Basically you need to start PEP treatment within 2 hours for it to be effective.

Also, it appears he didn't start PEP treatment[1], they probably didn't deem it necessary at the time; PEP itself can have some serious side effects.

[1]: I read in the article linked by @Grazester that you need to take PEP for about a month, and I wasn't aware of him drinking any special medications during that time.

I was exposed to HIV last year - a guy who didn't use a condom even though I told him to, and who a friend later told me was very probably HIV+. I got on PEP, but not in 2 hours, but within about 12 hours. The earlier the better, but doctors suggest that up to 72 hours is fine.

The medication given differs based on country - basically, the same set of drugs used for HIV are used, but different health systems will rotate through different drug sets.

I was on Truvada (emtricitabine and tenofovir disoproxil fumarate), which is also used for PrEP. One pill a day for 28 days. I was also on Kaletra (lopinavir/ritonavir), two pills twice a day. The doctors also gave me a whole load of generic anti-diarrhea pills because that's a common side effect of the Kaletra. They also told me that they were going to soon be changing the protocol for PEP and substituting a different drug for the Kaletra, specifically to ease the side effects.

The side effects for me were pretty bad: lots of tiredness, some nausea, diarrhea, vomiting and other gastro-intestinal issues. I was also trying hard to deal with the pretty ghastly feeling of being sexually assaulted. Two weeks in, they also did a test to make sure the drugs weren't causing me any liver problems, as that's a known but very rare side effect.

I'm glad that it is available: every hospital in Britain is set up to hand out PEP in emergency departments, and you are handled quickly. There's also a standard 'checklist' test that doctors use to decide in the case of both sexual and occupational exposure whether to prescribe PEP.

And as you said in your post, I had flu and cold like symptoms (because, duh, it was winter) and I misinterpreted them as seroconversion symptoms.

In my case: I've had regular blood tests for HIV every three months since exposure according to schedule. All negative so far. :)

(And the police can take no action against the guy, because the laws in this country are shit and ignoring someone's safe sex preferences isn't a criminal offence. And everyone scoffs when feminists talk about 'rape culture'. The assault/trust issue side of it has given me panic attacks but I'm coping a lot better than a lot of people.)