This is exciting news:

A 1% tenofovir gel used intravaginally both before and after sex reduced the incidence of HIV infection among women by up to 54%.

For 20 years, researchers have been testing potential anti-HIV microbicides in humans, with no success. Now, the first of a new generation of antiretroviral-based microbicides has proven efficacious in a randomized, placebo-controlled trial conducted in both urban and rural South Africa.

A total of 889 sexually active, HIV-uninfected women (age range, 18–40) received either 1% tenofovir gel or placebo gel, with instructions to administer the gel intravaginally within 12 hours before sex and also within 12 hours after sex. Gel adherence was measured using returned applicators and was classified as either high (>80%), intermediate (50%–80%), or low (<50%). Mean follow-up was 18 months.

Overall, the study retention rate was 95%, and the average rate of gel adherence was 72%. In an intent-to-treat analysis, the incidence of HIV infection was 5.6 per 100 person-years in the tenofovir group versus 9.1 per 100 person-years in the placebo group, for an incidence rate ratio (IRR) of 0.61 (95% confidence interval [CI], 0.40–0.94; P=0.017). Efficacy correlated with gel adherence: Tenofovir reduced the incidence of HIV infection by 54% among women with high adherence, 38% among women with intermediate adherence, and 28% among women with low adherence. The tenofovir and placebo groups had similar rates of adverse events. Importantly, the women who became HIV-infected in the tenofovir group did not show evidence of tenofovir-related resistance mutations or thymidine analogue mutations.

Unpublished data presented at the 2010 International AIDS Conference (Abstract TUSS0502) showed that the tenofovir group also had a 51% reduction in the incidence of herpes simplex virus (HSV)-2 infection, apparently independent of the effect on HIV. The incidence of new HSV-2 infections was 9.9 per 100 person-years in the tenofovir group versus an alarming 20.2 per 100 person-years in the placebo group (IRR, 0.49; 95% CI, 0.30–0.78; P=0.003).

Comment: These solid data provide proof of concept that topical antiretrovirals can serve as effective anti-HIV microbicides. Given the efficacy and pharmacology of tenofovir in HIV treatment, and the positive animal studies leading up to this trial, the results should not necessarily be surprising, but they are most welcome. Additional trials are now needed to confirm these findings, including the reduced HSV-2 incidence. The ongoing VOICE trial, conducted by the NIH-funded Microbicide Trials Network, should provide additional efficacy data on tenofovir gel as well as oral tenofovir and oral tenofovir/FTC (Truvada) in the next 3 years. Other ongoing studies are now evaluating potentially more convenient or longer-acting modes of microbicide delivery, such as intravaginal rings, and additional antiretroviral classes. We are still far from having a microbicide available clinically, but at least, a female-controlled HIV prevention method finally looks possible.

And if that comes through, it would lend a strong helping hand to female-empowerment in preventing the spread of HIV! Truly exciting indeed.

Time and again, I’ve been asked this question: Is it safe to take the H1N1 vaccine?

Well, it’s safe, as far as the risk of developing Guillian-Barre Syndrome is concerned.

New CDC data strengthen the evidence that the risk for Guillain-Barré syndrome (GBS) associated with the 2009 H1N1 vaccine is similar to the risk seen with seasonal flu vaccines, according to an MMWR report.

The CDC’s analysis of data from October 2009 through March 2010 found that the incidence of GBS was 1.92 per 100,000 person-years among vaccinated individuals and 1.21 per 100,000 person-years among the unvaccinated. If final data confirm this finding, the CDC says, then this would translate to 0.8 excess GBS cases for every 1 million vaccinations — a rate comparable to that found with seasonal flu vaccination.

You can read the MMWR article here.

A boxed warning has been added to the hyperthyroidism drug propylthiouracil (PTU) to alert clinicians about the drug’s risk for severe liver injury, the FDA announced on Wednesday.

The new labeling is based in part on postmarketing safety reports of severe liver injury — including 15 deaths — in 23 adult and 11 pediatric patients taking PTU. A warning about the potential dangers of the drug was issued by the agency last June.

The FDA recommends that PTU only be used in patients who cannot tolerate methimazole or other treatments for hyperthyroidism and in women just before and during their first trimester of pregnancy.

Down load the FDA Safety Communication and the 2009 FDA Drug Safety Information.

Our Cardiologist blogger, Heart of the Matter, has an update on Aspirin in the primary prevention of heart attacks. Primary prevention means preventing something which has not happened, and in the case of aspirin, it means people who have not had a heart attack before but take aspirin to prevent one from ever happening.

At the just concluded ACC Annual Scientific Meeting at Atlanta, Georgia, Dr Jay Das and group re-reviewed the ATTC data, plus another three aspirin trials ( the JPAD, POPADAD, AAA ) and also concluded basically, that althought there was some small benefit with aspirin, there was a significant level of side effects. They concluded that there was no role for aspirin in the primary prevention of heart attacks.

So once again, the message needs to go out to primary care doctors (and indeed the lay public), there is no role for aspirin in the primary prevention of heart attacks.

(via MIMS Online)

Ng Kee-Chong, Chan Yoke-Hwee

In 2005, the International Liaison Committee on Resuscitation (ILCOR) – with the American Heart Association, the European Resuscitation Council and other resuscitation organisations- reviewed, updated and issued guidelines for resuscitation. through rigorous evidence evaluation, the Consensus on Science and Treatment Recommendations were published in Resuscitation and Circulation in December 2005. Changes to the Paediatric Life Support Guidelines were based on these recommendations.

Download the Full article (PDF)

The WHO has updated their Guidelines for the treatment of malaria. The main changes from the first edition of the guidelines, which was originally published in 2006, are the emphasis on testing before treating and the addition of a new artemisinin-based combination therapy (ACT) to the list of recommended treatments.
You can download the guideline here (PDF format)

A recent population study on Singaporeans suggests an association with soft drink consumption and pancreatic consumption. The data is from the Singapore Chinese Health Study (study size 60,524, over 14 years) which looked at the consumption of soft drinks, juice, other dietary items, lifestyle factors and environmental exposures, collected at recruitment to the study. Medscape reports:

At 14 years and a cumulative 648,387 person-years of follow-up, 140 incident pancreatic cancers developed in people who were cancer free at baseline. After adjustment for confounders such as BMI, type 2 diabetes mellitus, and fruit juice intake, the authors found that those consuming 2 or more soft drinks per week experienced a statistically significant increased risk for pancreatic cancer (hazard ratio [HR], 1.87; 95% confidence interval [CI], 1.10 – 3.15).
Although people who consumed 2 or more juice drinks a week had an increased risk for pancreatic cancer of approximately 30%, elevated HR was not statistically significant after adjustment for variables.
However, in an age-adjusted analysis, smoking was also a risk factor. After excluding former smokers, the authors found that current smokers had a 49% increased risk for pancreatic cancer, compared with never smokers (HR, 1.49; 95% CI, 0.98 – 2.27). This risk factor remained unaffected after adjustment for diabetes and BMI.

A word of caution is that studies like these can only determine statistical association, which is not quite the same as cause and effect. However it does make sense to curb smoking and the consumption of excessive sugary drinks like soft drinks. Diet coke anyone?

Long-acting beta agonists should not be used alone in asthma, the FDA warns. The drugs at issue include the single-agent LABAs Serevent and Foradil.

Because LABAs have been associated with severe worsening of symptoms, the agency is requiring that labels carry the following guidance:

* LABAs are contraindicated without the use of a controller medication, such as an inhaled corticosteroid.
* Long-term use is only indicated for patients whose disease doesn’t respond to controller medications.
* LABAs should be used for the shortest period possible.
* To ensure compliance, children and adolescents should only use LABAs that contain an inhaled corticosteroid.

The recommendations do not apply to use of LABAs in chronic obstructive pulmonary disease.

Read the FDA announcement.

A bit of not-so-good news for those of us who are on statins.

Statin use is accompanied by a small but measurable risk for developing diabetes, according to a meta-analysis released online by the Lancet.

Analysts, using data from 13 randomized trials comprising some 90,000 subjects, found a 9% increase in diabetes risk among those receiving statins compared with controls. Adjustments for BMI and change in LDL cholesterol did not affect the results substantially. However, the statin-diabetes association was stronger with increasing age.

The authors say the association may stem from residual confounding factors, such as improved survival with statin therapy.

The authors calculate that 255 patients would have to be treated with statins for 4 years to produce an additional case of diabetes. They say that this small absolute risk “is outweighed by cardiovascular benefit in the short and medium term.” A commentator concludes that “it seems reasonable to add glucose to the list of tests to monitor in older patients who are on statins.”

Read the abstract in Lancet here.

Women who use aspirin regularly after breast cancer diagnosis might be less likely to die from the illness, according to an observational study in the Journal of Clinical Oncology.

The analysis included nearly 4200 Nurses’ Health Study participants who were diagnosed with stage I, II, or III breast cancer from 1976 to 2002. Aspirin use was assessed via questionnaire beginning one year after diagnosis and until death or June 2006.

Roughly 8% of participants died from breast cancer. After adjustment for cancer stage, treatment, and other confounders, breast cancer mortality was about 70% less likely among women who used aspirin regularly (2–5 days/week or 6–7 days/week), compared with never-users. Distant recurrence was also reduced with regular aspirin use.

The authors suggest several possible mechanisms underlying the observed association, including the potential for aspirin to lower serum estradiol.

Download the pdf file.

If you have IBD (inflammatory bowel disease) and is wondering when would be a good time to get another colonoscopy, the American Gastroenterological Association has released a position paper on screening patients with inflammatory bowel disease (IBD) for colorectal cancer.

The statement, published in Gastroenterology, says that disease duration, extensive disease, primary sclerosing cholangitis, and family history of colorectal cancer are associated with increased risk for colorectal cancer in patients with IBD.

Among the recommendations:

* Colonoscopy is advised within 8 years of IBD onset. After two negative examinations, panel members recommend screening intervals of 1 to 3 years.
* Patients who have more extensive or left-sided colitis should start surveillance 1 to 2 years after the initial endoscopy.
* Colectomy is advised for patients with non–adenoma-like dysplasia-associated lesion or mass.
* Polypectomy and continued surveillance is recommended for patients with adenoma-like dysplasia-associated lesion or mass with no evidence of other flat dysplasia.

You may download the free article here: AGA Position Paper on Colorectal screening for patients with IBD

Attention couch potatoes. A recent Aussie study suggests you should get off your butt, watch less TV and exercise more. Common sense right? But the chilling statistics might be just the thing to spur you to do the right thing. MedPageToday reports

Too much television watching could be shortening lifespans, a study of Australian adults showed.
Aussies who reported watching four or more hours of TV a day were 46% more likely to die during a 6.6-year period than those who watched less than two hours a day, according to David Dunstan, PhD, of Monash University in Melbourne, and colleagues.
The risk of dying from cardiovascular disease during follow-up was 80% greater in the excessive viewers, although statistically, the result attained only borderline significance (P=0.05), the researchers reported online in Circulation: Journal of the American Heart Association.
The associations were independent of leisure-time exercise and traditional risk factors such as smoking, poor diet, high blood pressure, and abdominal obesity.
“Sedentary living provokes coronary artery disease,” commented Gerald Fletcher, MD, a cardiologist at the Mayo Clinic in Jacksonville, Fla., and spokesman for the American Heart Association who was not involved in the study.
“Even if you exercise, if you have a lot of sedentary living with the things that go along with it — the bad diet and everything else — you still have a net degree of physical inactivity, which is a coronary artery disease risk factor,” Fletcher told MedPage Today.

OK now I have to juggle between Fringe, LOS, Bing Bang Theory to keep it down to under 2 hours a day