The Typical Antipsychotics are also called Conventional or First Generation Antipsychotics because they were the first kind of antipsychotics to be developed. For many decades and up until the 1990s they were the main form of medications used for for treating psychosis, but ever since the Atypical Antipsychotics came into use the Typicals have been less commonly prescribed, at least in North America.
The Typical Antipsychotics achieve their therapeutic effects mainly by blocking dopamine signaling in the brain. The main drawback of this is that they tend to cause significant extrapyramidal side-effects and can also produce feelings of mental slowness, lack of motivation or initiative, and depressed moods. It is for this reason that over the years their use has diminished. Nevertheless, they remain very effective treatment options and when taken in low doses their side-effects can be quite manageable [ref].
Typical versus Atypical Antipsychotics
Although these days the Atypical Antipsychotics are usually considered the first-line choices when antipsychotic medications are required, there is some good evidence that the differences between Typicals and Atypicals may not be as significant as many think. For instance, when it comes to treating Schizophrenia, the Atypicals overall do not tend to be much more effective than the Typicals, offer little added benefit for managing negative symptoms of Schizophrenia, and seem to cause similar rates of extrapyramidal side-effects as low-potency Typicals [ref, ref, ref].
The Typical Antipsychotics are often grouped according to their potency levels, which corresponds to the strength with which they block dopamine receptors in the brain. High-potency Typical Antipsychotics tend to cause extrapyramidal side-effects quite easily, and for this reason need to be used in low doses.
Low-potency Typical Antipsychotics tend to block a number of other neurotransmitter systems besides dopamine, and have antihistamine, anticholinergic and anti-adrenergic properties; this means that they may produce slightly lower rates of extrapyramidal side-effects, but on the other hand tend to cause more in the way of sedation, dizziness and faintness, and anticholinergic side-effects. They are also known to lead to weight gain.
Mid-potency Typicals tend to fall somewhere in the middle range, and for this reason may offer a good balance in terms of their side-effect profile.
Here is a list of various common Typical Antipsychotics according to their potency levels:
High-potency Typical Antipsychotics
Mid-potency Typical Antipsychotics
Low-potency Typical Antipsychotics