The Product Information ( PI ) for Strontium ranelate has been updated following the completion of a TGA review into the medicine's benefit–risk profile.
Strontium ranelate is used to treat severe osteoporosis in postmenopausal women who are at high risk of fracture and men who are at increased risk of fracture. It is marketed in Australia under the brand name Protos.
The Product Information changes include an update to the indications requiring that Strontium ranelate only be used if all other treatments are deemed unsuitable, either due to contraindications or intolerance.
Other changes emphasise the contraindications, reinforce precautions, highlight the need for regular monitoring and update data relating to the risk of adverse events.
A black box warning has also been added to the Product Information, which summarises the changes.
Protos should only be used when other medications for the treatment for osteoporosis are considered unsuitable. Protos is contraindicated and must not be used in patients with established, current or past history of: ischaemic heart disease, peripheral vascular disease, cerebrovascular disease, uncontrolled hypertension, venous thromboembolism, pulmonary embolism. It should also not be used in patients who are temporarily or permanently immobilised. Protos should be used with caution in patients with risk factors for cardiovascular events or venous thrombosis: hypertension, diabetes mellitus, smoking, hyperlipidaemia. All patients prescribed Protos should be fully informed of the risk of cardiovascular events and venous thrombosis. Patients should be regularly monitored, every six months.
Data from randomised controlled trials show that Strontium ranelate is associated with an increased risk of myocardial infarction and venous thromboembolism.
In pooled randomised placebo-controlled studies of postmenopausal osteoporotic patients, a significant increase of myocardial infarction was observed in patients treated with Strontium ranelate as compared to placebo ( 5.7 per 1000 patient-years vs 3.6 per 1000 patient-years ), with a relative risk [ RR ] of 1.6 ( 95% CI 1.07–2.38 ).
In phase III studies, venous thromboembolism occurred in 2.7% of patients in the Strontium ranelate group and 1.9% of those in the placebo group, with a relative risk of 1.4 ( 95% CI 1.0–2.0 ).
Information for health professionals
Health professionals are encouraged to advise patients of the potential cardiovascular and venous thromboembolic adverse events associated with Strontium ranelate.
In particular, note that Strontium ranelate should only be used if all alternative treatments are considered unsuitable.
Strontium ranelate is contraindicated in patients who have: history of ischaemic heart disease, peripheral arterial disease or cerebrovascular disease systolic blood pressure greater than or equal to 160 mmHg, or diastolic blood pressure greater than or equal to 90 mmHg current or previous venous thromboembolic events, including deep vein thrombosis and pulmonary embolism temporary or permanent immobilisation ( for example, post-surgical recovery or prolonged bed rest ) severe renal impairment known hypersensitivity to Strontium ranelate or to any of the excipients.
Treatment should be stopped if the patient develops any of these conditions after being prescribed this drug.
If the patient becomes immobilised, treatment can be resumed if the event or illness causing the immobilisation is resolved and mobility returns.
Patients should be evaluated for relevant risk factors, including hypertension, diabetes mellitus, smoking, hyperlipidaemia, before being treated with Strontium ranelate.
Patients receiving ongoing treatment with Strontium ranelate should be monitored every six months. ( Xagena )
Source: TGA - Medicines Safety Update, Volume 5, Number 3, 2014