1. 1 Adherence to ARV Therapy and Resistance HAIVN Havard Medical School AIDS Initiative in Vietnam

2. 2 By the end of this session, participants will be able to: Present the importance of good adherence to ARV therapy List the 5 main reasons leading to non adherence Describe 3 types of adherence Explain the relationship between adherence and drug resistance Learning Objectives

3. 3 Adherence

4. 4 Adherence means taking right drugs, in proper dose and on time To achieve the best effect with ARV therapy, adherence rate is required to be above 95% Example: If medications are prescribed 2 times a day, don’t forget more than 2 doses a month. Definition

5. Common types of adherence Howard AIDS 2002; Ickovics Antiviral Ther 2002; Moss CID 2004 Adherence Treatment time (month) 100% 0% 0 1224 Three types of patient’s adherence Very good adherence Reduced adherence Non adherence

6. 6 Any activity: support, or help to improve the health of people with HIV / AIDS pay attention to the care and treatment of people with HIV, including: Physical health status Mental, psychosocial well-being Extended definition of adherence

7. 7 Maximal inhibition of viral load Reduce drug resistance Ensure effect time of drug All above helps: Slow progression of HIV Prolong survival Goals of adherence to ARV drugs

8. 8 Drug resistance

9. Improve physical health No more opportunistic infections Clinical status CD4 count increases: At least from 50-150 cells in the first year Increase 50-100 cells in the second year Immunology* Viral load is undetectable after 12 months Virology Adherence: Definition Adherence : according to Kaufman and Le Moing, WHO

10. 10 Patients who do not improve on clinical immunologic and viral outcome after starting ART therapy are considered not to respond to treatment Non adherence: Definition

11. 11 Resistance leads to the failure of ARV therapy Intolerance with ARV drugs aggravates the disease Drug interactions causes ARV levels below the threshold of viral suppression Non adherence: Causes

12. Drug level below the threshold of viral suppression Viral replication continues with the presence of drugs DRUG RESISTANCE Drug resistance Drug resistance is often, but not always due to non adherence

13. How does HIV drug resistance occur? Resistant virus Social/ personal issues Regimen issue Toxicity Poor quality drugs Wrong dose Host genetics Poor absorption Rapid clearance Poor activation Drug interaction Transmission Poor adherence Insufficient drug level Viral replication in the presence of drug

14. 14 HIV has an extremely high rate of replication The new generation of virus is little different from the previous generation Some structural changes can improve the ability of viral replication When virus can multiply in the presence of ARV drugs, it can be said that virus is resistant to drugs How does HIV develop resistance?

15. 15 Level of drugs below the threshold of treatment Wild-type virus Resistant virus Effect of non adherence to the development of viral mutations

16. The relationship between the level of adherence and the risk of drug resistance Williams & Fiedland, 1997 Risk of drug resistance % Adherence 0100

17. 17 Some comments: 50% of people living with HIV (not taking into account the current status of treatment) there is evidence for at least one drug resistance 78% of people who have HIV treatment are resistant to at least one antiviral drug Resistant HIV CROSS-RESISTANCE: Resistance to a drug in a group often leads to resistance to another drug in that group!

18. 18 Drug resistant HIV can transmit: to new HIV infections as well as to co-infections Risk of transmission

19. 19 ARV therapy failure is often, but not always, due to drug resistance Failure of ARV therapy is expressed by: Increased viral load Reduced CD4 count + T cells Progression to AIDS ARV therapy failure

20. 20 Good adherence will reduce the risk of the development of ARV resistance Drug resistance is a major problem For individuals For society Why is adherence mentioned?

21. 21 Good adherence to ARV therapy is necessary but very difficult Non adherence results in low drug concentration in the blood and allows the development of drug resistant HIV ARV resistance leads to treatment failure Transmission of drug-resistant virus from one person to another occurs and is a public health problem Key points

22. 22 Thank you Question?