Girls who take the morning-after capsule are being warned that these taking widespread drugs may have a double dose after analysis discovered 400 undesirable pregnancies.
edicines regulators have issued a public warning, explaining that some medicines and natural cures can intrude with the emergency contraception.
The Medicines and Healthcare merchandise Regulatory Company (MHRA) issued new steerage over the capsule after analysis discovered tons of of undesirable pregnancies amongst these taking it.
The MHRA mentioned that girls taking medicines for epilepsy, natural cures containing St John’s Wort, and medicines for fungal infections would possibly want a double dose of the emergency contraceptive for it to be efficient.
Medication for tuberculosis and HIV had been additionally discovered to intrude with the effectiveness of the drugs.
The watchdog mentioned that the non-hormonal coil was probably the most appropriate type of emergency contraception for a lot of of these taking the day by day drugs.
But when this was not attainable, a double dose of the morning after capsule was advisable, consultants mentioned.
Dr Sarah Department, deputy director of MHRA’s vigilance and danger administration of medicines division, mentioned: “That is essential new recommendation for girls who need to use the emergency contraceptive capsule.
“It’s going to assist to guard girls who’re taking sure medicines towards undesirable pregnancies.
“Our new affected person data sheet offers data on what kinds of medicines might intrude with how the emergency contraceptive works.
“It tells girls what steps they should take to make sure they obtain the proper dose.
“The sooner that emergency contraception is taken after unprotected intercourse, the higher it really works.”
The MHRA mentioned it had information on 400 undesirable pregnancies in girls taking levonorgestrel because it was first licensed within the Nineteen Seventies. A spokesman mentioned it was not clear what number of of those pregnancies had been as a result of interactions with different medication, however mentioned analysis had discovered a hyperlink.
Levonorgestrel – marketed beneath manufacturers together with Levonelle and Plan B – needs to be taken inside 72 hours (three days) of unprotected intercourse.
The medication that may intrude with it embrace carbamazepine, barbiturates, primidone, phenytoin for epilepsy, rifampicin and rifabutin for TB, ritonavir and efavirenz for HIV, medication for fungal infections, together with griseofulvin, and any natural cures containing St John’s Wort, which is used to deal with despair.
The watchdog mentioned it first grew to become conscious of the problem in 2014, and had issued the brand new recommendation after a overview by the European Medicines Company, which accomplished in Could of this 12 months.
The brand new data sheet will likely be out there by GP surgical procedures and pharmacies.
Telegraph Media Group Restricted