psychiatric agents

Psychiatric Agents

By:Paula Rose Mae Cuario

Evita Lalaine Del MundoDennis Ragudo

Sheena Zarsuelo

ANTIPSYCHOTICS AND ANXIOLYTICS

Antipsycotics are used for psychosis.

Anxiolytics are for anxiety disorders.

Psychosis, or losing contact with reality, is usually characterized by more than one symptom.

Schizophrenia, a chronic disorder, is the major category of psychosis.

The symptoms of this psychotic disorder are divided into 2 groups: “positive” symptoms and “negative” symptoms.

Atypical antipsychotics are used to treat both groups.

Antipsychotics comprise the largest group of drugs used to treat mental illness.

The theory is that psychotic symptoms result from an imbalance in the neurotransmitter dopamine in the brain.

Antipsychotics are sometimes called dopamine antagonist.

When dopamine is blocked: Extrapyramidal symptoms (EPS) of parkinsonism results (pseudoparkinsonism)

- Tremors- -rigidity- Shuffling gait

ANTIPSYCHOTIC AGENTS

TWO MAJOR CATEGORIES:

Typical

-cause sedative, hypotensive, blocks dopamine

Atypical

-effective for treating schizophrenia & other psychotic disorders in client who do not respond to typical antipsychotics

-has decreased side effects

PHARMACOPHYSIOLOGIC MECHANISM OF ACTION

Antipsychotics block the actions of dopamine and thus may be classified as dopaminergic antagonists. There are five subtypes of dopamine receptors: D1 through D5.

ADVERSE REACTIONS

Pseudoparkinsonism, which resembles symptoms of Parkinson’s disease, is a major side effect of typical antipsychotic drugs

* The higher the strength of the drug, the more likely to have symptoms of pseudoparkinsonism

Pseudoparkinsonism -stooped posture -shuffling gait -rigidity -bradykinesia -tremors at rest -pill-rolling motion of the hand

Early treatment:- Dystonia- Akathisia

- Later phase:- Tardive dyskinesia

The symptoms of acute dystonia usually occur in 5% of clients within days of taking typical antipsychotics.

Acute dystonia -Facial grimacing -Involuntary upward eye movement -muscle spasms of the tongue,

face, neck and back -laryngeal spasms

Incidence of akathisia occurs in approximately 20% of clients who take a typical antipsychotic drug.

Akathisia -Restless -Trouble standing still -Paces the floor -Feet in constant motion rocking

back ang forth

Tardive dyskinesia is a serious adverse reaction occuring in clients who have taken a typical antipsychotic drug for more than a year.

Tardive dyskenesia -Protrusion and rolling of the tongue -Sucking and smaking movements of

the lips -Chewing motion -Facial dyskinesia -Involuntary movements of the body

and extremities

PHENOTHIAZINES

Subdivided into three groups: Aliphatic

Piperazine Piperidine

Aliphatic phenothiazines produce a strong sedative effect, decreased blood pressure, and may cause moderate EPS.

Piperazine phenothiazines produce a low sedative and strong antiemetic effect but have little effort on blood pressure

Piperidine phenothiazines have a strong sedative effect, causes few EPS, have a low to moderate effect on blood pressure and have no antiemetic effect

EX. Fluphenazine (Prolixin) is a

phenothiazine antipsychotic used to manage psychosis.

Pharmacokinetics

Oral absorption of Fluphenazine is rapid and not affected by food. This drug is strongly protein-bound and has a long half-life; therefore, the drug may accumulate. Fluphenazine is metabolized by the liver, crosses the blood-brain barrier and placenta, and is excreted as metabolites primarily in the urine. With hepatic dysfunction, the phenothiazine dose may need to be decreased. Lack of drug metabolism in the liver will cause an elevation in serum drug level.

Pharmacodynamics

Fluphenazine is prescribed primarily for psychotic disorders. This drug has anticholinergic properties and should be cautiously administered to clients with glaucoma, especially narrow-angle glaucoma. Antacids decrease the absorption rate of all phenothiazines so they should be given 1 hour before or 2 hours after an oral phenothiazine.

Antipsychotics may be given orally (tablet or liquid), IM, or IV.

If given orally, liquid is preferred.

Noncompliance with antipsychotics is common.

Encourage to take medication as prescribed.

Explain essential information to compensate for client’s knowledge deficit.

NONPHENOTIAZINES

-Butyrophenone (Haloperidol)-dibenzoxapines-dihydroindolone-thioxanthene

Pharmacokinetics

Haloperidol is absorbed well through the GI mucosa. It has a long half-life and is highly protein-bound, so the drug may accumulate. It is metabolized in the liver and excreted in urine and feces.

Pharmacodynamics

Haloperidol alters the effect of dopamine by blocking dopamine receptors; thus sedation and EPS may occur. Dosages need to be decreased in older adults because of decreased liver funtion and potential side effects.

SIDE EFFECTS AND ADVERSE REACTIONS

The most common side effect for all antipsychotic drug is drowsiness. Many of the antipsychotics have some anticholinergic effects: dry mouth, increased heart rate, urinary retention, and constipation.

Dermatologic side effects seen early in drug therapy are pruritus and marked photosensitivity. Clients are urged to sunscreen, hats, and protective clothing and to stay out of the sun.

Drug Interaction

Antipsychotics interact with alcohol, hypnotics, sedatives, narcotics, and benzodiazepines to potentiate the sedative effects of antipsychotics.

Antipsychotics should not be given with other antipsychotic or antidepressant drugs except to control psychotic behavior for selected individuals who are refractory to drug therapy.

When discontinuing antipsychotics, the drug dosage should be reduced gradually.

ANTIPSYCHOTIC DOSAGE for OLDER ADULTS

Older adults usually require smaller doses of antipsychotics from 25 -50% less than young and middle-aged adults. Regular to high doses of antipsychotics increase the risk of severe side effects. Dosage amounts need to be individualized according to the client’s age and physical status. In addition, dosage changes may be necessary during antipsychotic therapy.

ATYPICAL (SERETONIN/DOPAMINE ANTAGONISTS) ANTIPSYCHOTICS

effective in treating both positive and negative symptoms of schizophrenia

advantages: effective in treating negative symptoms & they are not likely to cause EPS or tardive dyskinesia

drugs available: Clozapine (Clozaril), risperidone (Risperdal), olanzapine (Zyprexa), qeutiapine (Seroquel), and paliperidone (Invega)

common side effect: weight gain

Clozapine (Clozaril)- adverse reaction: seizures and

agranulocytosis- indication: treatment of severely ill

schizophrenic clients- nsg consideration: Monitor WBC

count- side effect: dizziness, sedation,

tachycardia, orthostatic hypotension, constipation

Risperidone (Risperdal) & Olanzipine (Zyprexa)

- similar to clozapine but does not cause agarnulocytosis

Paliperidone (Invega)- major active metabolite of risperidone- adverse effect: EPS, insomnia,

headache, akathisia

ANXIOLYTICS

anxiety drugs used to treat anxiety and insomnia two types of anxiety: primary anxiety

(not caused by a medical condition or by drug use) and secondary anxiety (related to selected drug use or medical or psychiatric disorder)

major anxiolytic group: benzodiazepines

NONPHARMACOLOGIC MEASURES

Some of the symptoms of a severe or panic attack of anxiety include dyspnea, choking sensation, chest pain, heart palpitations, dizziness, faintness, sweating, trembling and shaking, & fear of losing control. Before giving anxiolytics, nonpharmacologic measures should be used for decreasing anxiety like relaxation technique, psychotherapy or support groups.

BENZODIAZEPINES

uses: anticonvulsants, sedative-hypnotics, preop drugs, anxiolytics

used mainly for severe or prolonged anxiety

e.g. chlordiazepoxide (Librium), diazepam (Valium), clorazepate dipotassium (Tranxene), lorazepam (Ativan), alprazolam (Xanax) and prazepam (Centrax).

most frequently prescribed: lorazepam (Ativan)

lorazepam (Ativan)- mild to moderate anxiety; control

alcohol syndrome- drowsiness and dizziness may occur- Pharmacokinetics: highly lipid-

soluble, rapidly absorbed from the GI tract, highly protein-bound, half-life is 10-20 hours, excreted in the urine.

Pharmacodynamics: acts on the limbic, thalamic & hypothalamic levels of the CNS. The onset of action is 15-30 minutes by mouth and 1-5 mnutes by IV.

Side effects: sedation, dizziness, headaches, dry mouth, blurred vision, rare urinary incontinence & constipation

Adverse Reactions: leucopenia with symptoms of fever, malaise and sore throat; tolerance to the drug dosage with continuous use; and physical dependency.

Antidepressants

Have been called mood elevators. They are used for depressive

episodes that are accompanied by feelings of hopelessness and helplessness.

Mood- stabilizer agents such as lithium are effective for bipolar affective disorder (manic-depressive illness).

Depression

Is the most common psychiatric problem

Is characterized primarily by mood changes and loss of interest in normal activities. It is second only to hypertension as the most common chronic clinical condition.

Antidepressants can mask suicidal tendencies.

Contributing Causes:

Genetic predispositionSocial and environmental factorsBiologic conditions

Signs of Major Depression:

loss of interest in most activitiesdepressed moodweight loss or gaininsomnia or hypersomnialoss of energyfatiguefeeling of despairdecreased ability to think or concentratesuicidal thoughts

3 Types of depression:

Reactive Major Bipolar affective disorder

1. Reactive Depression-usually has a sudden onset after a

precipitating event (e.g. depression resulting from loss, such as death of a loved one).

- benzodiazepine agent may be prescribed

2. Major DepressionLoss of interest in work and homeInability to complete tasksDeep depression ( dysphoria )Antidepressants have been effective

in treating major depression.

3. Bipolar affective disorder (manic- depressive illness)

Involves swing s between two moods, the manic (euphoric) and the depressive (dysphoria). Lithium was originally the drug of choice for treating this type of disorder. Divalproex sodium (Depakote) is currently the drug of choice for bipolar disorder.

Electroconvulsive therapy (ECT) Used to treat psychosis and depression

before the introduction of antipsychotics and antidepressants.

ECT may still prescribed for clients who are extremely depressed, suicidal, or do not respond to antidepressant therapy.

The use of thiopental (short-acting anesthetic) and succinylcholine (short- acting neuromuscular blocking agent which reduces the severe convulsive movements) has made ECT not as traumatic as it once was, and therefore a safer method for treating depression.

The use of ECT does not affect the person’s intellectual function, but may temporarily affect short- term memory.

Pathophysiology

Theories about the cause of major depression:

Common one suggests an insufficient amount of brain monoamine neurotransmitters (norepinephrine, serotonin, perhaps dopamine).

It is thought that decreased levels of serotonin permit depression to occur, and decreased levels of norepinephrine cause depression.

There can be other physiologic causes of depression as well as social and environmental factors.

Herbal Supplements for Depression

St. John’s wort and gingko biloba have been suggested for the management of mild depression.

St. John’s wort can decrease reuptake of the neurotransmitters serotonin, norepinephrine, and dopamine.

The use of these and many herbal products should be discontinued 1 to 2 weeks before surgery.

Antidepressants

Antidepressant AgentsIt is divided into four groups:-Tricyclic antidepressants (TCAs)-Selective Serotonin reuptake

inhibitors (SSRIs)-Atypical antidepressants that affect

various neurotransmitters-Monoamine oxidase inhibitors (MAOIs)

(a)Tricyclic antidepressants (TCAs)

It is used to treat major depression, because they are effective and less expensive than SSRIs and other drugs.

AMITRIPTYLINE HCL

Drug Class: Antidepressant, tricyclic antidepressant

Uses: To treat depression with or without: - Melancholia- manic and depressive phases of bipolar

disorder- - depression associated with organic

disease - alcoholism

- migraine headaches,- mixed symptoms of anxiety and

depression- urinary incontinence

SIDE EFFECTS:

Sedation Drowsiness Blurred vision Dry mouth and eyes Urinary retention Constipation Weight gain Dizziness Nervousness Nausea Anorexia Sexual dysfunctions

Example of Tricyclic Antidepressants Drugs:

Clomipramine HCL (anafranil) Uses and Considerations: To treat

obsessive- compulsive disorder. It may be used to alleviate anxiety or panic

disorder. Side effect- Tremor, dizziness, weight gain

and dry mouth.Imipramine HCL (Tofranil)

Uses and Considerations: For depression. Can be taken at bedtime to lessen dangers from sedative effect. Take with food if GI distress occurs. Avoid taking with alcohol or CNS depressants.

Side effects- Drowsiness, dry mouth, hypotension, delayed micturition.

(b) SELECTIVE SEROTONIN REUPTAKE INHIBITORS

This group was first classified as second- generation antidepressants. It block the reuptake of serotonin into the nerve terminal of the CNS, thereby enhancing it’s transmission at the serotonergic synapse.

FLUOXETINE

Drug Class: Antidepressant, selective serotonin reuptake inhibitor

USES: To treat depression with or without: melancholia manic and depressive phases of bipolar

disorder depression associated with organic

disease alcoholism migraine headaches, mixed symptoms of anxiety and

depression urinary incontinence

Side Effects: Headache Nervousness Restlessness Insomia Tremors GI distress Sexual dysfunction

Examples of SSRIs Drugs :

Citalopram (celexa) Uses and Considerations: For depression,

panic disorder, obsessive compulsive disorder.

Side effects- insomnia, sexual dysfunction, nausea, dry mouth

Fluoxetine HCL (Prozac) Uses and Considerations: For depression

and obsessive compulsive disorder. Lower dose for older adults and those with renal and hepatic disorders.

Side effects- dizziness, insomnia, headache, nausea, dry mouth, tremors and postural hypotension.

(c) ATYPICAL ANTIDEPRESSANTS (second- generation antidepressants)

It has been used for major depression, reactive depression, and anxiety.

They affect one or two of the three neurotransmitters: serotonin, norepinephrine, and dopamine.

Example of Atypical Antidepressants Drugs:

Amoxapine ( Asendin) Uses and Considerations: for

depression with anxiety and reactive depression. Do not take with MAOIs.

Side effects- Dizziness, drowsiness, postural hypotension, increase appetite, urinary retention.

Trazodone HCL (desyrel) Uses and Considerations: Can be

taken at bed time to lessens dangers from sedative effect.

Side effect: drowsiness, light headedness, orthostatic hypotension and dry mouth.

(d) MONOAMINE OXIDASE INHIBITORS

It is the fourth group of antidepressants.

The enzyme monoamine oxidase inactivates norepinephrine, dopamine, epinephrine, and serotonin.

Foods that Can Cause a Hypertensive Crisis When Taken with Monoamine Oxidase Inhibitors:

Foods

Cheese (cheddar, swiss) Bananas, raisins Pickled foods Red wine beer Cream, yogurt Chocolate, coffee Italian green beans Liver Yeast Soy sauce

Effects Sweating, tremors

Bounding heart rate Increased blood pressure Increased temperature

Example of MAOIs drugs:Isocarboxazid (Marplan) Uses and Considerations: for

depression that is refractory to TCAs. Avoid certain foods such as cheese, beer, figs, shrimp, bananas and chocolate and avoid drugs.

Nursing Interventions

Observe client for signs and symptoms of depression such as: mood changes, insomnia, apathy, or lack of interest in activities.

Check client’s vital signs. Orthostatic hypotension is common.

Check for anticholinergic- like symptoms: dry mouth, increased heart rate, urinary retention, or constipation.

Monitor client for suicidal tendencies when marked depression is present.

Observe client for seizures when client is taking an anticonvulsant: antidepressants lower the seizure thresh- old. The anticonvulsant dose might need to be increased.

Monitor for drug to drug and food- drug interactions.

Check client for extremely high blood pressure when taking MAOIs.

Mood Stabilizers

Used to treat bipolar affective disorder. Lithium was the first drug used to manage

this disorder. Some refer to lithium as an antimania

drug that is effective in controlling manic behavior that arises from underlying bipolar disorder

Lithium has a calming effect without impairing intellectual activity.

It controls any evidence of flight of ideas and hyperactivity.

If the person stops taking lithium, manic behavior may return.

Lithium is an inexpensive drug that must be closely monitored.

Lithium has a narrow therapeutic serum range: 0.5 to 1.5 mEq/L.

Serum Lithium levels greater than 1.5 to 2 mEq/L are toxic.

Lithium

Drug Class Mood stabilizer Trade names: Eskalith, Lithane, Lithonate,

Lithobid, Carbolith, Lithizine Pregnancy category: D CI: Liver and renal disease, pregnancy,

lactation, severe cardiovascular disease, severe dehydration, brain tumor or damage, sodium depletion, children< 12 y of age

Caution: Thyroid disease Dosage: A: PO: 300-600mg tid; maint:

300mg tid. qid max: 2.4 g/d Elderly: lower dosage Therapeutic drug range: 0.5-1.5

mEq/L Drug –Lab-Food Interactions

Drug: May increase lithium level with thiazide diuretics, methyldopa, haloperidol, NSAIDs, antidepressants, carbamazepine, theophylline, aminophylline, sodium bicarbonate, phenothiazines

Lab: Increase urine and blood glucose, protein; decrease serum sodium level

Food: Increase sodium intake; lithium may cause sodium depletion

Pharmacokinetics Absorption: PO: well absorbed Distribution: PB: UK Metabolism: t 1/2: 21-30 h; >36 h

with renal impairment or in elderly Excretion: 98% in urine, mostly

unchanged

Pharmacodynamics PO: Onset: UK Peak: 2-4 h Duration: 24h Therapeutic Effects/ Uses To treat bipolar manic- depressive

psychosis, manic episodes Mode of action: Alteration of ion transport

in muscle and nerve cells; increased receptor sensitivity to serotonin

Side Effects: Headache, lethargy, drowsiness,

dizziness, tremors, slurred speech, dry mouth, anorexia, vomiting, diarrhea, polyuria, hypotension, abdominal pain, muscle weakness, restlessness

Adverse Reactions: Urinary incontinence, clonic

movements, stupor, azotemia, leukocytosis, nephrotoxicity

Life Threatening: Cardiac dysrhythmias, circulatory

collapse

Generic (BRAND)

Lithium citrate (Eskalith, Lithibid) Carbamazepine (EquetroCarbatrol, Tegretol)

Route and Dosage

A: PO: 200mg bid; increase dose 200mg/d as needed; Max: 1600 mg/d

Uses & Considerations

For treatment of acute manic and mixed episodes associated with bipolar disorder.

CI in bone marrow depression. Pregnancy category: C; PB: 76%;t1/2:35-40 h

Nursing Intervention

-Observe client for signs and symptoms of depression: mood changes, insomnia, apathy, or lack of interest in activities.

-Record client’s vital signs. Orthostatic hypotension is common.

-When drawing blood to check for lithium levels, draw samples immediately before the next dose (8 to 12 hours after the previous dose.) Monitor for signs of lithium toxicity. Report high (greater than 1.5 mEq/L) or toxic (greater than 2.0 mEq/L) serum lithium levels immediately to health care provider.

-Monitor client for suicidal tendencies when marked depression is present.

-Evaluate client’s urine output and body weight. Fluid volume deficit may occur as a result of polyuria.

-Observe client for fine and gross motor tremors and presence of slurred speech, which are signs of adverse reaction.

-Check client’s cardiac status. Loss of fluids and electrolytes may cause cardiac dysrhythmias.

-Monitor client’s serum electrolytes. Report abnormal findings

Thank you…