European Medicines Agency confirms positive benefit-risk balance of Protelos / Osseor, but recommends new contraindications and revised warnings

Press release 16/03/2012

Medicines no longer recommended for use in immobilised patients or patients with venous thromboembolism (VTE); update of warnings regarding serious skin reactions.

The European Medicines Agency's Committee for Medicinal Products for Human Use (CHMP) has finalised a review of Protelos and Osseor (strontium ranelate), from Les Laboratoires Servier. The Committee concluded that these medicines remain an important treatment for women with osteoporosis, but that changes to the prescribing advice are necessary to better manage associated risks.

Protelos and Osseor are indicated for the treatment of osteoporosis in postmenopausal women to reduce the risk of broken bones in the hip and spine.

The review of Protelos and Osseor was started following the publication of a study in France identifying 199 severe adverse reactions reported with these medicines from January 2006 to March 2009. Around half of these were VTE events, and about a quarter related to skin reactions.

VTE and severe skin reactions are known risks of these medicines and have been kept under close review by the CHMP. The risk of VTE was identified in clinical trials and the risk of severe skin reactions, such as drug rash with eosinophilia and systemic symptoms (DRESS), Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) had been reported post marketing. Information on these risks had been included in the product information as warnings or listed as reported side effects.

The CHMP has reviewed all available data on the safety of Protelos and Osseor. The data show that the risk of VTE is higher in patients with a history of VTE, as well as in patients who are temporarily or permanently immobilised. The number of cases of VTE in elderly patients is also shown to be higher with Protelos and Osseor compared with placebo.

The data also show that the incidence rate of serious skin reactions such as DRESS, SJS and TEN is low and no possible mechanism of action has been identified so far. Because the best results in managing these conditions come from early diagnosis and immediate discontinuation of any suspect drug, it is very important that doctors and patients are alert to the time-to-onset and signs and symptoms of these conditions.

Advice for doctors and patients

  • Doctors should not prescribe Protelos and Osseor to patients with current VTE or a history of VTE, as well as patients who are temporarily or permanently immobilised.
  • Patients with current VTE or a history of VTE, and those who are temporarily or permanently immobilised are advised to discuss their treatment with their doctor at their next scheduled appointment.
  • When treating patients over 80 years of age at risk of VTE, doctors should re-evaluate the need to continue treatment with Protelos or Osseor.
  • Prescribers should make patients aware of the time to onset and likely signs and symptoms of severe skin reaction such as DRESS, SJS or TEN. The highest risk for occurrence of SJS or TEN is within the first weeks of treatment and usually around three to six weeks for DRESS. Symptoms or signs of SJS or TEN include progressive skin rash, often with blisters or mucosal lesions; symptoms of DRESS include rash, fever, eosinophilia and systemic involvement (e.g. adenopathy, hepatitis, interstitial nephropathy, interstitial lung disease).
  • Patients should stop treatment immediately when symptoms of severe allergic reactions, including skin rash, occur. Treatment should not be restarted at any time in these patients.


  • A European Commission decision on this opinion will be issued in due course.
  • The European review of Protelos and Osseor was conducted in the context of a formal review, initiated at the request of the European Commission under Article 20 of Regulation (EC) No 726/2004 on 14 October 2011.
  • The reference to the French study is as follows: Ranélate de strontium (Protelos): effets indésirables rapportés en France; Presse Med. 2011; 40(10):e453-e462.

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