Drug doubles the risk of congenital malformation
By Daniel Cressey
GlaxoSmithKline has issued a worldwide warning on the use of paroxetine (Seroxat) during pregnancy after new research linked the drug to birth defects.
The new study – details of which GSK has passed to the UK drug regulator – found paroxetine more than doubled the risk of congenital malformation when used during the first trimester (see box, below).
GSK posted a statement on its website warning of the results. In the US, it sent a letter jointly with the Food and Drug Administration urging doctors to exercise caution in using the drug in pregnant women.
The company also cited US-Danish research, reported by Pulse last month, which linked SSRIs to congenital – and particularly cardiac – malformations.
Dr Brian Crichton, RCGP prescribing adviser and a GP in Solihull, West Midlands, said: ‘Now we've had two studies the wealth of data that we've got really does challenge us.' He said prescribing software should flag up a warning and the BNF ‘needs to take this data seriously in terms of a prescribing warning'.
Dr Crichton said there might be a ‘very small' number of people who would still need to use the drug, but he stressed: ‘We need to take this very seriously. We should not be prescribing these drugs in pregnancy.'
A spokesperson for GSK said: ‘We have shared this information with regulators who are now considering it.'
The UK's Medicines and Healthcare Products Regulatory Agency told Pulse its expert committee had considered preliminary data from both studies in early September and requested further information.
‘In the meantime the product information for paroxetine is being updated Europe-wide to reflect these new data. Current advice is that paroxetine should only be used in pregnancy when strictly indicated.'
US paroxetine labels are being changed to reflect the information and GSK said it anticipated changes would be agreed with other countries' agencies.
The MHRA said: ‘We are in discussion with EU colleagues about a communication to health professionals which will inform them of the new data and reiterate the current prescribing advice.'
Two studies that sound a warning
•Looked at more than 700 paroxetine users in a sample of 3,241 taking antidepressants
•Congenital malformations increased 1.8-fold relative to other antidepressant use
•Congenital malformations increased 2.0-fold excluding other teratogenic exposures
•Cardiovascular malformations increased 2.1-fold with teratogenics excluded
•Looked at 1,054 women using SSRIs in first trimester
•Congenital malformation risk increased 1.4-fold
•Cardiac malformation risk increased 1.6-fold•In separate analysis of 994 women, preterm birth increased 1.4-fold