8. +
The term atypical is used because these drugs differ in their
side effect profiles, most notably a lower risk of
extrapyramidal side effects (EPS)
As of 20 1 3 , ten second-generation antipsychotic drugs were
approved by the Food and Drug Administration (FDA).
These include the following: Risperidone (Risperdal), Olanzapine
(Zyprexa), Quetiapine (Seroquel), Ziprasidone (Geodon),
Aripiprazole (Abilify), Paliperidone (Invega), Asenapine (Saphris),
Lurasidone (Latuda), Iloperidone (Fanapt), and Clo zapine
(Clozaril).
9. +
MECHAN ISMS OF ACTION
The presumed antipsychotic effects of the SDAs are blockade
of D2 dopamine receptors. Where the SDAs differ from older
antipsychotic drugs is their higher ratio interactions with
serotonin receptor subtypes, most notably the 5-HT2A
subtype, as well as with other neurotransmitter systems.
It is hypothesized that these properties account for the distinct
tolerability profiles associated with each of the SDAs. All SDAs
have different chemical structures, receptor affinities, and side
effect profiles.
10. +
THERAPEUTIC INDICATIONS
Schizophrenia
Acute Mania
Adjunctive therapy in major depressive disorder.
Posttraumatic stress disorder
Anxiety Disorders
**All of these agents are considered first-line drugs for
Schizophrenia except Clozapine
11. +
Risperidone (Risperdal)
INDICATIONS:
Acute and maintenance treatment of Schizophrenia in adults and
adolescents.
Short-term treatment of acute manic - mixed with lithium or
valproate
Irritability associated with autistic spectrum DO in 5-16 years of
age
On August 22, 2007, risperidone was approved as the ONLY drug agent available
for treatment of schizophrenia in youths, ages 13–17
12. +
Pharmacology
Extensive first pass hepatic metabolism to 9-hydroxy
risperidone
Peak plasma level for the parent compound – 1hr
Metabolite – 3hrs
Half-life - 20hrs (implication?)
If dose is below 6mg per day – less likely to cause EPS
13. +
Dosages
Availability – 0.25, 0.5, 1, 2, 3 and 4mg tablets and a 1mg/ml
oral solution.
Initial dosage is usually 1 to 2mg at night which can be
increased to 4mg per day.
14. +
Side Effects
EPS – dosage dependent
Weight gain
Anxiety
Nausea and vomiting
Erectile dysfunction
Elevated prolactin
15. +
Drug Interaction
Paroxetine and fluoxetine inhibits CYP2D6 – block formation
of risperidone’s active metabolite.
SSRIs + Risperidone = significant elevation of prolactin >
leading to?
16. +
PALIPERIDONE (INVEGA)
Indications:
Acute and maintenance treatment for
schizophrenia
Acute treatment of schizoaffective disorder as
monotherapy
Adjunct to mood stabilizers or antidepressants
17. +
Pharmacology
MAJOR active metabolite of risperidone
No dose adjustment required in patients with hepatic impairment
Peak plasma concentration – 24 hours after dosing
Steady-state concentrations – 4 or 5 days.
18. +
Dosage
Available in 3,6, and 9 mg tablets
Recommended dosage: 6mg OD in the morning.
No more than 12mg per day
(Invega Sustenna) – by IM once a month
39mg, 78mg, 117mg (recommended), 156mg, 234mg paliperidone
palmitate.
Half life = 25-49 days.
20. +
OLANZAPINE (Zyprexa)
Indications:
Schizophrenia
Monotherapy for the ACUTE treatment of manic
or mixed episodes associated with bipolar I
disorder adjunct to lithium or valproate
Adjunct to fluoxetine for the treatment of
depressive episodes associated with bipolar I
21. +
Pharmacology
85% absorbed in the GI
40% inactivated by first pass hepatic metabolism
Peak in 5 hours
Half life averages 31 hours
Once daily dosing
22. +
Dosages
2.5, 5, 7.5, 10, 15, and 20mg oral tablets.
Initial dosage for psychosis – 5 or 10mg
Acute mania – 10 or 15mg
30 to 40mg – treatment-resistant patients.
23. +
DRUG INTERACTIONS
Cimetidine (Tagamet) – increases concentration of Olanzapine
Carbamazepine and phenytoin – decreases serum
concentration of Olanzapine
Ethanol increases olanzapine absorption by more than 25
percent
24. +
SIDE EFFECT
More frequent WEIGHT GAIN
Somnolence, dry mouth, dizziness, constipation, dyspepsia,
increased appetite, akathisia, and tremor
Dose related EPS
26. +
Quetiapine (Seroquel)
Indications:
Schizophrenia
Acute treatment of manic episodes associated with bipolar I disorder
(monotherapy or adjunct to lithium or divalproex)
27. +
Pharmacology
Structurally related to clozapine
Rapidly absorbed in the GI tract, peak plasma concentrations
reached 1-2 hours
Steady state half life 7 hours (dosing is two or three times a
day)
Not associated with EPS
28. +
Dosages
25, 50, 100, 200, 300, and 400mg tablets
Dosing should begin 25mg twice daily, with doses increased
by 25 to 50mg per dose every 2 to 3 days, up to a target of 300
to 400mg a day.
More aggressive dosing is both tolerated and effective
25 to 300mg at night – used for insomnia
30. +
Side Effect
Somnolence, postural hypotension, and dizziness – most
common
Least likely to cause EPS
Transient weight gain
31. +
Ziprasidone (Geodon)
Indications:
Schizophrenia
Monotherapy for the acute treatment of manic or mixed episodes
associated with bipolar I DO adjunct to lithium or valproate
32. +
Pharmacology
Peak 2-6 hours
Recommended twice daily dosing
Peak serum concentrations of IM ziprasidone occur
approximately 1 hour, with a half life of 2 to 5 hours.
33. +
Dosages
20, 40, 60 and 80mg capsules
IM use – single use 20mg/ml vial.
Oral ziprasidone dosing should be initiated at 40mg a day
divided into two daily doses.
34. +
Side Effects
Somnolence, headache, dizziness, nausea, and
lightheadedness are the most common adverse effects
Prolongation of QTc complex
35. +
Aripiprazole (Abilify)
D2 antagonist, partial D2 agonist and potent 5-HT2A
antagonist
Indications:
Schizophrenia and schizoaffective disorders
Acute and maintenance treatment and adjunctive
therapy to either lithium or valproate for manic and
mixed episodes associated with bipolar I disorder.
Treatment of irritability associated with autistic disorder.
36. +
Aripiprazole (Abilify)
Well absorbed, reaching peak plasma
concentrations after 3 to 5 hours.
Absorption is not affected by food.
Mean elimination half-life: 75 hours
Clearance is reduced in elderly persons.
minimal EPS and may cause orthostatic
hypotension.
Primarily metabolized by CYP3A4 and CYP2D6
genes.
37. +
Aripiprazole (Abilify)
Drug Interactions:
Carbamazepine and valproate reduce serum
concentrations
Ketoconazole, fluoxetine, paroxetine, and
quinidine increase serum concentrations
Combined with antihypertensives may cause
hypotension. Drugs that inhibit CYP2D6
activity reduce elimination.
38. +
Aripiprazole (Abilify)
Dosage and guidelines
Available as 5, 1 0, 1 5, 20, and 30 mg tablets.
The effective dosage range is 10 to 30 mg per day. Starting dose
is 10 to 15 mg per day.
Initial dose of 5 mg increases tolerability.
Side effects
Headache, somnolence, agitation, dyspepsia, anxiety, and nausea
Akathisia, Insomnia, weight gain or diabetes
39. +
ASENAPINE (SAPHRIS)
Acute treatment of adults with schizophrenia and of manic or
mixed episodes associated with bipolar I disorder with or
without psychotic features.
Affinity for several receptors: serotonin, noradrenergic,
dopaminergic and histamine.
Negligible affinity for muscarinic-1 cholinergic receptors
40. +
ASENAPINE (SAPHRIS)
Dosage
5 mg and 10 mg sublingual tablets
Bioavailability is <2% when swallowed, but is 35% when
absorbed sublingually.
Avoid drinking or eating for 10 minutes after because this may
lower the blood levels.
Recommended starting and target dose for schizophrenia is
5mg BID and 5-10 mg BID for Bipolar disorder.
41. +
ASENAPINE (SAPHRIS)
Side Effects
somnolence, dizziness, EPS other than
akathisia, and increased weight.
can elevate prolactin levels during chronic
administration
Galactorrhea, amenorrhea, gynecomastia, and
impotence.
42. +
CLOZAPINE (CLOZARIL)
Most effective drug treatment for patients who have failed to
respond to standard therapies and also benefits patients with
severe tardive dyskinesia.
treatment of psychotic patients who are intolerant of EPS caused
by other agents, treatment-resistant mania, severe psychotic
depression, idiopathic Parkinson's disease, Huntington's disease,
and suicidal patients with schizophrenia or schizoaffective disorder
Pervasive developmental disorder, autism of childhood, and OCD
43. +
CLOZAPINE (CLOZARIL)
It is rapidly absorbed with peak plasma levels reached in about
2 hours.
Steady state is achieved in less than 1 week if twice daily
dosing is used. Elimination half-life is about 12 hours
An antagonist of 5-HT2A, D1, D3, D4, and adrenergic
receptors. It has relatively low potency as a D2 receptor
antagonist.
44. +
CLOZAPINE (CLOZARIL)
Dosage and interactions
Available in 25 mg and 100 mg tablets. Initial dose is usually 25
mg OD or BID.
The dosage can then be increased gradually to 300 mg a day in
divided doses and up to 900 mg a day.
Agranulocytosis or bone marrow suppression.
Lithium may increase the risk of seizures, confusion, and
movement disorders. Clomipramine (Anafanil) can increase the
risk of seizure.
Risperidone, fluoxetine, paroxetine, and fluvoxamine increase
serum concentrations. Paroxetine may precipitate clozapine-
associated neutropenia.
45. +
CLOZAPINE (CLOZARIL)
Side effects
Most common: sedation, dizziness, syncope, tachycardia,
hypotension, ECG changes, nausea, and vomiting.
Fatigue, weight gain, various GI symptoms (most commonly
constipation), anticholinergic effects.
Hypersalivation, is a side effect that begins early in treatment and is
most evident at night.
Risk of seizures is about 4% in patients taking dosages >600 mg a
day
Leukopenia, granulocytopenia, agranulocytosis, and fever
Containdications: WBC count <3,500 cells per mm3; a
previous bone marow disorder; history of agranulocytosis; drugs that
suppress the bone marrow such as carbamazepine (Tegretol).
46. +
ILOPERIDONE (FANAPT)
For acute treatment of schizophrenia in adults.
peak concentration of 2 to 4 hours and a half-life that is
dependent on hepatic metabolism (18 – 37 hrs)
47. +
ILOPERIDONE (FANAPT)
Side Effects
Prolongs the QT interval at12mg twice daily.
dizziness, dry mouth, fatigue, sedation,
tachycardia, and orthostatic hypotension
Dosing
Titrated slowly to avoid orthostatic hypotension
Effective dose(12 mg) should be reached in
approximately 4 days based on a twice-a-day dosing.
The maximum recommended dose is 12 mg BID.
48. +
LURASIDONE HCL (LATUDA)
Oral, once-daily, atypical antipsychotic indicated for schizophrenia.
Side Effects
somnolence, akathesia, nausea, parkinsonism, and agitation.
Causes less weight gain and metabolic changes than asenapine and
iloperidone.
Drug Interactions
should not be used in combination with a strong CYP3A4 inhibitor
(e.g., ketoconazole) or CYP3A4 inducer (e.g., rifampin).
Dose should not exceed 40 mg per day with coadministration with a
moderate CYP3A4 inhibitor such as diltiazem.
49. +
LURASIDONE HCL (LATUDA)
20, 40, 80, and 120 mg tablets. Recommended starting dose is
40 mg OD and should be taken with food.
Effective in a dose range of 40 to 120 mg per day.
Dose adjustment for patients with renal impairment. <80 mg per
day for moderate and <40mg severe renal impairment.
50. +
CLINICAL GUIDELINES FOR SDAS
All SDAs are appropriate for the management of an initial
psychotic episode, but clozapine is reserved for persons who
are refractory to all other antipsychotic dugs.
The choice of drug should be based on the patient's clinical
stats
and history of response to medication.
Use of all SDAs must be initiated at low dosages and gradually
tapered upward to therapeutic dosages.
Patient's history should include information about blood
disorders, epilepsy, cardiovascular disease, hepatic and renal
diseases, and drug abuse.
51. +
CLINICAL GUIDELINES FOR
SDAS
The physical examination should include supine and standing
blood pressure measurements to screen for orthostatic
hypotension.
The laboratory examination should include an ECG and several
complete blood counts with WBC counts and liver and renal
function tests. Blood glucose, lipids, and body weight.
Persons who developed agranulocytosis while taking clozapine
can safely switch to olanzapine.
SDA use by pregnant women has not been studied, but
consideration should be given to the potential of risperidone to
raise prolactin concentrations, sometimes up to three to four times
the upper limit of the normal range. Because the drugs can be
excreted in breast milk, they should not be taken by nursing
mothers.
Editor's Notes
Galactorrhea
acts as a modulator and acts on both postsynaptic D2 receptors and presynaptic autoreceptors.
hence less incidence of dry mouth, blurred vision, constipation, and urinary retention.
hepatic isoenzyme metabolism (CYP2D6 and CYP3A4)
18 to 26 hrs in CYP2D6 extensive metabolizers and is 31 to 37 hrs in CY2D6 poor metabolizers.
associated with arrhythmia and sudden death.
Cardiovascular disease, hypokalemia, hypomagnesemia, bradycardia, congenital prolongation of QT interval, and concurrent use of inhibitors of CYP3A4 or CYP2D6 may increase the risk of QT prolongation.