Expecting the worst

Taking any sort of medicine these days carries an element of risk. Even some of the most thoroughly tested compounds can have unexpected side-effects in some individuals, never mind more recent therapies like Viagra and Cialis, which are now implicated in loss of vision in some men, and Vioxx and Lipobay, both withdrawn following a number of fatalities.

In today's litigious society it is no wonder then that the list of contraindications on the patient instruction leaflet is approaching the size of a small encyclopedia in some cases.

But are we playing it too safe? Is the drug companies' fear of being sued leading to unnecessary suffering among patients? Or are we right to err on the side of caution in case of doing more harm than good?

Last month a leading doctor in the UK accused the pharma manufacturers of being overcautious in advising women to avoid many useful medicines if they are pregnant or breast-feeding, even though there is no evidence that these drugs would harm the unborn child.

According to Dr Jim Kennedy, the Royal College of GPs' head of prescribing, expectant mothers are being denied use of drugs for everything from headaches and depression to infections and, in some cases, they may be risking their own health unnecessarily by not taking things like statins or antiepilepsy drugs.

Ironically, his claim came in the same week as news that a drug prescribed to pregnant women to reduce the risk of premature birth might actually be responsible for causing up to 1,000 pre-term births in the UK each year. In a study of 900 high-risk women, the antibiotic metronidazole was found to double the risk of premature birth rather than reduce it, although it still had the benefit of cutting the risk of infection in the baby.

For obvious reasons, women who are pregnant - or even where there is the slightest possibility that they might be - are not included in clinical trials. Consequently there is no evidence of common medicines harming the unborn child. But equally, there is no evidence that they do not.

The probability is that these products are safe, but just how big an element of risk would be acceptable? Fifty years on, the shadow of thalidomide still lingers, and if there is even the remotest chance that a drug taken to relieve a cough or a headache might damage their baby, the majority of mothers-to-be would sooner suffer the symptoms than take that risk.