In pharmacology, an antitarget (or off-target) is a receptor, enzyme, or other biological target that, when affected by a drug, causes undesirable side-effects. During drug design and development, it is important for pharmaceutical companies to ensure that new drugs do not show significant activity at any of a range of antitargets, most of which are discovered largely by chance.[1][2]
Among the best-known and most significant antitargets are the hERG channel and the 5-HT2B receptor, both of which cause long-term problems with heart function that can prove fatal (long QT syndrome and cardiac fibrosis, respectively), in a small but unpredictable proportion of users. Both of these targets were discovered as a result of high levels of distinctive side-effects during the marketing of certain medicines, and, while some older drugs with significant hERG activity are still used with caution, most drugs that have been found to be strong 5-HT2B agonists were withdrawn from the market, and any new compound will almost always be discontinued from further development if initial screening shows high affinity for these targets.[3][4][5][6][7][8]
Agonism of the 5-HT2A receptor is an antitarget because 5-HT2A receptor agonists are associated with hallucinogenic effects.[9] According to David E. Nichols, "Discussions over the years with many colleagues working in the pharmaceutical industry have informed me that if upon screening a potential new drug is found to have serotonin 5-HT2A agonist activity, it nearly always signals the end to any further development of that molecule."[9] There are some exceptions however, for instance efavirenz and lorcaserin, which can activate the 5-HT2A receptor and cause psychedelic effects at high doses.[10][11][12]
The growth of the field of chemoproteomics has offered a variety of strategies to identify off-targets on a proteome wide scale.[13]
See also
[edit]References
[edit]- ^ Klabunde, T.; Evers, A. (2005). "GPCR antitarget modeling: pharmacophore models for biogenic amine binding GPCRs to avoid GPCR-mediated side effects". ChemBioChem. 6 (5): 876–889. doi:10.1002/cbic.200400369. PMID 15791686. S2CID 33198528.
- ^ Price, D.; Blagg, J.; Jones, L.; Greene, N.; Wager, T. (2009). "Physicochemical drug properties associated with in vivo toxicological outcomes: a review". Expert Opinion on Drug Metabolism & Toxicology. 5 (8): 921–931. doi:10.1517/17425250903042318. PMID 19519283. S2CID 34208589.
- ^ De Ponti, F.; Poluzzi, E.; Cavalli, A.; Recanatini, M.; Montanaro, N. (2002). "Safety of non-antiarrhythmic drugs that prolong the QT interval or induce torsade de pointes: an overview". Drug Safety. 25 (4): 263–286. doi:10.2165/00002018-200225040-00004. PMID 11994029. S2CID 37288519.
- ^ Recanatini, M.; Poluzzi, E.; Masetti, M.; Cavalli, A.; De Ponti, F. (2005). "QT prolongation through hERG K(+) channel blockade: current knowledge and strategies for the early prediction during drug development". Medicinal Research Reviews. 25 (2): 133–166. doi:10.1002/med.20019. PMID 15389727. S2CID 34637861.
- ^ Raschi, E.; Vasina, V.; Poluzzi, E.; De Ponti, F. (2008). "The hERG K+ channel: target and antitarget strategies in drug development". Pharmacological Research. 57 (3): 181–195. doi:10.1016/j.phrs.2008.01.009. PMID 18329284.
- ^ Raschi, E.; Ceccarini, L.; De Ponti, F.; Recanatini, M. (2009). "hERG-related drug toxicity and models for predicting hERG liability and QT prolongation". Expert Opinion on Drug Metabolism & Toxicology. 5 (9): 1005–1021. doi:10.1517/17425250903055070. PMID 19572824. S2CID 207490564.
- ^ Huang, X.; Setola, V.; Yadav, P.; Allen, J.; Rogan, S.; Hanson, B.; Revankar, C.; Robers, M.; Doucette, C.; Roth, B. L. (2009). "Parallel Functional Activity Profiling Reveals Valvulopathogens Are Potent 5-Hydroxytryptamine2B Receptor Agonists: Implications for Drug Safety Assessment". Molecular Pharmacology. 76 (4): 710–722. doi:10.1124/mol.109.058057. PMC 2769050. PMID 19570945.
- ^ Bhattacharyya, S.; Schapira, A. H.; Mikhailidis, D. P.; Davar, J. (2009). "Drug-induced fibrotic valvular heart disease". The Lancet. 374 (9689): 577–85. doi:10.1016/S0140-6736(09)60252-X. PMID 19683643. S2CID 205953943.
- ^ a b Nichols DE (2016). "Psychedelics". Pharmacol. Rev. 68 (2): 264–355. doi:10.1124/pr.115.011478. PMC 4813425. PMID 26841800.
- ^ Treisman GJ, Soudry O (2016). "Neuropsychiatric Effects of HIV Antiviral Medications". Drug Saf. 39 (10): 945–57. doi:10.1007/s40264-016-0440-y. PMID 27534750. S2CID 6809436.
- ^ Gatch MB, Kozlenkov A, Huang RQ, Yang W, Nguyen JD, González-Maeso J, Rice KC, France CP, Dillon GH, Forster MJ, Schetz JA (2013). "The HIV antiretroviral drug efavirenz has LSD-like properties". Neuropsychopharmacology. 38 (12): 2373–84. doi:10.1038/npp.2013.135. PMC 3799056. PMID 23702798.
- ^ "Schedules of Controlled Substances: Placement of Lorcaserin into Schedule IV". 2013-05-08.
- ^ Moellering, Raymond E.; Cravatt, Benjamin F. (January 2012). "How Chemoproteomics Can Enable Drug Discovery and Development". Chemistry & Biology. 19 (1): 11–22. doi:10.1016/j.chembiol.2012.01.001. ISSN 1074-5521. PMC 3312051.
Well, that’s interesting to know that Psilotum nudum are known as whisk ferns. Psilotum nudum is the commoner species of the two. While the P. flaccidum is a rare species and is found in the tropical islands. Both the species are usually epiphytic in habit and grow upon tree ferns. These species may also be terrestrial and grow in humus or in the crevices of the rocks.
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