This page has been archived on the Web

Information identified as archived is provided for reference, research or recordkeeping purposes. It is not subject to the Government of Canada Web Standards and has not been altered or updated since it was archived. Please contact us to request a format other than those available.

Health professional risk communication

New Safety Information Regarding the Co-Administration of Videx and Viread, and either Sustiva or Viramune – Bristol-Myers Squibb Canada and Gilead Sciences Inc. –- For Health Professionals

Starting date:
June 9, 2005
Posting date:
July 18, 2005
Type of communication:
Dear Healthcare Professional Letter
Subcategory:
Drugs
Source of recall:
Health Canada
Issue:
New safety information
Audience:
Healthcare Professionals
Identification number:
RA-170001260

This is duplicated text of a letter from Bristol-Myers Squibb Canada and Gilead Sciences, Inc..
Contact the company for a copy of any references, attachments or enclosures.

Notice about Health Canada advisories

 
[Text of letter begins]

Health Canada Endorsed Important Safety Information on the co-administration of Videx and Viread, and either Sustiva or Viramune

Bristol-Myers Squibb Canada

June 9, 2005

Subject: New safety information regarding the co-administration of Videx and Viread, and either Sustiva or Viramune

Dear Health Care Professional,

Bristol-Myers Squibb Canada & Gilead Sciences, Inc. are writing to inform you of important new clinical data regarding the co-administration of Videx EC (didanosine delayed-release capsules enteric-coated beadlets [ddI EC]), Viread (tenofovir disoproxil fumarate [TDF]), and either Sustiva (efavirenz [EFV]) or Viramune (nevirapine [NVP]).

Co-administering tenofovir DF and didanosine should be undertaken with caution, and patients should be carefully monitored for efficacy and for didanosine-related adverse events. Didanosine should be discontinued in patients who develop didanosine-related adverse events.

  • Reports from recent, investigator-sponsored trials have indicated a potential for a high rate of virological failure and emergence of resistance associated with the co-administration of didanosine and tenofovir DF with a non-nucleoside reverse transcriptase inhibitor (NNRTI) in antiretroviral treatment-naive HIV-infected adults with high baseline viral loads and low CD4 cell countsFootnote 1 Footnote 2 Footnote 3.
  • Such early virologic failure appears to be limited to the specific combination of didanosine and tenofovir DF with either efavirenz or nevirapine as there are data from large scale trials supporting the efficacy of tenofovir DF and efavirenz-based regimens as well as didanosine and efavirenz-based regimens in treatment-naive HIV patientsFootnote 4 Footnote 5 Footnote 6 Footnote 7.
  • Pharmacokinetic studies have shown that co-administration of didanosine and tenofovir DF results in 40-60% increase in systemic exposure to didanosine. Increases in didanosine concentration of this magnitude could potentiate didanosine-associated adverse events, including pancreatitis, lactic acidosis and neuropathy. The Product Monographs for Videx EC and Viread have been revised to include a recommendation to reduce the dose of Videx EC when co-administered with Viread and to carefully monitor patients for efficacy and didanosine-related adverse events. The recommended dose of didanosine EC is 250 mg for HIV-infected adults with body weight ≥60 kg and creatinine clearance ≥60 mL/min when co-administered with 300 mg tenofovir DF. For patients <60 200 kg, and creatinine clearance ≥60 mL min, a reduced dose of mg didanosine EC is recommended. Data are not available to recommend adjustment the buffered tablet formulation (Videx).< li>

The identification, characterization, and management of marketed health product-related adverse reactions are dependent on the active participation of health care professionals in adverse reaction reporting programmes. Any occurrences of a serious and/or unexpected adverse reaction in patients receiving Videx and Viread, and either Sustiva or Viramune should be reported to Bristol-Myers Squibb Canada and Gilead Sciences, Inc. or Health Canada at the following addresses:

For medical inquiries regarding VIDEX, contact:
Bristol-Myers Squibb Canada
Medical Services
Call toll free at: 1-800-267-1088
or Fax at: 1-888-267-6211

and

For medical inquiries regarding VIREAD, contact:
Gilead Sciences, Inc
Gilead Medical Information
Call toll free at: 1-800-GILEAD-5
1-800-445-3235

Any suspected adverse reaction can also be reported to:
Canadian Adverse Drug Reaction Monitoring Program (CADRMP)
Marketed Health Products Directorate
HEALTH CANADA
Address Locator: 0701C
OTTAWA, Ontario, K1A 0K9
Tel: (613) 957-0337 or Fax: (613) 957-0335
To report an Adverse Reaction, consumers and health professionals may call toll free:
Tel: 866 234-2345
Fax: 866 678-6789
Email: cadrmp@hc-sc.gc.ca

For other inquiries, please refer to contact information:
Bureau of Gastroenterology, Infection and Viral Diseases (BGIVD)
Email: bgivd_enquiries@hc-sc.gc.ca
Telephone: (613) 941-3207
Fax: (613) 941-1183

The AR Reporting Form and the AR Guidelines can be found on the Health Canada web site or in The Canadian Compendium of Pharmaceuticals and Specialties.

original signed by

A.Tom Koutsavlis, MD, MSc, CSPQ, FRCPC
Director
Medical Affairs

original signed by

Jay Toole, MD, Ph.D.
Senior Vice President
Clinical Research

[Text of letter ends]
 

Footnotes

Footnote 1

Podzamczer D, Ferrer E, Gatell JM, Niubo J, Dalmau D, Knobel H, Polo C, Iniguez D, Ruiz I. Early virologic failure with a combination of tenofovir, didanosine and efavirenz. Antiviral Therapy 2005,10:171-177.

Return to footnote 1 referrer

Footnote 2

Moyle G, Maitland D, Hand J, Mandalia S, Nelson M, Gazzard B. Early virologic failure in persons with viral loads >100000 cps/mL and CD4 counts <200 12 30 2004 mm3 receiving didanosine tenofovir efavirenz as initial therapy: week results from a randomized comparative trial [poster]. 44th Interscience Conference on Antimicrobial Agents and Chemotherapy; October - November 2; Washington, D.C., U.S.A. Poster H-566.< p>

Return to footnote 2 referrer

Footnote 3

Leon A, Martinez E, Malloloas J, Laguno M, Blanco JL, Fumarola T, Gatell JM. Early virological failure in treatment-naive HIV-infected adults receiving didanosine and tenofovir plus efavirenz or nevirapine. AIDS 2005,19(2):213-215,

Return to footnote 3 referrer

Footnote 4

Viread (tenofovir disoproxil fumarate) Canadian Product Monograph.

Return to footnote 4 referrer

Footnote 5

Emtriva (emtricitabine) US Product Information.

Return to footnote 5 referrer

Footnote 6

Saag M, Cahn P, Raffi F et al. Efficacy and safety of emtricitabine vs stavudine in combination therapy in antiretroviral-naive patients: a randomized trial. JAMA 2004,292:180-189.

Return to footnote 6 referrer

Footnote 7

Perez-Elias, MJ et al. High virological failure rate in HIV patients after switching to a regimen with two nucleoside reverse transcriptase inhibitors plus tenofovir. AIDS 2005,19(7):695-698.

Return to footnote 7 referrer

Footnote 8

Videx EC (didanosine) US Package Insert - January 2004.

Return to footnote 8 referrer