With no explanation, label text_A→text_B with either "not_related" or "related".
text_A: Life Is Peachy is the second studio album by Korn.
text_B: Levomethadone -LRB- INN ; L-Polamidon , L-Polamivet , Levadone , Levothyl -RRB- , or levamethadone , is a synthetic opioid analgesic and antitussive which is marketed in Europe and is used for pain management and in opioid maintenance therapy .. INN. International Nonproprietary Name. synthetic. Chemical synthesis. opioid. opioid. analgesic. analgesic. antitussive. antitussive. Europe. Europe. pain management. pain management. opioid maintenance therapy. opioid replacement therapy. In addition to being used as a pharmaceutical drug itself , levomethadone , or R - - methadone , is the active enantiomer of methadone , having approximately 50x the potency of the S - - enantiomer as well as greater μ-opioid receptor selectivity .. opioid. opioid. pharmaceutical. pharmaceutical. drug. drug. active. biological activity. enantiomer. enantiomer. methadone. methadone. potency. potency ( pharmacology ). μ-opioid receptor. μ-opioid receptor. selectivity. binding selectivity. opioid receptor. opioid receptor. Accordingly , it is about twice as potent as methadone by weight and its effects are virtually identical in comparison .. methadone. methadone. In addition to its activity at the opioid receptors , levomethadone has been found to act as a weak competitive antagonist of the N-methyl-D-aspartate -LRB- NMDA -RRB- receptor complex and as a potent noncompetitive antagonist of the α3β4 nicotinic acetylcholine -LRB- nACh -RRB- receptor .. opioid. opioid. competitive. competitive inhibition. antagonist. receptor antagonist. noncompetitive. noncompetitive inhibition. There is now an asymmetric synthesis available to prepare both levomethadone -LSB- R - - methadone -RSB- and dextromethadone -LSB- S - - methadone -RSB- .. methadone. methadone. dextromethadone. dextromethadone. The separation of the stereoisomers is one of the easier in organic chemistry and is described in the original patent .. It involves `` treatment of racemic methadone base with d - - tartaric acid in an acetone / water mixture -LSB- which -RSB- precipitates almost solely the dextro-methadone levo-tartrate , and the more potent levo-methadone can easily be retrieved from the mother liquor in a high state of optical purity ''. methadone. methadone
not_related.