Adefovir

What is Adefovir?

• Adefovir (Hepsera) is an acyclic nucleotide analogue of adenosine used either alone or in combination with other agents as therapy of chronic hepatitis B.

Adefovir

Adefovir dipivoxil structure

What are the uses of this medicine?

• Adefovir (Hepsera) is a medicine used to treat patients at least 12 years of age with continuing (chronic) infections with active hepatitis B virus.

Limitations of use:

• Hepsera has not been studied in adults over the age of 65 and is not recommended for use in children less than 12 years of age.
• Hepsera will not cure your chronic hepatitis B.
• Hepsera may help lower the amount of hepatitis B virus in your body.
• Hepsera may lower the ability of the virus to multiply and infect new liver cells.
• We do not know if Hepsera will reduce your chances of getting liver cancer or liver damage (cirrhosis) from chronic hepatitis B.
• We do not know how long Hepsera may help your hepatitis. Sometimes viruses change in your body and medicines no longer work. This is called drug resistance.
• Hepsera does not stop you from spreading hepatitis B virus to others by sex or sharing needles. So practice safe sex and needle use.

How does this medicine work?

• Adefovir dipivoxil (bis-pom PMEA) is an acyclic nucleotide analog and prodrug of adefovir (a def' oh vir).
• The dipivoxil moiety is hydrolyzed after absorption, and adefovir is phosphorylated intracellularly to its active form, adefovir triphosphate, which competes with deoxyadenosine triphosphate for incorporation into the growing HBV DNA strand, causing inhibition of the viral DNA polymerase and chain termination.
• Adefovir is indicated for the treatment of chronic hepatitis B as a single agent and with lamivudine for lamivudine-resistant HBV infection.

Who Should Not Use this medicine ?

This medicine cannot be used in patients who:

• are allergic to any of the ingredients in Hepsera.
• are already taking VIREAD, TRUVADA or ATRIPLA.

What drug interactions can this medicine cause?

• Tell your doctor and pharmacist what prescription and nonprescription medications, vitamins, nutritional supplements, and herbal products you are taking or plan to take.

Be sure to mention any of the following:

• aminoglycoside antibiotics such as amikacin, gentamicin, kanamycin, neomycin, streptomycin, and tobramycin (Tobi,)
• aspirin and other nonsteroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen (Advil, Motrin) and naproxen (Aleve, Naprosyn)
• cyclosporine (Gengraf, Neoral, Sandimmune)
• tacrolimus (Prograf)
• vancomycin
• lamivudine (Combivir, Epivir, Epivir-HBV, Epzicom, Triumeq, or Trizivir) or tenofovir (Viread, in Atripla, in Complera, in Stribild, in Truvada)

Is this medicine FDA approved?

• Adefovir was approved by the FDA in 2002 as therapy for hepatitis B.

How should this medicine be used?

Recommended dosage:

• The recommended dose of Hepsera in chronic hepatitis B patients for patients ≥12 years of age with adequate renal function is 10 mg, once daily, taken orally, without regard to food.

Dose Adjustment in Renal Impairment: Creatinine Clearance (mL/min):

• ≥50:10 mg every 24 hours
• 30–49: 10 mg every 48 hours
• 10–29:10 mg every 72 hours
• Hemodialysis Patients:10 mg every 7 days following dialysis

No dose recommendations for:

• Non-hemodialysis patients with creatinine clearance <10mL/min.
• Adolescent patients with renal impairment.

Administration:

• Adefovir comes as a tablet to take by mouth.
• It is usually taken once a day with or without food.
• Take adefovir at around the same time every day.

What are the dosage forms and brand names of this medicine?

This medicine is available in fallowing doasage form:

• As Tablets: 10 mg

This medicine is available in fallowing brand namesː

• Hepsera

What side effects can this medication cause?

The most common side effects of this medicine include:

• weakness, headache, stomach pain, nausea, flatulence (intestinal gas), diarrhea, indigestion and changes in the way the kidneys work.

• Additional side effects in liver transplant patients with chronic hepatitis B are vomiting, rash and itching. Some patients with liver transplants also had undesirable effects on their kidneys, including failure of the kidneys.

Other side effects reported since Hepsera may include:

• kidney failure, damage to kidney cells, muscle pain or weakness and weakening of the bone, which could cause them to break (both associated with kidney problems), and inflammation of the pancreas.

Hepsera can cause the following serious side effects:

• very serious hepatitis
• nephrotoxicity
• Hepsera may increase the chances your HIV infection
• lactic acidosis

What special precautions should I follow?

• Severe acute exacerbation of hepatitis has been reported in patients who have discontinued anti-hepatitis B therapy, including therapy with Hepsera. Monitor hepatic function closely at repeated intervals for at least several months in patients who discontinue Hepsera.
• Nephrotoxicity characterized by a delayed onset of gradual increases in serum creatinine and decreases in serum phosphorus was historically shown. Monitor renal function during therapy for all patients, particularly those with pre-existing or other risks for renal impairment. Dose adjustment may be required.
• Offer HIV testing to all patients prior to initiating Hepsera. Untreated HIV may result in HIV resistance.
• Lactic acidosis and severe hepatomegaly with steatosis, including fatal cases, have been reported with the use of nucleoside analogs alone or in combination with antiretrovirals. If suspected, suspend treatment.
• Hepsera should not be used concurrently with VIREAD (tenofovir disoproxil fumarate) or tenofovir disoproxil fumarate-containing products including TRUVADA (emtricitabine/tenofovir disoproxil fumarate combination tablet) and ATRIPLA (efavirenz/emtricitabine/tenofivir disoproxil fumarate combination tablet). Do not administer Hepsera concurrently with VIREAD or other tenofovir-containing products.
• For patients with lamivudine-resistant HBV use adefovir dipivoxil in combination with lamivudine. For all patients, consider modifying treatment in case serum HBV DNA remains above 1000 copies/mL with continued treatment.
• Adefovir does not appear to be a significant cause of drug induced liver injury, but initiation of therapy and sudden withdrawal of therapy can induce a transient exacerbation of the underlying hepatitis B.

What to do in case of emergency/overdose?

Symptoms of overdosage may include:

• gastrointestinal side effects such upset stomach,stomach discomfort.

Treatment of overdosage:

• If overdose occurs the patient must be monitored for evidence of toxicity, and standard supportive treatment applied as necessary.
• Following a 10 mg single dose of Hepsera, a four-hour hemodialysis session removed approximately 35% of the adefovir dose.

Can this medicine be used in pregnancy?

• Pregnancy Category C.
• There are no adequate and well-controlled studies of Hepsera in pregnant women.
• Hepsera should be used during pregnancy only if clearly needed and after careful consideration of the risks and benefits.

Can this medicine be used in children?

• Hepsera is not recommended for use in children below 12 years of age.

What are the active and inactive ingredients in this medicine?

• Active Ingredient: adefovir dipivoxil
• Inactive Ingredients: croscarmellose sodium, lactose monohydrate, magnesium stearate, pregelatinized starch, and talc

Who manufactures and distributes this medicine?

Manufactured for:

• Gilead Sciences, Inc.
• Foster City, CA

What should I know about storage and disposal of this medication?

• Store in original container at 25 °C (77 °F), excursions permitted to 15–30 °C (59–86 °F).
• Do not use if seal over bottle opening is broken or missing.

Antiviral agents

Drugs for HIV Infection, in the Subclass Antiretroviral Agents

• Fusion Inhibitors (HIV)
  • Enfuvirtide, Maraviroc

• Integrase Inhibitors (HIV)
  • Dolutegravir, Elvitegravir, Raltegravir

• Monoclonal Antibodies
  • Ibalizumab

• Nonnucleoside Reverse Transcriptase Inhibitors (HIV)
  • Delavirdine, Efavirenz, Etravirine, Nevirapine, Rilpivirine

• Nucleoside Analogues (HIV)
  • Abacavir, Didanosine, Emtricitabine, Lamivudine, Stavudine, Tenofovir, Zidovudine

• Protease Inhibitors (HIV)
  • Amprenavir, Atazanavir, Darunavir, Fosamprenavir, Indinavir, Lopinavir, Nelfinavir,Ritonavir, Saquinavir, Tipranavir

Drugs for Hepatitis B

• • Alpha Interferon, Adefovir, Emtricitabine, Entecavir, Lamivudine, Telbivudine, Tenofovir

Drugs for Hepatitis C

• Interferon Based Therapies
  • Alpha Interferon and Peginterferon, Ribavirin

HCV NS5A Inhibitors

• Daclatasvir, Elbasvir, Ledipasvir, Ombitasvir, Pibrentasvir, Velpatasvir

HCV NS5B (Polymerase) Inhibitors

• Dasabuvir, Sofosbuvir

HCV Protease Inhibitors

• Asunaprevir, Boceprevir, Glecaprevir, Grazoprevir, Paritaprevir, Simeprevir, Telaprevir, Voxilaprevir

Combination Therapies

• Epclusa, Harvoni, Mavyret, Technive, Viekira Pak, Vosevi, Zepatier

Drugs for Herpes Virus Infections (HSV, CMV, others)

• Acyclovir, Cidofovir, Famciclovir, Foscarnet, Ganciclovir, Valacyclovir, Valganciclovir

Drugs for Influenza

• Amantadine, Oseltamivir, Peramivir, Rimantadine, Zanamivir

• Dailymed label info on Adefovir
• FDA Adefovir

Adefovir Resources
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