Statins dosage: Patients on the anti-cholesterol drug rosuvastatin should inform their doctors immediately if they suffer from any unexplained muscle pain, weakness or cramps, according to the Irish Medicines Board (IMB).
And the drug, whose brand name is Crestor, should be discontinued if muscular symptoms are severe and causing daily discomfort, the IMB said yesterday.
Concerns that the new anti-cholesterol drug could cause the muscle-wasting disorder rhabdomyolysis were highlighted in the US Senate last week by the safety director of the Food and Drug Administration (FDA).
The IMB, which regulates drug use in the Republic, said renal effects such as proteinuria (protein in the urine) had been observed in patients treated with higher doses of the drug - in particular, a daily dose of 40mg. However, it said this had not yet been shown to be predictive of acute or progressive renal disease. Concerns about Crestor saw the share value of its manufacturer, AstraZeneca, fall by 9 per cent in recent days.
The Lancet medical journal last year accused AstraZeneca of "unprincipled" marketing of the drug while regulators in Germany blocked it on alleged safety grounds. Meanwhile, the Scientific Committee of the European Medicines Agency last week began a review of Crestor following concern about possible effects of high dosages. The minimum starting dose for Crestor is currently 10mg in Ireland, with a view to doubling the dose after four weeks, though some experts believe 5 mg is more appropriate.
AstraZeneca said: "We have a very robust clinical monitoring programme and we have seen no significant safety signal from that follow-up. The safety profile of Crestor is consistent with other statins and the efficacy profile offers significant advantages over other statins."