Penciclovir

Indications

Penciclovir is used for: herpes simplex labialis

Adult Dose

Topical/Cutaneous Recurrent herpes simplex labialis Adult: As 1% cream: Appy 2 hrly during waking hr (approx 8 times daily) for 4 days. Initiate treatment at earliest sign or symptom.

Child Dose

Topical/Cutaneous Recurrent herpes simplex labialis Child: >12 yr As 1% cream: Appy 2 hrly during waking hr (approx 8 times daily) for 4 days. Initiate treatment at earliest sign or symptom.

Renal Dose

Administration

Contra Indications

Hypersensitivity to penciclovir, famciclovir.

Precautions

Immunocompromised patients (e.g. AIDS patients, bone marrow transplant recipients). Not recommended for application to mucous membranes (e.g. eyes, mouth, nose, genitals). Pregnancy and lactation. Monitoring Parameters Monitor reduction in virus shedding, negative cultures for herpes virus; resolution of pain and healing of cold sore lesion.

Pregnancy-Lactation

Pregnancy Drug is not absorbed systemically following topical administration and maternal use is not expected to result in fetal exposure to drug Lactation Drug is not absorbed systemically by the mother following topical administration and breastfeeding is not expected to result in exposure of child to drug

Interactions

Adverse Effects

Side effects of Penciclovir : > 10% Milde erythema 1-10% Application site reaction (1%) Headache (5%) <1% Hypesthesia/local anesthesia Erythematous rash Local edema Oropharyngeal edema Paresthesia Parosmia Skin discoloration Pain Urticaria Taste perversion

Mechanism of Action

Penciclovir has in vitro and in vivo inhibitory activity against various Herpesviridae, including herpes simplex virus types 1 and 2 (HSV-1 and HSV-2), varicella zoster virus (VZV), and EpsteinBarr virus (EBV). In cells infected w/ HSV-1 or HSV-2, viral thymidine kinase phosphorylates penciclovir to a monophosphate form which, in turn, is converted to penciclovir triphosphate by cellular kinases. Penciclovir triphosphate inhibits HSV polymerase competitively w/ deoxyguanosine triphosphate. Consequently, herpes viral DNA synthesis and, therefore, replication are selectively inhibited.