Andre Charest - Academia.edu (original) (raw)

Papers by Andre Charest

Research paper thumbnail of Anticoagulant Use in Patients with Chronic Renal Impairment

American Journal of Cardiovascular Drugs, 2005

Patients with renal failure have an increased risk of both thrombotic and bleeding complications.... more Patients with renal failure have an increased risk of both thrombotic and bleeding complications. A number of antithrombotic drugs undergo renal clearance. Therefore, estimation of renal function is necessary when prescribing these drugs to patients with renal dysfunction. Pharmacokinetic and clinical data in patients with chronic renal impairment are limited for several anticoagulants, and adequate administration information is often absent. Dose adjustment of anticoagulants may be indicated when the creatinine clearance falls below 30 mL/min. Unfractionated heparin, argatroban, and vitamin K antagonists generally do not require dose adjustment with renal dysfunction. However, smaller doses of warfarin may be required to achieve a particular target international normalized ratio. Close monitoring of anticoagulation is recommended when argatroban or high doses of unfractionated heparin are administered in patients with severe chronic renal impairment. Low-molecular weight heparins, danaparoid sodium, hirudins, and bivalirudin all undergo renal clearance. Lower doses and closer anticoagulation monitoring may be advisable when these agents are used in patients with chronic renal failure. We recommend that fondaparinux sodium and ximelagatran (not yet licensed) be avoided in the presence of severe renal impairment and be used with caution in patients with moderate renal dysfunction. While acknowledging the lack of pharmacokinetic data, this review provides specific recommendations for the use of anticoagulants in patients with chronic renal impairment.

Research paper thumbnail of Disorders of Water, Sodium, and Potassium Homeostasis

Clinical Critical Care Medicine, 2006

Research paper thumbnail of A randomized comparison of intradermal and intramuscular vaccination against hepatitis B virus in incident chronic hemodialysis patients

American Journal of Kidney Diseases, 2000

• Hepatitis B virus (HBV) remains a threat to hemodialysis patients. Nevertheless, the vaccinatio... more • Hepatitis B virus (HBV) remains a threat to hemodialysis patients. Nevertheless, the vaccination rate against this virus is low, perhaps because of the low conversion rate. Although intradermal (ID) vaccination has been proven to be effective (even in patients nonresponsive to intramuscular [IM] vaccination), the duration of immunity was short. The impact of vaccination route and a greater peak antibody (Ab) titer on conversion rate and duration of immunity after ID or IM vaccination was compared in incident hemodialysis patients. Forty-nine patients were randomly assigned to treatment with 5 g of recombinant hepatitis B vaccine (Engerix B; Smith Kline Beecham Pharma Inc, Oakville, ON, Canada) ID every 2 weeks up to either a peak Ab titer of 1,000 IU/L or greater or 52 doses, whereas 48 patients were administered 40 g IM at 0, 1, 2, and 6 months. Group demographics were similar. Conversion was achieved in 97.6% of the ID group and 90.5% of the IM group (P ‫؍‬ 0.16). There was no difference between ID and IM groups in time required to convert, peak Ab titer reached, and proportion of patients with a peak Ab titer of 1,000 IU/L or greater. Overall, the duration of immunity was not different after ID or IM vaccination (P ‫؍‬ 0.683), and patients in the IM group with a peak Ab titer of 1,000 IU/L or greater had a longer duration of immunity (P ‫؍‬ 0.001). In conclusion, a high conversion rate and long duration of immunity against HBV can be achieved cost-effectively in the end-stage renal disease population using the ID or IM route and aiming for an Ab titer exceeding 1,000 IU/L. Based on these data, we provide recommendations for vaccination and surveillance in this population.

Research paper thumbnail of Defining conditions that lead to the retention of water: the importance of the arterial sodium concentration

Kidney …, 2005

Kidney International aims to inform the renal researcher and practicing nephrologists on all aspe... more Kidney International aims to inform the renal researcher and practicing nephrologists on all aspects of renal research. Clinical and basic renal research, commentaries, The Renal Consult, Nephrology sans Frontieres, minireviews, reviews, Nephrology Images, Journal Club. Published ...

Research paper thumbnail of Are North American Nephrologists Biased against Peritoneal Dialysis?

Peritoneal Dialysis International, 2001

Objective To examine possible bias against peritoneal dialysis (PD) by nephrologists less familia... more Objective To examine possible bias against peritoneal dialysis (PD) by nephrologists less familiar with it. Design Secondary analysis of a previously reported survey. Participants All practicing Canadian nephrologists (n = 290, response rate 66.2%) and a subgroup of American nephrologists who were members of the National Kidney Foundation Council on Dialysis (n = 507, response rate 47.3%). Responses were then subdivided by type of dialysis practice: mainly or only hemodialysis (HD, n = 117), mainly or only PD (n = 16), or both HD and PD (n = 232). Intervention Self-administered mailed questionnaire. Main Outcome Measures Opinions and attitudes of nephrologists concerning patient characteristics favoring one dialysis modality over the other, as well as the relative utilization of HD and PD currently and in a hypothetical ideal situation. Results The main differences were present between physicians practicing mainly HD and physicians practicing mainly PD, with those practicing both gi...

Research paper thumbnail of Evolution of naturally acquired hepatitis B immunity in the long-term hemodialysis population

Research paper thumbnail of Anticoagulant Use in Patients with Chronic Renal Impairment

American Journal of Cardiovascular Drugs, 2005

Patients with renal failure have an increased risk of both thrombotic and bleeding complications.... more Patients with renal failure have an increased risk of both thrombotic and bleeding complications. A number of antithrombotic drugs undergo renal clearance. Therefore, estimation of renal function is necessary when prescribing these drugs to patients with renal dysfunction. Pharmacokinetic and clinical data in patients with chronic renal impairment are limited for several anticoagulants, and adequate administration information is often absent. Dose adjustment of anticoagulants may be indicated when the creatinine clearance falls below 30 mL/min. Unfractionated heparin, argatroban, and vitamin K antagonists generally do not require dose adjustment with renal dysfunction. However, smaller doses of warfarin may be required to achieve a particular target international normalized ratio. Close monitoring of anticoagulation is recommended when argatroban or high doses of unfractionated heparin are administered in patients with severe chronic renal impairment. Low-molecular weight heparins, danaparoid sodium, hirudins, and bivalirudin all undergo renal clearance. Lower doses and closer anticoagulation monitoring may be advisable when these agents are used in patients with chronic renal failure. We recommend that fondaparinux sodium and ximelagatran (not yet licensed) be avoided in the presence of severe renal impairment and be used with caution in patients with moderate renal dysfunction. While acknowledging the lack of pharmacokinetic data, this review provides specific recommendations for the use of anticoagulants in patients with chronic renal impairment.

Research paper thumbnail of Disorders of Water, Sodium, and Potassium Homeostasis

Clinical Critical Care Medicine, 2006

Research paper thumbnail of A randomized comparison of intradermal and intramuscular vaccination against hepatitis B virus in incident chronic hemodialysis patients

American Journal of Kidney Diseases, 2000

• Hepatitis B virus (HBV) remains a threat to hemodialysis patients. Nevertheless, the vaccinatio... more • Hepatitis B virus (HBV) remains a threat to hemodialysis patients. Nevertheless, the vaccination rate against this virus is low, perhaps because of the low conversion rate. Although intradermal (ID) vaccination has been proven to be effective (even in patients nonresponsive to intramuscular [IM] vaccination), the duration of immunity was short. The impact of vaccination route and a greater peak antibody (Ab) titer on conversion rate and duration of immunity after ID or IM vaccination was compared in incident hemodialysis patients. Forty-nine patients were randomly assigned to treatment with 5 g of recombinant hepatitis B vaccine (Engerix B; Smith Kline Beecham Pharma Inc, Oakville, ON, Canada) ID every 2 weeks up to either a peak Ab titer of 1,000 IU/L or greater or 52 doses, whereas 48 patients were administered 40 g IM at 0, 1, 2, and 6 months. Group demographics were similar. Conversion was achieved in 97.6% of the ID group and 90.5% of the IM group (P ‫؍‬ 0.16). There was no difference between ID and IM groups in time required to convert, peak Ab titer reached, and proportion of patients with a peak Ab titer of 1,000 IU/L or greater. Overall, the duration of immunity was not different after ID or IM vaccination (P ‫؍‬ 0.683), and patients in the IM group with a peak Ab titer of 1,000 IU/L or greater had a longer duration of immunity (P ‫؍‬ 0.001). In conclusion, a high conversion rate and long duration of immunity against HBV can be achieved cost-effectively in the end-stage renal disease population using the ID or IM route and aiming for an Ab titer exceeding 1,000 IU/L. Based on these data, we provide recommendations for vaccination and surveillance in this population.

Research paper thumbnail of Defining conditions that lead to the retention of water: the importance of the arterial sodium concentration

Kidney …, 2005

Kidney International aims to inform the renal researcher and practicing nephrologists on all aspe... more Kidney International aims to inform the renal researcher and practicing nephrologists on all aspects of renal research. Clinical and basic renal research, commentaries, The Renal Consult, Nephrology sans Frontieres, minireviews, reviews, Nephrology Images, Journal Club. Published ...

Research paper thumbnail of Are North American Nephrologists Biased against Peritoneal Dialysis?

Peritoneal Dialysis International, 2001

Objective To examine possible bias against peritoneal dialysis (PD) by nephrologists less familia... more Objective To examine possible bias against peritoneal dialysis (PD) by nephrologists less familiar with it. Design Secondary analysis of a previously reported survey. Participants All practicing Canadian nephrologists (n = 290, response rate 66.2%) and a subgroup of American nephrologists who were members of the National Kidney Foundation Council on Dialysis (n = 507, response rate 47.3%). Responses were then subdivided by type of dialysis practice: mainly or only hemodialysis (HD, n = 117), mainly or only PD (n = 16), or both HD and PD (n = 232). Intervention Self-administered mailed questionnaire. Main Outcome Measures Opinions and attitudes of nephrologists concerning patient characteristics favoring one dialysis modality over the other, as well as the relative utilization of HD and PD currently and in a hypothetical ideal situation. Results The main differences were present between physicians practicing mainly HD and physicians practicing mainly PD, with those practicing both gi...

Research paper thumbnail of Evolution of naturally acquired hepatitis B immunity in the long-term hemodialysis population