Benztropine
Encyclopedia
Benzatropine also known as benztropine (USAN
, BAN
), is an anticholinergic
marketed under the trade name
Cogentin which is used in the treatment of Parkinson's disease
, parkinsonism
, akathisia
, and dystonia
.
treatment, such as parkinsonism
and akathisia
. Benzatropine is also a second-line drug for the treatment of Parkinson's disease
. It improves tremor
and rigidity but not bradykinesia. Benzatropine is also sometimes used for the treatment of dystonia
, a rare disorder that causes abnormal muscle contraction, resulting in twisting postures of limbs, trunk, or face.
While some studies suggest that use of anticholinergics increases the risk of tardive dyskinesia
(a long-term side effect of antipsychotics), other studies have found no association between anticholinergic exposure and risk of developing tardive dyskinesia, although symptoms may be worsened.
/antihistamine
agent resulting from the combination of the tropine portion of the atropine
molecule and the benzohydryl portion of diphenhydramine
. Animal studies have indicated that anticholinergic activity of benzatropine is approximately one-half that of atropine, while its antihistamine activity approaches that of mepyramine
. Its anticholinergic effects have been established as therapeutically significant in the management of parkinsonism. Benzatropine antagonises the effect of acetylcholine
, decreasing the imbalance between the neurotransmitters acetylcholine and dopamine
, which may improve the symptoms of early Parkinson's disease.
and diphenyldiazomethane.
United States Adopted Name
United States Adopted Names are unique nonproprietary names assigned to pharmaceuticals marketed in the United States. Each name is assigned by the USAN Council, which is co-sponsored by the American Medical Association , the United States Pharmacopeial Convention , and the American Pharmacists...
, BAN
British Approved Name
A British Approved Name is the official non-proprietary or generic name given to a pharmaceutical substance, as defined in the British Pharmacopoeia...
), is an anticholinergic
Anticholinergic
An anticholinergic agent is a substance that blocks the neurotransmitter acetylcholine in the central and the peripheral nervous system. An example of an anticholinergic is dicycloverine, and the classic example is atropine....
marketed under the trade name
Trade name
A trade name, also known as a trading name or a business name, is the name which a business trades under for commercial purposes, although its registered, legal name, used for contracts and other formal situations, may be another....
Cogentin which is used in the treatment of Parkinson's disease
Parkinson's disease
Parkinson's disease is a degenerative disorder of the central nervous system...
, parkinsonism
Parkinsonism
Parkinsonism is a neurological syndrome characterized by tremor, hypokinesia, rigidity, and postural instability. The underlying causes of parkinsonism are numerous, and diagnosis can be complex...
, akathisia
Akathisia
Akathisia, or acathisia, is a syndrome characterized by unpleasant sensations of inner restlessness that manifests itself with an inability to sit still or remain motionless...
, and dystonia
Dystonia
Dystonia is a neurological movement disorder, in which sustained muscle contractions cause twisting and repetitive movements or abnormal postures. The disorder may be hereditary or caused by other factors such as birth-related or other physical trauma, infection, poisoning or reaction to...
.
Indications
Benzatropine is used in patients to reduce the side effects of antipsychoticAntipsychotic
An antipsychotic is a tranquilizing psychiatric medication primarily used to manage psychosis , particularly in schizophrenia and bipolar disorder. A first generation of antipsychotics, known as typical antipsychotics, was discovered in the 1950s...
treatment, such as parkinsonism
Parkinsonism
Parkinsonism is a neurological syndrome characterized by tremor, hypokinesia, rigidity, and postural instability. The underlying causes of parkinsonism are numerous, and diagnosis can be complex...
and akathisia
Akathisia
Akathisia, or acathisia, is a syndrome characterized by unpleasant sensations of inner restlessness that manifests itself with an inability to sit still or remain motionless...
. Benzatropine is also a second-line drug for the treatment of Parkinson's disease
Parkinson's disease
Parkinson's disease is a degenerative disorder of the central nervous system...
. It improves tremor
Tremor
A tremor is an involuntary, somewhat rhythmic, muscle contraction and relaxation involving to-and-fro movements of one or more body parts. It is the most common of all involuntary movements and can affect the hands, arms, eyes, face, head, vocal folds, trunk, and legs. Most tremors occur in the...
and rigidity but not bradykinesia. Benzatropine is also sometimes used for the treatment of dystonia
Dystonia
Dystonia is a neurological movement disorder, in which sustained muscle contractions cause twisting and repetitive movements or abnormal postures. The disorder may be hereditary or caused by other factors such as birth-related or other physical trauma, infection, poisoning or reaction to...
, a rare disorder that causes abnormal muscle contraction, resulting in twisting postures of limbs, trunk, or face.
Side effects
These are principally anticholinergic:- Dry mouth
- Blurred vision
- Cognitive changes
- ConstipationConstipationConstipation refers to bowel movements that are infrequent or hard to pass. Constipation is a common cause of painful defecation...
- Urinary retentionUrinary retentionUrinary retention, also known as ischuria, is a lack of ability to urinate. It is a common complication of benign prostatic hyperplasia , although it can also be caused by nerve dysfunction, constipation, infection, or medications...
- TachycardiaTachycardiaTachycardia comes from the Greek words tachys and kardia . Tachycardia typically refers to a heart rate that exceeds the normal range for a resting heart rate...
- AnorexiaAnorexia (symptom)Anorexia is the decreased sensation of appetite...
- PsychosisPsychosisPsychosis means abnormal condition of the mind, and is a generic psychiatric term for a mental state often described as involving a "loss of contact with reality"...
(in overdose)
While some studies suggest that use of anticholinergics increases the risk of tardive dyskinesia
Tardive dyskinesia
Tardive dyskinesia is a difficult-to-treat form of dyskinesia that can be tardive...
(a long-term side effect of antipsychotics), other studies have found no association between anticholinergic exposure and risk of developing tardive dyskinesia, although symptoms may be worsened.
Pharmacology
Benzatropine is a centrally acting anticholinergicAnticholinergic
An anticholinergic agent is a substance that blocks the neurotransmitter acetylcholine in the central and the peripheral nervous system. An example of an anticholinergic is dicycloverine, and the classic example is atropine....
/antihistamine
Antihistamine
An H1 antagonist is a histamine antagonist of the H1 receptor that serves to reduce or eliminate effects mediated by histamine, an endogenous chemical mediator released during allergic reactions...
agent resulting from the combination of the tropine portion of the atropine
Atropine
Atropine is a naturally occurring tropane alkaloid extracted from deadly nightshade , Jimson weed , mandrake and other plants of the family Solanaceae. It is a secondary metabolite of these plants and serves as a drug with a wide variety of effects...
molecule and the benzohydryl portion of diphenhydramine
Diphenhydramine
Diphenhydramine hydrochloride is a first-generation antihistamine possessing anticholinergic, antitussive, antiemetic, and sedative properties which is mainly used to treat allergies. Like most other first-generation antihistamines, the drug also has a powerful hypnotic effect, and for this reason...
. Animal studies have indicated that anticholinergic activity of benzatropine is approximately one-half that of atropine, while its antihistamine activity approaches that of mepyramine
Mepyramine
Mepyramine, also known as pyrilamine, is a first generation antihistamine, targeting the H1 receptor. However, it rapidly permeates the brain often causing drowsiness. It also has anticholinergic properties. It is used in over-the-counter combination products to treat the common cold and menstrual...
. Its anticholinergic effects have been established as therapeutically significant in the management of parkinsonism. Benzatropine antagonises the effect of acetylcholine
Acetylcholine
The chemical compound acetylcholine is a neurotransmitter in both the peripheral nervous system and central nervous system in many organisms including humans...
, decreasing the imbalance between the neurotransmitters acetylcholine and 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...
, which may improve the symptoms of early Parkinson's disease.
Chemistry
Benztropine, 3-(diphenylmethoxy)tropane, is synthesized by the reaction of tropineTropine
Tropine is a derivative of tropane containing a hydroxyl group at third carbon. It is also called 3-tropanol.Benzatropine and etybenzatropine are derivatives of tropine. It is also a building block of atropine, a cholinergic drug prototypical of the muscarinic antagonist class.-External Links:*...
and diphenyldiazomethane.
- R.F. Phillips, N.J. Westfield, (1952).