FDA asks Asians to cut down on Crestor

Its public health advisory recommends that all patients taking Crestor use the lowest possible dose. The agency, in particular, suggests a 5-mg starting dose for Asian patients, those with serious kidney problems and for patients who might have other risk factors for muscle problems.

Asians appear to process the drug differently. A clinical trial in the US found that levels of Crestor in Asian patients were double those of Caucasians taking the same dose, increasing the chance of muscle damage.

The FDA also issued a general warning that high doses of the drug, about 40 mg, was harmful for all. The agency sounded the warning after an expert group said the drug should be banned.

About 4 million people in the US are said to be on the cholesterol-lowering drug, marketed by AstraZeneca, since its launch in August 2003.

While no data on people using the drug in India is available, about half-dozen companies here are already manufacturing copies of the drug. Ranbaxy, Lupin and Microlabs were the first ones to come out with their versions. The most common brands here are Rosuvas (Ranbaxy), Turbovas (Microlabs), Novastatin (Lupin) and Rozucor (Torrent).

While Astra-Zeneca has revised the package insert for Crestor, after a discussion with the FDA, the government has not come out with any specific warning or instruction to drug manufacturers so far.

‘‘The black boxes and warnings on medicines are an ongoing process. We have conducted our own trials and given approval. They (FDA) are talking about higher doses,’’ says Dr Ashwini Kumar, the Drug Controller General of India. ‘‘I feel we should not prescribe the drug until further studies are conducted here. India is a vast country and we have to have specific largescale trials. The fresh warning should be an eye-opener,’’ says Dr Anoop Misra, Professor of Internal Medicine at AIIMS.

No trials were conducted by AstraZeneca in India and the trial data available was based on studies in the US, Europe, Canada, South Africa and Australia. Even as the DCGI grants approval, based on clinical data from Europe or US, confirmatory trials by Indian generic companies in about 120 patients so far is too little to reveal any adverse reactions.

As Indian companies are marketing three doses — 5 mg, 10 mg and 20 mg — the efficacy studies sampled about 30 to 40 people for each dose.

‘‘A trial, with only 25 to 30 patients, will have less than one per cent patients reporting adverse events. Also, as there are genetic differences, the DCGI should insist on studies on different ethnic Indian populations like Aryans, Dravidians and people from the North-East,’’ said an expert.