This is almost heartbreakingly sad. Rick Shapiro, never the most consistent comedians at the best of times, is simply too ill to be doing stand-up.

He has no focus or concentration, and the droves  of people who walk out during the course of his show in pure disappointment of a man not fit for the job makes for a tragic image.

The Fringe programme entry for Rebirth talks of the car crash he was in four years ago that gave him amnesia.  But after that went to press, he was admitted to hospital with cardiac problems, where he stayed for 75 days, getting out a little over a month before the Fringe. ‘I’m on more drugs now that I was when I was a heroin addict,’ he jokes in one of the few lines he manages to slur out OK.

His doctor told him: ‘You can’t do comedy.’ Which is about as effective a review as I could give. But, like a washed-up boxer stepping into the ring since that’s all he knows,  he’s stepping back on to the stage.

You can understand his need to get back to doing what he does, which if this was some Hollywood script, would be a movingly heroic move.  But the truth is that he’s not yet ready to return: incoherent, forgetful and clearly ill – it’s only sympathy that leaves him with any audience at all.

For all that comedy should about honesty, which Shapiro’s certainly is, it’s also about communication and laughter – which are very scarce resources tonight. ‘These jokes are going to suck for ten minutes,’ he tells us at the start, then to those still remaining after 40 minutues: ‘I forgot all my jokes, that’s the truth.’

Elsewhere another plea comes: ‘Let me fuck up…’ which is a latitude every comedian needs sometimes – but not at £14 a ticket.

For Shapiro, narrative is something that happens to other people, and he stumbles around disconnected ideas, hoping for something to land. Sometimes the ideas seem old, such as women using sex to emasculate their men, or pondering ‘how come all the bad actors dies yet Matthew McConaughey is still alive?’ for which he must owe Bill Hick royalties.

Yet in rare, fleeting moments of clarity, there are tantalising glimpses of what this could be, a brutal, angry look at the real miseries of his harsh life, contrasted to the spoiled idiot he heard whine: ‘I NEED a zucchini muffin.’ Isolated – very isolated one-liners provide points of laughter, but the whole show seems like intruding on a recovery process.

He says comedy’s role is to go where life is horrible and pull out the happy face… but Shapiro is just as likely to pull out a severed head. A bleak theatrical ending, largely autobiographical, about a young man driven from home and into a spiral of drugs and prostitution, would be a poignant end to a powerful stand-up show – but here it just underlines the heart-rendingly sad hour we’ve just witnessed.

The recuperation Shapiro needs is more than Dr Theatre can provide. Get well soon.