Typical antipsychotic | |
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Drug class | |
Synonyms | First generation antipsychotics, conventional antipsychotics, classical neuroleptics, traditional antipsychotics, major tranquilizers |
Legal status | |
In Wikidata |
Typical antipsychotics (also known as major tranquilizers , and first generation antipsychotics) are a class of antipsychotic drugs first developed in the 1950s and used to treat psychosis (in particular, schizophrenia). Typical antipsychotics may also be used for the treatment of acute mania, agitation, and other conditions. The first typical antipsychotics to come into medical use were the phenothiazines, namely chlorpromazine which was discovered serendipitously. [1] Another prominent grouping of antipsychotics are the butyrophenones, an example of which is haloperidol. The newer, second-generation antipsychotics, also known as atypical antipsychotics, have largely supplanted the use of typical antipsychotics as first-line agents due to the higher risk of movement disorders with typical antipsychotics.
Both generations of medication tend to block receptors in the brain's dopamine pathways, but atypicals at the time of marketing were claimed to differ from typical antipsychotics in that they are less likely to cause extrapyramidal symptoms (EPS), which include unsteady Parkinson's disease-type movements, internal restlessness, and other involuntary movements (e.g. tardive dyskinesia, which can persist after stopping the medication). [2] More recent research has demonstrated the side effect profile of these drugs is similar to older drugs, causing the leading medical journal The Lancet to write in its editorial "the time has come to abandon the terms first-generation and second-generation antipsychotics, as they do not merit this distinction." [3] While typical antipsychotics are more likely to cause EPS, atypicals are more likely to cause adverse metabolic effects, such as weight gain and increase the risk for type II diabetes. [4]
Typical antipsychotics block the dopamine 2 receptor (D2) receptor, causing a tranquilizing effect. [5] It is thought that 60–80% of D2 receptors need to be occupied for antipsychotic effect. [5] For reference, the typical antipsychotic haloperidol tends to block about 80% of D2 receptors at doses ranging from 2 to 5 mg per day. [5] On the aggregate level, no typical antipsychotic is more effective than any other, though people will vary in which antipsychotic they prefer to take based on individual differences in tolerability and effectiveness. [5] Typical antipsychotics can be used to treat, e.g., schizophrenia or severe agitation. [5] Haloperidol, due to the availability of a rapid-acting injectable formulation and decades of use, remains the most commonly used antipsychotic for treating severe agitation in the emergency department setting. [5]
Adverse effects vary among the various agents in this class of medications, but common effects include: dry mouth, muscle stiffness, muscle cramping, tremors, EPS and weight gain. EPS refers to a cluster of symptoms consisting of akathisia, parkinsonism, and dystonia. Anticholinergics such as benztropine and diphenhydramine are commonly prescribed to treat the EPS. 4% of users develop rabbit syndrome while on typical antipsychotics. [6]
There is a risk of developing a serious condition called tardive dyskinesia as a side effect of antipsychotics, including typical antipsychotics. The risk of developing tardive dyskinesia after chronic typical antipsychotic usage varies on several factors, such as age and gender, as well as the specific antipsychotic used. The commonly reported incidence of TD among younger patients is about 5% per year. Among older patients incidence rates as high as 20% per year have been reported. The average prevalence is approximately 30%. [7] There are few treatments that have consistently been shown to be effective for the treatment of tardive dyskinesia, though an VMAT2 inhibitor like valbenazine may help. [8] The atypical antipsychotic clozapine has also been suggested as an alternative antipsychotic for patients experiencing tardive dyskinesia. [9] Tardive dyskinesia may reverse upon discontinuation of the offending agent or it may be irreversible, withdrawal may also make tardive dyskinesia more severe. [10]
Neuroleptic malignant syndrome (NMS) is a rare, but potentially fatal side effect of antipsychotic treatment. NMS is characterized by fever, muscle rigidity, autonomic dysfunction, and altered mental status. Treatment includes discontinuation of the offending agent and supportive care.
The role of typical antipsychotics has come into question recently as studies have suggested that typical antipsychotics may increase the risk of death in elderly patients. A 2005 retrospective cohort study from the New England Journal of Medicine showed an increase in risk of death with the use of typical antipsychotics that was on par with the increase shown with atypical antipsychotics. [11] This has led some to question the common use of antipsychotics for the treatment of agitation in the elderly, particularly with the availability of alternatives such as mood stabilizing and antiepileptic drugs.
Traditional antipsychotics are classified as high-potency, mid-potency, or low-potency based on their potency for the D2 receptor:
Potency | Examples | Adverse effect profile |
---|---|---|
high | fluphenazine and haloperidol | more extrapyramidal side effects (EPS) and less antihistaminic effects (e.g. sedation), alpha adrenergic antagonism (e.g. orthostatic hypotension), and anticholinergic effects (e.g. dry mouth) |
middle | perphenazine and loxapine | intermediate D2 affinity, with more off-target effects than high-potency agents |
low | chlorpromazine | less risk of EPS but more antihistaminic effects, alpha adrenergic antagonism, and anticholinergic effects |
Prochlorperazine (Compazine, Buccastem, Stemetil) and Pimozide (Orap) are less commonly used to treat psychotic states, and so are sometimes excluded from this classification. [12]
A related concept to D2 potency is the concept of "chlorpromazine equivalence", which provides a measure of the relative effectiveness of antipsychotics. [13] [14] The measure specifies the amount (mass) in milligrams of a given drug that must be administered in order to achieve desired effects equivalent to those of 100 milligrams of chlorpromazine. [15] Another method is "defined daily dose" (DDD), which is the assumed average dose of an antipsychotic that an adult would receive during long-term treatment. [15] DDD is primarily used for comparing the utilization of antipsychotics (e.g. in an insurance claim database), rather than comparing therapeutic effects between antipsychotics. [15] Maximum dose methods are sometimes used to compare between antipsychotics as well. [15] It is important to note that these methods do not generally account for differences between the tolerability (i.e. the risk of side effects) or the safety between medications. [15]
For a list of typical antipsychotics organized by potency, see below:
†: discontinued or withdrawn products [16]
Some typical antipsychotics have been formulated as a long-acting injectable (LAI), or "depot", formulation. Depot injections are also used on persons under involuntary commitment to force compliance with a court treatment order when the person would refuse to take daily oral medication. This has the effect of dosing a person who doesn't consent to take the drug. The United Nations Special Rapporteur On Torture has classified this as a human rights violation and cruel or inhuman treatment. [17]
The first LAI antipsychotics (often referred to as simply "LAIs") were the typical antipsychotics fluphenazine and haloperidol. [18] Both fluphenazile and haloperidol are formulated as decanoates, referring to the attachment of a decanoic acid group to the antipsychotic molecule. [18] These are then dissolved in an organic oil. [18] Together, these modifications prevent the active medications from being released immediately upon injection, attaining a slow release of the active medications (note, though, that the fluphenazine decanoate product is unique for reaching peak fluphenazine blood levels within 24 hours after administration [19] ). [18] Fluphenazine decanoate can be administered every 7 to 21 days (usually every 14 to 28 days), [19] while haloperidol decanoate can be administered every 28 days, though some people receive more or less frequent injections. [18] If a scheduled injection of either haloperidol decanoate or fluphenazine decanoate is missed, recommendations for administering make-up injectable dose(s) or providing antipsychotics to be taken by mouth vary by, e.g., how long ago the last injection was and how many previous injections the person has received (i.e., if steady state levels of the medication have been reached or not). [19]
Both of the typical antipsychotic LAIs are inexpensive in comparison to the atypical LAIs. [18] Doctors usually prefer atypical LAIs over typical LAIs due to the differences in adverse effects between typical and atypical antipsychotics in general. [19]
Medication | Brand name | Class | Vehicle | Dosage | Tmax | t1/2 single | t1/2 multiple | logPc | Ref |
---|---|---|---|---|---|---|---|---|---|
Aripiprazole lauroxil | Aristada | Atypical | Water a | 441–1064 mg/4–8 weeks | 24–35 days | ? | 54–57 days | 7.9–10.0 | |
Aripiprazole monohydrate | Abilify Maintena | Atypical | Water a | 300–400 mg/4 weeks | 7 days | ? | 30–47 days | 4.9–5.2 | |
Bromperidol decanoate | Impromen Decanoas | Typical | Sesame oil | 40–300 mg/4 weeks | 3–9 days | ? | 21–25 days | 7.9 | [20] |
Clopentixol decanoate | Sordinol Depot | Typical | Viscoleo b | 50–600 mg/1–4 weeks | 4–7 days | ? | 19 days | 9.0 | [21] |
Flupentixol decanoate | Depixol | Typical | Viscoleo b | 10–200 mg/2–4 weeks | 4–10 days | 8 days | 17 days | 7.2–9.2 | [21] [22] |
Fluphenazine decanoate | Prolixin Decanoate | Typical | Sesame oil | 12.5–100 mg/2–5 weeks | 1–2 days | 1–10 days | 14–100 days | 7.2–9.0 | [23] [24] [25] |
Fluphenazine enanthate | Prolixin Enanthate | Typical | Sesame oil | 12.5–100 mg/1–4 weeks | 2–3 days | 4 days | ? | 6.4–7.4 | [24] |
Fluspirilene | Imap, Redeptin | Typical | Water a | 2–12 mg/1 week | 1–8 days | 7 days | ? | 5.2–5.8 | [26] |
Haloperidol decanoate | Haldol Decanoate | Typical | Sesame oil | 20–400 mg/2–4 weeks | 3–9 days | 18–21 days | 7.2–7.9 | [27] [28] | |
Olanzapine pamoate | Zyprexa Relprevv | Atypical | Water a | 150–405 mg/2–4 weeks | 7 days | ? | 30 days | – | |
Oxyprothepin decanoate | Meclopin | Typical | ? | ? | ? | ? | ? | 8.5–8.7 | |
Paliperidone palmitate | Invega Sustenna | Atypical | Water a | 39–819 mg/4–12 weeks | 13–33 days | 25–139 days | ? | 8.1–10.1 | |
Perphenazine decanoate | Trilafon Dekanoat | Typical | Sesame oil | 50–200 mg/2–4 weeks | ? | ? | 27 days | 8.9 | |
Perphenazine enanthate | Trilafon Enanthate | Typical | Sesame oil | 25–200 mg/2 weeks | 2–3 days | ? | 4–7 days | 6.4–7.2 | [29] |
Pipotiazine palmitate | Piportil Longum | Typical | Viscoleo b | 25–400 mg/4 weeks | 9–10 days | ? | 14–21 days | 8.5–11.6 | [22] |
Pipotiazine undecylenate | Piportil Medium | Typical | Sesame oil | 100–200 mg/2 weeks | ? | ? | ? | 8.4 | |
Risperidone | Risperdal Consta | Atypical | Microspheres | 12.5–75 mg/2 weeks | 21 days | ? | 3–6 days | – | |
Zuclopentixol acetate | Clopixol Acuphase | Typical | Viscoleo b | 50–200 mg/1–3 days | 1–2 days | 1–2 days | 4.7–4.9 | ||
Zuclopentixol decanoate | Clopixol Depot | Typical | Viscoleo b | 50–800 mg/2–4 weeks | 4–9 days | ? | 11–21 days | 7.5–9.0 | |
Note: All by intramuscular injection. Footnotes:a = Microcrystalline or nanocrystalline aqueous suspension. b = Low-viscosity vegetable oil (specifically fractionated coconut oil with medium-chain triglycerides). c = Predicted, from PubChem and DrugBank. Sources:Main: See template. |
The original antipsychotic drugs were happened upon largely by chance and then tested for their effectiveness. The first, chlorpromazine, was developed as a surgical anesthetic after an initial report in 1952. [5] It was first used in psychiatric institutions because of its powerful tranquilizing effect; at the time it was advertised as a "pharmacological lobotomy". [31] (Note that "tranquilizing" here only refers to changes in external behavior, while the experience a person has internally may be one of increased agitation but inability to express it.) [32]
Until the 1970s there was considerable debate within psychiatry on the most appropriate term to use to describe the new drugs. [33] In the late 1950s the most widely used term was "neuroleptic", followed by "major tranquilizer" and then "ataraxic". [33] The word neuroleptic was coined in 1955 by Delay and Deniker after their discovery (1952) of the antipsychotic effects of chlorpromazine. [33] It is derived from the Greek : "νεῦρον" (neuron, originally meaning "sinew" but today referring to the nerves) and "λαμβάνω" (lambanō, meaning "take hold of"). Thus, the word means taking hold of one's nerves. It was often taken to refer also to common effects such as reduced activity in general, as well as lethargy and impaired motor control. Although these effects are unpleasant and harmful, they were, along with akathisia, considered a reliable sign that the drug was working. [31] These terms have been largely replaced by the term "antipsychotic" in medical and advertising literature, which refers to the medication's more-marketable effects. [33]
Antipsychotics, previously known as neuroleptics and major tranquilizers, are a class of psychotropic medication primarily used to manage psychosis, principally in schizophrenia but also in a range of other psychotic disorders. They are also the mainstay, together with mood stabilizers, in the treatment of bipolar disorder. Moreover, they are also used as adjuncts in the treatment of treatment-resistant major depressive disorder.
Haloperidol, sold under the brand name Haldol among others, is a typical antipsychotic medication. Haloperidol is used in the treatment of schizophrenia, tics in Tourette syndrome, mania in bipolar disorder, delirium, agitation, acute psychosis, and hallucinations from alcohol withdrawal. It may be used by mouth or injection into a muscle or a vein. Haloperidol typically works within 30 to 60 minutes. A long-acting formulation may be used as an injection every four weeks for people with schizophrenia or related illnesses, who either forget or refuse to take the medication by mouth.
Fluphenazine, sold under the brand name Prolixin among others, is a high-potency typical antipsychotic medication. It is used in the treatment of chronic psychoses such as schizophrenia, and appears to be about equal in effectiveness to low-potency antipsychotics like chlorpromazine. It is given by mouth, injection into a muscle, or just under the skin. There is also a long acting injectable version that may last for up to four weeks. Fluphenazine decanoate, the depot injection form of fluphenazine, should not be used by people with severe depression.
The atypical antipsychotics (AAP), also known as second generation antipsychotics (SGAs) and serotonin–dopamine antagonists (SDAs), are a group of antipsychotic drugs largely introduced after the 1970s and used to treat psychiatric conditions. Some atypical antipsychotics have received regulatory approval for schizophrenia, bipolar disorder, irritability in autism, and as an adjunct in major depressive disorder.
Risperidone, sold under the brand name Risperdal among others, is an atypical antipsychotic used to treat schizophrenia and bipolar disorder, as well as irritability associated with autism. It is taken either by mouth or by injection. The injectable versions are long-acting and last for 2–4 weeks.
Perphenazine is a typical antipsychotic drug. Chemically, it is classified as a piperazinyl phenothiazine. Originally marketed in the United States as Trilafon, it has been in clinical use for decades.
Tardive dyskinesia (TD) is an iatrogenic disorder that results in involuntary repetitive body movements, which may include grimacing, sticking out the tongue or smacking the lips, which occurs following treatment with medication. Additional motor symptoms include chorea or athetosis. In about 20% of people with TD, the disorder interferes with daily functioning. If TD is present in the setting of a long-term drug therapy, reversibility can be determined primarily by severity of symptoms and how long symptoms have been present before the long-term drug has been stopped.
Haloperidol decanoate, sold under the brand name Haldol Decanoate among others, is a typical antipsychotic which is used in the treatment of schizophrenia. It is administered by injection into muscle at a dose of 100 to 200 mg once every 4 weeks or monthly. The dorsogluteal site is recommended. A 3.75-cm (1.5-inch), 21-gauge needle is generally used, but obese individuals may require a 6.5-cm (2.5-inch) needle to ensure that the drug is indeed injected intramuscularly and not subcutaneously. Haloperidol decanoate is provided in the form of 50 or 100 mg/mL oil solution of sesame oil and benzyl alcohol in ampoules or pre-filled syringes. Its elimination half-life after multiple doses is 21 days. The medication is marketed in many countries throughout the world.
Flupentixol (INN), also known as flupenthixol, marketed under brand names such as Depixol and Fluanxol is a typical antipsychotic drug of the thioxanthene class. It was introduced in 1965 by Lundbeck. In addition to single drug preparations, it is also available as flupentixol/melitracen—a combination product containing both melitracen and flupentixol . Flupentixol is not approved for use in the United States. It is, however, approved for use in the UK, Australia, Canada, Russian Federation, South Africa, New Zealand, Philippines, Iran, Germany, and various other countries.
Extrapyramidal symptoms (EPS) are symptoms that are archetypically associated with the extrapyramidal system of the brain's cerebral cortex. When such symptoms are caused by medications or other drugs, they are also known as extrapyramidal side effects (EPSE). The symptoms can be acute (short-term) or chronic (long-term). They include movement dysfunction such as dystonia, akathisia, parkinsonism characteristic symptoms such as rigidity, bradykinesia, tremor, and tardive dyskinesia. Extrapyramidal symptoms are a reason why subjects drop out of clinical trials of antipsychotics; of the 213 (14.6%) subjects that dropped out of one of the largest clinical trials of antipsychotics, 58 (27.2%) of those discontinuations were due to EPS.
Fluspirilene is a diphenylbutylpiperidine typical antipsychotic drug, used for the treatment of schizophrenia. It is administered intramuscularly. It was discovered at Janssen Pharmaceutica in 1963. A 2007 systematic review investigated the efficacy of fluspirilene decanoate for people with schizophrenia:
Bromperidol, sold under the brand names Bromidol and Impromen among others, is a typical antipsychotic of the butyrophenone group which is used in the treatment of schizophrenia. It was discovered at Janssen Pharmaceutica in 1966. An ester prodrug, bromperidol decanoate, is a long-acting form of bromperidol used as a depot injectable.
Zuclopenthixol, also known as zuclopentixol, is a medication used to treat schizophrenia and other psychoses. It is classed, pharmacologically, as a typical antipsychotic. Chemically it is a thioxanthene. It is the cis-isomer of clopenthixol. Clopenthixol was introduced in 1961, while zuclopenthixol was introduced in 1978.
Pipotiazine (Piportil), also known as pipothiazine, is a typical antipsychotic of the phenothiazine class used in the United Kingdom and other countries for the treatment of schizophrenia. Its properties are similar to those of chlorpromazine. A 2004 systematic review investigated its efficacy for people with schizophrenia:
Aripiprazole lauroxil, sold under the brand name Aristada, is a long-acting injectable atypical antipsychotic that was developed by Alkermes. It is an N-acyloxymethyl prodrug of aripiprazole that is administered via intramuscular injection once every four to eight weeks for the treatment of schizophrenia. Aripiprazole lauroxil was approved by the U.S. Food and Drug Administration (FDA) on 5 October 2015.
Bromperidol decanoate, sold under the brand names Bromidol Depot, Bromodol Decanoato, and Impromen Decanoas, is an antipsychotic which has been marketed in Europe and Latin America. It is an antipsychotic ester and long-acting prodrug of bromperidol which is administered by depot intramuscular injection once every 4 weeks.
Perphenazine enanthate, sold under the brand name Trilafon Enantat among others, is a typical antipsychotic and a depot antipsychotic ester which is used in the treatment of schizophrenia and has been marketed in Europe. It is formulated in sesame oil and administered by intramuscular injection and acts as a long-lasting prodrug of perphenazine. Perphenazine enanthate is used at a dose of 25 to 200 mg once every 2 weeks by injection, with a time to peak levels of 2 to 3 days and an elimination half-life of 4 to 7 days.
Oxyprothepin decanoate, sold under the brand name Meclopin, is a typical antipsychotic which was used in the treatment of schizophrenia in the Czech Republic but is no longer marketed. It is administered by depot injection into muscle. The medication has an approximate duration of 2 to 3 weeks. The history of oxyprothepin decanoate has been reviewed.
A depot injection, also known as a long-acting injectable (LAI), is a term for an injection formulation of a medication which releases slowly over time to permit less frequent administration of a medication. They are designed to increase medication adherence and consistency, especially in patients who commonly forget to take their medicine. Depot injections can be created by modifying the drug molecule itself, as in the case of prodrugs, or by modifying the way it is administered, as in the case of oil/lipid suspensions. Depot injections can have a duration of action of one month or greater and are available for many types of drugs, including antipsychotics and hormones.
An antipsychotic ester is an ester of an antipsychotic. They are used clinically as prodrugs to increase fat solubility and thereby prolong duration when antipsychotics are used as depot injectables.