Jim Smith had severe herpes labialis while he was in college. At that time, the doctor at the student health service prescribed penciclovir cream to decrease the severity and duration of his many cold sores. After 2 weeks of treatment, Mr. Smith's cold sores had mostly healed. However, he developed itching, redness, and blistering around the mouth in the areas where he had applied penciclovir. The drug was discontinued, Mr. Smith was given antihistamines, and the rash healed within a week. Now, at age 28, Mr. Smith has recently changed jobs and moved to a new city following the breakup of a long-term relationship. He has been under great stress at work and has been getting little sleep. He visited his physician because painful eruptions developed on his chest the previous day. His doctor diagnosed acute herpes zoster (shingles) and prescribed oral famciclovir 500 mg every 8 hours

Khare MD and Sharland M. Cytomegalovirus treatment options in immunocompromised patients. Expert Opin Pharmacother 2001;2:1247-1257.

Leung DT and Sacks SL. Current recommendations for the treatment of genital herpes. Drugs 2000;60:1329-1352.

Rajan P and Rivers JK. Varicella zoster virus: Recent advances in management. Can Fam Physician 2001;47:2299-2304.

Sen GC. Viruses and interferons. Annu Rev Microbiol 2001;55:255-281.

for 7 days. Later that day, after beginning his course of treatment, Mr. Smith went to the emergency department complaining of wheezing and an itchy rash over much of his body. His symptoms were consistent with those of a mild anaphylactoid reaction. What happened?

Answer: Famciclovir is a prodrug that is rapidly converted to penciclovir, with a bioavailability of 77%. Maximal plasma concentrations of penciclovir are reached within 45 to 60 minutes of famciclovir administration. Mr. Smith developed an allergy to topical penciclovir when he was treated with this drug during college. This prior contact sensitization to penciclovir allowed him to develop an anaphylactoid reaction following the conversion of oral famciclovir to penciclovir by hepatic first-pass metabolism.

Case Study Picking Up More Than Knowledge in College

10 Ways To Fight Off Cancer

10 Ways To Fight Off Cancer

Learning About 10 Ways Fight Off Cancer Can Have Amazing Benefits For Your Life The Best Tips On How To Keep This Killer At Bay Discovering that you or a loved one has cancer can be utterly terrifying. All the same, once you comprehend the causes of cancer and learn how to reverse those causes, you or your loved one may have more than a fighting chance of beating out cancer.

Get My Free Ebook

Post a comment