Tyzeka


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telbivudine

(tel-bi-vu-deen) ,

Sebivo

(trade name),

Tyzeka

(trade name)

Classification

Therapeutic: antivirals
Pharmacologic: nucleoside analogues
Pregnancy Category: B

Indications

Management of chronic hepatitis B with evidence of currently active disease.

Action

Converted intracellularly to the triphosphate active metabolite which inhibits DNA polymerase by acting as a nucleoside analogue. Result is inhibition of viral replication.

Therapeutic effects

Decreased progression of chronic hepatitis B infection.

Pharmacokinetics

Absorption: Rapidly absorbed following oral administration; bioavailability unknown.
Distribution: Widely distributed into tissues.
Metabolism and Excretion: Excreted entirely as unchanged drug; no metabolism.
Half-life: Effective—15 hr; elimination half–life—40–49 hr.

Time/action profile (blood levels)

ROUTEONSETPEAKDURATION*
POunknown1–4 hr24 hr
*Patients with normal renal function.

Contraindications/Precautions

Contraindicated in: Hypersensitivity; Concurrent use of pegylated interferon alfa-2a Lactation: Lactation.
Use Cautiously in: Moderate to severe renal impairment (dosage modification recommended for CCr <50 mL/min); Discontinuation of medication (may result in exacerbation of hepatitis B); Geriatric: Consider age-related ↓ in renal function; Obstetric: Use only if maternal benefit outweighs fetal risk; Pediatric: Children <16 yr (safety not established).

Adverse Reactions/Side Effects

Cardiovascular

  • fatigue
  • headache

Gastrointestinal

  • hepatomegaly

Hematologic

  • neutropenia

Metabolic

  • lactic acidosis (life-threatening)

Musculoskeletal

  • myopathy

Neurologic

  • peripheral neuropathy

Miscellaneous

  • fever

Interactions

Drug-Drug interaction

↑ risk of peripheral neuropathy when used with pegylated interferon alfa-2a ; concurrent use contraindicated.Drugs that alter renal function may alter blood levels and effectiveness.

Route/Dosage

Oral (Adults and Children ≥16 yr) 600 mg daily.

Renal Impairment

Oral (Adults and Children ≥16 yr) CCr 30–49 mL/min—600 mg every 48 hr; CCr <30 mL/min (not on dialyis)—600 mg every 72 hr; End stage renal disease—600 mg every 96 hr.

Availability

Tablets: 600 mg

Nursing implications

Nursing assessment

  • Monitor signs of hepatitis (jaundice, fatigue, anorexia, pruritus) during therapy.
  • Assess for signs of myopathy (diffuse myalgias, muscle tenderness or muscle weakness with increases in creatine kinase). Interrupt therapy if myopathy is suspected and discontinue therapy if myopathy is diagnosed.
  • Lab Test Considerations: Monitor liver function tests during and for at least several months following discontinuation of therapy. May cause ↑ serum CPK, ALT, AST, lipase, amylase, and total bilirubin.
    • May cause neutropenia and thrombocytopenia.
    • Monitor HBV DNA every 6 mo to determine response to therapy.

Potential Nursing Diagnoses

Risk for infection (Indications)

Implementation

  • Oral: Administer without regard to food.

Patient/Family Teaching

  • Instruct patient to take telbivudine as directed and not to discontinue therapy without consulting health care professional. Severe acute exacerbations of hepatitis B have occurred when therapy was discontinued. Take missed doses as soon as remembered unless almost time for next dose; do not double doses. Advise patients to read the patient package insert prior to therapy and with each prescription refill.
  • Advise patient to notify health care professional promptly if signs of lactic acidosis (weakness or tiredness, unusual muscle pain, trouble breathing, nausea and vomiting, feeling cold, especially in arms or legs, dizziness, fast or irregular heart beat), hepatotoxicity (yellow skin or eyes, dark urine, light colored stools, lack or appetite, nausea, lower stomach pain) or myopathy (unexplained muscle aches, pain, tenderness or weakness) occur or if new symptoms occur.
  • Inform patient that telbivudine does not cure hepatitis B. Telbivudine does not reduce the risk of transmission of hepatitis B to others through sexual contact or blood contamination. Caution patient to use a condom during sexual contact and avoid sharing needles or donating blood to prevent spreading hepatitis B to others. Advise patient that the long-term effects of telbivudine are unknown.
  • Encourage pregnant female patients to register in the AntiRetroviral Pregnancy Registry at 1-800-258-4263 to monitor fetal outcomes. Advise patients not to breastfeed during therapy.

Evaluation/Desired Outcomes

  • Decreased progression of chronic hepatitis B infection. For patients with incomplete viral suppression (HBV DNA ≥300 copies/mL) after 24 wk of treatment, alternate therapy should be instituted. HBV DNA should be monitored every 6 mo to assure continued response. If patients test positive for HBV DNA at any time after their initial response, alternate treatment should be instituted.

Tyzeka

a trademark for telbivudine.
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References in periodicals archive ?
Tyzeka was studied in a year-long international clinical trial in 1,367 patients with chronic HBV.
Tyzeka is not a cure for hepatitis B, and tong-term treatment benefits of this drug are not known.
In clinical studies Tyzeka was generally well tolerated, and most reported adverse events were mild to moderate.