In the course of packing up some of my brother's things last Friday I unzipped a bag and looked inside to check it was his. A copy of William Burroughs's Junky was resting on the top. I looked no further, this was indeed his bag. And how fitting to find such a book in a such a place at such a time - just as we were clearing away his funeral supper.

My brother Luke was a strapping 35-year-old. He looked healthy and well cared for, not - as one of the nurses in intensive care told me the previous week - like some of the "riff-raff" they see. (I thought this rather unkind at the time, but then I don't work on the accident and emergency front- line). Not perhaps the sort you'd expect to collapse on the street with a syringe of methadone at his side. And looking at him as he lay on the life-support machine, I could almost agree. The wires that fed vital juices into his bloodstream neatly obscured the fresh track marks on his inner arm, while the sheet covering his body gave no hint of the punctured, dug-out groin that lay beneath. Like many junkies (this is how he referred to himself), he ran out of plump, accessible veins some time ago and took to assaulting the parts of his battered carcass that offered least resistance. A reasonable lifestyle gave him a covering of normality, but underneath he was a man at war with himself.

I didn't know he liked Burroughs but, as it turned out, I didn't know a lot of things. I had also been a fan of this "compelling and brilliant" (as described by the Washington Post) author - right up until I discovered we had a real live smack-head in the family. It was then that his compelling and brilliant accounts of how much heroin/opium/cockroach poison/general junk he could pump into himself started to wear thin. Indeed, on the day Luke opened up his arm for the very last time, I'd been writing an article called "The Unbearable Boredom of Drug Taking". I'd had it in mind since the Will Self/heroin in the Prime Minister's toilet fiasco and my main point was just as the title indicated, drugs can really bore your pants off.

This tedium rarely features in the media's portrayal of big drugs. From the wired anti-heroes of Trainspotting, to the wasted kids modelling heroin chic, to the tabloids' hysterical rhyming headlines - the consensus seems to be that street drugs are mysteriously powerful and painfully exotic. When also linked to creative talent (as in Self's case) the equation gathers momentum and magics itself into a dastardly cocktail of glamorous, doomed brilliance. The idea of the artist as fabulously flawed (ie, with a habit) has great currency but unfortunately it doesn't read the other way. That is to say: getting a habit won't turn you into an artist.

No, in real life the average junky suffers from a chronic lack of both glamour and creativity. On a physical level anyone regularly overloading their bloodstream with poisons and chemicals is bound to cop the consequences. Luke himself suffered from the classic junky complaint of diabolical constipation, which made him bloated and bad tempered. He was also plagued by phlegm balls and torrential sweating. And he never acquired the fashionable wasted image; in fact, drug-related bouts of "the munchies" (craving for sweet foods) made him fat. Ironically, it was when he was on the life-support machine that Luke looked better than he had for some time, partly because he'd been detoxing for the previous few months and partly because the artificial adrenalin and oxygen transformed his usual grey pallor into a rosy glow. It pains me to paint this picture, but he didn't look like a Calvin Klein ad.

One thing the mass media do acknowledge is the deeply enticing and delicious nature of many street drugs - but it doesn't always pass on how temporary it is. In retrospect, I think Luke started sustained and heavy usage about 15 years ago. He seemed very happy and optimistic then - he was young, good-looking and sussed, always out and about. He must have been having a real love affair with existence itself: to be so hip while also discovering the nerve-bending delights of the Class A drug range. His heroin habit was several months on before things got intravenous. Then, like Burroughs says: "One morning you wake up sick and you're an addict." And sick he was. Once Luke was hooked, the ecstatic rush he first experienced never returned and so he - like all other junkies - spent his time simply trying to ward off the pain of withdrawal (which starts as soon as the effect of the last hit wears off). No devilish joy, no glamorous release, just the grim cycle of scoring and using. Indeed he once told me was only happy when he was asleep.

Luke hid his habit for several years. When it came out and my parents and I got over the initial shock, we set about getting him "cured'". We travelled miles, made appointments, talked it through - and when he was clean we all went home. A few months later he was back on and so were we. How repetitious it became. We got locked into Luke's pattern of lying, confessing, coming off, going back on - and the tired, unending path of absolutely last chances. Even dramatic junky-style events like getting arrested lose their shock impact after a while. "Nothing ever happens in the junk world," says Burroughs. Quite. It just gets unbearably boring.

I am ashamed to say that even on that terrible day when I got the call saying Luke was in intensive care, I thought it was but another event in the continuing story. Of course, I was stunned and upset - but I was also angry. There was one hour before the last train and I had 30 minutes to rearrange my work and upturn domestic arrangements before starting the five-hour journey. Again I had no idea how serious it was. I imagined he would wake up, be sick, and re-start the process. Again.

Later, when I found Luke's copy of Junky I kept it. I wanted to have what he was reading before he died. I was also searching for clues. I'd read it years ago when my friends and I thrilled to the "legendary account of heroin addiction drawn from William Burroughs's own life". We (safe, drug-free students) thought we were so avant-garde. But re-reading it on the train after the funeral gave me a rather different perspective. Although it contains some powerful truths, there are also some fundamental omissions. What strikes me now is the lack of cost. The self-obsessed, loveless, amoral existence it describes may not have cost the cold-eyed protagonist much, but someone, somewhere paid for it. Given that most junkies are too sick to work, their most basic requirement is money, so they either rely on their families, sign on, sell their ass or steal. But this isn't an issue for Burroughs because hey - he's lucky - he has a private income.

The other cost is human. Many junkies only survive for as long as they do because other people take care of them. In contrast, Burroughs's alter ego is a lone and friendless figure, operating in an apparent vacuum. But in reality such a lifestyle comes with an emotional price tag, as Burroughs should know. He is the man who got loaded and shot his wife.

I was alone with Luke for a number of hours just before he died. Nurses came by, telling me in snatches that it was less and less likely that he would ever wake up. I countered my rising panic by making all the usual bizarre promises to who/whatever - if only he'd pull through. But I knew in my heart that we'd lost him years ago. When my father first told me that Luke was injecting heroin I was devastated. I went to see him and cried about how I was so very sorry we'd drifted apart, I was a lousy sister, I felt for his pain, I wanted to help. But when I made to embrace him I saw he was somewhere else completely - he'd "nodded out" and off into his own padded envelope of opiates. He hadn't heard a word.

It is hard to maintain a meaningful relationship with someone who always has a prior engagement with their drug. We all did love him, but it was a strain. My parents argued between themselves about what should be done and I argued with them; at one point we barely spoke for a year. Meanwhile my own relationship took a battering. Things got particularly bad last Christmas (junk is no respecter of public holidays), and on Boxing Day I ended up weeping to the Crack Helpline while my partner's family waited patiently downstairs, the festive dinner congealed and tension between the two of us mounting, and continuing to mount over the difficult weeks that followed.

But this is tiny compared to Luke's pain. His final hit was an accidental overdose. We are assured it was accidental, but what does this mean for someone who regularly buys off the street and assaults themselves with a needle? He took risks and was clearly in torment. Sadly the whole drug thing obscured the real issue of his unhappiness, and my big regret is not trying harder to get through it and reach him.

I also wish Luke himself had tried a bit harder with Burroughs. From what I've since gathered, Luke thought he was a grand old junky hero. What he didn't perhaps get his head around is that Junky is only a book. Old Uncle Bill (as Burroughs fondly refers to himself) says that junk gets you when there's nothing else (ie, when there's a gap in your life). But what he fails to add is that he personally does have something else - he's a writer. Junky may well represent some of his experience but it's not the whole story. He can't have always lived such a chaotic, aimless life, because when did he sit down and write the book?

In the end the thing that marks Burroughs out as great is his writing, not his drugs. Junk didn't get him but it did get Luke and many, many others. The drug fills their gap, obscures their problems and (contrary to the myth that links drug-taking with talent) it saps their creativity. Indeed, Old Uncle Bill is currently marching on into his late eighties, while my mum sits at home with her son's ashesn

All names have been changed.