Publications

We recommend that regulatory agencies add the extent of drug metabolism (i.e., >or=90% metabolized) as an alternate method in defining Class 1 marketed drugs suitable for a waiver of in vivo studies of bioequivalence. That is, >or=90% metabolized is an additional methodology that may be substituted for >or=90% absorbed. We propose that the following criteria be used to define>or=90% metabolized for marketed drugs: Following a single oral dose to humans, administered at the highest dose strength, mass balance of the Phase 1 oxidative and Phase 2 conjugative drug metabolites in the urine and feces, measured either as unlabeled, radioactive labeled or nonradioactive labeled substances, account for >or=90% of the drug dosed. This is the strictest definition for a waiver based on metabolism. For an orally administered drug to be >or=90% metabolized by Phase 1 oxidative and Phase 2 conjugative processes, it is obvious that the drug must be absorbed. This proposal, which strictly conforms to the present>or=90% criteria, is a suggested modification to facilitate a number of marketed drugs being appropriately assigned to Class 1.

OBJECTIVE

To determine the prevalence of illicit drug use and the impact on HIV treatment.

DESIGN

Multivariable regression of cross-sectional data from 1163 HIV-infected and 294 controls from the Study of Fat Redistribution and Metabolic Change in HIV Infection (FRAM).

METHODS

An analysis of (1) prevalence of specific illicit drug use (ever, current), (2) being on HAART among those with an indication and (3) current HIV RNA and CD4 cell count among HAART users.

RESULTS

Median age was 42 years, approximately 50% were non-Caucasian and 33% were women. Eighty-six percent of HIV-infected and 67% of controls reported ever using illicit drugs (P < 0.0001); 28% of HIV-infected and 16% of controls reported current use (P = 0.0001). In adjusted models, current cocaine use and past heroin use were associated with not currently being on HAART. Among HAART users, those reporting past heroin use were as likely to have an undetectable HIV viral load as those who had never used heroin. Current and past cocaine use and current heroin use was associated with lower odds of undetectable HIV RNA. Past amphetamine use was associated with having an undetectable HIV. Similar results were seen for CD4 lymphocyte counts.

CONCLUSION

Illicit drug use in the US is common, although far fewer report current use than past use. Among HIV-infected patients, understanding of the type of illicit drugs used and whether drug use was in the past or ongoing is important, because of their differential effects on HIV treatment outcomes.

Although the transient receptor potential vanilloid 4 (TRPV4) has been implicated in the process of osmomechanical transduction, it appears to make little contribution to the normal somatosensory detection of mechanical stimuli. However, evidence suggests that it may play an important role in mechanical hyperalgesia. In the present study, we examined the common requirement for TRPV4 in mechanical hyperalgesia associated with diverse pain models and investigated whether the very close association observed between TRPV4 and mechanical hyperalgesia, regardless of etiology, reflects a close functional connection of TRPV4 with other molecules implicated in mechanical transduction. In models of painful peripheral neuropathy associated with vincristine chemotherapy, alcoholism, diabetes, and human immunodeficiency virus/acquired immune deficiency syndrome therapy, mechanical hyperalgesia was markedly reduced by spinal intrathecal administration of oligodeoxynucleotides antisense to TRPV4. Similarly, mechanical hyperalgesia induced by paclitaxel, vincristine, or diabetes was strongly reduced in TRPV4 knock-out mice. We also show that alpha2beta1 integrin and Src tyrosine kinase, which have been implicated in mechanical transduction, are important for the development of mechanical hyperalgesia, and that their contribution requires TRPV4. Furthermore, we establish a direct interaction between TRPV4, alpha2 integrin, and the Src tyrosine kinase Lyn in sensory neurons. We suggest that TRPV4 plays a role in mechanotransduction, as a component of a molecular complex that functions only in the setting of inflammation or nerve injury.

BACKGROUND

Infection with multidrug-resistant, community-associated, methicillin-resistant Staphylococcus aureus (MRSA) has been reported but seems to be isolated.

OBJECTIVE

To determine the incidence of a multidrug-resistant MRSA clone (USA300) in San Francisco, and to determine risk factors for the infection.

DESIGN

Population-based survey and cross-sectional study using chart review.

SETTING

9 hospitals in San Francisco (population-based survey) and 2 outpatient clinics in San Francisco and Boston (cross-sectional study).

PATIENTS

Persons with culture-proven MRSA infections in 2004 to 2006.

MEASUREMENTS

Annual incidence, spatial clustering, and risk factors for multidrug-resistant USA300 infection. Pulsed-field gel electrophoresis, polymerase chain reaction assays, and DNA sequencing were used to characterize MRSA isolates.

RESULTS

The overall incidence of multidrug-resistant USA300 infection in San Francisco was 26 cases per 100,000 persons (95% CI, 16 to 36 cases per 100,000 persons); the incidence was higher in 8 contiguous ZIP codes with a higher proportion of male same-sex couples. Male-male sex was a risk factor for multidrug-resistant USA300 infection (relative risk, 13.2 [CI, 1.7 to 101.6]; P < 0.001) independent of past MRSA infection (relative risk, 2.1 [CI, 1.2 to 3.7]; P = 0.007) or clindamycin use (relative risk, 2.1 [1.2 to 3.6]; P = 0.007). The risk seemed to be independent of HIV infection. In San Francisco, multidrug-resistant USA300 manifested most often as infection of the buttocks, genitals, or perineum. In Boston, the infection was recovered exclusively from men who had sex with men.

LIMITATIONS

The study was retrospective, and sexual risk behavior was not assessed.

CONCLUSION

Infection with multidrug-resistant USA300 MRSA is common among men who have sex with men, and multidrug-resistant MRSA infection might be sexually transmitted in this population. Further research is needed to determine whether existing efforts to control epidemics of other sexually transmitted infections can control spread of community-associated, multidrug-resistant MRSA.