Psychotropic Medications - Antidepressants, antipsychotics, mood stabilizers, anxiolytics,
hypnotics, stimulants
Organized by structure
MOA
Distinguished by subtle differences in molecular structure.
Most psychotropics are lipophilic and highly protein bound; thus, older adults have more
body fat and less protein, more likely to develop toxicity.
Pharmacology - Study of what drugs do and how they do it.
Pharmacokinetics - What the BODY does to the DRUG (ADME)
Pharmacodynamics - What the DRUG does to the BODY
Time course and intensity of a drug's effect
Drug MOA
Therapeutic Index - Measure of a toxicity or safety of a drug
The ratio of the median toxic dose to the median effective dose
The median toxic dose is the dose at which 50% of patients experience a toxic effect
If the therapeutic index is high, it is reflected by a wide range dosage of which the drug is
prescribed (Haloperidol, Depakote)
If the therapeutic index is low, careful monitoring of serum drug levels will be needed
(Lithium)
Suicidal Ideation and Antidepressant Tx - Higher risk up to age 24 in short term tx (4-16
wks)
BBW
Clozapine ADR - Agranulocytosis
Lamictal ADR - SJS
Nefazodone (Serzonel) ADR - Hepatic failure
Phenelizine (Nardil) ADR - Stroke
Thioridzaine (Mellaril) ADR - Heart Block
Longterm Complication of DRA Haldol - Tardive dyskinesia; increased risk of breast CA
(larger cumulative doses)
Somnolence - Often an intended effect of many psychotropic drugs
Treat insomnia, anxiety, or agitation
Clinician should alert patient to use caution when driving or operating heavy machinery
Management of somnolence can include:
- Adjusting the time or dosing of medication
, - Switch to an alternative medication
GI Disturbances - Consequence of muscarinic activity (Ach) - constipation, dry mouth
Most of the body's serotonin is in the GI tract
Serotenergic drugs cause: stomach pain, nausea, flatulence, diarrhea
Clinical management: use low doses or delayed release preparations to minimize GI effects.
Movement Disorders - Introduction of serotonin-dopamine antagonists have reduced the
incidence of medication-induced disorders (SDAs vs DRA)
Rare reports of SSRI induced movement disorders
Dose related parkinsonism, akathisia (restlessness), and dystonia - Zyprexa (Increased EPS),
Rspierdal (resembles older agents), Abilify (severe akathisia)
Sexual Dysfunction - Decreased libido, impaired ejaculation and erection, inhibition of
female orgasm
Common with SSRIs
Patients are not likely to report this SE
If the response to tx is good, treat the side effect
Clinical and patient can consider switching to an alternative medication if this adverse event
is not acceptable to the patient
Weight Gain - Can result from: retained fluid, increased caloric intake, decreased exercise,
altered metabolism
Histamine and serotonin systems mediate changes in weight
Genetic factors that regulate body weight seem to involve 5-HT2 receptor
SE for: Clozaril & Olanzapine
Insulin Resistance: Valproate (Depacon) & Olanzapine
Weight Loss - Initial weight loss may be seen with SSRI tx
Wellbutrin may cause sustainable weight loss
Topamax may help wt loss ( & Zonegran)
Most common SE of stimulants is wt loss
Cognitive Impairment - Disturbance in the capacity to think
Benzo's may cause this
Drugs with anticholinergic properties may worsen memory performance
Medications such as Lamotrigine, Lithium, and Gabapentin may impair memory and cause
difficulty with word finding
Also SSRIs, TCAs, Buproprion
Rash - SJS: Systemic, immune mediated reaction; usually starts as a rash; can be fatal or
result in permeant scarring or blindness; lesions may be widespread, can occur above the
neck and involve mucous membranes; fever
Clinical Management: Stop the offending medication, send patient to ER if S/S persist
Medication Induced Movement Disorders - Neuroleptic Malignant Syndrome
Medication-induced acute dystonia
Medication-induced acute akathisia
Tardive dyskinesia