Millions of women battling cystitis may be making it worse by taking ibuprofen for the symptoms.
Taking the common painkiller can make a urinary tract infection last three days longer and risks a kidney infection, a study has found.
More than half of women suffer a UTI such as cystitis during their lifetime, with one in five facing the misery of recurrent infections.
After doubt was cast last week on cranberry juice’s ability to tackle the problem, evidence now suggests ibuprofen is the wrong approach.
The study of almost 400 women by the University of Oslo found women given the over-the-counter drug without antibiotics took longer to get better.
They were around half as likely to have recovered by day four of the illness.
More than half of British women suffer from a urinary tract infection such as cystitis during their lifetime, and the condition is the second most common reason GPs prescribe antibiotics
Among the 181 given ibuprofen, seven developed a kidney infection and five were hospitalised.
It is believed antibiotics can cut a bladder infection short and provide quick relief from the symptoms, which include pain, fatigue and an urgent need to urinate.
But the advice on the NHS Choices website is still that it is possible to treat the symptoms at home, taking ibuprofen while drinking lots of water.
‘We cannot recommend ibuprofen alone’
The authors of the latest study, led by Ingvild Vik at the University of Oslo, say many women given ibuprofen do see their symptoms clear up without further treatment.
But they add: ‘Until we can identify those women in need of antibiotic treatment to prevent complications, we cannot recommend ibuprofen alone to women with uncomplicated UTIs.’
Urinary tract infections are the second most common reason that GPs prescribe antibiotics.
However previous studies have suggested up to two-thirds of female sufferers could recover without the powerful drugs by taking ibuprofen instead.
To test this, researchers split 383 women aged 18 to 60 into two groups and gave them either ibuprofen or the common antibiotic pivmecillinam.
The drugs were hidden in red capsules of the same weight and taken three times a day for three days.
Some women taking ibuprofen developed more serious infections
Only 39 per cent of women taking the painkiller were better by day four, compared to 74 per cent of those taking the antibiotic.
Within a fortnight, more than two in five women given ibuprofen had gone back to the doctor still in pain, compared to fewer than 10 per cent of the group on antibiotics.
Furthermore, 12 of the women taking ibuprofen developed a more serious upper urinary tract infection, causing fever and pain in their side.
No patients taking antibiotics developed kidney infections, but seven of those given painkillers did.
It comes a week after health watchdog NICE ruled there is ‘no evidence’ that cranberry juice works to tackle urinary infections, although it did say antibiotic prescriptions should be reduced.
Antibiotics are best but women with milder symptoms can ‘wait and see’
The latest study did find more than half of patients treated with ibuprofen got better without antibiotics but express concern over possible side effects.
The study, published in the journal PLOS Medicine, concludes: ‘Antibiotic treatment is the best treatment we have for uncomplicated UTI.’
Dr Ingvild Vik, who led the study, said: ‘Given the fact that a few patients developed a more serious infection, we cannot recommend treatment with ibuprofen alone to women with uncomplicated UTI.
‘However, a large amount of women did get well without antibiotic treatment, and we believe that for women with milder symptoms a wait-and-see strategy can be discussed.
‘These women should then be instructed to drink a lot of fluids and start taking antibiotics if she doesn’t recover within a few days or if her symptoms worsen.’