Famciclovir

Generic Name: famciclovir

Herpes Simplex Virus Nucleoside Analog DNA Polymerase Inhibitor [EPC]Over-the-Counter (OTC)

Brand Names:

Famciclovir

11 DESCRIPTION Famciclovir Tablets contain famciclovir, USP, an orally administered prodrug of the antiviral agent penciclovir. Chemically, famciclovir, USP is known as 2-[2-(2-amino-9 H -purin-9-yl)ethyl]-1,3-propanediol diacetate. It is a synthetic acyclic guanine derivative and has the following structure: C 14 H 19 N 5 O 4 M.W. 321.3 Famciclovir, USP is a white to pale yellow solid. It is freely soluble in acetone and methanol, and sparingly soluble in ethanol and isopropanol.

Overview

11 DESCRIPTION Famciclovir Tablets contain famciclovir, USP, an orally administered prodrug of the antiviral agent penciclovir. Chemically, famciclovir, USP is known as 2-[2-(2-amino-9 H -purin-9-yl)ethyl]-1,3-propanediol diacetate. It is a synthetic acyclic guanine derivative and has the following structure: C 14 H 19 N 5 O 4 M.W. 321.3 Famciclovir, USP is a white to pale yellow solid. It is freely soluble in acetone and methanol, and sparingly soluble in ethanol and isopropanol.

Uses

1 INDICATIONS AND USAGE Famciclovir tablets, a prodrug of penciclovir, are a deoxynucleoside analog DNA polymerase inhibitor indicated for: Immunocompetent Adult Patients ( 1.1 ) Herpes labialis (cold sores) Treatment of recurrent episodes Genital herpes Treatment of recurrent episodes Suppressive therapy of recurrent episodes Herpes zoster (shingles) Human Immunodeficiency Virus (HIV) -Infected Adult Patients ( 1.2 ) Treatment of recurrent episodes of orolabial or genital herpes Limitation of Use The efficacy and safety of famciclovir tablets have not been established for: Patients with first episode of genital herpes Patients with ophthalmic zoster Immunocompromised patients other than for the treatment of recurrent episodes of orolabial or genital herpes in HIV-infected patients Black a...

Dosage

2 DOSAGE AND ADMINISTRATION Famciclovir tablets may be taken with or without food. Immunocompetent Adult Patients ( 2.1 ) Herpes labialis (cold sores) 1500 mg as a single dose Genital herpes Treatment of recurrent episodes 1000 mg twice daily for 1 day Suppressive therapy 250 mg twice daily Herpes zoster (shingles) 500 mg every 8 hours for 7 days HIV-Infected Adult Patients ( 2.2 ) Recurrent episodes of orolabial or genital herpes 500 mg twice daily for 7 days Patients with renal impairment: Adjust dose based on creatinine clearance. ( 2.3 ) 2.1 Dosing Recommendation in Immunocompetent Adult Patients Herpes labialis (cold sores): The recommended dosage of famciclovir tablets for the treatment of recurrent herpes labialis is 1500 mg as a single dose.

Side Effects

6 ADVERSE REACTIONS Acute renal failure is discussed in greater detail in other sections of the label [see Warnings and Precautions ( 5 ) ] . The most common adverse events reported in at least 1 indication by greater than 10% of adult patients treated with famciclovir are headache and nausea. The most common adverse events reported in at least 1 indication by greater than 10% of adult patients are headache and nausea. ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact AvKARE at 1-855-361-3993 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch.

Interactions

7 DRUG INTERACTIONS Probenecid: May increase penciclovir levels. Monitor for evidence of penciclovir toxicity. ( 7.2 ) 7.1 Potential for Famciclovir to Affect Other Drugs The steady-state pharmacokinetics of digoxin were not altered by concomitant administration of multiple doses of famciclovir (500 mg three times daily). No clinically significant effect on the pharmacokinetics of zidovudine, its metabolite zidovudine glucuronide, or emtricitabine was observed following a single oral dose of 500 mg famciclovir coadministered with zidovudine or emtricitabine. An in vitro study using human liver microsomes suggests that famciclovir is not an inhibitor of CYP3A4 enzymes.

Warnings

5 WARNINGS AND PRECAUTIONS Acute renal failure: May occur in patients with underlying renal disease who receive higher than recommended doses of famciclovir for their level of renal function. Reduce dosage in patients with renal impairment. ( 2.3 , 8.6 ) 5.1 Acute Renal Failure Cases of acute renal failure have been reported in patients with underlying renal disease who have received inappropriately high doses of famciclovir for their level of renal function. Dosage reduction is recommended when administering famciclovir to patients with renal impairment [see Dosage and Administration ( 2.3 ), Use in Specific Populations ( 8.6 ) ] . 4 CONTRAINDICATIONS Famciclovir is contraindicated in patients with known hypersensitivity to the product, its components, or Denavir ® (penciclovir cream). Known hypersensitivity to the product, its components, or Denavir ® (penciclovir cream). ( 4 )

Pregnancy

8.1 Pregnancy Risk Summary Available data from pharmacovigilance reports with famciclovir use in pregnant women have not identified a drug-associated risk of major birth defects, miscarriage or adverse maternal or fetal outcomes. There are risks to the fetus associated with untreated herpes simplex virus during pregnancy (see Clinical Considerations) . After oral administration, famciclovir (prodrug) is converted to penciclovir (active drug).

Storage

16 HOW SUPPLIED/STORAGE AND HANDLING Famciclovir Tablets are supplied as follows: 125 mg – White, round, film-coated, unscored tablets, debossed with “8117” on one side and “93” on the other side. Available in bottles of 30 (NDC 42291-414-30). 250 mg – White, round, film-coated, unscored tablets, debossed with “8118” on one side and “93” on the other side.

Frequently Asked Questions

What is Famciclovir used for?

1 INDICATIONS AND USAGE Famciclovir tablets, a prodrug of penciclovir, are a deoxynucleoside analog DNA polymerase inhibitor indicated for: Immunocompetent Adult Patients ( 1.1 ) Herpes labialis (cold sores) Treatment of recurrent episodes Genital herpes Treatment of recurrent episodes Suppressive therapy of recurrent episodes Herpes zoster (shingles) Human Immunodeficiency Virus (HIV) -Infected Adult Patients ( 1.2 ) Treatment of recurrent episodes of orolabial or genital herpes Limitation of Use The efficacy and safety of famciclovir tablets have not been established for: Patients with first episode of genital herpes Patients with ophthalmic zoster Immunocompromised patients other than for the treatment of recurrent episodes of orolabial or genital herpes in HIV-infected patients Black a...

What are the side effects of Famciclovir?

6 ADVERSE REACTIONS Acute renal failure is discussed in greater detail in other sections of the label [see Warnings and Precautions ( 5 ) ] . The most common adverse events reported in at least 1 indication by greater than 10% of adult patients treated with famciclovir are headache and nausea. The most common adverse events reported in at least 1 indication by greater than 10% of adult patients are headache and nausea. ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact AvKARE at 1-855-361-3993 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch.

Can I take Famciclovir during pregnancy?

8.1 Pregnancy Risk Summary Available data from pharmacovigilance reports with famciclovir use in pregnant women have not identified a drug-associated risk of major birth defects, miscarriage or adverse maternal or fetal outcomes. There are risks to the fetus associated with untreated herpes simplex virus during pregnancy (see Clinical Considerations) . After oral administration, famciclovir (prodrug) is converted to penciclovir (active drug).

What are the important warnings for Famciclovir?

5 WARNINGS AND PRECAUTIONS Acute renal failure: May occur in patients with underlying renal disease who receive higher than recommended doses of famciclovir for their level of renal function. Reduce dosage in patients with renal impairment. ( 2.3 , 8.6 ) 5.1 Acute Renal Failure Cases of acute renal failure have been reported in patients with underlying renal disease who have received inappropriately high doses of famciclovir for their level of renal function. Dosage reduction is recommended when administering famciclovir to patients with renal impairment [see Dosage and Administration ( 2.3 ), Use in Specific Populations ( 8.6 ) ] . 4 CONTRAINDICATIONS Famciclovir is contraindicated in patients with known hypersensitivity to the product, its components, or Denavir ® (penciclovir cream). Known hypersensitivity to the product, its components, or Denavir ® (penciclovir cream). ( 4 )

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Medical Disclaimer

This drug information is for educational purposes only and should not replace professional medical advice. Drug information is sourced from the FDA National Drug Code Directory and Structured Product Labeling. Always consult with a healthcare provider before starting, stopping, or changing any medication.