Non-occupational post-exposure prophylaxis for HIV at St Michael's Hospital, Toronto: a retrospective review of patient eligibility and clinical outcomes

Stringent eligibility criteria, drug costs and antiretroviral toxicities are challenges in delivering HIV non-occupational post-exposure prophylaxis (nPEP). We reviewed patients’ nPEP eligibility and clinical outcomes at St Michael's Hospital, Toronto, Canada to identify opportunities for improvement. Of 241 patients, 59%, 36% and 6% presented for high- (receptive anal/vaginal, blood), medium- (insertive anal/vaginal) and low-risk (oral) sexual exposures, respectively, and nearly all (93%) presented within 72 hours. Of 205 patients given nPEP, 20 were known to have discontinued nPEP prematurely: three due to costs but none due to toxicities. Two HIV seroconversions occurred in patients with suspected ongoing potential exposures. Five asymptomatic syphilis diagnoses were made among 71 tested. Only 39% and 19% of nPEP patients returned to our institution for follow-up at 3–4 and six months, respectively. Our findings underscore the feasibility and importance of nPEP programmes to HIV and sexually transmitted infection control, while identifying opportunities for improvement.

Effect of ganglionic blockade on bronchial reactivity in atopic subjects

To determine the site in the parasympathetic pathway responsible for the increased bronchial reactivity in 5 atopic subjects, we studied the effect of premedication with aerosols of hexamethonium, a ganglionic blocking agent, and atropine, a postganglionic blocking agent, on the bronchomotor responses to histamine and methacholine aerosols. After 7 mg of aerosolized atropine, baseline specific airway resistance (SRaw) decreased, and the increases in SRaw produced by histamine and by methacholine were prevented in each subject (p < 0.001). After 1 g of hexamethonium, baseline SRaw was decreased to a similar level, and the increase in SRaw produced by histamine was again Prevented in each subject (P < 0.001); However, the increase in SRaw produced by methacholine was not affected significantly in 3 subjects (p > 0.5) and was increased or decreased only slightly in 2 subjects (p < 0.05). These results suggest that bronchial hyperreactivity in atopic subjects may be due to a change in the characteristics of the efferent parasympathetic pathway at a site distal to the ganglion, possibly at the smooth muscle, and that bronchodilation caused by atropine and hexamethonium cannot, by itself, account for their effects on bronchomotor responses.