SAFETY UPDATE: Drug resistance emerging during therapy with dolutegravir and other integrase inhibitors

November, 2015 –At least three B.C. patients have developed new integrase resistance mutations affecting dolutegravir and/or raltegravir and elvitegravir which emerged during treatment with dolutegravir 50 mg daily plus abacavir-lamivudine. Two of the three patients also developed new resistance to lamivudine and abacavir. One patient was treatment naïve and two were treatment experienced. None had previously documented drug resistance. Two of these patients achieved virologic suppression followed by rebound, while one never achieved a viral load <40 c/mL. Drug resistance emerged within 8-12 months after starting the dolutegravir-based regimen. Incomplete medication adherence appeared to be a contributing factor.

For more information: Click here to download the BC-CfE Safety Alert (PDF)

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During the Canada Post strike announced September 25, 2025, the following measures will be undertaken to minimize service disruption to BC-CfE clients and providers.

  • The BC-CfE Laboratory has transitioned to private courier for delivery of outgoing reports and documents. Results required urgently can be faxed upon request. (Lab Contact Information: Phone 604-806-8775; FAX 604-806-9463)
  • The BC-CfE Drug Treatment Program (DTP) will fax outgoing forms and documents to the provider’s office. (DTP Contact Information: Phone 604-806-8515; FAX 604-806-9044)
  • St. Paul’s Hospital Ambulatory Pharmacy has transitioned to private courier for delivery of medications. We recommend requesting medication at least 2 weeks in advance in case of delivery delays, particularly to rural/remote parts of BC. (Contact Information: Phone 1-800-547-3622; FAX 604-806-8675)

During the Canada Post strike, we recommend that documents be faxed or couriered to our sites, versus utilization of regular mail service

The BC-CfE Laboratory is streamlining reporting processes for certain tests in order to simplify distribution and record-keeping, and to ensure completeness of results. Beginning September 2, 2025, results for the ‘Resistance Analysis of HIV-1 Protease and Reverse Transcriptase’ (Protease-RT) and ‘HIV-1 Integrase Resistance Genotype’ tests will be combined into a single ‘HIV-1 Resistance Genotype Report’.
For more details and example reports, please click on the button below