The rupee today lost 42 paise to 55.60 against the US dollar in early trade on the Interbank Foreign Exchange market. as.Forex dealers said besides weakness in the euro against the dollar overseas on euro-zone worries, month-end demand for the American currency from importers also weighed on the rupee's value.The rupee ended 20 paise higher at close at 55.18 against the US currency yesterday.