Levodopa
Systematic (IUPAC) name
(S)-2-amino-3-(3,4-dihydroxyphenyl) propanoic acid
Identifiers
CAS number	59-92-7
ATC code	N04BA01
PubChem	6047
DrugBank	APRD00309
Chemical data
Formula	C9H11NO4
Mol. mass	197.19 g/mol
Pharmacokinetic data
Bioavailability	30%
Metabolism	Aromatic-L-amino-acid decarboxylase
Half life	0.75–1.5 hours
Excretion	renal 70–80%
Therapeutic considerations
Pregnancy cat.	B3(AU) C(US) Image File history File links No higher resolution available. ... Image File history File links No higher resolution available. ... IUPAC nomenclature is a system of naming chemical compounds and of describing the science of chemistry in general. ... CAS registry numbers are unique numerical identifiers for chemical compounds, polymers, biological sequences, mixtures and alloys. ... The Anatomical Therapeutic Chemical Classification System is used for the classification of drugs. ... A section of the Anatomical Therapeutic Chemical Classification System. ... PubChem is a database of chemical molecules. ... The DrugBank database available at the University of Alberta is a unique bioinformatics and cheminformatics resource that combines detailed drug (i. ... A chemical formula is a concise way of expressing information about the atoms that constitute a particular chemical compound. ... For other uses, see Carbon (disambiguation). ... This article is about the chemistry of hydrogen. ... General Name, symbol, number nitrogen, N, 7 Chemical series nonmetals Group, period, block 15, 2, p Appearance colorless gas Standard atomic weight 14. ... General Name, symbol, number oxygen, O, 8 Chemical series nonmetals, chalcogens Group, period, block 16, 2, p Appearance colorless (gas) pale blue (liquid) Standard atomic weight 15. ... The molecular mass (abbreviated Mr) of a substance, formerly also called molecular weight and abbreviated as MW, is the mass of one molecule of that substance, relative to the unified atomic mass unit u (equal to 1/12 the mass of one atom of carbon-12). ... In pharmacology, bioavailability is used to describe the fraction of an administered dose of unchanged drug that reaches the systemic circulation, one of the principal pharmacokinetic properties of drugs. ... Drug metabolism is the metabolism of drugs, their biochemical modification or degradation, usually through specialized enzymatic systems. ... Aromatic-L-amino-acid decarboxylase (EC 4. ... The biological half-life of a substance is the time required for half of that substance to be removed from an organism by either a physical or a chemical process. ... The kidneys are important excretory organs in vertebrates. ... Kidneys viewed from behind with spine removed The kidneys are bean-shaped excretory organs in vertebrates. ... The pregnancy category of a pharmaceutical agent is an assessment of the risk of fetal injury due to the pharmaceutical, if it is used as directed by the mother during pregnancy. ... For other uses, see Australia (disambiguation). ... Motto: (Out Of Many, One) (traditional) In God We Trust (1956 to date) Anthem: The Star-Spangled Banner Capital Washington D.C. Largest city New York City None at federal level (English de facto) Government Federal constitutional republic  - President George Walker Bush (R)  - Vice President Dick Cheney (R) Independence from...
Legal status	℞ Prescription only The regulation of therapeutic goods, that is drugs and therapeutic devices, varies by jurisdiction. ...
Routes	oral

Levodopa (INN) or L-DOPA (3,4-dihydroxy-L-phenylalanine) is an intermediate in dopamine biosynthesis. In clinical use, levodopa is administered in the management of Parkinson's disease. It is also used as a component in marine adhesives used by pelagic life. In pharmacology and toxicology, a route of administration is the path by which a drug, fluid, poison or other substance is brought into contact with the body. ... An International Nonproprietary Name (INN) is the official non-proprietary or generic name given to a pharmaceutical substance, as designated by the World Health Organization. ... // Hydroxyl group The term hydroxyl group is used to describe the functional group -OH when it is a substituent in an organic compound. ... Phenyl alanine is an α-amino acid with the formula HO2CCH(NH2)CH2C6H5. ... For other uses, see Dopamine (disambiguation). ... Biosynthesis is a phenomenon where chemical compounds are produced from simpler reagents. ... The pelagic zone is the part of the open sea or ocean comprising the water column, i. ...

Therapeutic use

Levodopa is used as a prodrug to increase dopamine levels for the treatment of Parkinson's disease, since it is able to cross the blood-brain barrier, whereas dopamine itself cannot. Once levodopa has entered the central nervous system (CNS), it is metabolized to dopamine by aromatic L-amino acid decarboxylase. However, conversion to dopamine also occurs in the peripheral tissues, causing adverse effects and decreasing the available dopamine to the CNS, so it is standard practice to co-administer a peripheral DOPA decarboxylase inhibitor – carbidopa or benserazide – and often a catechol-O-methyl transferase (COMT) inhibitor. However, Vitamin-B6 (pyridoxine) inhibits the conversion of levodopa to dopamine. Thus, it is necessary to limit pyridoxine intake, but with extreme care in dosing, for vitamin-B6 deficiency can lead to paresthesias, numbness of extremities, mental confusion, and depression. A prodrug is a pharmacological substance (drug) which is administered in an inactive (or significantly less active) form. ... For other uses, see Dopamine (disambiguation). ... The blood-brain barrier (BBB) is a membranic structure that acts primarily to protect the brain from chemicals in the blood, while still allowing essential metabolic function. ... A diagram showing the CNS: 1. ... Aromatic L-amino acid decarboxylase (EC 4. ... Aromatic-L-amino-acid decarboxylase (EC 4. ... Carbidopa (MK-486) is a drug given to people with Parkinsons disease in order to inhibit peripheral metabolism of levodopa. ... Benserazide is an inhibitor of DOPA decarboxylase that does not enter the central nervous system. ... Catechol-O-methyl transferase (COMT) (EC 2. ...

Adverse effects

Possible adverse drug reactions include: An adverse drug reaction (abbreviated ADR) is a term to describe the unwanted, negative consequences sometimes associated with the use of medications. ...

• Hypotension, especially if the dosage is too high
• Arrhythmias, although these are uncommon
• Nausea, which is often helped by taking the drug with food, although protein interferes with drug absorption
• Gastrointestinal bleeding
• Disturbed respiration, which is not always harmful, and can actually benefit patients with upper airway obstruction
• Hair loss
• Confusion
• Extreme emotional states, particularly anxiety, but also excessive libido
• Vivid dreams and/or fragmented sleep
• Visual and possibly auditory hallucinations
• Effects on learning; there is some evidence that it improves working memory, while impairing other complex functions
• Sleepiness and sleep attacks
• A condition similar to amphetamine psychosis.

Although there are many adverse effects associated with levodopa, particularly psychiatric ones, it has fewer than other anti-Parkinson's drugs, including anticholinergics, amantadine, and dopamine agonists. In physiology and medicine, hypotension refers to an abnormally low blood pressure. ... A cardiac arrhythmia, also called cardiac dysrhythmia, is a disturbance in the regular rhythm of the heartbeat. ... For other uses, see Nausea (disambiguation). ... A representation of the 3D structure of myoglobin, showing coloured alpha helices. ... In animal physiology, respiration is the transport of oxygen from the ambient air to the tissue cells and the transport of carbon dioxide in the opposite direction. ... Bald redirects here; for other uses see Bald (disambiguation). ... Look up Emotion in Wiktionary, the free dictionary. ... what up?? Anxiety is a physiological state characterized by cognitive, somatic, emotional, and behavioral components (Seligman, Walker & Rosenhan, 2001). ... For other uses, see Libido (disambiguation). ... For other uses, see Dream (disambiguation). ... A hallucination is a sensory perception experienced in the absence of an external stimulus, as distinct from an illusion, which is a misperception of an external stimulus. ... Working memory is a theoretical framework within cognitive psychology that refers to the structures and processes used for temporarily storing and manipulating information. ... Amphetamine psychosis is a form of psychosis which can result from amphetamine or methamphetamine use. ... An anticholinergic agent is a member of a class of pharmaceutical compounds which serve to reduce the effects mediated by acetylcholine in the central nervous system and peripheral nervous system. ... Amantadine, 1-aminoadamantane, is an antiviral drug that was approved by the FDA in 1976 for the treatment of influenza type A in adults. ... Dopamine agonist is a synthetic drug that mimics the effect of the neurotransmitter dopamine. ...

More serious are the effects of chronic levodopa administration, which include:

• End-of-dose deterioration of function
• On/off oscillations
• Freezing during movement
• Dose failure (drug resistance)
• Dyskinesia at peak dose.

Clinicians will try to avoid these by limiting levodopa dosages as far as possible until absolutely necessary. Organisms are said to be drug-resistant when they are no longer affected by drugs that are meant to neutralize them. ... Dyskinesia refers to an impairment of voluntary movement. ...

Biosynthesis

L-DOPA is produced from the amino acid tyrosine by the enzyme tyrosine hydroxylase. It is also the precursor molecule for the catecholamine neurotransmitters dopamine and norepinephrine (noradrenaline), and the hormone epinephrine (adrenaline). Dopamine is formed by the decarboxylation of L-DOPA. This article is about the class of chemicals. ... Tyrosine (from the Greek tyros, meaning cheese, as it was first discovered in 1846 by German chemist Justus von Liebig in the protein casein from cheese[1][2]), 4-hydroxyphenylalanine, or 2-amino-3(4-hydroxyphenyl)-propanoic acid, is one of the 20 amino acids that are used by cells... Tyrosine Hydroxylase is the enzyme responsible for catalysing the conversion of L-tyrosine, an amino acid, to dihydroxyphenylalanine (DOPA), a precursor to Dopamine in the process the body uses to synthesise adrenaline (epinephrin). ... tyrosine is the precursor of catecholamines epinephrine norepinephrine dopamine Synthesis Catecholamines are chemical compounds derived from the amino acid tyrosine containing catechol and amine groups. ... Chemical structure of D-aspartic acid, a common amino acid neurotransmitter. ... For other uses, see Dopamine (disambiguation). ... Norepinephrine (INN)(abbr. ... For other uses, see Hormone (disambiguation). ... Adrenaline redirects here. ...

The prefix L- references its property of levorotation (compared with dextrorotation or D-DOPA). Levorotation (also spelled laevorotation) is the counterclockwise rotation of plane polarized light. ... Dextrorotation is the property of rotating plane polarized light clockwise. ... D-DOPA (Dextrodopa) is similar to L-DOPA (levodopa, 3,4-dihydroxy-L-phenylalanine), but differs in its property of dextrorotation. ...

History

In work that earned him a Nobel Prize in 2000, Swedish scientist Arvid Carlsson first showed in the 1950s that administering levodopa to animals with Parkinsonian symptoms would cause a reduction of the symptoms. The neurologist Oliver Sacks describes this treatment in human patients with encephalitis lethargica in his book Awakenings, upon which the movie Awakenings is based. Emil Adolf von Behring was the first person to receive the Nobel Prize in physiology or Medicine, for his work on the treatment of diphtheria. ... Arvid Carlsson (b. ... Neurology is a branch of medicine dealing with disorders of the nervous system. ... Oliver Sacks in 2005. ... Encephalitis lethargica (EL) is an atypical form of encephalitis. ... Awakenings (1973, rev. ... This article is about a 1990 film. ...

The 2001 Nobel Prize in Chemistry was also related to L-DOPA: the Nobel Committee awarded one-fourth of the prize to William S. Knowles for his work on chirally-catalysed hydrogenation reactions, the most noted example of which was used for the synthesis of L-DOPA. This is a list of Nobel Prize laureates in Chemistry from 1901 to 2006. ... William S. Knowles (born June 1, 1917) is a American chemist. ... Hydrogenation is a class of chemical reactions which result an addition of hydrogen (H2) usually to unsaturated organic compounds. ...

Supplements containing L-DOPA

Herbal supplements containing standardized dosages of L-DOPA are available without a prescription. These supplements have recently increased in both availability and popularity in the United States and on the Internet. The most common plant source of L-DOPA marketed in this manner is a tropical legume, Mucuna pruriens, also known as "Velvet Bean" and by a number of other common names. This article is about the fruit of the plants also called legumes. For the plants themselves, see Fabaceae . ... Binomial name Mucuna pruriens (L.) DC. Mucuna pruriens (syn. ...

Two of the most popular brands of Mucuna pruriens are "DopaBean," marketed by Solaray, and "Mucuna," marketed by Physician Formulas, Inc. These preparations claim to contain standardized dosages of L-DOPA in enteric-coated capsules. The dosage claimed is usually about 50 mg per capsule, and the recommended dose is two capsules per day. A third product, "L-Dopa," marketed by Unique Nutrition, claims a higher effective dose of 250 mg. American Nutrition also carries a Mucuna Pruriens standardized to 40% L-DOPA under its NutraceuticsRx label.

Some of the claims made for the use of these supplements may have validity, whereas many do not. Among the most common claims are that the supplements will increase libido and aid in body-building (presumably by increasing testosterone in both cases). The long-term consequences of the use of these supplements by healthy individuals remains to be seen. Testosterone is a steroid hormone from the androgen group. ...

Adhesion

DOPA is a key molecule in the formation of marine adhesive proteins, such as those found in mussels. It is believed to be responsible for the water-resistance and rapid curing abilities of these proteins. DOPA may also be used to prevent surfaces from fouling by bonding antifouling polymers to a susceptible substrate.

Melanin formation

Both levodopa and the related amino acid L-tyrosine are precursors to the biological pigment melanin. The enzyme tyrosinase catalyzes the oxidation of L-dopa to the reactive intermediate dopaquinone, which reacts further, eventually leading to melanin oligomers. Tyrosine (from the Greek tyros, meaning cheese, as it was first discovered in 1846 by German chemist Justus von Liebig in the protein casein from cheese[1][2]), 4-hydroxyphenylalanine, or 2-amino-3(4-hydroxyphenyl)-propanoic acid, is one of the 20 amino acids that are used by cells... Broadly, melanin is any of the polyacetylene, polyaniline, and polypyrrole blacks and browns or their mixed copolymers. ...

References

• Waite, J. Herbert, et al. (2005). "Mussel Adhesion: Finding the Tricks Worth Mimicking". J Adhesion 81: 1-21. 
• Messersmith, Phillip B., et al. (2006). "Rapid Gel Formation and Adhesion in Photocurable and Biodegradable Block Copolymers with High DOPA Content". Macromolecules 39: 1740-1748. 

External links

• ScienceDaily: Study Reveals Details Of Mussels' Tenacious Bonds (Northwestern University) August 16, 2006