HIV: is there a morning after pill for HIV?

As a parent of two teenagers, I am worried about their risks of contracting sexually transmitted diseases and HIV. Is there an effective "morning-after pill" for HIV which can be taken if a condom breaks and you think there is a risk from your partner?

Unfortunately, there is no fully effective "morning-after pill" for HIV, and there is no reliable evidence about the best way of dealing with a risky sexual encounter after it has happened. The good news is that the risk of contracting HIV through a single episode of vaginal intercourse is only about three in 1,000. Anal intercourse is more risky. There is a complicated drug regime that is sometimes prescribed to health workers who are exposed to HIV risk at work. There are no UK guidelines for preventing HIV after exposure in people who are not health workers. If your children think they have been exposed to HIV, they should seek urgent advice from a sexual health clinic or casualty department.

Dr Fred Kavalier answers your health question:

Please mail your questions for Dr Fred to health@independent.co.uk. He regrets that he is unable to respond personally to questions.