Calcutta, Jan.18 :    Calcutta, Jan.18:  It's arrived. The wonder drug that could help a large segment of the male population suffering from erectile dysfunction, especially between the ages 40 and 70. Chemists in the city have stocked up sildenafil citrate, the basic ingredient of the revolutionary drug Viagra. Four of the six Indian companies that were last week given the green signal by the Drug Controller of India have entered Calcutta with their products, that cannot be purchased without a prescription. In all four, the drug is the same, and is available in three doses: 25 mg, 50 mg and 100 mg. The prices are surprisingly low, compared to the rates at which the smuggled Viagra was being sold in the grey market. For example, Sun Pharmaceuticals, which held its official launch in the city on Thursday, has priced the drug at Rs 12 for 25 mg, Rs 18 for 50 mg and Rs 27 for 100 mg. Their product is called Edegra. Cadilla has also supplied drug stores with its product, called Penegra, as has Torrent (Endoz) and Ranbaxy (Cavetra). Edegra, however, is more commonly available. The drug has already been prescribed by city doctors. Dr Uday Choudhury, consultant psychiatrist, has got a feedback from six of the eight patients he has prescribed the drug to in the last four days. 'All have said they have had good results.' Dr Dipak Mukherjee, consultant urologist, has been prescribing the drug (Viagra) for quite some time for those who could import it. 'Sildenafil will now be easier to get, now that it has been officially sanctioned.' Even doctors attached to government hospitals do not see any harm in prescribing the drug. Dr Subhankar Choudhury, senior endocrinologist at SSKM Hospital, said: 'With the new drug not being that expensive, it will be possible to prescribe it to more patients.' A man, married for the last three years, was among the first to pick up a strip of Edegra from a central Calcutta drug store on Thursday afternoon, albeit with a prescription. 'This could well help to turn around my marriage,' he said. Global studies say that about 52 per cent men between 40 and 70 suffer from dysfunction today. In India, one of every 10 patients has the problem. 'In India, men do not come forward with their problems. Hopefully, awareness will grow, now that an answer is available,' said Shyamal Ghosh, senior vice-president of Sun Pharma.