Drugs cheaper than threepenny: the market of extremely low-priced drugs within the National Health Insurance in Taiwan.

While most drug policy researches paid attention to the financial impact of expensive drugs, the market situation of low-priced drugs in a country was seldom analyzed. We used the nationally representative claims datasets to explore the status within the National Health Insurance (NHI) in Taiwan. In 2007, a total of 12,443 distinct drug items had been prescribed 853,250,147 times with total expenditure of 105,216,950,198 new Taiwan dollars (NTD). Among them, 7,366 oral drug items accounted for 701,353,383 prescribed items and 68,133,988,960 NTD. Besides, 2,887 items (39.2% of oral drug items) belonged to cheap drugs with the unit price ≤ 1 NTD (about 0.03 of US dollar). While the top one item among all oral drugs had already a market share of 5.0%, 30 items 30.3% and 107 items 50.0%, the cheap drugs with aggregate 332,893,462 prescribed items (47.5% of all prescribed oral drug items) only accounted for 2,750,725,433 NTD (4.0% of expenditure for oral drugs and 2.6% of total drug expenditure). The drug market of Taiwan's NHI was abundant in cheap drugs. The unreasonably low prices of drugs might not guarantee the quality of pharmaceutical care and the sustainability of a healthy pharmaceutical industry in the long run.