Master the board step 3

Psychiatry
Basic Science Correlate
Risperidone affects 6 receptors:
5HT
D1
D2
α1
α2
H1
Movement Disorders
Extrapyramidal symptoms (EPS) are the most common reason for failure to
comply with therapy. Be able to identify a patient with a medication-related
movement disorder and know how to minimize the symptoms.
The following table shows common medication-related movement disorders
and their management.
Acute Dystonia
Occurs in the first
week
Muscle spasms
(e.g., torticollis),
difficulty
swallowing
TIP: Young men are at
higher risk
-Reduce the dose
-Rx: Anticholinergics
• benztropine
• diphenhydramine
• trihexyphenidyl
Bradykinesia
(Parkinsonism)
Akathisia Tardive Dyskinesia Neuroleptic
Malignant
Syndrome
Within weeks Weeks to chronic use Months to years Anytime
Bradykinesia,
tremors, rigidity,
and other signs of
parkinsonism
TIP: Elderly are at
higher risk
-Reduce the dose
-Rx: Anticholinergics
• benztropine
• diphenhydramine
• trihexyphenidyl
Motor restlessness
Do not mistake
for anxiety for
agitation
TIP: Always review
medication list
-Reduce the dose
-Add benzodiazepines
or beta-blockers
-Switch to newer
antipsychotics
Choreoathetosis and
other involuntary
movements after
chronic use
Often irreversible
-Stop older
antipsychotics
-Switch to newer
antipsychotics
(e.g., clozapine)
TIP: Symptoms
commonly worsen
after medication
discontinuation
Muscle rigidity,
hyperthermia,
volatile vital
signs, altered
LOC, ↑ WBC &
CK
-Stop antipsychotic
TIP: Transfer to ICU
for monitoring,
mortality rate is 20%
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