Module 3: Hepatitis Agents

what is the benefit of Interferon therapy?

Highest likelihood of loss of HBsAg

How long for interferon trx?

48 weeks

• vs lifelong with nucleotide analogs

How frequently is interferon used?

every week

• take the same time each week

• take within 2 days of missed dose

How often Nucleotide Analogs get administered?

once daily

can we stop NA if the viral load is low?

No, the risk of rebound hepatitis upon discontinuation

• liver goes haywire

  → better to taper off or switch to another drug

what else besides liver, renal and GI effect should we monitor for pt on NA?

baseline bone mineral density if fracture or osteoprosis

• these meds can cause osteopenia

(bone and kidneys) → usually need dose adjustment

Which meds should we be cautious when co-administer with NA?

Nephrotoxic drugs

What are first-line therapy of NA?

Tenofovir (TDF and TAF)

Entecavir

• due to its low resistance rate

can TAF be taken w/out food?

No, need to take with food

Can TAF use for decompensated liver disease

No, only for compen.

TAF canNOT be used for pt with ESRD aka CrCl < 15 ml/min?

Yes

TDF converted to TFV in the lymphoid cell?

No, that’s with TAF

• TDF → TFV in plasma: hypothetically, this is attributed to kidney and bone toxicity

The dose of Entecavir is different b/w pt who nucleoside naive vs those with lamivudine resistance?

Yes

• naive: 0.5 mg PO QD

• resist: 1g PO QD

what is the upside of Entecavir over Tenefovir?

better tolerability profile

• some HA, fatigue, dizziness

What is the dose of Lamivudine for HIV/HBV infection?

• 150 mg BID vs 100mg QD for HBV only

• Structurally similar to Emtricitabine

  • Emtri: NOT FDA-approved for HBV

→ both Lami and Emtri are generally well-tolerated

→ not a big concern for renal toxicity

Tenofovir is usually formulated with Emtricitabine?

Yes, they are packed in the same pill → 2 active agents for HBV

-previr is suffix of which drug class?

Protease inhibitor

-buvir is replication complex inhi. ?

NO

→ -buvir is polymerase inhibitor

How long we typically treat HCV?

12-24 weeks

What are some common DDI with HCV agents?

1/Acid-reducing agents

2/ Amiodarone

3/ Pgp inducers

4/-statin (Rosuvastatin)

5/TDF - nephrotoxicity

What are some Pgp inducers?

rifampin

carbamazepine

phenytoin

St John Wort

Sofosbuvir with Ledipasvir or Velpatasvir are considered SAFE with HIV concomitant therapy?

YES

• but Sofo/Velpat$/Voxil$ = Caution with co-administration with HIV therapy

which genotype we canNOT use Sofo/Ledipa

2 and 3

Sofo/Velpat is taken with what med for DECOMPENSATED cirrhotics?

Ribavirin

Which HIV med should be avoid if pt is taking Sofo/Velpat

Efavirenz

can we use Sofo/Velpat/Voxila in DECOMPENSATED pt?

NO, only for compensated cirrhotics

• Need to monitor digoxin level along with other DDI (acid-reducing, -statin, TDF)

how long should Elbasvir/Grazoprevir should be used?

12-16 weeks

• Genotype 1a - add Ribavirin and treat for 16 weeks

do we need RENAL ADJ for Elba/Grazo?

NO

• also: d/c HIV agents while on this

besides TDF, which HBV meds does Elba/Grazo interact with and should be avoided taking together?

Emtricitabine

what is important CP if pt is taking Glecaprevir/Pibrentasvir?

need to take with food

• use with caution with concomitant HIV therapy

how long should we treat pt who are therapy naive with Gleca/Pibren

8 weeks (NOT 12 weeks as usual)

which one unique med we need to avoid taking together with Gleca/Pibren?

Ethinyl-estradiol oral BC (spiked LFTs)

which one unique med we need to MONITOR while pt is taking Gleca/Pibren?

Dabigatran

• think about the heart

  • avoid Digoxin and 2 statin (Prava and Rosu)

What is the benefits of adding Ribavirin into HCV regimen?

to give boost to achieve SVR

Ribavirin is fixed dosing or weight-based doing?

Weight-based

• cut-off value is 75 kg

  • < 75 kg: 1000mg QD in divided dose (higher dose in the AM)

  • 75 kg: 1200 mg QD in divided dose

What important CP when pt’s on Ribavirin?

1. Pregnancy test monthly: during and 6mo after taking the med

• women: avoid preg; men: avoid any sexual contact

• risk of teratogenicity

2. Take with food to minimize diarrhea

will Ribavirin interact with other ANEMIA-containing drugs?

Yes

• be cautious when pt undergo chemo or take other anemic meds