41. Gilead Sciences Inc . and Triangle Pharmaceuticals Inc . are also developing Non-nucleoside Reverse Transcriptase Inhibitors. 42. AZT sticks to and blocks reverse transcriptase , one of the enzymes that HIV needs to replicate. 43. Third, for any virus that does enter cells, the microbicide would block an enzyme, reverse transcriptase . 44. Viread is a member of the class of antiretroviral drugs known as nucleoside reverse transcriptase inhibitors. 45. Delaviridine is the second in a new class of drugs known as non-nucleoside reverse transcriptase inhibitors. 46. Sustiva binds directly to the gene-deciphering enzyme and is known as a non-nucleoside reverse transcriptase inhibitor. 47. These chemicals are called reverse transcriptase and protease. 48. Four HIV drugs currently marketed work by blocking reverse transcriptase , a protein active earlier in the cycle. 49. Calanolide A is unique among NNRTIs in that it may bind two distinct sites in reverse transcriptase . 50. These two drugs attack the same target, an enzyme component of the virus known as reverse transcriptase .
