{"ATC Code":"N04BA01","Abbreviation":["DOPA","L-DOPA"],"Absorption, Distribution and Excretion":"Orally inhaled levodopa reaches a peak concentration in 0.5 hours with a bioavailability than is 70% that of the immediate release levodopa tablets with a peripheral dopa decarboxylase inhibitor like carbidopa or benserazide.","Adverse Effects":"The common adverse effects of Levodopa treatment are nausea, dizziness, headache, and somnolence. Increasing carbidopa is recommended to relieve nausea, and domperidone can be helpful if additional carbidopa is ineffective. Special precaution is necessary for elderly patients because they may be more sensitive to the central nervous system (CNS) effects. The most common side effects in older patients taking levodopa can be confusion, hallucinations, delusions, psychosis, and agitation. There may be a greater risk of hip fractures in older adults due to levodopa mildly increasing homocysteine levels as an adverse effect. Patients presenting with an idiopathic parkinsonian disorder and who are on levodopa can also develop low serum vitamin B12, elevated methylmalonic acid levels, and greater chances of sensorimotor peripheral neuropathy.","Biological Half-Life":"2.3 hours for orally inhaled levodopa. Oral levodopa has a half life of 50 minutes but when combined with a peripheral dopa decarboxylase inhibitor, the half life is increased to 1.5 hours.","CAS":"59-92-7","Chemical Classes":"Biological Agents -\u003e Amino Acids and Derivatives","ChemicalClasses":["amino acid","catecholamine"],"Chirality":"absolute","ChiralityAminoAcid":true,"Color/Form":"Colorless to white crystals or crystalline powder; needles from water","Decomposition":"When heated to decomposition it emits toxic fumes of /nitrogen oxides/.","Drug Classes":["Breast Feeding","Lactation","Milk, Human","Antiparkinson Agents","Dopamine Agents"],"Drug Indication":"Levodopa on its own is formulated as an oral inhalation powder indicated for intermittent treatment of off episodes in Parkinson's patients who are already being treated with carbidopa and levodopa. Levodopa is most commonly formulated as an oral tablet with a peripheral dopa decarboxylase inhibitor indicated for treatment of Parkinson's disease, post-encephalitic parkinsonism, and symptomatic parkinsonism following carbon monoxide intoxication or manganese intoxication.","Drug Warnings":"PT WITH CARDIAC ARRHYTHMIAS OR HISTORY OF MYOCARDIAL INFARCTION SHOULD UNDERGO INITIAL THERAPY WITH LEVODOPA ONLY IN FACILITY EQUIPPED FOR INTENSIVE CORONARY CARE. ...DIABETIC PT...SHOULD BE CAREFULLY MONITORED FOR ANY NECESSITY TO MODIFY THEIR REGIMEN. CAUTION ALSO NECESSARY IN PT WITH HISTORY OF PEPTIC ULCER, CONVULSIONS...","EliminationHalfLife":"0.75 – 1.5 hours","Esters":[],"European Community (EC) Number":"200-445-2","FDA Pharmacological Classification":"46627O600J","Formating":[],"HMDB ID":"HMDB0000181","HeavyAtomCount":14,"Human Drugs":"Breast Feeding; Lactation; Milk, Human; Antiparkinson Agents; Dopamine Agents","IUPACName":"(2S)-2-amino-3-(3,4-dihydroxyphenyl)propanoic acid","InChI":"InChI=1S/C9H11NO4/c10-6(9(13)14)3-5-1-2-7(11)8(12)4-5/h1-2,4,6,11-12H,3,10H2,(H,13,14)/t6-/m0/s1","InChIKey":"WTDRDQBEARUVNC-LURJTMIESA-N","Interactions":"The pharmacokinetics of levodopa (LD) with \u0026 without pramipexole in men \u0026  postmenopausal women with Parkinson's disease /were studied/. Patients on stable dose of carbidopa/LD were  randomized to receive escalating doses of placebo or pramipexole over 7 wks. LD \u0026 pramipexole  pharmacokinetics were performed after a single test dose 25/100 of carbidopa/LD, before  initiation of pramipexole or placebo, at 1.5 mg/d \u0026 4.5 mg/d of pramipexole or placebo.  Compared to men, women had greater LD bioavailability. Pramipexole did not alter LD  bioavailability, \u0026 pramipexole pharmacokinetics were equivalent in men \u0026 women.","MeSH Pharmacological Classification":"Agents used in the treatment of Parkinson\u0026apos;s disease. The most commonly used drugs act on the dopaminergic system in the striatum and basal ganglia or are centrally acting muscarinic antagonists.","Mechanism of Action":"Levodopa by various routes crosses the blood brain barrier, is decarboxylated to form dopamine. This supplemental dopamine performs the role that endogenous dopamine cannot due to a decrease of natural concentrations and stimulates dopaminergic receptors.","Melting Point":"284-286 °C","Metabolism/Metabolites":"Levodopa is either converted to dopamine by aromatic-L-amino-acid decarboxylase or O-methylated to 3-O-methyldopa by catechol-O-methyltransferase. 3-O-methyldopa cannot be metabolized to dopamine. Once levodopa is converted to dopamine, it is converted to sulfated or glucuronidated metabolites, epinephrine E, or homovanillic acid through various metabolic processes. The primary metabolites are 3,4-dihydroxyphenylacetic acid (13-47%) and homovanillic acid (23-39%).","MolecularFormula":"C\u003csub\u003e9\u003c/sub\u003eH\u003csub\u003e11\u003c/sub\u003eNO\u003csub\u003e4\u003c/sub\u003e","MolecularWeight":"197.19 g/mol","Non-Human Toxicity Values":"LD50 Rat oral 1780 mg/kg","Odor":"Odorless","Opticalactivity":"UNSPECIFIED","Pharmacodynamics":"Levodopa is able to cross the blood-brain barrier while dopamine is not. The addition of a peripheral dopa decarboxylase inhibitor prevents the conversion of levodopa to dopamine in the periphery so that more levodopa can reach the blood-brain barrier. Once past the blood-brain barrier, levodopa is converted to dopamine by aromatic-L-amino-acid decarboxylase.","Physical Description":"Colorless to white odorless solid; [Merck Index] White crystalline solid; [Sigma-Aldrich MSDS]","PubChemId":6047,"Record Description":["LiverTox|CNS|Parkinsons agent|Dopamine precursor"],"Records":{"UNII":{"Impurities":["3-o-methyldopa, dl-","dopa, d-","6-hydroxydopa, l-","tyrosine","l-veratrylglycine"]}},"RefCount":3,"RefCur":"","References":[{"Name":"Wikipedia","Urls":[{"Link":"https://en.wikipedia.org/wiki/Levodopa","Name":"3,4-Dihydroxyphenylalanine","Sub":false}]},{"Name":"Wikidata","Urls":[{"Link":"https://www.wikidata.org/wiki/Q106345614","Name":"3,4-Dihydroxyphenylalanine","Sub":false}]},{"Name":"DrugBank","Urls":[{"Link":"https://go.drugbank.com/drugs/DB01235","Name":"3,4-Dihydroxyphenylalanine","Sub":false}]},{"Name":"PubChem","Urls":[{"Link":"https://pubchem.ncbi.nlm.nih.gov/compound/6047","Name":"3,4-Dihydroxyphenylalanine","Sub":false}]},{"Name":"Common Chemistry","Urls":[{"Link":"https://commonchemistry.cas.org/detail?cas_rn=59-92-7","Name":"3,4-Dihydroxyphenylalanine","Sub":false}]},{"Name":"HMDB","Urls":[{"Link":"https://hmdb.ca/metabolites/HMDB0000181","Name":"3,4-Dihydroxyphenylalanine","Sub":false}]},{"Name":"KEGG","Urls":[{"Link":"https://www.kegg.jp/entry/C00355","Name":"3,4-Dihydroxyphenylalanine","Sub":false}]},{"Name":"UNII","Urls":[{"Link":"https://gsrs.ncats.nih.gov/ginas/app/ui/substances/46627O600J","Name":"3,4-Dihydroxyphenylalanine","Sub":false}]},{"Name":"EPA DSSTox","Urls":[{"Link":"https://comptox.epa.gov/dashboard/chemical/details/DTXSID9023209","Name":"3,4-Dihydroxyphenylalanine","Sub":false}]}],"Refs":["National Center for Biotechnology Information. PubChem Compound Summary for CID 6047, Levodopa. Accessed November 13, 2025. \u003ca href=https://pubchem.ncbi.nlm.nih.gov/compound/6047\u003ehttps://pubchem.ncbi.nlm.nih.gov/compound/6047\u003c/a\u003e","U.S. Food and Drug Administration; National Center for Advancing Translational Sciences. 3,4-Dihydroxyphenylalanine. UNII: 46627O600J. Global Substance Registration System. Accessed November 13, 2025. \u003ca href=https://gsrs.ncats.nih.gov/ginas/app/beta/substances/46627O600J\u003ehttps://gsrs.ncats.nih.gov/ginas/app/beta/substances/46627O600J\u003c/a\u003e"],"SMILES":"C1=CC(=C(C=C1C[C@@H](C(=O)O)N)O)O","SaltData":[],"Salts":[],"Scheduling":[{"gov":"Australia","ref":[],"schedule":"S4 substance"},{"gov":"United Kingdom","ref":[],"schedule":"prescription only substance"},{"gov":"United States","ref":[],"schedule":"prescription only substance"},{"gov":"European Union","ref":[],"schedule":"prescription only substance"}],"Solubility":"5mM","Stability/Shelf Life":"IN PRESENCE OF MOISTURE RAPIDLY OXIDIZED BY ATMOSPHERIC OXYGEN \u0026 DARKENS","StereoisomerData":[],"Stereoisomers":[],"Structure":"\u003csvg xmlns=\"http://www.w3.org/2000/svg\" preserveAspectRatio=\"none\" style=\"display:block\" viewBox=\"0 0 106.638 67.131\"\u003e\u003crect width=\"100%\" height=\"100%\" fill=\"#fff\"/\u003e\u003cdesc\u003eGenerated by the Chemistry Development Kit 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51.251h-.62v-2.286H1.173v2.286H.56v-4.9h.613v2.072h2.512v-2.072h.62z\"/\u003e\u003c/g\u003e\u003cpath stroke=\"#ff0d0d\" d=\"m96.229 24.045-4.957-2.862M33.525 60.128l.001-5.659M10.404 46.908l4.96-2.864M10.404 46.908l4.96-2.864\" class=\"hi\"/\u003e\u003c/g\u003e\u003c/g\u003e\u003c/svg\u003e","Taste":"Tasteless","Therapeutic Uses":"Levodopa is indicated to alleviate symptoms and allow more normal body movements with improved muscle control in the treatment of idiopathic Parkinson's disease, postencephalitic parkinsonism, or symptomatic parkinsonism that may follow injury to the nervous system by carbon monoxide intoxication or manganese intoxication. It is also indicated in parkinsonism associated with cerebral arteriosclerosis. /Included in US product labeling/","Title":"3,4-Dihydroxyphenylalanine","Toxicity Data":"LD50: 2363 mg/kg (Oral, Mouse) (A308)\nLD50: 609 mg/kg (Oral, Rabbit) (A308)\nLD50: 1780 mg/kg (Oral, Rat) (A308)","Treatment":"Hospitalization is advised, and general supportive measures should be employed, along with immediate gastric lavage and repeated doses of charcoal over time. This may hasten the elimination of entacapone in particular, by decreasing its absorption/reabsorption from the GI tract.  Intravenous fluids should be administered judiciously and an adequate airway maintained. The adequacy of the respiratory, circulatory and renal systems should be carefully monitored and appropriate supportive measures employed. Electrocardiographic monitoring should be instituted and the patient carefully observed for the development of arrhythmias; if required, appropriate antiarrhythmic therapy should be given. The possibility that the patient may have taken other drugs, increasing the risk of drug interactions (especially catechol-structured drugs) should be taken into consideration. Hemodialysis or hemoperfusion is unlikely to reduce entacapone levels due to its high binding to plasma proteins. (L1712)","UNII":"46627O600J","Wikidata":"Q106345614","Wikipedia":"Levodopa","XLogP":-2.7}