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Update on Drugs and Drug News: February 2010


Name/Company Approval Dates and Comments

Imiquimod 3.75% Cream
Zyclara™
Graceway Pharmaceuticals

Health Canada approved this topical immune response modifier in December 2009 for the treatment of actinic keratoses located on the face or balding scalp in adults.

Acyclovir + Hydrocortisone Cream
Xerclear®/Lipsovir®
Medivir AB

The Swedish Medical Products Agency approved this topical combination product in December 2009 for the treatment of early signs and symptoms of recurrent herpes labialis to reduce the progression of cold sore episodes to ulcerative lesions in immunocompetent adults and children =12 years of age.


Drug News

Titanium dioxide (TiO2) is ubiquitous in manufacturing, with vast ranging uses including pigment and cosmetic applications. Trouiller et al.* report that although TiO2 is chemically inert, TiO2 nanoparticles can induce adverse health effects, such as respiratory tract cancer in rats. The mechanisms by which the genotoxic and carcinogenic effects occur have not yet been satisfactorily elucidated. Study investigators use a murine model to explore TiO2 nanoparticles-induced genotoxicity, oxidative DNA damage, and inflammation. Mice were treated with TiO2 nanoparticles in drinking water and the extent of DNA damage was measured. Researchers also determined mRNA levels of inflammatory cytokines in the peripheral blood. Results showed that TiO2 nanoparticles induced 8-hydroxy-2’-deoxyguanosine, gamma-H2AX foci, micronuclei, and DNA deletions. The formation of gamma-H2AX foci, indicative of DNA double-strand breaks, was the most sensitive marker of DNA damage. A moderate inflammatory response was also detected. Collectively, these findings describe the first comprehensive study of TiO2 nanoparticles-induced genotoxicity in vivo in mice, concievably caused by a secondary genotoxic mechanism associated with inflammation and/or oxidative stress. With the increasing use of TiO2 nanoparticles, this study arouses concern regarding potential health risks linked with exposure to TiO2 nanoparticles. *Trouiller B, et al. Titanium dioxide nanoparticles induce DNA damage and genetic in
* Trouiller B, et al. Titanium dioxide nanoparticles induce DNA damage and genetic instability in vivo in mice. Cancer Res 69(22):8784-9 (2009 Nov 15).

In November 2009, dose-ranging study results were announced on valomaciclovir (EPB-348), a novel broad-spectrum antiviral in Phase 2b development for varicella zoster infections. Tyring et al. of the University of Texas Health Sciences Center conducted a randomized double-blind study involving 373 patients comparing once daily valomaciclovir with 3 times daily valacyclovir. Patients were randomized into 1 of 3 arms: 1g of once daily EPB-348, 2g of once daily EPB-348, or 1g 3 times daily valacyclovir; 18 patients also received 3g of once daily EPB-348. Once daily EPB-348 at 2g met its primary endpoint of non-inferiority (in terms of time to complete crusting of the shingles rash) to valacyclovir. Non-inferiority of valomaciclovir to valacyclovir was also demonstrated in the secondary endpoints of time to complete pain resolution, time to rash resolution, and time to cessation of new lesion formation. The highest dose of valomaciclovir (3g once daily) was superior to valacyclovir according to the primary endpoint (p < 0.007). A dose-dependent relationship was observed, with higher dose EPB-348 treatment arms exhibiting improved pain resolution in patients >50 years of age and more rapid resolution of severe pain across subjects of all ages when compared with valacyclovir. No differences in significant adverse events were seen between valomaciclovir and valacyclovir treatment groups.


In this issue:

  1. Pruritus: Control of Itch in Patients Undergoing Dialysis
  2. Drug Treatments for Skin Disease Introduced in 2009
  3. Update on Drugs and Drug News - February 2010