The European Medicines Agency (EMA) has completed a review of strontium ranelate (Protelos®). A positive benefit-risk balance has been confirmed but new contraindications and revised warnings have been recommended.
The review was initiated by a French study that identified almost 200 adverse drug reports. Approximately half of these were reports of venous thromboembolism (VTE) and about a quarter were skin reactions. These are both known reactions; VTE was identified during clinical trials and skin reactions, including drug rash with eosinophilia and systemic symptoms (DRESS), Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) identified during post-marketing surveillance.
The review identified that VTE risk is highest in individuals with a personal history of VTE or who are temporarily or permanently immobilised. Skin reactions are best managed by early diagnosis and immediate discontinuation of any suspect drug.
The EMA has made the following recommendations:
- Strontium ranelate should not be prescribed to patients with current VTE or a history of VTE, as well as patients who are temporarily or permanently immobilised.
- Current treatment with strontium ranelate in such patients should be reviewed at the next routine appointment.
- Patients should be warned about the potential for serious skin reactions. SJS and TEN usually occur in the first weeks of treatment while DRESS more usually occurs between 3 and 6 weeks.
- Patients should be advised to stop treatment immediately if severe allergic reactions arise (including skin reactions) and treatment should never be recommenced
Action: Clinicians should be aware of this review and implement any changes to practice made necessary by these new recommendations.