Foetal abnormalities risk over ACE inhibitors and ARB prescriptions
By Emma Wilkinson
Warnings on treating women of childbearing age with ACE inhibitors or ARBs need to be toughened up to underline the risk of foetal abnormalities, say UK researchers.
Their study of referrals to a hospital hypertension clinic found almost half of women aged between 16 and 45 were prescribed the drugs.
Both NICE and BHS guidelines advise against use of ACE inhibitors and ARBs in women who wish to become pregnant.
Last December, the Medicines and Healthcare Products Regulatory Agency reiterated the risks following findings from a US study finding the drugs raised the odds of major congenital malformations almost three-fold.
But Dr Una Martin, senior lecturer in clinical pharmacology at the University of Birmingham and leader of the new study, said the findings demonstrated a ‘potentially serious problem' in implementing the guidelines.
She conceded that for some of the women in the study the choice of ACE inhibitor or ARB might have been a last resort, but warned that as many as 40% of pregnancies were unplanned and the risks to the foetus from both classes of drugs were ‘significant'.
‘Many GPs continue to prescribe ACE inhibitors and ARBs to women of childbearing age despite concerns that these agents may increase foetotoxicity and may be teratogenic.
‘Care needs to be taken to avoid ACE inhibitors and ARBs in fertile women and further clarification of the BHS and NICE guidelines may be needed to make this message clearer.'
The study of 1,500 referrals from general practice – published in October's Journal of Clinical Pharmacy and Therapeutics - found that 101 women were aged 16 to 45, of whom 47 were on an ACE inhibitor or ARB.
Some 26 of these women were under 40, and eight were using no contraception while three were only using barrier methods.
Dr Stewart Findlay, a GP in Bishop Auckland, County Durham and treasurer of the Primary Care Cardiovascular Society said it was ‘disappointing' that women were being put on the drugs without adequate contraception.
‘It's a message we have to get across to GPs – these drugs are not safe in pregnant women.
They should think very carefully about whether they should use these medications at all in women of childbearing age. The risk of complications from hypertension in young women is very low.'