High potency antipsychotics have a higher risk for extrapyramidal symptoms (EPS) and hyperprolactinemia. Low potency antipsychotics have more anticholingeric symptoms and are more sedating. Typical antipsychotics have a higher propensity to cause EPS, where as atypicals are more likely to cause metabolic syndrome.
High- and low-potency antipsychotics also seem to differ in their side-effects. Low-potency drugs cause sedation and poor muscle strength, whereas high-potency drugs produce side-effects such as movement disorders (the inability to sit still, uncontrollable shaking and difficulty in walking).
The high-potency, first-generation antipsychotics, such as fluphenazine, trifluoperazine, haloperidol, loxapine, pimozide, perphenazine, and thiothixene, are dosed in the range of one to tens of milligrams.
Chlorpromazine is a low potency antipsychotic which is used with psychosis, schizophrenia and manic episodes. This drug has the side effect of hypotension and also has anti-histamine properties, which counteract the extrapyramidal symptoms experienced with antipsychotics.
A highly potent drug (e.g., fentanyl, alprazolam, risperidone, ) evokes a given response at low concentrations, while a drug of lower potency (meperidine, ziprasidone, furosemide) evokes the same response only at higher concentrations. Higher potency does not necessarily mean greater effectiveness or more side effects.
The low-potency drugs (e.g., chlorpromazine, thioridazine) are used to treat mania and, as a last resort, to treat aggressive behavior and severe agitation in children.
Results: Potency is an expression of the activity of a drug in terms of the concentration or amount of the drug required to produce a defined effect, whereas clinical efficacy judges the therapeutic effectiveness of the drug in humans.
High-potency antipsychotics have a strong antipsychotic effect even at relatively low doses, but they also more commonly cause neurologic side effects (e.g., extrapyramidal symptoms) than low-potency antipsychotics.
This may explain why olanzapine has a relatively large sedative effect even though it is a high-potency medication. Of the antipsychotics studied, haloperidol had the lowest affinity for the histamine H1 receptors. Quetiapine and risperidone had the lowest affinity of the atypical antipsychotics.
Great care must be taken if low-potency agents (such as chlorpromazine, thioridazine, and clozapine) are combined with other highly anticholinergic drugs because the additive anticholinergic activity may produce confusion, urinary retention, or constipation.
Typical antipsychotics tend to more strongly block dopamine. Atypical antipsychotics have greater effects on serotonin. Both groups of antipsychotics share similar side effects, such as dry mouth, sleepiness, and weight gain. But typical antipsychotics have a higher risk of uncontrollable body movements.
[Olanzapine--high potency antipsychotic drug inducing significant weight gain: a case report]
Aripiprazole is a low potency partial agonist at the 5-HT1A receptor stably expressed in 1ACHO cells. Inhibition of forskolin-stimulated cAMP production was compared for serotonin and aripiprazole.
Haloperidol is a high potency first-generation (typical) antipsychotic and one of the most frequently used antipsychotic medications used worldwide.
The main difference between the two types of antipsychotics is that the first generation drugs block dopamine and the second generation drugs block dopamine and also affect serotonin levels.
First-generation antipsychotics are dopamine receptor antagonists (DRA) and are known as typical antipsychotics. Second-generation antipsychotics are serotonin-dopamine antagonists and are also known as atypical antipsychotics.
high-potency antipsychotic
any of various conventional antipsychotics that have either a relatively high degree of affinity for the dopamine D2 receptor or significant extrapyramidal symptoms. High-potency antipsychotics include fluphenazine, haloperidol, thiothixene (see thioxanthene), trifluoperazine, and pimozide.
Abstract. Typical antipsychotic drugs act on the dopaminergic system, blocking the dopamine type 2 (D2) receptors. Atypical antipsychotics have lower affinity and occupancy for the dopaminergic receptors, and a high degree of occupancy of the serotoninergic receptors 5-HT2A.
Second-generation antipsychotics such as risperidone, ziprasidone, paliperidone, and aripiprazole are all potent antagonists of dopamine D2 receptors, while clozapine and quetiapine are weak D2 antagonists.
In general, potency refers to a drug's concentration, while efficacy refers to a drug's ability. A higher potency does not necessarily mean a higher efficacy.
Potency (strength) refers to the amount of drug (usually expressed in milligrams) needed to produce an effect, such as relief of pain or reduction of blood pressure. For instance, if 5 milligrams of drug A relieves pain as effectively as 10 milligrams of drug B, drug A is twice as potent as drug B.
: the quality or state of being potent. : the ability or capacity to achieve or bring about a particular result.