• Switching antiretroviral agents in a regimen may improve lipid profiles in patients with dyslipidemias. Most often, the protease inhibitor is switched with a non-nucleoside agent or with abacavir.1-7

• To date, the most experience has been with nevirapine.1, 2 In studies reported, viral rebound is uncommon with patients maintaining virologic control after the switch is made.

• There is conflicting data regarding the effectiveness of switching to efavirenz.3-5 Some studies show an improvement in lipid profiles, while others do not.

• At present, switching to abacavir appears promising. However, there is concern regarding early viral load rebound in some cases.6, 7

References:

1. Tebas P, Yarasheski K, Powderly WG, et al. A prospective open-label pilot trial of a maintenance nevirapine (NVP)-containing regimen in patients with undetectable viral loads (VL) on protease inhibitor (PI) regimens for at least 6 months. 7th Conference on Retroviruses and Opportunistic Infections, San Francisco, CA; Jan 30 - Feb 2, 2000. Abstract 45.

2. Martinez E, Conget I, Lozano L et al. Reversion of metabolic abnormalities after switching from HIV-1 protease inhibitors to nevirapine. AIDS. 1999;13:805-10.

3. Viciana P, Alarcon A, Martin D et al. Partial improvement of lipodystrophy after switching from HIV-1 protease inhibitors (PI) to efavirenz (EFV). 7th Conference on Retroviruses and Opportunistic Infections, San Francisco, CA; Jan 30 - Feb 2, 2000. Abstract 48.

4. Bonnet E, Lepec R, Bluteau M. Evaluation of lipodystrophy syndrome and lipid profile in HIV patients after switching from protease inhibitors to efavirenz. 7th Conference on Retroviruses and Opportunistic Infections, San Francisco, CA; Jan 30 - Feb 2, 2000. Abstract 49.

5. Martinez E, Blanco JL, Garcia MA et al. Impact of switching from HIV-1 protease inhibitors (PI) to efavirenz (EFV) in patients with lipodystrophy. 7th Conference on Retroviruses and Opportunistic Infections, San Francisco, CA; Jan 30 - Feb 2, 2000. Abstract 50.

6. Goebel FD, Walli RK. A novel use of abacavir to simplify therapy in PI-experienced patients successfully treated with HAART: CNA 30017. 7th Conference on Retroviruses and Opportunistic Infections, San Francisco, CA; Jan 30 - Feb 2, 2000. Abstract 51.

7. Rozenbaum W, Molina JM, Delfraissy JF et al. Improvement of lipodystrophy in HIV-1-infected subjects switching from 2 NRTI/PI to 2 NRTI/abacavir (French Substudy, CNA30017). 7th Conference on Retroviruses and Opportunistic Infections, San Francisco, CA; Jan 30 - Feb 2, 2000. Abstract 47.