Euro battle over denying mercury sphygmos to GPs
By Daniel Cressey
The UK drug regulator is fighting European proposals that may jeopardise accurate measurement of blood pressure by denying GPs the use of mercury sphygmomanometers.
The European Commission is discussing proposals from four member states to expand a phase-out of mercury devices to cover those used for health care, such as thermometers and sphygmos.
The Medicines and Healthcare Products Regulatory Agency has instructed UK officials to lobby for medical devices to be excepted, after expressing serious concerns over the accuracy of available alternatives.
The MHRA's committee on blood pressure monitoring in clinical practice warned last year that oscillometric devices were often unsuitable for the diagnosis of hypertension, while its researchers have found aneroid devices are often out by 3mmHg or more.
An agency spokesperson told Pulse: 'Some countries are very concerned about the effects of mercury on the environment and want the widest possible restrictions on its use.
'So it is by no means certain that an exemption for medical devices using mercury can be obtained.'
Professor Andrew Shennan, who chaired the MHRA committee, told Pulse it would be five to 10 years before there were accurate non-mercury devices, and that it would be 'dangerous' to phase out mercury devices before then.
Professor Shennan, professor of obstetrics at King's College London, said: 'People probably aren't aware how bad the alternatives are. The vast majority are not up to clinical use.'
He added: 'I would hope within five to 10 years there would be a wide range of alternatives that are accurate. To ban mercury sphygmos today would be dangerous. The problem is there aren't enough validated devices out there and we also need a reference to assess new devices.'
The MHRA has briefed the UK representative on the European discussions to request an exemption for mercury sphygmos 'while alternative methods are established'.
Dr Peter McCartney, a GP in Bristol and another member of the blood pressure monitoring committee, said it was vital mercury devices were retained, at least for calibration purposes.
'They're the most reliable machine around, and the least prone to error. Before mercury is abandoned we need alternatives for calibration,' he warned.