelet antiaggregants preoperatively. A significant increase in postoperative hemorrhage and a higher percentage of reoperations for this reason was observed in the patients treated with ticlopidine. However, there were no major differences in the platelet counts among the groups compared.

Prolonged bleeding time

The bleeding time is the most frequently used test of platelet function. This review of the literature relating to the bleeding time outlines the causes and management of prolonged bleeding time. The bleeding time appears to have its greatest utility in evaluation of a patient with active bleeding or one with a well-documented bleeding history. It should not be used as a substitute for a clinical history, since there is insufficient information available to calculate its sensitivity, specificity, or predictive value with regard to peri- or postoperative hemorrhage.

Toxicological assessment of the hemostatic system, regulatory requirements, and industry practice

Disturbances of the hemostatic system which may be caused by chemicals include hemorrhagic diathesis, caused by inhibition of blood clotting, impairment of platelet function, and hyperactivity of fibrinolysis. Activation of the plasmatic clotting system, platelet aggregation, and inhibition of fibrinolysis may lead to thromboembolic complications. Although much is known about the functions of the hemostatic system a rational and cost-effective approach for its assessment in industrial toxicology is lacking. In this review the physiology of hemostasis and the available laboratory tests are discussed, current regulatory requirements are described, and industry practice is analyzed based on experience accumulated over the last 23 years. Proposals for a more flexible and scientific approach to testing of hemostatic mechanisms in toxicology are made.

The effect of ticlopidine on human endothelial cells in culture

The effect of ticlopidine at various concentrations (150, 30, 6 microM), has been studied on cultured endothelial cells derived from human umbilical cord vein. Ticlopidine affects the initial attachment of endothelial cells to artificial substrata and has an inhibitory effect on endothelial cell growth rate which correlates to the concentration of the chemical in the culture medium. These effects are related to a marked reduction of intra- and extracellular fibronectin as evidentiated by immunofluorescence. The drug seems to interfere with the formation of fibronectin filaments from intracellular granules. The reduction of fibronectin availability could affect platelet adhesion to subendothelium as well as endothelial cell repair, and subsequently influence the bleeding time. The inhibition of cell proliferation and its possible effect on the thickness of the vessel wall should be considered as additional mechanisms of action for this substance.