Telbivudine

Pronunciation: tel-BIV-ue-deen
Class: Antiviral

Trade Names

Tyzeka
- Tablets, oral 600 mg
- Solution, oral 100 mg per 5 mL

Sebivo (Canada)

Pharmacology

Telbivudine is phosphorylated by cellular kinases to the active triphosphate form. The telbivudine 5′-triphosphate is incorporated into viral DNA, causing DNA chain termination that results in inhibition of hepatitis B virus (HBV) replication.

Slideshow: How A Little Blue Pill Changed The World

Pharmacokinetics

Absorption

C max is approximately 3.7 mcg/mL and occurs between 1 and 4 h. Steady state is achieved after approximately 5 to 7 days.

Distribution

Plasma protein binding is low (3.3%). Vd exceeds total body water, suggesting wide distribution into tissues.

Metabolism

Metabolites were not detected.

Elimination

Terminal half-life is 40 to 49 h. Elimination is primarily as unchanged drug in the urine.

Special Populations

Renal Function Impairment

Because renal excretion is the predominant route of elimination, dosage adjustment is recommended in patients with CrCl less than 50 mL/min.

Hepatic Function Impairment

No differences in pharmacokinetics based on hepatic impairment.

Elderly

Pharmacokinetic studies have not been conducted.

Children

Pharmacokinetic studies have not been conducted.

Gender

No differences in pharmacokinetics based on gender.

Race

No differences in pharmacokinetics based on race.

Indications and Usage

Treatment of chronic hepatitis B in adults with evidence of viral replication and either evidence of persistent elevations in serum aminotransaminases (ALT or AST) or histologically active disease.

Contraindications

Coadministration with pegylated interferon alfa-2a.

Dosage and Administration

Adults and Adolescents 16 y of age and older

PO 600 mg once daily.

Renal Function Impairment
Adults and Adolescents 16 y of age and older

PO

CrCl 30 to 49 mL/min Tablets

600 mg every 48 h.

Oral solution

400 mg (20 mL) daily.

CrCl less than 30 mL/min (not requiring dialysis) Tablets

600 mg every 72 h.

Oral solution

200 mg (10 mL) once daily.

ESRD Tablets

600 mg every 96 h. Administer after hemodialysis.

Oral solution

120 mg (6 mL) once daily.

General Advice

  • May be taken without regard to meals.

Storage/Stability

Store at 59° to 86°F. Use solution within 2 mo after opening. Do not freeze.

Drug Interactions

Drugs associated with myopathy (eg, azole antifungal agents [eg, ketoconazole], chloroquine, corticosteroids, cyclosporine, erythromycin, fibric acid derivatives [eg, gemfibrozil], HMG-CoA reductase inhibitors [eg, simvastatin], hydroxychloroquine, niacin, penicillamine, zidovudine)

Myopathy has been reported during postmarketing experience with telbivudine. It is unknown if the risk of myopathy increases with coadministration of telbivudine and other drugs associated with myopathy. Closely monitor patients for signs and symptoms of unexplained muscle pain, tenderness, or weakness if telbivudine is coadministered with another drug associated with myopathy. Interrupt telbivudine treatment if myopathy is suspected, and discontinue if confirmed.

Drugs that alter renal function (eg, cyclosporine, tacrolimus)

May alter telbivudine plasma concentrations. Monitor renal function and adjust the telbivudine dose as needed.

Interferons (eg, pegylated interferon alfa-2a)

Coadministration has been associated with an increased risk of peripheral neuropathy occurrence and severity. Coadministration with pegylated interferon alfa-2a is contraindicated. The risk of peripheral neuropathy when coadministered with other alfa interferons cannot be excluded. Therefore, closely monitor patients. Interrupt telbivudine treatment if peripheral neuropathy is suspected, and discontinue if confirmed.

Adverse Reactions

CNS

Fatigue (13%); headache (10%); dizziness (4%); insomnia (3%); hypoesthesia, paresthesia (postmarketing).

Dermatologic

Rash (4%); pruritus (2%).

GI

Diarrhea, upper abdominal pain (6%); nausea (5%); abdominal distension, abdominal pain, dyspepsia (3%).

Hematologic-Lymphatic

Neutropenia (2%).

Lab Tests

Elevated creatine kinase (79%); increased ALT (7%); increased AST (6%); increased lipase (2%).

Metabolic-Nutritional

Lactic acidosis (postmarketing).

Musculoskeletal

Arthralgia, back pain (4%); myalgia (3%); rhabdomyolysis (postmarketing).

Respiratory

Cough (6%); pharyngolaryngeal pain (5%).

Miscellaneous

Pyrexia (4%); hepatitis B exacerbation, neutropenia (2%).

Precautions

Warnings

Lactic acidosis and severe hepatomegaly with steatosis, including fatal cases, have been reported with use of nucleoside analogs alone or in combination with antiretrovirals. Severe acute exacerbations of hepatitis B have been reported in patients who have discontinued anti–hepatitis B therapy, including telbivudine.


Monitor

Monitor HBV DNA every 6 months to ensure continued response; institute alternate therapy for any patient who tests positive for HBV DNA at any time after their initial response. Closely monitor hepatic function with clinical and laboratory follow-up for at least several months in patients who discontinue anti–hepatitis B therapy. Monitor for signs and symptoms of unexplained muscle pain, tenderness, or weakness. Monitor renal function in elderly patients and patients taking drugs that may alter renal function.


Pregnancy

Category B .

Lactation

Undetermined.

Children

Safety and efficacy not established in children younger than 16 y of age.

Elderly

Use with caution, taking into consideration the greater frequency of decreased renal function due to concomitant diseases or other drug therapy.

Renal Function

Dose adjustment is recommended in patients with CrCl less than 50 mL/min.

Liver transplant patients

Safety and efficacy not established.

Myopathy

Cases of myopathy/myositis have been reported several weeks to months after starting therapy.

Peripheral neuropathy

Has been reported; the risk may be greater when coadministered with interferons. Interrupt therapy is peripheral neuropathy is suspected; discontinue therapy if peripheral neuropathy is confirmed.

Overdosage

Symptoms

No adverse reactions were noted with dosages of up to 1,800 mg/day for 4 days.

Patient Information

  • Advise patients to read the Medication Guide before using product the first time and with each refill.
  • Advise patients to promptly report unexplained muscle weakness, tenderness, pain, burning sensations, or numbness and/or tingling in the arms and/or legs.
  • Explain to patients that telbivudine is not a cure for hepatitis B and that the long-term benefits and relationship of initial treatment response to outcome are unknown.
  • Inform patients that deterioration of liver disease may occur in some cases if treatment is discontinued, and to discuss any change in regimen with a health care provider.
  • Inform patients that treatment has not been shown to reduce HBV transmission through sexual contact.
  • Advise patients on a low-sodium diet that telbivudine solution contains approximately 47 mg of sodium per 600 mg (30 mL) dose.

Copyright © 2009 Wolters Kluwer Health.

Hide
(web3)