Antiviral cross-restance chart

Cross-Resistance of Current HBV Drugs

Resistance to HBV antiviral drugs can limit which treatment options are
available in the future. If HBV is resistant to one drug, it will sometimes
be resistant to similar drugs in the same group. This is called
"cross-resistance" and it means that some anti-HBV drugs will not work even
though they have not used been used before.

If resistant to: Lamivudine
Then, will be resistant to these drugs:
Yes = Lamivudine
No = Adefovir
No = Tenofovir
Yes = Telbivudine
*Reduced = Entecavir


If resistant to: Adefovir
Then, will be resistant to these drugs:
No = Lamivudine
Yes = Adefovir
**Reduced = Tenofovir
No = Telbivudine
No = Entecavir


If resistant to: Telbivudine
Then, will be resistant to these drugs:
Yes = Lamivudine
No = Adefovir
No  = Tenofovir
Yes = Telbivudine
**Reduced = Entecavir


If resistant to: Entecavir
Then, will be resistant to these drugs:
Yes = Lamivudine
No = Adefovir
No = Tenofovir
Yes = Telbivudine
Yes = Entecavir


* Reduced ­ initially the drug-resistant virus is sensitive to entecavir,
but often the virus eventually becomes resistant to the drug.

** Reduced ­ in the lab, the virus is sensitive to the drug; clinically,
it¹s resistant (probably because of higher drug levels in humans).

Sources:
Locarnini S. Molecular virology and the development of resistant mutants:
implications for therapy. Semin Liver Dis. 2005;25 Suppl 1:9-19.
Fournier C. and Zoulim, F. Antiviral therapy of chronic hepatitis B:
prevention of drug resistance. Clin Liver Dis (2007) 869-892.

[cajim]

Very clear and helpful.  Thanks.

[zellyf]

Restance? Really? No.  RESISTANCE. Doh.

[NashPred]

LOL...I think we've all wished for an edit feature on these boards a time or two.
Lucky for all of us that we're not being graded on mis-spelled words.

[stevenNYer]

Awesome post.