The MHRA regulates many herbal medicines but there are still remedies that are available on the market that have not been licensed. It is important that any suspected ADR which occurs from an herbal remedy is reported and includes as much information as possible about the ingredients, the source, supplier and reason for prescription.
Patients and healthcare professionals should also be aware that interactions between herbal and other prescribed or OTC medications can cause unwanted effects, e.g. St John’s Wort causing reduced blood concentrations of some commonly prescribed drugs including warfarin, ciclosporin, oral contraceptives, digoxin, theophylline and SSRI’s, leading to a loss of drug effect with potentially serious outcomes.
Further information regarding the safety of herbal medicines can be found on the MHRA website