text: Five drugs in the class of NNRTIs have been approved by regulatory authorities. These are the first generation NNRTIs nevirapine, delavirdine and efavirenz and the next generation NNRTIs etravirine, and rilpivirine. Several other NNRTIs underwent clinical development but were discontinued due to unfavourable pharmacokinetic, efficacy and/or safety factors.
  Currently there are four other NNRTIs undergoing clinical development, IDX899, RDEA-428 and lersivirine (table 2).