Second Generation Antipsychotics

Second generation antipsychotics are used primarily for the treatment of psychosis and other mental health disorders such as depression and bipolar.   Extrapyramidal side effects are much less common when compared with first generation antipsychotics.  Side-effects are treated with benztropine or diphenhydramine.  Weight gain is higher risk with second generation antipsychotics when compared with first generation.  Clozapine is known to cause bone marrow suppression and requires regular monitoring. Olanzapine is particularly known to increase risk of weight gain, and ziprasidone is contraindicated in patients with a history of cardiac arrhythmias.

Class Drugs

• Aripiprazole

• Asenapine

• Clozapine

• Iloperidone

• Lurasidone

• Olanzapine

• Paliperidone

• Quetiapine

• Risperidone

• Ziprasidone

Class Mechanism of Action

• Competitive blockade of D2 receptors

• Inhibition of serotonin receptors

Class Application

Antipsychotic Effects

• Improves 'positive' symptoms of schizophrenia such as hallucinations, delusions, and paranoia

• Blocks D2 receptor in mesolimbic system

• Some effect on 'negative' symptoms of schizophrenia

Antiemetic effects

• Blocks D2 receptors in medulla

Anticholinergic effects

• May help reduce extrapyramidal side effects

Class Adverse Effects

Weight Gain

• Higher risk in 2nd generation antipsychotics

• Watch for Type II DM and hyperlipidemia

• Results in patient non-compliance

Prolonged QT interval

Extrapyramidal side effects - much less common than in 1st generation antipsychotics

• Akathisia (restlessness)

• Dystonia (prolonged contraction of muscles)

• Parkinsonism (bradykinesia, rigidity, tremor)

• Treatments

Diphenhydramine and Benztropine

Tardive dyskinesia (abnormal repetitive movements: lip smacking, neck and limb movements) -  much less common than in 1st generation antipsychotics

• Long-term effect (occurs after both short-term and long-term use)

Anticholinergic effects

Neuroleptic malignant syndrome -  much less common than in 1st generation antipsychotics

• Muscle rigidity, fever, altered mental status, unstable blood pressure

• Therapy

Discontinue causative agent

• Supportive care

• May use dantrolene or bromocriptine

Drug Table

Drug Name	Application	Comments	Image
Aripiprazole	Also approved for bipolar; Adjunct for depression; Used in autism		"Air" "Pipe"
Asenapine			"Ass" "Pine"
Clozapine	Reserved for refractory schizophrenia	Side Effects; -Bone marrow suppression; -Requires frequent monitoring of blood counts; -Orthostasis; -Seizures	"Claw" and "Pine Tree"
Iloperidone			"Ill" Pear" "Done"
Lurasidone			Fishing "Lure" "Done"
Olanzapine		Side Effects; High weight gain	"Hola" "Zapping"
Paliperidone			"Pale" "Pear" "Done"
Quetiapine	Also approved for bipolar; Adjunct for depression		"Quiet Sign" "Pine Tree"
Risperidone	Also approved for bipolar; Used in autism		"Rice" Pear" "Done"
Ziprasidone		Side Effects; ; Contraindicated in patients with history of cardiac arrhythmia and prolonged QT interval; Low weight gain	"Zipper"