HIV prevention – PrEP
Researchers in the UK are planning to offer pre-exposure prophylaxis for HIV to gay men who visit some sexual health clinics for treatment of a sexually transmitted infection.
The offer will be part of a bigger study which is planned to look at delivering more intensive HIV risk reduction counselling through sexual health clinics in England.
The study will also involve asking men to attend clinics for check-ups regularly, even if they don’t have STI symptoms.
A large international study in gay and bisexual men recently found that use of PrEP reduced the risk of infection by 44% overall – but reduced the risk of infection by 73% in men who took the pills most regularly.
However, an international study looking at the effectiveness of PrEP in women has just been stopped.
It involved over 1500 women in Kenya, South Africa and Tanzania. Women in the study were randomised to receive either PrEP consisting of Truvada or a placebo.
The study was halted because researchers concluded that even if the study went on for another two years, it wouldn’t be able to show any effect of PrEP in the women recruited.
At this stage researchers don’t know why PrEP appeared not to reduce the risk of HIV. Two more studies in Africa will continue to test PrEP in women.
PrEP for couples who want to have a baby
Pre-exposure prophylaxis (PrEP) has already been used in the UK by couples wanting to have a baby.
The treatment was used by HIV-negative women whose partner was HIV-positive.
Researchers from Brighton told a recent conference that the treatment was used by a small number of couples trying to conceive.
Before being provided with PrEP, the couples had intensive counselling about what PrEP involved, and also discussed sperm washing and adoption. They were encouraged to have a “no blame” attitude, in case PrEP didn’t work and HIV transmission occurred.
Because this use of antiretroviral drugs is unlicensed and there’s a risk of HIV transmission, couples had to confirm they understood the risk before proceeding.
All the men were taking HIV treatment and had an undetectable viral load. The risk of HIV transmission in these circumstances is thought to be very low.
The women were advised to take one or two doses of tenofovir or Truvada (tenofovir and FTC combined in one pill) between 24 and 36 hours before sex, and then another dose one to two hours afterwards. The couples were advised to limit unprotected sex to the days of the month during ovulation (and taught how to tell when the woman was ovulating).
Five couples have so far participated in the programme. There have been four pregnancies, and no HIV transmissions.
HIV treatment – side-effects of atazanavir
Atazanavir is usually taken with a ritonavir booster and is now the first choice protease inhibitor for patients starting or changing HIV treatment in London.
It’s an effective and safe drug and is less likely to cause diarrhoea, nausea and vomiting than some other protease inhibitors. It is also less likely to cause an increase in blood lipids (fats).
However, it can cause a non-dangerous yellowing of the skin and whites of the eyes (jaundice).
Researchers at the Chelsea and Westminster Hospital in London have found that kidney stones are a rare side-effect of the drug.
Each year about 0.75% of patients taking atazanavir developed kidney stones – this compared to just 0.19% of patients taking other drugs.
The researchers also found that patients taking atazanavir were about 50% more likely to develop renal impairment than patients treated with the commonly prescribed non-nucleoside reverse transcriptase inhibitor (NNRTI) efavirenz (Sustiva, also in the combination pill Atripla). But an even greater risk was associated with the protease inhibitor Kaletra (lopinavir/ritonavir).
Kidney function is monitored as part of routine HIV care, so this means that any potential problems can be spotted early and appropriate treatment provided.
HIV and the liver
None of the patients in the study were co-infected with either hepatitis B or hepatitis C, which are the main causes of liver disease in patients with HIV.
The research involved 1112 patients who started HIV treatment between 1996 and 2006.
Two different methods were used to monitor the health of the patients’ livers.
When they entered the study, 81% of patients had either no liver damage or only mild fibrosis.
But, depending on the method of assessment used, between 8 and 31% of patients were found to have hardening of the liver.
Older age and injecting drug use were both associated with deterioration in liver health.
However, starting HIV treatment at a higher CD4 cell count protected against the progression of fibrosis.
The researchers believe this finding has significance for the current debate about the best time to start HIV therapy. Some doctors advocate starting treatment at higher CD4 cell counts as a way of avoiding non-HIV-related illnesses.
Patients with a significant risk of liver disease are already especially recommended to start treatment when their CD4 cell count is between 350 and 500 cell/mm3.