His family denied reports he had attempted to take his own life.
The 31-year-old has lost two stone in recent weeks as he faces the prospect of going on trial accused of murdering his wife in South Africa.
Wedding photo: Anni Dewani, 28, died after gunmen hijacked the newlyweds' taxi in South Africa last November. Shrien, left, has been accused of ordering the killing but denies any involvement. He is now said to have 'severe post-traumatic stress disorder'
He had not been sleeping - and his representative said he had been suffering from 'severe post-traumatic stress disorder'.
A family spokesman said: 'Shrien had a reaction to his sleeping tablets on Sunday and was taken to hospital as a precaution.
Tragic: Honeymooner Anni Dewani
'There was no intention to kill himself. He continues to suffer from severe post-traumatic stress disorder under the most extreme pressures from South Africa.'
His condition has been exacerbated by 'recent revelations about the sexual assault of his wife in South Africa and unhelpful and prejudicial comments from senior officials', the spokesman added.
New evidence has emerged in recent days reportedly indicating that Mrs Dewani was sexually assaulted before her murder and casting further doubt on the theory that she was killed on her husband's orders.
He is recovering in the Bristol Royal Infirmary but was expected to be discharged later.
The suspect, from Westbury-on-Trym, near Bristol, had reportedly lost 12kg in recent weeks.
He is facing an extradition hearing at City of Westminster Magistrates' Court in May.
His lawyers have argued he should not be sent to South Africa as he will not get a fair trial.
Traumatised: Shrien Dewani answers bail at Southmead Police Station in Bristol earlier today
'It was 10kg a couple of weeks ago and he has lost more since then. He is in a very fragile state and has not been eating or sleeping and has been giving his family and friends increasing concern.
'The nightmare has been made worse by the untrue accusations which have come out.
'He is OK in hospital but when he comes out will have to have 24-hour medical care at home.
'This hasn't just happened in the last week, it's been building up after Anni's death and obviously what happened would have traumatised anybody.
'We are hoping he will be home soon but he is very, very fragile, both physically and psychologically.'
Menzi Simelani, director of prosecutions in South Africa, has said: 'This is a pure criminal matter of somebody who murdered his wife while he should be celebrating his honeymoon.
'The facts here are that the accused, who is sought to be extradited, came to the country and committed what is a very heinous crime.'
His wife Anni died in a carjacking on their honeymoon which Mr Dewani is accused of ordering. He denies any involvement.
The carjackers' driver Zola Tongo, 31, was jailed for 18 years but claimed the honeymooner had paid him to have his wife killed.
Xolile Mngeni and Mziwamadoda Qwabe will appear before a judge on Friday accused of murder, robbery and kidnap following the killing in the Gugulethu township.
Read more: http://www.dailymail.co.uk/news/article-1359413/Shrien-Dewani-Honeymoon-murder-suspect-tried-commit-suicide-pills-overdose.html#ixzz1EiNeeSgw