Isotretinoin is used to treat severe acne. It should only be prescribed by physicians with expertise treating severe acne which has not responded to other treatments, such as antibiotics and creams or gels. Isotretinoin is known to cause birth defects in infants exposed when mothers take the drug whilst pregnant, as well as mental health and sexual function side effects. Because of the risk to infants, women prescribed isotretinoin who have the potential to become pregnant are required to enter a Pregnancy Prevention Programme (PPP) so they are fully informed of the risks and to prevent potential harm to an unborn baby from isotretinoin exposure. The PPP includes the agreement to use contraception and undergo pregnancy testing during, and one month subsequent to, treatment. Although isotretinoin is mainly prescribed by specialists in hospital settings, some prescribing can take place in primary care by general practitioners with an extended role (GPwER). The Medicines and Healthcare products Regulatory Agency (MHRA) has received information that some women are being exposed to isotretinoin during pregnancy, but the extent of this is unknown. There is also interest in understanding the extent of GPwER isotretinoin prescribing more broadly due to wider risks of mental health and sexual function side-effects. This feasibility study aims to estimate the available sample size for a potential future study on isotretinoin prescribing in primary care and exposure during pregnancy. This work will support possible further regulatory action to ensure the safe use of isotretinoin.
Isotretinoin is an orally administered systemic retinoid used to treat severe acne where other treatments have proved ineffective. Isotretinoin is known to cause birth defects and is also associated with neuropsychiatric and sexual function side-effects. Isotretinoin is predominantly prescribed by specialists in secondary care and to a lesser extent by GPs with an extended role (GPwER). Prior to initiating treatment, patients must sign an Acknowledgement of Risk Form (AoRF) indicating they have been informed of the potential risks described above. Women of child-bearing potential must undergo pregnancy testing before, during and 1 month after ending treatment and use contraception as part of the PPP. The MHRA has received information that some women are being exposed to isotretinoin during pregnancy, but the extent of this is unknown. There is also interest in understanding the extent of GPwER isotretinoin prescribing more broadly in men and women of all ages because of other side effects. This feasibility study aims to estimate the available sample size for a potential future study on isotretinoin prescribing in primary care and exposure during pregnancy. The study will use the Aurum primary care data to ascertain isotretinoin prescriptions and the pregnancy register to ascertain pregnancy dates from 1st January 2015 onwards.
The objectives are to:
1. Calculate rates/proportions of men and women prescribed oral isotretinoin and their age distribution.
2. Calculate proportions of pregnancies exposed to oral isotretinoin and the maternal age distribution.
3. Tabulations of isotretinoin prescribing falling before and within pregnancy dates and their outcomes.
This feasibility study and any future resulting research will improve our understanding of the effectiveness of current regulatory requirements for isotretinoin prescribing, and the need for further intervention and monitoring, to ensure patient safety.
Rates/proportions of men and women prescribed isotretinoin; Numbers/proportions of pregnancies exposed to oral isotretinoin; Age-groups of women with maternal isotretinoin exposure (<12 years, 12-17 years, 18-24 years, 25-34 years, 35-44 years, 45+ years); Pregnancy outcomes following maternal isotretinoin exposure; Distribution (histogram) of the numbers of isotretinoin prescriptions issued in men, women and exposed pregnancies stratified by age-groups; Numbers/proportions of isotretinoin exposed women where prescriptions ended before a pregnancy.
Craig Allen - Chief Investigator - MHRA
Craig Allen - Corresponding Applicant - MHRA
CPRD Aurum Pregnancy Register