NURS-220 : Psychopharmacology

dopamine

Excitatory neurotransmitter responsible for emotional response, cognition, pleasure and reward. Affected by stress, the levels of this causes the manifestations of schizophrenia.

serotonin

Inhibitory neurotransmitter responsible for mood, attention, sleep, and sexual behavior. It’s complexity contributes itself to a variety of d/o’s : anxiety, depression, and psychotic.

norepinephrine

The most common in NS, an excitatory neurotransmitter responsible for learning, sleep, mood, memory and attention. Released in response to stress and higher levels present in traumatized pts. Manifests as anxiety and depression.

histamine

Neuromodulating factor, altering activity of NS by delivering signals to specific nerves or brain regions. Mediates the affects of alertness and wakefulness, as well as allergic response and cardiac stimulation.

Gama Amino Butryric Acid (GABA)

Amino acid which serves as an inhibitory neurotransmitter which modulates other neurotransmitters. Responsible for promoting neuronal development, improving sleeplessness, minimizing anxiety/depression manifestations. Reduces anxiety and induces sleep.

glutamine

An excitatory amino neurotransmitter responsible for motor, affective, and cognitive function. Serves as a precursor for pt developing psychosis, as it’s release in large amounts is a response to severe head injury/stroke. This excess is toxic to neurons causing permanent damage over time.

acetylcholine

Inhibitory and excitatory neurotransmitter found in skeletal muscles, the primary neurotransmitter for muscle function (and sleep-wake cycle). Alzheimers pts have decreased levels.

alprazolam, diazepam, lorazepam, and chlordiazepoxide

Benzodiazepines - An antianxiety class which works by enhancing the GABA effect in CNS. High potential for physical dependency. Worried about sedation, fall risk, and paradoxical response.

Overdose —> Give flumazenil

buspirone and hydroxyzine

Non-benzo Anxiolytic - A partial serotonin receptor antagonist and a weak dopamine receptor antagonist which does NOT cause physical dependency as it does not affect GABA receptors. Takes several weeks for pt to feel effects and has s/e of sedation, nausea, HA, and dizziness.

phenelzine (Nardil) and selegiline transdermal system (EMSAM)

Monoamine Oxidase Inhibitors (MAOIs) - An antidepressant which works by disabling monoamine oxidase to increase the time that neurotransmitters like serotonin and dopamine can function before degradation. S/e - wt gain, daytime sedation, sexual dysfunction, and insomnia.

Essential education - Pt must be careful to avoid foods high in tyramine (charcuterie foods) due to increased risk of hypertensive crisis. This risk can also be increased by taking MAOIs with TCAs or OTC drugs with ephedrine.

amipitryptyline (Elavil), imipramine (Tofranil), desipramine (Norpramine), and doxepine (Sinequan)

Tricyclic Antidepressants (TCA’s) - An antidepressant which works by blocking the reuptake of serotonin and norEpi in presynaptic receptors. May take 2-4 weeks to work. S/e - dry mouth, constipation, and risk for ortho hypotension.

Be aware - Assess regularly for suicidality, because if the patient is saving up their TCAs to commit suicide they are very likely to be successful.

citalopram (Celexa), escitalopram (Lexapro), fluoxetine (Prozac), paroxetine (Paxil), and sertraline (Zoloft)

Selective Serotonine Reuptake Inhibitor (SSRI) - An antidepressant which affects serotonin by selectively blocking the reuptake of presynaptic receptors increasing availability. May take 4-6 weeks to work. S/e - nausea, agitation, and sexual dysfunction.

Reference : Serotonin Syndrome

duloxetine (Cymbalta), venlafaxine (Effexor), and desvenlafaxine (Pristiq)

Serotonin Norepinephrine Reuptake Inhibitors (SNRI’s) - An antidepressant which works by affecting serotonin and norEpi by selectively blocking their reuptake increasing the time it takes to find a receptor (making them more likely to go to postsynaptic receptors). May take 4-6 weeks to work. S/e - anorexia, nausea, agitation, and sexual dysfunction.

Reference : Serotonin Syndrome

chloropromazine (Thorazine), fluphenazine (Prolixin), and haloperidol (Haldol)

First Generation Agents (FGA’s) - Antipsychotic (aka conventional or typical). Very potent dopamine antagonists (see Dopamine) effective for treating severe positive manifestations of schizophrenia.

Common adverse effects - see ISHADE, anticholinergic effects/ neuroendocrine s/e’s.

clozapine (Clozaril), olanzapine (Zyprexa), quetiapine (Seroquel), risperidone (Risperdal), and ziprasidone (Geodon)

Second Generation Agents (SGA’s) - Antipsychotic (aka atypical), often the first rx as the block a wider range of schizophrenic manifestations with fewer s/e’s. Works by blocking dopamine receptors to a lesser degree and inhibiting the reuptake of serotonin.

Common adverse effects - metabolic (increase bglc, BP, and cholesterol) and see ISHADE, anticholinergic effects/ neuroendocrine s/e’s.

Clozapine - see agranulocytosis

aripriprazole (Abilify), cariprazine (Vraylar), and brexipriprazole (Rexulti)

Third Generation Agents (TGAs) - Antipsychotic, actually medicines which used to be considered SGAs but work by regulating dopamine transmission when reception is too high or low.

Common adverse effects - see ISHADE, anticholinergic effects/ neuroendocrine s/e’s.

ISHADE

Common side effects when taking antipsychotics :

I - Impotence

S - Sedation/Seizures

H - Hypotension

A - Akathisia or intense restlessness not remedied by movement

D - Dermatological like rashes

E - EPS (see Extrapyramidal Syndrome)

anticholinergic effects / neuroendocrine s/e’s

Anticholinergic manifestations are common with antipsychotics and antidepressants causing :

• dry mouth, constipation, blurred vision, drowsiness, urinary retention, tachycardia, and orthostatic hypotension

Neuroendocrine side effects can be common with antipsychotics due to the medications increasing levels of prolactin, a hormone responsible for lactation and breast development.

• gynecomastia, decreased sex drive, menstrual irregularities, and sex drive.

lithium

Mood Stabilizers - Medication class used to relieve manifestations of mood dysregulation found in d/o’s like BPD. Blood levels of lithium must be monitored weekly as it has a slim therapeutic index : >0.5 mEq/L to <1.5 mEq/L. S/e’s - nausea, diarrhea, anorexia, tremor, polydipsia, and polyuria.

S/S of toxicity - sedation, poor coordination, severe hypotension, blurred vision, and stupor → coma → death.

Education - emphasize nonpharmacological to reduce stress, consume plenty of water to help excrete medication, and consume adequate salt (as that's how lithium is excreted).

carbamazepine (Tegretol), valproic acide (Depakene), and lamotrigine (Lamictal)

Anticonvulsants - A medication class used if the pt didn’t tolerate lithium well. S/e - sedation, dry mouth, and either wt gain or loss.

dextroamphetamine/amphetamine (Adderall), lisdexamfetamine (Vyvanse), and methylphenidate (Ritaline)

Stimulants - A medication class used for ADHD which works by releasing nerve terminal stores of norEpi, promoting nerve impulses of transmission. S/e - nausea, dry mouth, heart palpitation, irritability, and anorexia.

Activation Syndrome

A set of manifestation which includes impulsivity and suicidal ideation that may present right after beginning an antidepressant. Possibly developing within the first few hours through the first few weeks.

S/S - irritability, anxiety, impulsivity, aggressiveness, agitation, and increased suicidality.

Serotonin Syndrome

A high influx of serotonin caused by a severe drug interaction. Causes :

• Intentional overdose in antidepressant medication

• Taking multiple classes of antidepressants

• Illicit drug use of LSD and ecstasy

• Combining herbal remedies (St John’s Wort) with antidepressants

• Mixing antidepressants with migraine and pain medications

S/S - restlessness, sweating, dilated pupils, tachycardia, elevated BP, muscle rigidity, loss of muscle coordination

Interventions - vital signs stabilization, sedation with Benzos, and administering a serotonin antagonist like cyproheptadine

Antidepressant Discontinuation Syndrome (ADS)

A collection of withdrawal symptoms when the pt suddenly stops taking an antidepressant. Manifestations may persist for weeks, which is why pts must be tapered off antidepressants instead.

S/S - difficulty sleeping, anxiety, depression, flu-like symptoms and possibly electric shock like sensations. If suddenly stops MAOIs → psychosis.

Agranulocytosis

A severe adverse effect of the SGA or atypical antipsychotic Clozapine. Agranulocytois is a potentially life threatening condition where the blood has a lower than normal number of WBCs.

S/S - flu-like symptoms, sore throat, fatigue, fever, and muscle aches.

Neurolyptic Malignant Syndrome (NMS)

A potentially life threatening reaction to antipsychotic drugs, after initial exposure or the abrupt discontinuation of the medication.

S/S - a very high fever, altered mental status, muscle rigidity, vital signs instability, encephalopathy, and an elevated creatinine kinase.

Interventions - Hold, monitor (l) + e-lytes, cooling measures, cardiac monitoring, and anticipate order for dopaminergic agent (bromocriptine) or skeletal muscle relaxing med (dantrolene)

Extrapyramidal Symptoms (EPS)

A set of neurological s/s as an effect of blocking dopamine transmission from midbrain to brainstorm due to antipsychotics.

• Acute dystonia - muscle rigidity or spasms causing difficulty opening ones mouth, locked gaze, or most severely an inability to control eye movement for hours at a time. Very painful.

• Akathisia - severe feelings of restlessness not relieved by movement. Makes patient likely to self discontinue medication or develop suicidal ideation.

• Pseudoparkinsonism - s/s which resemble Parkinson’s disease; slumped posture, shuffling gait, drooling, tremors, and pill-rolling finger movement.

• Tardive dyskinesia - permanent involuntary movement of face, tongue, neck and upper/lower extremities. Ex : lip smacking, tongue thrusting, and head tilting.

Treatment : administering anticholinergic drugs like diphenhydramine (Benadryl; sedation) and benzotropine (Cogentin; non-sedating)