Famciclovir

openFDA label record#

This page contains supplementary openFDA label data. For the canonical label presentation, use the corresponding DailyMed Structured Product Label.

Verified complete openFDA source JSON (canonical bytes are SHA-256 checked before publication)

Brand name
Famciclovir
Generic name
FAMCICLOVIR
Manufacturer
Bryant Ranch Prepack
Product type
HUMAN PRESCRIPTION DRUG
SPL set ID
d3faac3a-5c8c-4987-9703-c161fb29ec56
SPL ID
f8a739c5-2fac-409e-a788-85300bdad173
Version
1
Effective date
2025-10-28
Source export date
2026-09-28
Source partition
7
Source file
https://download.open.fda.gov/drug/label/drug-label-0007-of-0014.json.zip
Source object key
raw/openfda/drug-label/2026-09-28/bb1af06e95bcf9567b07e56fcf3a03c0cac3c7c82ff89d4c970881174949e5b7/drug-label-0007-of-0014.json.zip
Source manifest SHA-256
cd2e66336a5cd2223fa3995098fdbdb84c6a7ee5c0a4addb236ccb22dd1e6887
Import run
20260929T050834Z
Imported at
2026-09-29 05:46:25
Harmonized routes table
Harmonized routes
ORAL

Warnings cross-check#

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Warnings sections page 1 of 1 · 1 matching rows.

warnings and cautions

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 tablets to patients with renal impairment [see Dosage and Administration ( 2.3 ), Use in Specific Populations ( 8.6 )].

Adverse reactions cross-check#

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Adverse reactions sections page 1 of 1 · 3 matching rows.

adverse reactions

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 Macleods Pharma USA, Inc. at 1-888-943-3210 or 1-855-926-3384 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch 6.1 Clinical Trials Experience in Adult Patients Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared with rates in the clinical trials of another drug and may not reflect the rates observed in practice. Immunocompetent patients: The safety of famciclovir has been evaluated in active- and placebo-controlled clinical studies involving 816 famciclovir treated patients with herpes zoster (famciclovir , 250 mg three times daily to 750 mg three times daily); 163 famciclovir treated patients with recurrent genital herpes ( famciclovir, 1000 mg twice daily); 1,197 patients with recurrent genital herpes treated with famciclovir as suppressive therapy (125 mg once daily to 250 mg three times daily) of which 570 patients received famciclovir (open-labeled and/or double-blind) for at least 10 months; and 447 famciclovir treated patients with herpes labialis ( famciclovir, 1500 mg once daily or 750 mg twice daily). Table 2 lists selected adverse events. Table 2: Selected Adverse Events (all grades and without regard to causality) Reported by Greater Than or Equal to 2% of Patients in Placebo-Controlled Famciclovir Trials Patients may have entered into more than one clinical trial Incidence Events Herpes Zoster 7 days of treatment Recurrent Genital Herpes 1 day of treatment Genital Herpes- Suppression daily treatment Herpes Labialis Famciclovir (n=273) % Placebo (n=146) % Famciclovir (n=163) % Placebo (n=166) % Famciclovir (n=458) % Placebo (n=63) % Famciclovir (n=447) % Placebo (n=254) % Nervous System Headache 22.7 17.8 13.5 5.4 39.3 42.9 8.5 6.7 Paresthesia 2.6 0.0 0.0 0.0 0.9 0.0 0.0 0.0 Migraine 0.7 0.7 0.6 0.6 3.1 0.0 0.2 0.0 Gastrointestinal Nausea 12.5 11.6 2.5 3.6 7.2 9.5 2.2 3.9 Diarrhea 7.7 4.8 4.9 1.2 9.0 9.5 1.6 0.8 Vomiting 4.8 3.4 1.2 0.6 3.1 1.6 0.7 0.0 Flatulence 1.5 0.7 0.6 0.0 4.8 1.6 0.2 0.0 Abdominal Pain 1.1 3.4 0.0 1.2 7.9 7.9 0.2 0.4 Body as a Whole Fatigue 4.4 3.4 0.6 0.0 4.8 3.2 1.6 0.4 Skin and Appendages Pruritus 3.7 2.7 0.0 0.6 2.2 0.0 0.0 0.0 Rash 0.4 0.7 0.0 0.0 3.3 1.6 0.0 0.0 Reproductive Female Dysmenorrhea 0.0 0.7 1.8 0.6 7.6 6.3 0.4 0.0 Table 3: selected laboratory abnormalities in genital herpes suppression trials Table 3 Selected Laboratory Abnormalities in Genital Herpes Suppression Studies Percentage of patients with laboratory abnormalities that were increased or decreased from baseline and were outside of specified ranges. Parameter Famciclovir (n = 660) n values represent the minimum number of patients assessed for each laboratory parameter. % Placebo (n = 210) % Anemia (<0.8 x NRL) 0.1 0.0 Leukopenia (<0.75 x NRL) 1.3 0.9 Neutropenia (<0.8 x NRL) 3.2 1.5 AST (SGOT) (>2 x NRH) 2.3 1.2 ALT (SGPT) (>2 x NRH) 3.2 1.5 Total Bilirubin (>1.5 x NRH) 1.9 1.2 Serum Creatinine (>1.5 x NRH) 0.2 0.3 Amylase (>1.5 x NRH) 1.5 1.9 Lipase (>1.5 x NRH) 4.9 4.7 NRH = Normal Range High. NRL = Normal Range Low. HIV-infected patients: In HIV-infected patients, the most frequently reported adverse events for famciclovir (500 mg twice daily; n=150) and acyclovir (400 mg, 5x/day; n=143), respectively, were headache (17% vs. 15%), nausea (11% vs. 13%), diarrhea (7% vs. 11%), vomiting (5% vs. 4%), fatigue (4% vs. 2%), and abdominal pain (3% vs. 6%). 6.2 Postmarketing Experience The adverse events listed below have been reported during post-approval use of famciclovir tablets. Because these events are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure: Blood and lymphatic system disorders: Thrombocytopenia Hepatobiliary disorders: Abnormal liver function tests, cholestatic jaundice Immune system disorders : Anaphylactic shock, anaphylactic reaction Nervous system disorders: Dizziness, somnolence, seizure Psychiatric disorders: Confusion (including delirium, disorientation, and confusional state occurring predominantly in the elderly), hallucinations Skin and subcutaneous tissue disorders: Urticaria, erythema multiforme, Stevens-Johnson syndrome, toxic epidermal necrolysis, angioedema (e.g., face, eyelid, periorbital, and pharyngeal edema), hypersensitivity vasculitis Cardiac disorders: Palpitations

adverse reactions table

<table cellspacing="0" cellpadding="0" border="0" width="100%"><caption/><tbody><tr styleCode="Botrule"><td styleCode="Lrule Rrule" colspan="9" align="center" valign="top"> <content styleCode="bold">Table 2: Selected Adverse Events (all grades and without regard to causality) Reported by Greater Than or Equal to 2% of Patients in Placebo-Controlled Famciclovir Trials<footnote ID="fn1387">Patients may have entered into more than one clinical trial</footnote></content></td></tr><tr styleCode="Botrule"><td styleCode="Lrule Rrule" colspan="9" align="center" valign="top"> <content styleCode="bold">Incidence</content></td></tr><tr styleCode="Botrule"><td styleCode="Lrule Rrule" rowspan="2" valign="top"> <content styleCode="bold">Events</content> </td><td styleCode="Rrule" colspan="2" align="center" valign="top"> <content styleCode="bold">Herpes Zoster<footnote ID="fn1383">7 days of treatment</footnote></content></td><td styleCode="Rrule" colspan="2" align="center" valign="top"> <content styleCode="bold">Recurrent Genital Herpes<footnote ID="fn1384">1 day of treatment</footnote></content></td><td styleCode="Rrule" colspan="2" align="center" valign="top"> <content styleCode="bold">Genital Herpes- Suppression<footnote ID="fn1385">daily treatment</footnote></content></td><td styleCode="Rrule" colspan="2" align="center" valign="top"> <content styleCode="bold">Herpes Labialis<footnoteRef IDREF="fn1384"/> </content></td></tr><tr styleCode="Botrule"><td styleCode="Lrule Rrule" align="center" valign="top"> <content styleCode="bold">Famciclovir</content> <content styleCode="bold">(n=273) %</content></td><td styleCode="Rrule" valign="top"> <content styleCode="bold">Placebo (n=146) %</content></td><td styleCode="Rrule" align="center" valign="top"> <content styleCode="bold">Famciclovir</content> <content styleCode="bold">(n=163) %</content></td><td styleCode="Rrule" align="center" valign="top"> <content styleCode="bold">Placebo</content> <content styleCode="bold">(n=166) %</content></td><td styleCode="Rrule" align="center" valign="top"> <content styleCode="bold">Famciclovir</content> <content styleCode="bold">(n=458) %</content></td><td styleCode="Rrule" align="center" valign="top"> <content styleCode="bold">Placebo (n=63) %</content></td><td styleCode="Rrule" align="center" valign="top"> <content styleCode="bold">Famciclovir</content> <content styleCode="bold">(n=447) %</content></td><td styleCode="Rrule" align="center" valign="top"> <content styleCode="bold">Placebo (n=254)</content> <content styleCode="bold"> %</content></td></tr><tr styleCode="Botrule"><td styleCode="Lrule Rrule" colspan="9" valign="top"><content styleCode="bold"> Nervous System</content></td></tr><tr styleCode="Botrule"><td styleCode="Lrule Rrule" valign="top"> Headache</td><td styleCode="Rrule" align="center" valign="top"> 22.7</td><td styleCode="Rrule" align="center" valign="top"> 17.8</td><td styleCode="Rrule" align="center" valign="top"> 13.5</td><td styleCode="Rrule" align="center" valign="top"> 5.4</td><td styleCode="Rrule" align="center" valign="top"> 39.3</td><td styleCode="Rrule" align="center" valign="top"> 42.9</td><td styleCode="Rrule" align="center" valign="top"> 8.5</td><td styleCode="Rrule" align="center" valign="top"> 6.7</td></tr><tr styleCode="Botrule"><td styleCode="Lrule Rrule" valign="top"> Paresthesia</td><td styleCode="Rrule" align="center" valign="top"> 2.6</td><td styleCode="Rrule" align="center" valign="top"> 0.0</td><td styleCode="Rrule" align="center" valign="top"> 0.0</td><td styleCode="Rrule" align="center" valign="top"> 0.0</td><td styleCode="Rrule" align="center" valign="top"> 0.9</td><td styleCode="Rrule" align="center" valign="top"> 0.0</td><td styleCode="Rrule" align="center" valign="top"> 0.0</td><td styleCode="Rrule" align="center" valign="top"> 0.0</td></tr><tr styleCode="Botrule"><td styleCode="Lrule Rrule" valign="top"> Migraine</td><td styleCode="Rrule" align="center" valign="top"> 0.7</td><td styleCode="Rrule" align="center" valign="top"> 0.7</td><td styleCode="Rrule" align="center" valign="top"> 0.6</td><td styleCode="Rrule" align="center" valign="top"> 0.6</td><td styleCode="Rrule" align="center" valign="top"> 3.1</td><td styleCode="Rrule" align="center" valign="top"> 0.0</td><td styleCode="Rrule" align="center" valign="top"> 0.2</td><td styleCode="Rrule" align="center" valign="top"> 0.0</td></tr><tr styleCode="Botrule"><td styleCode="Lrule Rrule" colspan="9" valign="top"> <content styleCode="bold">Gastrointestinal</content></td></tr><tr styleCode="Botrule"><td styleCode="Lrule Rrule" valign="top"> Nausea</td><td styleCode="Rrule" align="center" valign="top"> 12.5</td><td styleCode="Rrule" align="center" valign="top"> 11.6</td><td styleCode="Rrule" align="center" valign="top"> 2.5</td><td styleCode="Rrule" align="center" valign="top"> 3.6</td><td styleCode="Rrule" align="center" valign="top"> 7.2</td><td styleCode="Rrule" align="center" valign="top"> 9.5</td><td styleCode="Rrule" align="center" valign="top"> 2.2</td><td styleCode="Rrule" align="center" valign="top"> 3.9</td></tr><tr styleCode="Botrule"><td styleCode="Lrule Rrule" valign="top"> Diarrhea</td><td styleCode="Rrule" align="center" valign="top"> 7.7</td><td styleCode="Rrule" align="center" valign="top"> 4.8</td><td styleCode="Rrule" align="center" valign="top"> 4.9</td><td styleCode="Rrule" align="center" valign="top"> 1.2</td><td styleCode="Rrule" align="center" valign="top"> 9.0</td><td styleCode="Rrule" align="center" valign="top"> 9.5</td><td styleCode="Rrule" align="center" valign="top"> 1.6</td><td styleCode="Rrule" align="center" valign="top"> 0.8</td></tr><tr styleCode="Botrule"><td styleCode="Lrule Rrule" valign="top"> Vomiting</td><td styleCode="Rrule" align="center" valign="top"> 4.8</td><td styleCode="Rrule" align="center" valign="top"> 3.4</td><td styleCode="Rrule" align="center" valign="top"> 1.2</td><td styleCode="Rrule" align="center" valign="top"> 0.6</td><td styleCode="Rrule" align="center" valign="top"> 3.1</td><td styleCode="Rrule" align="center" valign="top"> 1.6</td><td styleCode="Rrule" align="center" valign="top"> 0.7</td><td styleCode="Rrule" align="center" valign="top"> 0.0</td></tr><tr styleCode="Botrule"><td styleCode="Lrule Rrule" valign="top"> Flatulence</td><td styleCode="Rrule" align="center" valign="top"> 1.5</td><td styleCode="Rrule" align="center" valign="top"> 0.7</td><td styleCode="Rrule" align="center" valign="top"> 0.6</td><td styleCode="Rrule" align="center" valign="top"> 0.0</td><td styleCode="Rrule" align="center" valign="top"> 4.8</td><td styleCode="Rrule" align="center" valign="top"> 1.6</td><td styleCode="Rrule" align="center" valign="top"> 0.2</td><td styleCode="Rrule" align="center" valign="top"> 0.0</td></tr><tr styleCode="Botrule"><td styleCode="Lrule Rrule" valign="top"> Abdominal Pain</td><td styleCode="Rrule" align="center" valign="top"> 1.1</td><td styleCode="Rrule" align="center" valign="top"> 3.4</td><td styleCode="Rrule" align="center" valign="top"> 0.0</td><td styleCode="Rrule" align="center" valign="top"> 1.2</td><td styleCode="Rrule" align="center" valign="top"> 7.9</td><td styleCode="Rrule" align="center" valign="top"> 7.9</td><td styleCode="Rrule" align="center" valign="top"> 0.2</td><td styleCode="Rrule" align="center" valign="top"> 0.4</td></tr><tr styleCode="Botrule"><td styleCode="Lrule Rrule" colspan="9" valign="top"> <content styleCode="bold">Body as a Whole</content></td></tr><tr styleCode="Botrule"><td styleCode="Lrule Rrule" valign="top"> Fatigue</td><td styleCode="Rrule" align="center" valign="top"> 4.4</td><td styleCode="Rrule" align="center" valign="top"> 3.4</td><td styleCode="Rrule" align="center" valign="top"> 0.6</td><td styleCode="Rrule" align="center" valign="top"> 0.0</td><td styleCode="Rrule" align="center" valign="top"> 4.8</td><td styleCode="Rrule" align="center" valign="top"> 3.2</td><td styleCode="Rrule" align="center" valign="top"> 1.6</td><td styleCode="Rrule" align="center" valign="top"> 0.4</td></tr><tr styleCode="Botrule"><td styleCode="Lrule Rrule" colspan="9" valign="top"> <content styleCode="bold">Skin and Appendages</content></td></tr><tr styleCode="Botrule"><td styleCode="Lrule Rrule" valign="top"> Pruritus</td><td styleCode="Rrule" align="center" valign="top"> 3.7</td><td styleCode="Rrule" align="center" valign="top"> 2.7</td><td styleCode="Rrule" align="center" valign="top"> 0.0</td><td styleCode="Rrule" align="center" valign="top"> 0.6</td><td styleCode="Rrule" align="center" valign="top"> 2.2</td><td styleCode="Rrule" align="center" valign="top"> 0.0</td><td styleCode="Rrule" align="center" valign="top"> 0.0</td><td styleCode="Rrule" align="center" valign="top"> 0.0</td></tr><tr styleCode="Botrule"><td styleCode="Lrule Rrule" valign="top"> Rash</td><td styleCode="Rrule" align="center" valign="top"> 0.4</td><td styleCode="Rrule" align="center" valign="top"> 0.7</td><td styleCode="Rrule" align="center" valign="top"> 0.0</td><td styleCode="Rrule" align="center" valign="top"> 0.0</td><td styleCode="Rrule" align="center" valign="top"> 3.3</td><td styleCode="Rrule" align="center" valign="top"> 1.6</td><td styleCode="Rrule" align="center" valign="top"> 0.0</td><td styleCode="Rrule" align="center" valign="top"> 0.0</td></tr><tr styleCode="Botrule"><td styleCode="Lrule Rrule" colspan="9" valign="top"> <content styleCode="bold">Reproductive Female</content></td></tr><tr><td styleCode="Lrule Rrule" valign="top"> Dysmenorrhea</td><td styleCode="Rrule" align="center" valign="top"> 0.0</td><td styleCode="Rrule" align="center" valign="top"> 0.7</td><td styleCode="Rrule" align="center" valign="top"> 1.8</td><td styleCode="Rrule" align="center" valign="top"> 0.6</td><td styleCode="Rrule" align="center" valign="top"> 7.6</td><td styleCode="Rrule" align="center" valign="top"> 6.3</td><td styleCode="Rrule" align="center" valign="top"> 0.4</td><td styleCode="Rrule" align="center" valign="top"> 0.0</td></tr></tbody></table>

adverse reactions table

<table cellspacing="0" cellpadding="0" border="0" width="100%"><tbody><tr styleCode="Botrule"><td styleCode="Lrule Rrule" colspan="3" align="center" valign="top"> <content styleCode="bold"> Table 3 Selected Laboratory Abnormalities in Genital Herpes Suppression Studies<footnote ID="fn1388">Percentage of patients with laboratory abnormalities that were increased or decreased from baseline and were outside of specified ranges.</footnote></content></td></tr><tr styleCode="Botrule"><td styleCode="Lrule Rrule" valign="top"> <content styleCode="bold">Parameter</content></td><td styleCode="Rrule" align="center" valign="top"> <content styleCode="bold">Famciclovir (n = 660)<footnote ID="fn1389">n values represent the minimum number of patients assessed for each laboratory parameter.</footnote> %</content></td><td styleCode="Rrule" align="center" valign="top"> <content styleCode="bold">Placebo (n = 210)<footnoteRef IDREF="fn1389"/> %</content></td></tr><tr styleCode="Botrule"><td styleCode="Lrule Rrule" valign="top"> Anemia (&lt;0.8 x NRL)</td><td styleCode="Rrule" align="center" valign="top"> 0.1</td><td styleCode="Rrule" align="center" valign="top"> 0.0</td></tr><tr styleCode="Botrule"><td styleCode="Lrule Rrule" valign="top"> Leukopenia (&lt;0.75 x NRL)</td><td styleCode="Rrule" align="center" valign="top"> 1.3</td><td styleCode="Rrule" align="center" valign="top"> 0.9</td></tr><tr styleCode="Botrule"><td styleCode="Lrule Rrule" valign="top"> Neutropenia (&lt;0.8 x NRL)</td><td styleCode="Rrule" align="center" valign="top"> 3.2</td><td styleCode="Rrule" align="center" valign="top"> 1.5</td></tr><tr styleCode="Botrule"><td styleCode="Lrule Rrule" valign="top"> AST (SGOT) (&gt;2 x NRH)</td><td styleCode="Rrule" align="center" valign="top"> 2.3</td><td styleCode="Rrule" align="center" valign="top"> 1.2</td></tr><tr styleCode="Botrule"><td styleCode="Lrule Rrule" valign="top"> ALT (SGPT) (&gt;2 x NRH)</td><td styleCode="Rrule" align="center" valign="top"> 3.2</td><td styleCode="Rrule" align="center" valign="top"> 1.5</td></tr><tr styleCode="Botrule"><td styleCode="Lrule Rrule" valign="top"> Total Bilirubin (&gt;1.5 x NRH)</td><td styleCode="Rrule" align="center" valign="top"> 1.9</td><td styleCode="Rrule" align="center" valign="top"> 1.2</td></tr><tr styleCode="Botrule"><td styleCode="Lrule Rrule" valign="top"> Serum Creatinine (&gt;1.5 x NRH)</td><td styleCode="Rrule" align="center" valign="top"> 0.2</td><td styleCode="Rrule" align="center" valign="top"> 0.3</td></tr><tr styleCode="Botrule"><td styleCode="Lrule Rrule" valign="top"> Amylase (&gt;1.5 x NRH)</td><td styleCode="Rrule" align="center" valign="top"> 1.5</td><td styleCode="Rrule" align="center" valign="top"> 1.9</td></tr><tr><td styleCode="Lrule Rrule" valign="top"> Lipase (&gt;1.5 x NRH)</td><td styleCode="Rrule" align="center" valign="top"> 4.9</td><td styleCode="Rrule" align="center" valign="top"> 4.7</td></tr></tbody></table>

Reported adverse events (FAERS/openFDA)#

Adverse event summaries are temporarily unavailable. Other product information remains available.