Tiospirone
Encyclopedia
Tiospirone also sometimes called tiaspirone or tiosperone, is an atypical antipsychotic
drug
of the azapirone class. It acts as a 5-HT1A receptor
partial agonist
, 5-HT2A
, 5-HT2C
, and 5-HT7 receptor
inverse agonist
, and D2, D4, and α1-adrenergic receptor
antagonist
.
Tiospirone was tested in clinical trial
s for the treatment of schizophrenia
in the late 1980s, and was found to have efficacy equivalent to that of typical antipsychotic
s without causing extrapyramidal side effect
s. However, development was not continued and it was never marketed.
Perospirone
, another azapirone derivative with antipsychotic properties, was synthesized and assayed several years after tiospirone. It was found to be both more potent and more selective
in comparison and was commercialized instead.
Atypical antipsychotic
The atypical antipsychotics are a group of antipsychotic tranquilizing drugs used to treat psychiatric conditions. Some atypical antipsychotics are FDA approved for use in the treatment of schizophrenia...
drug
Drug
A drug, broadly speaking, is any substance that, when absorbed into the body of a living organism, alters normal bodily function. There is no single, precise definition, as there are different meanings in drug control law, government regulations, medicine, and colloquial usage.In pharmacology, a...
of the azapirone class. It acts as a 5-HT1A receptor
5-HT1A receptor
The 5-HT1A receptor is a subtype of 5-HT receptor that binds the endogenous neurotransmitter serotonin . It is a G protein-coupled receptor that is coupled to Gi/Go and mediates inhibitory neurotransmission...
partial agonist
Partial agonist
Partial agonists bind and activate a given receptor, but have only partial efficacy at the receptor relative to a full agonist...
, 5-HT2A
5-HT2A receptor
The mammalian 5-HT2A receptor is a subtype of the 5-HT2 receptor that belongs to the serotonin receptor family and is a G protein-coupled receptor . This is the main excitatory receptor subtype among the GPCRs for serotonin , although 5-HT2A may also have an inhibitory effect on certain areas such...
, 5-HT2C
5-HT2C receptor
The 5-HT2C receptor is a subtype of 5-HT receptor that binds the endogenous neurotransmitter serotonin . It is a G protein-coupled receptor that is coupled to Gq/G11 and mediates excitatory neurotransmission. HTR2C denotes the human gene encoding for the receptor, that in humans is located at the...
, and 5-HT7 receptor
5-HT7 receptor
The 5-HT7 receptor is a member of the GPCR superfamily of cell surface receptors and is activated by the neurotransmitter serotonin The 5-HT7 receptor is coupled to Gs and is expressed in a variety of human tissues, particularly in the brain, the gastrointestinal tract, and in various...
inverse agonist
Inverse agonist
In the field of pharmacology, an inverse agonist is an agent that binds to the same receptor as an agonist but induces a pharmacological response opposite to that agonist....
, and D2, D4, and α1-adrenergic receptor
Alpha-1 adrenergic receptor
The alpha-1 adrenergic receptor is a G protein-coupled receptor associated with the Gq heterotrimeric G-protein. It consists of three highly homologous subtypes, including α1A-, α1B-, and α1D-adrenergic...
antagonist
Receptor antagonist
A receptor antagonist is a type of receptor ligand or drug that does not provoke a biological response itself upon binding to a receptor, but blocks or dampens agonist-mediated responses...
.
Tiospirone was tested in clinical trial
Clinical trial
Clinical trials are a set of procedures in medical research and drug development that are conducted to allow safety and efficacy data to be collected for health interventions...
s for the treatment of schizophrenia
Schizophrenia
Schizophrenia is a mental disorder characterized by a disintegration of thought processes and of emotional responsiveness. It most commonly manifests itself as auditory hallucinations, paranoid or bizarre delusions, or disorganized speech and thinking, and it is accompanied by significant social...
in the late 1980s, and was found to have efficacy equivalent to that of typical antipsychotic
Typical antipsychotic
Typical antipsychotics are a class of antipsychotic drugs first developed in the 1950s and used to treat psychosis...
s without causing extrapyramidal side effect
Side effect
In medicine, a side effect is an effect, whether therapeutic or adverse, that is secondary to the one intended; although the term is predominantly employed to describe adverse effects, it can also apply to beneficial, but unintended, consequences of the use of a drug.Occasionally, drugs are...
s. However, development was not continued and it was never marketed.
Perospirone
Perospirone
Perospirone is an atypical antipsychotic of the azapirone chemical class. It was introduced in Japan in 2001 by Dainippon Sumitomo Pharma for the treatment of schizophrenia and acute bipolar mania. Perospirone acts as a 5-HT1A receptor partial agonist, 5-HT2A receptor inverse agonist, and D2, D4,...
, another azapirone derivative with antipsychotic properties, was synthesized and assayed several years after tiospirone. It was found to be both more potent and more selective
Functional Selectivity
Functional selectivity is the ligand-dependent selectivity for certain signal transduction pathways in one and the same receptor. This can be present when a receptor has several possible signal transduction pathways...
in comparison and was commercialized instead.