FAMCICLOVIR (famciclovir)

There are 0 contraindications.

There are 4 severe contraindications. Adequate patient monitoring is recommended for safer drug use.

Severe List
Chronic kidney disease stage 3A (moderate) GFR 45-59 ml/min
Chronic kidney disease stage 3B (moderate) GFR 30-44 ml/min
Chronic kidney disease stage 4 (severe) GFR 15-29 ml/min
Chronic kidney disease stage 5 (failure) GFr<15 ml/min

There are 1 moderate contraindications. Clinically significant contraindication, where the condition can be managed or treated before the drug may be given safely.

Moderate List
Severe hepatic disease

There are 15 severe adverse reactions.

More Frequent	Less Frequent
None.	Neutropenic disorder

Rare/Very Rare
Abnormal hepatic function tests Acute cognitive impairment Anaphylaxis Angioedema Erythema multiforme Hallucinations Hypersensitivity angiitis Leukopenia Obstructive hyperbilirubinemia Seizure disorder Skin rash Stevens-johnson syndrome Thrombocytopenic disorder Toxic epidermal necrolysis

There are 14 less severe adverse reactions.

More Frequent	Less Frequent
Diarrhea Headache disorder Nausea	Dizziness Dysmenorrhea Fatigue Flatulence Paresthesia Pruritus of skin Vomiting

Rare/Very Rare
Drowsy Migraine Palpitations Urticaria

Reproduction studies using oral famciclovir dosages up to 1 g/kg daily in rats and rabbits (approximately 3.6-21.6 and 1.8-10.8 times the human systemic exposure to penciclovir, respectively, based on AUC comparisons) and IV dosages of 360 mg/kg daily in rats (2-12 times the human dose based on body surface area comparisons) or 120 mg/kg daily in rabbits (1.5-9 times the human dose based on body surface area comparisons) have not revealed evidence of adverse effects on embryofetal development. Similar studies using IV penciclovir dosages up to 80 mg/kg daily in rats (0.4-2.6 times the human dose based on body surface area comparisons) or 60 mg/kg daily in rabbits (0.7-4.2 times the human dose based on body surface area comparisons) also did not reveal evidence of adverse effects on embryofetal development. There are no adequate and well-controlled studies to date using famciclovir in pregnant women, and the drug should be used during pregnancy only when clearly needed.

To monitor maternal-fetal outcome of pregnant women exposed to famciclovir, the manufacturer maintains a Famciclovir Pregnancy Registry. The registry may be contacted by calling 888-669-6682. Reproduction studies using famciclovir or penciclovir in rats, mice, and dogs revealed evidence of testicular toxicity following repeated oral administration of high dosages.

Testicular changes, including atrophy of the seminiferous tubules, reduction in sperm count, and/or increased incidence of sperm with abnormal morphology or reduced motility, were observed. The degree of toxicity was related to dose and duration of exposure. In male rats, decreased fertility was observed following 10 weeks of dosing at 500 mg/kg daily (1.9-11.4 times the human AUC).

Administration of famciclovir to male rats in dosages of 50 mg/kg daily (0.2-1.2 times the human systemic exposure based on AUC comparisons) for 26 weeks did not reveal evidence of sperm or testicular toxicity. Testicular toxicity was observed following administration of dosages of 600 mg/kg daily (0.4-2.4 times the human systemic exposure based on AUC comparisons) for 104 weeks in male mice and dosages of 150 mg/kg daily (1.7-10.2 times the human system exposure based on AUC comparisons) for 26 weeks in male dogs. No effect on spermatogenesis was observed in human males with genital herpes following oral famciclovir dosages of 250 mg twice daily for 18 weeks.

It is not known whether famciclovir or penciclovir is distributed into milk in humans. Following oral administration of famciclovir to lactating rats, penciclovir was distributed into breast milk at concentrations higher than those observed in plasma. Data on safety of famciclovir in infants currently is not available.

No enhanced Geriatric Use information available for this drug.