Atypical Antipsychotics

Atypical or second-generation antipsychotics, introduced in the 1990’s, treat a wide range of manifestations of schizophrenia and bipolar disorder and help manage the irritability associated with autism. Initially believed to be more effective than the conventional antipsychotics, studies have found them to be equally as effective. The significant difference is the occurrence of adverse medication reactions. The atypical antipsychotics are less likely to cause extrapyramidal effects, or EPS, but more likely to cause metabolic side effects, such as diabetes, weight gain, and dyslipidemia.

Prototype and Other Medications

Risperidone is the prototype for atypical, second-generation antipsychotics that treat schizophrenia. Other medications in this category are olanzapine, quetiapine, aripiprazole, ziprasidon, clozapine, and lumateperone. Clozapine was actually the first atypical antipsychotic available, but doctors now use others in this classification more frequently.

Expected Pharmacologic Action

Atypical antipsychotics block the receptors for dopamine, but more strongly block those for serotonin. Since the dopamine receptor blockade is less than that of conventional antipsychotic medications, they precipitate fewer extrapyramidal manifestions and subsequently fewer side and adverse effects.

Adverse Drug Reactions

Atypical antipsychotics cause drowsiness, insomnia, dizziness, and other CNS effects. Clients may also experience weight gain, onset of new diabetes or worsening of existing diabetes, and increased cholesterol levels. Extrapyramidal effects, such as dystonia, akathisia, and Parkinson-like manifestations, occur with higher doses of risperidone but less often than with conventional antipsychotics.

Interventions

When caring for clients taking an atypical antipsychotic medication, monitor for drowsiness, insomnia, dizziness, and other CNS effects. Implement fall-risk measures, such as assisting with ambulation. Monitor weight, blood glucose, cholesterol, and triglyceride levels periodically for elevations.

Monitor for extrapyramidal effects and report the occurrence of any of these to the provider. If medications of acute dystonia develop, anticipate giving an anticholinergic medication. If manifestations of Parkinsonism develop, anticipate giving an anti-Parkinson medication. If either of these types of manifestations develops, anticipate changing the client’s prescription to another antipsychotic medication.

Administration

When administering an atypical antipsychotic, such as risperidone, mix oral solutions with juice, milk, water, or coffee. Do not mix with tea or soft drinks. Remove the rapidly disintegrating form from its packaging immediately before administration to avoid disruption of the tablet. Administer the long-acting IM form of risperidone every 2 weeks using a large gluteal muscle and the needle provided. For clients switching from oral risperidone to biweekly risperidone injection, continue giving oral risperidone for 3 weeks after they start therapy to maintain therapeutic levels of the medication.

Client Instructions

When giving clients instructions about atypical antipsychotics, tell them not to drive or participate in activities that require mental alertness until they know the medication’s CNS effects. Clients should report extrapyramidal effects immediately to the provider. And, due to the risk of diabetes mellitus developing or worsening, advise that they increase exercise and consume a low-fat, low-carbohydrate diet. If polyuria, which is excessive urination, or polydipsia, which is excessive thirst, develops, they should notify the provider because these are possible manifestations of diabetes. Clients with diabetes mellitus should monitor their blood glucose more closely.

Contraindications and Precautions

Contraindications for risperidone include clients who are allergic to the medication or are lactating, who have severe CNS disorders, certain ECG abnormalities, psychosis related to dementia in older adults, or an increased risk for cerebrovascular accident or stroke. Clients frequently exposed to sunlight or who use tanning beds should not take this medication. Children younger than 13 years should not take risperidone for schizophrenia. Contraindications include even younger children for bipolar disorder and autism. Use risperidone with caution for older adults and for clients who have Parkinson’s disease, liver and renal disorders, hypotension, seizure disorders, fluid or electrolyte disturbances, diabetes mellitus, or CNS depression.

Interactions

Atypical antipsychotics increase the effects of antihypertensive mediations. Clozapine increases risperidone levels, while phenytoin, carbamazepine, phenobarbital, and rifampin decrease risperidone levels.

Safety Alert

Risperdone has a boxed warning that older adults who have dementia and take antipsychotics are at an increased risk for death. Due to the blocking effect that risperidone has on dopamine receptors, clients who are taking an anti-Parkinson’s medication for Parkinson’s disease may have an increase in manifestations. Monitor for decreased mobility and the ability to perform daily activities for clients taking both types of medications. Report these findings to the provider and assist clients with safe ambulation and self-care activities.