NHS Greater Glasgow & Clyde Area Drug and Therapeutics Committee
Greater Glasgow and Clyde Medicines
Medicines Update

Safety updates: Nitrofurantoin, contraceptives

Nitrofurantoin in renal impairment

The MHRA has intimated plans to amend the contraindication against use of nitrofurantoin in renal impairment from CrCl <60 mL/min to eGFR < 30mL/min. There will be additional advice that nitrofurantoin may be used with caution in eGFR 30-44mL/min for short term treatment of lower UTI involving resistant pathogens, when the benefits outweigh the risks of undesirable effects. Nitrofurantoin should not be used alongside alkalinising agents, eg potassium citrate.


Each of the UK Marketing Authorisation Holders of nitrofurantoin products will be asked to submit applications to MHRA to update their respective Summary of Product Characteristics which is likely to take a few months. The NHSGGC Therapeutics Handbook and antibiotic guidelines will be updated in light of this change.


Safety Update: Contraceptive Interaction

St John’s wort (Hypericum perforatum L.) is a herbal medicine used to relieve slightly low mood and mild anxiety. The MHRA advise that St John’s wort interacts with all hormonal contraceptives and reduces the effectiveness so increasing the risk of unplanned pregnancy. This applies to all hormonal contraceptives except intrauterine devices, for which there are currently no data. Women taking hormonal contraceptives should be advised not to take herbal products containing St John’s wort and encouraged to read the Patient Information Leaflet with their hormonal contraceptive.


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