Carbidopa
Encyclopedia
Carbidopa is a drug
given to people with Parkinson's disease
in order to inhibit peripheral
metabolism
of levodopa
.
of L-tryptophan to serotonin
and in the biosynthesis of L-DOPA to Dopamine
(DA).
Along with carbidopa, other DDC inhibitors are benserazide
(Ro-4-4602), difluromethyldopa, and α-methyldopa.
on the periphery, as well as increasing the concentration of L-DOPA and dopamine in the brain.
The combination of carbidopa/levodopa
carries the brand names of Sinemet, Parcopa and Atamet; while Stalevo
is a combination with entacapone
, which enhances the bioavailability of carbidopa and levodopa.
Carbidopa is also used in combination with 5-HTP, a naturally occurring amino acid which is a precursor to the neurotransmitter serotonin
and an intermediate in tryptophan
metabolism. Carbidopa prevents 5-HTP's metabolism in the liver and the resulting elevated levels of serotonin in the blood. Research shows that co-administration of 5-HTP and carbidopa greatly increases plasma 5-HTP levels. 5-HTP has no reported cases of heart valve disease associated with it as found in the peer reviewed literature. In Europe, 5-HTP is prescribed with carbidopa to prevent the conversion of 5-HTP into serotonin until it reaches the brain. Several cases of scleroderma-like illness have been reported in patients using carbidopa and 5-HTP.
Medication
A pharmaceutical drug, also referred to as medicine, medication or medicament, can be loosely defined as any chemical substance intended for use in the medical diagnosis, cure, treatment, or prevention of disease.- Classification :...
given to people with Parkinson's disease
Parkinson's disease
Parkinson's disease is a degenerative disorder of the central nervous system...
in order to inhibit peripheral
Peripheral nervous system
The peripheral nervous system consists of the nerves and ganglia outside of the brain and spinal cord. The main function of the PNS is to connect the central nervous system to the limbs and organs. Unlike the CNS, the PNS is not protected by the bone of spine and skull, or by the blood–brain...
metabolism
Metabolism
Metabolism is the set of chemical reactions that happen in the cells of living organisms to sustain life. These processes allow organisms to grow and reproduce, maintain their structures, and respond to their environments. Metabolism is usually divided into two categories...
of levodopa
Levodopa
L-DOPA is a chemical that is made and used as part of the normal biology of some animals and plants. Some animals including humans make it via biosynthesis from the amino acid L-tyrosine. L-DOPA is the precursor to the neurotransmitters dopamine, norepinephrine , and epinephrine collectively...
.
Pharmacology
Carbidopa inhibits aromatic-L-amino-acid decarboxylase (DOPA Decarboxylase or DDC), an enzyme important in the biosynthesisBiosynthesis
Biosynthesis is an enzyme-catalyzed process in cells of living organisms by which substrates are converted to more complex products. The biosynthesis process often consists of several enzymatic steps in which the product of one step is used as substrate in the following step...
of L-tryptophan to serotonin
Serotonin
Serotonin or 5-hydroxytryptamine is a monoamine neurotransmitter. Biochemically derived from tryptophan, serotonin is primarily found in the gastrointestinal tract, platelets, and in the central nervous system of animals including humans...
and in the biosynthesis of L-DOPA to Dopamine
Dopamine
Dopamine is a catecholamine neurotransmitter present in a wide variety of animals, including both vertebrates and invertebrates. In the brain, this substituted phenethylamine functions as a neurotransmitter, activating the five known types of dopamine receptors—D1, D2, D3, D4, and D5—and their...
(DA).
Along with carbidopa, other DDC inhibitors are benserazide
Benserazide
Benserazide is a peripherally-acting aromatic L-amino acid decarboxylase or DOPA decarboxylase inhibitor, which is unable to cross the blood-brain barrier.- Indications :...
(Ro-4-4602), difluromethyldopa, and α-methyldopa.
Uses
Used in tandem with L-DOPA (trade name levodopa, a dopamine precursor converted in the body to dopamine), it increases the plasma half-life of levodopa from 50 minutes to 1½ hours. CarbiDOPA cannot cross the blood brain barrier, so it inhibits only peripheral DDC. It thus prevents the conversion of L-DOPA to dopamine peripherally. This reduces the side effects caused by dopamineDopamine
Dopamine is a catecholamine neurotransmitter present in a wide variety of animals, including both vertebrates and invertebrates. In the brain, this substituted phenethylamine functions as a neurotransmitter, activating the five known types of dopamine receptors—D1, D2, D3, D4, and D5—and their...
on the periphery, as well as increasing the concentration of L-DOPA and dopamine in the brain.
The combination of carbidopa/levodopa
Carbidopa/levodopa
Carbidopa/levodopa is the combination of carbidopa and levodopa and is used to treat Parkinson's disease and dopamine-responsive dystonia . It is sold under several brand names, including Sinemet, Parcopa, and Atamet...
carries the brand names of Sinemet, Parcopa and Atamet; while Stalevo
Stalevo
Stalevo is an anti-parkinsonian dopaminergic combination medication that contains carbidopa, levodopa, and entacapone for the treatment of Parkinson's disease...
is a combination with entacapone
Entacapone
Entacapone is a drug that functions as a catechol-O-methyl transferase inhibitor. It is used in the treatment of Parkinson's disease....
, which enhances the bioavailability of carbidopa and levodopa.
Carbidopa is also used in combination with 5-HTP, a naturally occurring amino acid which is a precursor to the neurotransmitter serotonin
Serotonin
Serotonin or 5-hydroxytryptamine is a monoamine neurotransmitter. Biochemically derived from tryptophan, serotonin is primarily found in the gastrointestinal tract, platelets, and in the central nervous system of animals including humans...
and an intermediate in tryptophan
Tryptophan
Tryptophan is one of the 20 standard amino acids, as well as an essential amino acid in the human diet. It is encoded in the standard genetic code as the codon UGG...
metabolism. Carbidopa prevents 5-HTP's metabolism in the liver and the resulting elevated levels of serotonin in the blood. Research shows that co-administration of 5-HTP and carbidopa greatly increases plasma 5-HTP levels. 5-HTP has no reported cases of heart valve disease associated with it as found in the peer reviewed literature. In Europe, 5-HTP is prescribed with carbidopa to prevent the conversion of 5-HTP into serotonin until it reaches the brain. Several cases of scleroderma-like illness have been reported in patients using carbidopa and 5-HTP.