Cycloserine

{{Short description|Tuberculosis medication}} {{About|the tuberculosis medicine|the nerve agent|Cyclosarin}} {{cs1 config |name-list-style=vanc|display-authors=6}} {{Infobox drug | Watchedfields = changed | verifiedrevid = 460111047 | image = Cycloserine.svg | image_class = skin-invert-image | width = 150px | image2 = Cycloserine ball-and-stick model.png | image_class2 = bg-transparent | width2 = 125px

| tradename = Seromycin | Drugs.com = {{drugs.com|monograph|cycloserine}} | DailyMedID = Seromycin | pregnancy_category = | routes_of_administration = Oral | class = Antibiotic; Alanine racemase inhibitor; D-Alanine–D-alanine ligase inhibitor; NMDA receptor partial agonist; GABA-T inhibitor | ATC_prefix = J04 | ATC_suffix = AB01 | ATC_supplemental =

| legal_US = Rx-only | legal_status =

| CAS_number_Ref = {{cascite|correct|??}} | CAS_number = 68-41-7 | PubChem = 6234 | DrugBank_Ref = {{drugbankcite|correct|drugbank}} | DrugBank = DB00260 | ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}} | ChemSpiderID = 5998 | UNII_Ref = {{fdacite|correct|FDA}} | UNII = 95IK5KI84Z | KEGG_Ref = {{keggcite|correct|kegg}} | KEGG = D00877 | ChEBI_Ref = {{ebicite|correct|EBI}} | ChEBI = 40009 | ChEMBL_Ref = {{ebicite|correct|EBI}} | ChEMBL = 771 | NIAID_ChemDB = 007654 | synonyms = {{sc|d}}-cycloserine, 4-amino-3-isoxazolidinone

| IUPAC_name = (''R'')-4-Amino-1,2-oxazolidin-3-one | C = 3 | H = 6 | N = 2 | O = 2 | SMILES = O=C1NOC[C@H]1N | StdInChI_Ref = {{stdinchicite|correct|chemspider}} | StdInChI = 1S/C3H6N2O2/c4-2-1-7-5-3(2)6/h2H,1,4H2,(H,5,6)/t2-/m1/s1 | StdInChIKey_Ref = {{stdinchicite|correct|chemspider}} | StdInChIKey = DYDCUQKUCUHJBH-UWTATZPHSA-N

| melting_point = 155 | melting_high = 156 | melting_notes = (dec.) }}  '''Cycloserine''', sold under the brand name '''Seromycin''', is a broad-spectrum antibiotic used as a second-line treatment for advanced tuberculosis and, rarely, urinary tract infections (UTIs).<ref name=drugs/> Specifically, it is used in conjunction with other antituberculosis medications for the treatment of active drug resistant tuberculosis.<ref name=drugs/> Cycloserine's use for the treatment of UTIs is similarly alternative, with the drug being primarily reserved for when conventional therapies have failed and antimicrobial susceptibility is demonstrated.<ref name=drugs/> It is administered orally.<ref name="drugs">{{cite web|title=Cycloserine|url=https://www.drugs.com/monograph/cycloserine.html|publisher=Drugs.com, The American Society of Health-System Pharmacists|date=2024|access-date=28 November 2024}}</ref>

Cycloserine is a structural analogue of the amino acid D-alanine and works by inhibiting bacterial cell wall synthesis.<ref name=drugs/> As cycloserine is able to penetrate the central nervous system, it may cause side effects including headaches, drowsiness, depression, dizziness, vertigo, confusion, paresthesias, dysarthria, hyperirritability, psychosis, convulsions, and shaking (tremors).<ref name="Nitsche - DCS-bg">{{cite journal | vauthors = Nitsche MA, Jaussi W, Liebetanz D, Lang N, Tergau F, Paulus W | date = August 2004 | title = Consolidation of human motor cortical neuroplasticity by D-cycloserine | journal = Neuropsychopharmacology | volume = 29 | issue = 8 | pages = 1573–1578 | doi = 10.1038/sj.npp.1300517 | doi-access = free | pmid = 15199378 }}</ref><ref name=NIH>{{cite web|title=CYCLOSERINE: Human Health Effects|url=http://toxnet.nlm.nih.gov/cgi-bin/sis/search/r?dbs+hsdb:@term+@rn+68-41-7|publisher=National Institutes of Health|archive-url=https://web.archive.org/web/20140416080623/http://toxnet.nlm.nih.gov/cgi-bin/sis/search/r?dbs+hsdb%3A%40term+%40rn+68-41-7|archive-date=2014-04-16}}</ref> Overdose of cycloserine may result in paresis, seizures, and coma, while alcohol consumption may increase the risk of seizures.<ref name=NIH /> Coadministration of pyridoxine, or vitamin B6, may reduce the incidence of some CNS-related side effects.<ref>{{cite web |title=Vitamin B6 Fact Sheet for Health Professionals |url=https://ods.od.nih.gov/factsheets/VitaminB6-HealthProfessional/ |website=Office of Dietary Supplements |publisher=National Institutes of Health |access-date=24 May 2026}}</ref> Cycloserine is not recommended for those with kidney failure, epilepsy, depression, or alcoholism.<ref name=drugs/> While animal studies have shown adverse effects, it is unknown if cycloserine use during pregnancy poses a developmental risk to human fetuses.<ref name=drugs/><ref>{{cite web |title=Cycloserine Pregnancy and Breastfeeding Warnings |url=https://www.drugs.com/pregnancy/cycloserine.html |website=Drugs.com |access-date=24 May 2026}}</ref>

Derived simultaneously by Eli Lilly and Merck from ''Streptomyces'' in 1954,<ref>{{cite book | vauthors = Gottlieb D, Shaw PD | date = 2012 | title = Mechanism of Action | publisher = Springer Science & Business Media | page = 41 | isbn = 978-3-642-46051-7 | url = https://books.google.com/books?id=xjPtCAAAQBAJ&pg=PA41 | archive-date = 2016-12-20 | archive-url = https://web.archive.org/web/20161220092417/https://books.google.ca/books?id=xjPtCAAAQBAJ&pg=PA41 | url-status = live }}</ref> Cycloserine was widely used in the 1950s and 1960s as a primary treatment for acute UTIs and tuberculosis. Upon the discovery of its neuropsychiatric side effects, usage decreased dramatically beginning in the 1970s.<ref name="Sapko_2024">{{cite journal | vauthors = Sapko MT, Manyak M, Panicucci R, Javitt JC | date = March 2024 | title = NRX-101 (D-Cycloserine + Lurasidone) Is Active against Drug-Resistant Urinary Pathogens In Vitro | journal = Antibiotics | publisher = National Institutes of Health | volume = 13 | issue = 4 | page = 308 | doi = 10.3390/antibiotics13040308 | doi-access = free | pmc = 11047644 | pmid = 38666984 }}</ref> Cycloserine is classified as a Group B agent for the treatment of multidrug-resistant tuberculosis by the World Health Organization, a classification that defines it as a "conditionally recommended [agent] of second choice."<ref>{{cite web |title=WHO consolidated guidelines on drug-resistant tuberculosis treatment |url=https://iris.who.int/server/api/core/bitstreams/30d89c8e-8e59-4f52-82b4-9a30882a09bf/content |website=Institutional Repository for Information Sharing |publisher=World Health Organization |access-date=24 May 2026}}</ref> Additionally, it is on the World Health Organization's List of Essential Medicines.<ref name="WHO21st">{{cite book | vauthors = ((World Health Organization)) | year = 2019 | title = World Health Organization model list of essential medicines: 21st list 2019 | publisher = World Health Organization | hdl = 10665/325771 | author-link = World Health Organization | location = Geneva | id = WHO/MVP/EMP/IAU/2019.06. License: CC BY-NC-SA 3.0 IGO | hdl-access = free }}</ref> Cycloserine has received some research interest from the field of psychiatry, most notably in the formulation of cycloserine/lurasidone as a treatment for bipolar depression and suicidal ideation.<ref name="Sapko_2024" />

==Medical uses== ===Tuberculosis=== Cycloserine is used primarily for the treatment of multidrug-resistant (MDR-TB) and extensively drug-resistant (XDR-TB) strains of ''M. tuberculosis'', remaining a second- or third-line of treatment for the condition due to its significant neurological and psychological side effects. Cycloserine is always used as part of a multidrug regimen. Because the drug leaves users susceptible to high blood concentrations and systemic toxicity, users require frequent renal, hepatic and hematologic laboratory monitoring.<ref name=drugs/>

===Urinary tract infections=== Cycloserine has demonstrated clinical efficacy against multi-drug resistant urinary pathogens, being approved for the treatment of acute UTIs caused by ''E. coli'' and ''Enterobacter'' species.<ref name=drugs/> Additionally, cycloserine has shown in vitro activity against drug-resistant strains of ''Pseudomonas aeruginosa'', ''Klebsiella pneumoniae'' and ''Acinetobacter baumannii''.<ref name="Sapko_2024" /> Cycloserine's use in treating UTIs is extremely uncommon both due to its comparatively lower efficacy against traditional antibiotics, as well as its significant neurological and psychological side effects.<ref name=drugs/> Consequently, it is treated as a drug of last resort, used when other primary options have been exhausted.

==Pharmacology== ===Mechanism of action=== Cycloserine works as an antibiotic by inhibiting cell-wall biosynthesis in bacteria.<ref name="Lambert-tuberculosis">{{cite journal | vauthors = Lambert MP, Neuhaus FC | date = June 1972 | title = Mechanism of D-cycloserine action: alanine racemase from Escherichia coli W | journal = Journal of Bacteriology | volume = 110 | issue = 3 | pages = 978–987 | doi = 10.1128/JB.110.3.978-987.1972 | pmc = 247518 | pmid = 4555420 }}</ref><ref name=Prosser>{{cite journal | vauthors = Prosser GA, de Carvalho LP | date = February 2013 | title = Kinetic mechanism and inhibition of Mycobacterium tuberculosis D-alanine:D-alanine ligase by the antibiotic D-cycloserine | journal = The FEBS Journal | volume = 280 | issue = 4 | pages = 1150–1166 | doi = 10.1111/febs.12108 | doi-access = free | pmid = 23286234 | s2cid = 22305408 }}</ref> As a cyclic analogue of D-alanine, cycloserine acts against two crucial enzymes important in the cytosolic stages of peptidoglycan synthesis: alanine racemase (Alr) and D-alanine:D-alanine ligase (Ddl).<ref name=Prosser /> The first enzyme is a pyridoxal 5'-phosphate-dependent enzyme which converts the L-alanine to the D-alanine form.<ref name=Prosser /> The second enzyme is involved in joining two of these D-alanine residues together by catalyzing the formation of the ATP-dependent D-alanine-D-alanine dipeptide bond between the resulting D-alanine molecules.<ref name=Prosser /> If both of these enzymes are inhibited, then D-alanine residues cannot form and previously formed D-alanine molecules cannot be joined.<ref name=Prosser /> This effectively leads to inhibition of peptidoglycan synthesis.<ref name=Prosser />

Psychiatric use is suggested based on partial NMDA receptor agonism, which improves neural plasticity in lab animals. The degree of clinical usefulness is, as aforementioned, unclear and still being explored, as of 2016.<ref name=schade/>

L-Cycloserine is known to act as a GABA transaminase inhibitor (GABA-T inhibitor) and to have anticonvulsant effects.<ref name="PolcPieriBonetti1986">{{cite journal | vauthors = Polc P, Pieri L, Bonetti EP, Scherschlicht R, Moehler H, Kettler R, Burkard W, Haefely W | title = L-cycloserine: behavioural and biochemical effects after single and repeated administration to mice, rats and cats | journal = Neuropharmacology | volume = 25 | issue = 4 | pages = 411–418 | date = April 1986 | pmid = 3012401 | doi = 10.1016/0028-3908(86)90236-4 | publisher = Elsevier BV | s2cid = 462885 }}</ref><ref name="WoodPeeskerGorecki1978">{{cite journal | vauthors = Wood JD, Peesker SJ, Gorecki DK, Tsui D | title = Effect of L-cycloserine on brain GABA metabolism | journal = Canadian Journal of Physiology and Pharmacology | volume = 56 | issue = 1 | pages = 62–68 | date = February 1978 | pmid = 638858 | doi = 10.1139/y78-009 | url = }}</ref>

==Chemistry== ===Chemical properties=== Under mildly acidic conditions, cycloserine hydrolyzes to give hydroxylamine and D-serine.<ref name=Kaushal /><ref name="Silverman-GABA">{{cite journal| vauthors = Silverman R |title=An Aromatization Mechanism of Inactivation of γ-Aminobutyric Acid Aminotransferase for the Antibiotic l-Cycloserine|journal=Journal of the American Chemical Society|year=1998|volume=120|issue=10|pages=2256–2267|doi=10.1021/ja972907b |bibcode=1998JAChS.120.2256O }}</ref> Cycloserine can be conceptualized as a cyclized version of serine, with an oxidative loss of dihydrogen to form the nitrogen-oxygen bond.{{citation needed|date=August 2022}}

Cycloserine is stable under basic conditions, with the greatest stability at pH = 11.5.<ref name=Kaushal>{{cite journal | vauthors = Kaushal G, Ramirez R, Alambo D, Taupradist W, Choksi K, Sirbu C | date = October 2011 | title = Initial characterization of D-cycloserine for future formulation development for anxiety disorders | journal = Drug Discoveries & Therapeutics | volume = 5 | issue = 5 | pages = 253–260 | doi = 10.5582/ddt.2011.v5.5.253 | doi-access = free | pmid = 22466372 }}</ref>

===Synthesis=== Initial approaches to synthesize the compound was first published in 1955, when the Stammer group produced a racemic synthesis from {{sc|dl}}‐β‐aminoxyalanine ethyl ester. In 1957, Platter ''et al.'' managed to synthesis the pure D-enantiomer by cyclizing the corresponding α‐amino‐β‐chlorohydroxamic acids. Chemical synthesis of the compound was revolutionized in the 2010s, when several approaches starting with the cheap {{sc|d}}-serine (mirror form of normal L-serine) were published by different groups.<ref>{{cite journal | vauthors = Holt GR | title=Principles of Plastic Surgery of Congenital Facial Abnormalities | journal=Facial Plastic Surgery | date=1986 | volume=3 | issue=03 | pages=147–154 | doi=10.1055/s-2008-1064836 | pmid=3459696 }}</ref>

The biosynthesis of the compound is defined by a ten-gene cluster. {{sc|l}}-serine and {{sc|l}}-arginine are converted to O-ureido-{{sc|l}}-serine, flipped to O-ureido-{{sc|d}}-serine, then turned into the final compound by cyclization. In 2013, Uda ''et al.'' successfully used recombinant versions of three enzymes in the cluster to produce the compound.<ref>{{cite journal | vauthors = Uda N, Matoba Y, Kumagai T, Oda K, Noda M, Sugiyama M | title = Establishment of an in vitro D-cycloserine-synthesizing system by using O-ureido-L-serine synthase and D-cycloserine synthetase found in the biosynthetic pathway | journal = Antimicrobial Agents and Chemotherapy | volume = 57 | issue = 6 | pages = 2603–2612 | date = June 2013 | pmid = 23529730 | pmc = 3716191 | doi = 10.1128/AAC.02291-12 }}</ref>

A 1963 patent describes industrial production of the drug by bacterial fermentation.<ref>{{cite web | vauthors = Harned RL |title= US3090730A Process for the production of cycloserine |website=Google Patents |url=https://patents.google.com/patent/US3090730A/en |date=21 May 1963}}</ref> It is unclear what process is used in the 21st century, fermentation, or chemical synthesis.{{citation needed|date=December 2022}}

==History== The compound was first isolated nearly simultaneously by two teams. Workers at Merck isolated the compound, which they called oxamycin, from a species of ''Streptomyces''.<ref>{{cite journal | vauthors = Kuehl Jr FA, Wolf FJ, Trenner NR, Peck RL, Buhs RP, Howe E, Putter I, Hunnewell BD, Ormond R, Downing G, Lyons JE | year = 1955 | title = D-4-Amino-3-isoxazolidinone, a new antibiotic | journal = Journal of the American Chemical Society | volume = 77 | issue = 8 | pages = 2344–2345 | doi = 10.1021/ja01613a105 | bibcode = 1955JAChS..77.2344K }}</ref> The same team prepared the molecule synthetically.<ref>{{cite journal | vauthors = Hidy PH, Hodge EB, Young VV, Harned RL, Brewer GA, Phillips WF, Runge WF, Stavely HE, Pohland A, Boaz H, Sullivan HR | year = 1955 | title = Synthesis of D-4-amino-3-isoxazolidinone | journal = Journal of the American Chemical Society | volume = 77 | issue = 8 | pages = 2346–2347 | doi = 10.1021/ja01613a107 | author-link4 = Karl Folkers | bibcode = 1955JAChS..77.2346S }}</ref> Workers at Eli Lilly isolated the compound from strains of ''Streptomyces orchidaceus''. It was shown to hydrolyze to serine and hydroxylamine.<ref>{{cite journal | vauthors = Hidy PH, Hodge EB, Young VV, Harned RL, Brewer GA, Phillips WF, Runge WF, Stavely HE, Pohland A, Boaz H, Sullivan HR | year = 1955 | title = Structure and reactions of cycloserine | journal = Journal of the American Chemical Society | volume = 77 | issue = 8 | pages = 2345–2346 | doi = 10.1021/ja01613a106 | bibcode = 1955JAChS..77.2345H }}</ref>

==Society and culture== ===Economics=== In the U.S., the price of cycloserine increased from $500 for 30 pills to $10,800 in 2015 after the Chao Center for Industrial Pharmacy and Contract Manufacturing changed ownership to Rodelis Therapeutics in August 2015.<ref name=NYT2015>{{cite news | vauthors = Pollack A |title=Drug Goes From $13.50 a Tablet to $750, Overnight|work=The New York Times |url=https://www.nytimes.com/2015/09/21/business/a-huge-overnight-increase-in-a-drugs-price-raises-protests.html?ref=health&_r=0|access-date=21 September 2015|date=20 September 2015|url-status=live|archive-url=https://web.archive.org/web/20150925195708/http://www.nytimes.com/2015/09/21/business/a-huge-overnight-increase-in-a-drugs-price-raises-protests.html?ref=health&_r=0|archive-date=25 September 2015}}</ref>

The price increase was rescinded after the previous owner, the Purdue University Research Foundation, which retained "oversight of the manufacturing operation" intervened and Rodelis returned the drug to an NGO of Purdue University. The foundation now will charge $1,050 for 30 capsules, twice what it charged before". Eli Lilly has been criticised for not ensuring that the philanthropic initiative continued. Due to US antitrust laws, however, no company may control the price of a product after it is outlicensed.<ref name=NYT2015B/>

In 2015, the cost in the United States was increased to {{Currency|3,150|USD|linked=no}} a month and then decreased to {{Currency|1,050|USD|linked=no}} per month.<ref name=NYT2015B>{{cite news | vauthors = Pollack A |title=Big Price Increase for Tuberculosis Drug Is Rescinded|url=https://www.nytimes.com/2015/09/22/business/big-price-increase-for-tb-drug-is-rescinded.html?_r=0|access-date=24 September 2015|work=NYT|date=21 September 2015|url-status=live|archive-url=https://web.archive.org/web/20150926033207/http://www.nytimes.com/2015/09/22/business/big-price-increase-for-tb-drug-is-rescinded.html?_r=0|archive-date=26 September 2015}}</ref>

==Research== ===Psychiatric disorders=== A 2015 Cochrane review found no evidence of benefit in anxiety disorders as of 2015.<ref>{{cite journal | vauthors = Ori R, Amos T, Bergman H, Soares-Weiser K, Ipser JC, Stein DJ | title = Augmentation of cognitive and behavioural therapies (CBT) with d-cycloserine for anxiety and related disorders | journal = The Cochrane Database of Systematic Reviews | volume = 2015 | issue = 5 | article-number = CD007803 | date = May 2015 | pmid = 25957940 | doi = 10.1002/14651858.CD007803.pub2 | pmc = 8939046 }}</ref> Another review found preliminary evidence of benefit.<ref name="schade">{{cite journal | vauthors = Schade S, Paulus W | title = D-Cycloserine in Neuropsychiatric Diseases: A Systematic Review | journal = The International Journal of Neuropsychopharmacology | volume = 19 | issue = 4 | article-number = pyv102 | date = April 2016 | pmid = 26364274 | pmc = 4851259 | doi = 10.1093/ijnp/pyv102 }}</ref> Evidence for use in addiction is tentative but also unclear.<ref>{{cite journal | vauthors = Myers KM, Carlezon WA | date = June 2012 | title = D-cycloserine effects on extinction of conditioned responses to drug-related cues | journal = Biological Psychiatry | volume = 71 | issue = 11 | pages = 947–955 | doi = 10.1016/j.biopsych.2012.02.030 | pmc = 4001849 | pmid = 22579305 }}</ref>

Reviews in 2016-17 found that cycloserine produced a small improvement in cognitive behavioral therapy for anxiety, obsessive-compulsive disorder, and post-traumatic stress disorder,<ref name="mataix">{{cite journal | vauthors = Mataix-Cols D, Fernández de la Cruz L, Monzani B, Rosenfield D, Andersson E, Pérez-Vigil A, Frumento P, de Kleine RA, Difede J, Dunlop BW, Farrell LJ, Geller D, Gerardi M, Guastella AJ, Hofmann SG, Hendriks GJ, Kushner MG, Lee FS, Lenze EJ, Levinson CA, McConnell H, Otto MW, Plag J, Pollack MH, Ressler KJ, Rodebaugh TL, Rothbaum BO, Scheeringa MS, Siewert-Siegmund A, Smits JA, Storch EA, Ströhle A, Tart CD, Tolin DF, van Minnen A, Waters AM, Weems CF, Wilhelm S, Wyka K, Davis M, Rück C, Altemus M, Anderson P, Cukor J, Finck C, Geffken GR, Golfels F, Goodman WK, Gutner C, Heyman I, Jovanovic T, Lewin AB, McNamara JP, Murphy TK, Norrholm S, Thuras P | title = D-Cycloserine Augmentation of Exposure-Based Cognitive Behavior Therapy for Anxiety, Obsessive-Compulsive, and Posttraumatic Stress Disorders: A Systematic Review and Meta-analysis of Individual Participant Data | journal = JAMA Psychiatry | volume = 74 | issue = 5 | pages = 501–510 | date = May 2017 | pmid = 28122091 | doi = 10.1001/jamapsychiatry.2016.3955 | hdl = 2066/174490 | hdl-access = free }}{{Erratum|doi=10.1001/jamapsychiatry.2017.0144|pmid=28297011|checked=yes}}</ref> and had potential for use as a therapy in psychiatric diseases.<ref name="schade"/> Adding D-cycloserine to exposure therapy did not improve results over exposure therapy alone in a 2025 meta-analysis of children and teenagers with OCD.<ref>{{cite journal | vauthors = Steele DW, Kanaan G, Caputo EL, Freeman JB, Brannan EH, Balk EM, Trikalinos TA, Adam GP | date = December 2024 | title = Treatment of Obsessive-Compulsive Disorder in Children and Youth: A Meta-Analysis | journal = Pediatrics | volume = 155 | issue = 3 | doi = 10.1542/peds.2024-068992 | pmid = 39639456 | doi-access = free }}</ref>

Recent research has investigated the use of cycloserine for augmentation of transcranial magnetic stimulation in the treatment of depression, based on its putative effects as a neuroplastogen.<ref>{{cite journal | vauthors = DeMayo MM, Watson M, Harris AD, McGirr A | title = Serum levels of D-cycloserine predict antidepressant effects in pharmacologically enhanced intermittent theta-burst stimulation | journal = Journal of Affective Disorders | volume = 377 | pages = 60–67 | date = May 2025 | pmid = 39986577 | doi = 10.1016/j.jad.2025.02.062 | doi-access = free }}</ref> Preliminary studies have found adding cycloserine improves response and remission rates compared to rTMS alone.<ref>{{cite journal | vauthors = Vaughn D, Marino B, Dojnov A, Stine M, Weiss N, Engelbertson A, Vila-Rodriguez F, Nanos G, Downar J | date = April 2025 | title = Real-World Effectiveness of a Single-Day Regimen for Transcranial Magnetic Stimulation Using Optimized, Neuroplastogen-Enhanced Techniques in Anxiety (ONE-A). | journal = Transcranial Magnetic Stimulation | volume = 3 | page = 100123 }}</ref><ref>{{cite journal | vauthors = Cole J, Sohn MN, Harris AD, Bray SL, Patten SB, McGirr A | title = Efficacy of Adjunctive D-Cycloserine to Intermittent Theta-Burst Stimulation for Major Depressive Disorder: A Randomized Clinical Trial | journal = JAMA Psychiatry | volume = 79 | issue = 12 | pages = 1153–1161 | date = December 2022 | pmid = 36223114 | pmc = 9557938 | doi = 10.1001/jamapsychiatry.2022.3255 }}</ref>

===Possible hallucinogenic effects=== Cycloserine is closely structurally related to muscimol, a GABAA receptor agonist and hallucinogen found in ''Amanita muscaria''.<ref name="BrimblecombePinder1975">{{cite book | vauthors = Brimblecombe RW, Pinder RM | date = 1975 | chapter = Miscellaneous Hallucinogens | title = Hallucinogenic Agents | publisher = Wright-Scientechnica | pages = 196–216 | isbn = 978-0-85608-011-1 | url = https://bitnest.netfirms.com/external/Books/978-0-85608-011-1 | location = Bristol | oclc = 2176880 | ol = OL4850660M | quote = However, the closely related antibiotic oxamycin [(d-cycloserine)] (7.6) produces mental confusion, acute psychotic episodes, convulsions, and other abnormal behavioural states in man reminiscent of the isoxazoles [like muscimol and ibotenic acid] contained in Amanita muscaria (Farnsworth, 1968). }}</ref> It has been said to produce effects in humans, including mental confusion, acute psychosis, convulsions, and other abnormal behavioral states, which are reminiscent of those of muscimol.<ref name="BrimblecombePinder1975" />

== References == {{Reflist}}

== Further reading == {{refbegin}} * {{cite book | vauthors = Frahm AW, Hager HH, von Bruchhausen F, Albinus M, Hager H | date = 1999 | title = Hagers Handbuch der pharmazeutischen Praxis: Folgeband 4: Stoffe A–K. | publisher = Birkhäuser | isbn = 978-3-540-52688-9 }} {{refend}}

{{Antimycobacterials}} {{Cell wall disruptive antibiotics}} {{Neurotransmitters}} {{GABA metabolism and transport modulators}} {{Ionotropic glutamate receptor modulators}} {{Glutamate metabolism and transport modulators}} {{Portal bar | Medicine}} {{Authority control}}

Category:Aldols Category:Anti-tuberculosis drugs Category:GABA transaminase inhibitors Category:Isoxazolidinones Category:NMDA receptor agonists Category:Wikipedia medicine articles ready to translate Category:World Health Organization essential medicines