Psychopharmacology PDF

# Psychopharmacology ## Medication Management Medication management is a crucial issue that influences the outcomes of treatment for many clients with mental disorders. The following sections discuss categories of medications used to treat mental disorders (psychotropic drugs): - Antipsychotic...

# Psychopharmacology ## Medication Management Medication management is a crucial issue that influences the outcomes of treatment for many clients with mental disorders. The following sections discuss categories of medications used to treat mental disorders (psychotropic drugs): - Antipsychotics - Antidepressants - Mood Stabilizers - Anxiolytics - Stimulants Nurses should understand: - How these drugs work. - Side effects - Contraindications - Interactions - The nursing interventions required to help clients manage medication regimens. ## Terms Used in Discussions of Drugs and Drug Therapy Several terms are important for nurses to understand: - **Efficacy:** The maximal therapeutic effect that a drug can achieve. - **Potency:** The amount of drug needed to achieve that maximum effect. - **Half-life:** The time it takes for half of the drug to be removed from the bloodstream. ## The U.S. Food and Drug Administration (FDA) The U.S. Food and Drug Administration is responsible for supervising the testing and marketing of medications for public safety. These activities include: - Clinical drug trials for new drugs - Monitoring the effectiveness and side effects of medications The FDA approves each drug for use in a particular population and for specific diseases. - **Off-label use:** When a drug proves effective for a disease that differs from the one involved in the original testing and FDA approval. ## Principles that Guide Pharmacologic Treatment Several principles guide the use of medications to treat psychiatric disorders: - **Medication Selection:** A medication is selected based on its effect on the client's target symptoms, such as delusional thinking, panic attacks, or hallucinations. The medication's effectiveness is evaluated by its ability to diminish or eliminate the target symptoms. - **Dosage and Time:** Many psychotropic drugs must be given in adequate dosages for some time before their full effects are realized. For example, tricyclic antidepressants can require 4 to 6 weeks before the client experiences optimal therapeutic benefit. - **Dosage Adjustment:** The dosage of medication is often adjusted to the lowest effective dosage for the client. Sometimes, higher dosages may be needed to stabilize the client's target symptoms, while lower dosages are used to sustain those effects over time. - **Age and Dosage:** As a rule, older adults require lower dosages of medications than do younger clients to experience therapeutic effects. It may also take longer for a drug to achieve its full therapeutic effect in older adults. - **Gradual Dosage Reduction:** Psychotropic medications are often decreased gradually (tapering) rather than abruptly. This is because of potential problems with: - **Rebound:** Temporary return of symptoms - **Recurrence:** Return of original symptoms - **Withdrawal:** New symptoms resulting from discontinuation of the drug. - **Follow-up Care:** Follow-up care is essential to ensure compliance with the medication regimen, to make needed adjustments in dosage, and to manage side effects. - **Compliance:** Compliance with the medication regimen is often enhanced when the regimen is as simple as possible in terms of both the number of medications prescribed and the number of daily doses. ## Antipsychotic Drugs - Formerly known as neuroleptics. - Used to treat the symptoms of psychosis, such as the delusions and hallucinations seen in schizophrenia, schizoaffective disorder, and the manic phase of bipolar disorder. - Off-label uses of antipsychotics include treatment of anxiety and insomnia; aggressive behavior; and delusions, hallucinations, and other disruptive behaviors that sometimes accompany Alzheimer's disease. - **Mechanism of Action:** Antipsychotic drugs work by blocking receptors of the neurotransmitter dopamine. They have been in clinical use since the 1950s. They are the primary medical treatment for schizophrenia. They are also used in psychotic episodes of acute mania, psychotic depression, and drug-induced psychosis. Clients with dementia who have psychotic symptoms sometimes respond to low dosages of conventional antipsychotics. Second-generation antipsychotics can increase mortality rates in elderly clients with dementia-related psychosis. Short-term therapy with antipsychotics may be useful for transient psychotic symptoms such as those seen in some clients with borderline personality disorder. ## Antipsychotic Drugs: Table |Generic (Trade) Name | Forms | Daily Dosage* | Extreme Dosage Ranges * | |---|---|---|---| | **Conventional or first-generation antipsychotics** | | | | | **Phenothiazines** | | | | | Chlorpromazine (Thorazine) | T, L, INJ | 200-1,600 | 25-2,000 | | Perphenazine (Trilafon) | T, L, INJ | 16-32 | 4-64 | | Fluphenazine (Prolixin) | T, L, INJ | 2.5-20 | 1-60 | | Thioridazine (Mellaril) | T, L | 200-600 | 40-800 | | Mesoridazine (Serentil) | T, L, INJ | 75-300 | 30-400 | | Trifluoperazine (Stelazine) | T, L, INJ | 6-50 | 2-80 | | **Thioxanthene** | | | | | Thiothixene (Navane) | C, L, INJ | 6-30 | 6-60 | | **Butyrophenones** | | | | | Haloperidol (Haldol) | T, L, INJ | 2-20 | 1-100 | | Droperidol (Inapsine) | INJ | 2.5 | | **Dibenzazepine** | | | | | Loxapine (Loxitane) | C, L, INJ | 60-100 | 30-250 | | **Dihydroindolone** | | | | | Molindone (Moban) | T, L | 50-100 | 15-250 | | **Atypical or second-generation antipsychotics** | | | | | Clozapine (Clozaril) | T | 150-500 | 75-700 | | Fazaclo (clozapine) | DT | 150-500 | 75-700 | | Risperidone (Risperdal) | T, L, DT | 2-8 | 1-16 | | Olanzapine (Zyprexa) | T | 5-15 | 5-20 | | Quetiapine (Seroquel) | T | 300-600 | 200-750 | | Ziprasidone (Geodon) | C, INJ | 40-160 | 20-200 | | Paliperidone (Invega) | T | 6 | 3-12 | | Iloperidone (Fanapt) | T | 12-24 | 2-24 | | Asenapine (Saphris) | T (SL) | 10-20 | 10-20 | | Lurasidone (Latuda) | T | 40-80 | 20-160 | | **Third-generation antipsychotics** | | | | | Aripiprazole (Abilify) | T | 15-30 | 10-40 | | Cariprazine (Vraylar) | C | 3-6 | 1.5-6 | | Brexpiprazole (Rexulti) | T | 1-3 | 5-4 | *Values are in milligrams per day for oral doses only. C, capsule; DT, orally disintegrating tablet; INJ, injection for IM (usually prn) use; L, liquid for oral use; SL, sublingual; T, tablet. ## Antipsychotic Drugs: Mechanism of Action - The major action of all antipsychotics in the nervous system is to block receptors for the neurotransmitter dopamine. The therapeutic mechanism of action, however, is only partially understood. - Dopamine receptors are classified into subcategories (D1, D2, D3, D4, and D5), and D2, D3, and D4 have been associated with mental illness. - Conventional, or first-generation antipsychotic drugs are potent antagonists (blockers) of D2, D3, and D4. This not only makes them effective in treating target symptoms but also produces many extrapyramidal side effects because of the blocking of the D2 receptors. - Newer, atypical or second-generation antipsychotic drugs, such as clozapine, are relatively weak blockers of D2. This may account for the lower incidence of extrapyramidal side effects. - Second-generation antipsychotics inhibit the reuptake of serotonin, as do some of the antidepressants, increasing their effectiveness in treating the depressive aspects of schizophrenia. - Paliperidone, iloperidone, asenapine, and lurasidone are the newest second-generation agents. - Paliperidone is chemically similar to risperidone; however, it is an extended-release preparation. This means the client can take one daily dose in most cases, which may be a factor in increased compliance. - Asenapine is a sublingual tablet, so clients must avoid food or drink for 10 to 15 minutes after the medication dissolves. - Third-generation antipsychotics, called dopamine system stabilizers, are being developed. These drugs are thought to stabilize dopamine output, preserving or enhancing dopaminergic transmission when it is too low and reducing it when it is too high. This results in control of symptoms without some of the side effects of other antipsychotic medications. ## Antipsychotic Drugs Side Effects - **Extrapyramidal Side Effects (EPSs):** Serious neurologic symptoms which are the major side effects of antipsychotic drugs. They include acute dystonia, pseudoparkinsonism, and akathisia. Each of these reactions has distinct features. One client can experience all the reactions in the same course of therapy, which makes distinguishing among them difficult. Blockade of D2 receptors in the midbrain region of the brain stem is responsible for the development of EPSs. First-generation antipsychotic drugs cause a greater incidence of EPSs than do second-generation antipsychotic drugs. - **Drug-Induced Parkinsonism or Pseudoparkinsonism:** Symptoms resemble those of Parkinson's disease and include a stiff, stooped posture, masklike facies; decreased arm swing, a shuffling, festinating gait; cogwheel rigidity, drooling; tremor; bradycardia; coarse pill-rolling movements of the thumb and fingers while at rest. Treatment involves changing to an antipsychotic medication that has a lower incidence of EPS or by adding an oral anticholinergic agent or amantadine, which is a dopamine agonist that increases transmission of dopamine blocked by the antipsychotic drug. - **Akathisia:** The client reports restlessness or anxious and agitated, often with a rigid posture or gait and a lack of spontaneous gestures. This feeling of internal restlessness and the inability to sit still or rest often leads clients to discontinue their antipsychotic medication. Treatment involves a change in antipsychotic medication or by the addition of an oral agent such as a beta-blocker, anticholinergic, or benzodiazepine. - **Neuroleptic Malignant Syndrome (NMS):** A potentially fatal idiosyncratic reaction to an antipsychotic drug. The major symptoms of NMS are rigidity, high fever, autonomic instability such as unstable blood pressure, diaphoresis, and pallor, delirium, and elevated levels of enzymes, particularly creatine phosphokinase. Clients with NMS are usually confused and often mute, and they may fluctuate from agitation to stupor. All antipsychotics seem to have the potential to cause NMS, but high dosages of high-potency drugs increase the risk. NMS most often occurs in the first 2 weeks of therapy or after an increase in dosage, but it can occur at any time. Dehydration, poor nutrition, and concurrent medical illness all increase the risk for NMS. Treatment includes immediate discontinuance of all antipsychotic medications and the institution of supportive medical care to treat dehydration and hyperthermia until the client's physical condition stabilizes. After NMS, the decision to treat the client with other antipsychotic drugs requires full discussion between the client and the physician to weigh the relative risks against the potential benefits of therapy. - **Tardive Dyskinesia (TD):** A syndrome of permanent involuntary movements, most commonly caused by the long-term use of conventional antipsychotic drugs. About 20% to 30% of patients on long-term treatment develop symptoms of TD, and the pathophysiology is still unclear. The symptoms of TD include involuntary movements of the tongue, facial and neck muscles, upper and lower extremities, and truncal musculature. Tongue thrusting and protruding, lip smacking, blinking, grimacing, and other excessive unnecessary facial movements are characteristic. After it has developed, TD is irreversible, although decreasing or discontinuing antipsychotic medications can arrest its progression. Unfortunately, antipsychotic medications can mask the beginning symptoms of TD; that is, increased dosages of the antipsychotic medication cause the initial symptoms to disappear temporarily. As the symptoms of TD worsen, however, they "break through" the effect of the antipsychotic drug. - **Tardive Dyskinesia Treatment:** The FDA approved valbenazine and deutetrabenazine as the first drugs to treat TD in 2017. These drugs are vesicular monoamine transporter 2 (VMAT2) inhibitors. It is believed that these drugs decrease activity of monoamines, such as dopamine, serotonin, and norepinephrine, thereby decreasing the abnormal movements associated with Huntington chorea and TD. Valbenazine has a dosage range of 40 to 80 mg daily, and deutetrabenazine ranges from 12 to 48 mg daily. Both drugs cause somnolence, QT prolongation, akathisia, and restlessness. In addition, valbenazine can cause nausea, vomiting, headache, and balance disturbances. Deutetrabenazine can also cause NMS and increased depression and suicidality in patients with Huntington chorea. - **Preventing Tardive Dyskinesia:** The primary goal when administering antipsychotics. This can be done by keeping maintenance dosages as low as possible, changing medications, and monitoring the client periodically for initial signs of TD using a standardized assessment tool, such as the Abnormal Involuntary Movement Scale. ## Antipsychotic Drugs: Other Side Effects - **Anticholinergic side effects:** Orthostatic hypotension, dry mouth, constipation, urinary hesitancy or retention, blurred near vision, dry eyes, photophobia, nasal congestion, and decreased memory. These side effects usually decrease within 3 to 4 weeks but do not entirely remit. The client taking anticholinergic agents for EPSs may have increased problems with anticholinergic side effects. Using calorie-free beverages or hard candy may alleviate dry mouth, and stool softeners, adequate fluid intake, and the inclusion of grains and fruit in the diet may prevent constipation. - **Other side effects:** Antipsychotic drugs also increase blood prolactin levels. Elevated prolactin may cause breast enlargement and tenderness in men and women; diminished libido, erectile and orgasmic dysfunction, and menstrual irregularities; and increased risk for breast cancer. It can also contribute to weight gain. Weight gain can accompany most antipsychotic medications, but it is most likely with the second-generation antipsychotic drugs, with ziprasidone (Geodon) being the exception. Weight increases are most significant with clozapine (Clozaril) and olanzapine (Zyprexa). Since 2004, the FDA has made it mandatory for drug manufacturers that atypical antipsychotics carry a warning of the increased risk for hyperglycemia and diabetes. Though the exact mechanism of this weight gain is unknown, it is associated with increased appetite, binge eating, carbohydrate craving, food preference changes, and decreased satiety in some clients. Prolactin elevation may stimulate as yet undetermined interplay of multiple neurotransmitter and receptor interactions with resultant antagonism in appetite, energy intake, and may be feeding centers, histamine changes in stimulates appetite, and feeding behavior. Penninx and Lange (2018) found that genetics can also make clients more prone to weight gain and metabolic syndrome. - **Metabolic Syndrome:** A cluster of conditions that increase the risk for heart disease, diabetes, and stroke. The syndrome is diagnosed when three or more of the following are present: - **Obesity:** Excess weight, increased body mass index (BMI), and increased abdominal girth because of fat deposits. - **Increased blood pressure** - **High blood sugar level** - **High cholesterol:** With at least 150 mg/dL of triglyceride; less than 40 mg/dL of high-density lipoprotein for women and 50 mg/dL for men. - **Cardiovascular Effects:** Postural hypotension, palpitations, and tachycardia. - **QT Interval:** Certain antipsychotic drugs can cause a lengthening of the QT interval. A QT interval longer than 500 ms is considered dangerous and is associated with life-threatening dysrhythmias and sudden death. - **Torsade de Pointes:** A rapid heart rhythm of 150 to 250 beats/minute, resulting in a "twisted" appearance on the electrocardiogram (hence the name "torsade de pointes"). - **Agranulocytosis:** A potentially fatal side effect of clozapine. This develops suddenly and is characterized by fever, malaise, ulcerative sore throat, and leukopenia. The side effect may not manifest immediately and can occur up to 24 weeks after the initiation of therapy. Initially, clients needed to have a weekly white blood cell (WBC) count above 3,500/mm3 to obtain the next week's supply of clozapine. Currently, all clients must have weekly WBCs drawn for the first 6 months. If the WBC is 3,500/mm3 and the absolute neutrophil count (ANC) is 2,000/mm3, the client may have these labs monitored every 2 weeks for 6 months and then every 4 weeks. This decreased monitoring is dependent on continuous therapy with clozapine. Any interruption in therapy requires a return to more frequent monitoring for a specified period of time. After clozapine has been discontinued, weekly monitoring of the WBC and ANC is required for 4 weeks. ## Antipsychotic Drugs: Client Teaching - Inform clients about types of side effects that may occur, and encourage clients to report such problems to the physician instead of discontinuing the medication. - Teach clients methods of managing or avoiding unpleasant side effects and maintaining the medication regimen. - Drinking sugar-free fluids and eating sugar-free hard candy eases dry mouth. The client should avoid calorie-laden beverages and candy because they promote dental caries, contribute to weight gain, and do little to relieve dry mouth. - Methods to prevent or relieve constipation include exercising and increasing water and bulk-forming foods in the diet. - Stool softeners are permissible, but the client should avoid laxatives. The use of sunscreen is recommended because photosensitivity can cause the client to sunburn easily. - Clients should monitor the amount of sleepiness or drowsiness they feel. - They should avoid driving and performing other potentially dangerous activities until their response times and reflexes seem normal. - If the client forgets a dose of antipsychotic medication, he or she can take the missed dose if it is only 3 or 4 hours late. If the dose is more than 4 hours overdue or the next dose is due, the client can omit the forgotten dose. - The nurse encourages clients who have difficulty remembering to take their medication to use a chart and to record doses when taken or to use a pillbox that can be prefilled with accurate doses for the day or week. ## Antidepressant Drugs - Primarily used in the treatment of major depressive illness, anxiety disorders, the depressed phase of bipolar disorder, and psychotic depression. - Off-label uses of antidepressants include the treatment of chronic pain, migraine headaches, peripheral and diabetic neuropathies, sleep apnea, dermatologic disorders, panic disorder, and eating disorders. - Antidepressants somehow interact with the two neurotransmitters, norepinephrine and serotonin. They regulate mood, arousal, attention, sensory processing, and appetite. - Antidepressants are divided into four groups: - Tricyclic and the related cyclic antidepressants - Selective serotonin reuptake inhibitors (SSRIs) - MAO inhibitors (MAOIs) - Other antidepressants such as desvenlafaxine, venlafaxine, bupropion, duloxetine, trazodone, and nefazodone. ## Antidepressant Drugs: Table | Generic (Trade) Name | Forms| Usual Daily Dosages | Extreme Dosage Ranges* | |---|---|---|---| |**Selective serotonin reuptake inhibitors** | | | | | Fluoxetine (Prozac) | C, L | 20-60 | 10-80 | | Fluvoxamine (Luvox) | T | 150-200 | 50-300 | | Paroxetine (Paxil) | T | 20-40 | 10-50 | | Sertraline (Zoloft) | T | 100-150 | 50-200 | | Citalopram (Celexa) | T, L | 20-40 | 20-60 | | Escitalopram (Lexapro) | T | 10-20 | 5-30 | |**Cyclic compounds** | | | | | Imipramine (Tofranil) | T, C, INJ | 150-200 | 50-300 | | Desipramine (Norpramin) | T,C | 150-200 | 50-300 | | Amitriptyline (Elavil) | T, INJ | 150-200 | 50-300 | | Nortriptyline (Pamelor) | C, L | 75-100 | 25-150 | | Doxepin (Sinequan) | C, L | 150-200 | 25-300 | | Trimipramine (Surmontil) | C | 150-200 | 50-300 | | Protriptyline (Vivactil) | T | 15-40 | 10-60 | | Maprotiline (Ludiomil) | T | 100-150 | 50-200 | | Mirtazapine (Remeron) | T| 15-45 | 15-60 | | Amoxapine (Asendin) | T| 150-200 | 50-250 | | Clomipramine (Anafranil) | C, INJ | 150-200 | 50-250 | |**Other compounds **| | | | | Buproprion (Wellbutrin) | T | 200-300 | 100-450 | | Venlafaxine (Effexor) | T, C| 75-225 | 75-375 | | Desvenlafaxine (Pristiq) | T | 50-100 | 50 every other day - 400| | Trazodone (Desyrel) | T | 200-300 | 100-600 | | Nefazodone (Serzone) | T | 300-600 | 100-600 | | Duloxetine (Cymbalta) | C | 60 | 30-90 | | Vilazodone (Viibryd) | T | 20-4 | 10-40 | |**Monoamine oxidase inhibitors** | | | | | Phenelzine (Nardil) | T | 45-60 | 15-90 | | Tranylcypromine (Parnate) | T | 30-50 | 10-90 | | Isocarboxazid (Marplan) | T | 20-40 | 10-60 | *Values are in milligrams per day for oral doses only. C, capsule; INJ, injection for IM use; L, liquid; T, tablet. ## Antidepressant Drugs: Mechanism of Action - The precise mechanism by which antidepressants produce their therapeutic effects is not known, but much is known about their action on the CNS. The major interaction is with the monoamine neurotransmitter systems in the brain, particularly norepinephrine and serotonin. They help regulate arousal, vigilance, attention, mood, sensory processing, and appetite. - Norepinephrine, serotonin, and dopamine are removed from the synapses after release by reuptake into presynaptic neurons. - After reuptake, these three neurotransmitters are reloaded for subsequent release or metabolized by the enzyme MAO. - SSRIs block the reuptake of serotonin. - Cyclic antidepressants and venlafaxine block the reuptake of norepinephrine primarily and block serotonin to some degree. - MAOIs interfere with enzyme metabolism. The blockade of serotonin and norepinephrine reuptake and the inhibition of MAO occur in a matter of hours, while antidepressants are rarely effective until taken for several weeks. The cyclic compounds may take 4 to 6 weeks to be effective, MAOIs need 2 to 4 weeks for effectiveness, and SSRIs may be effective in 2 to 3 weeks. Researchers believe that the actions of these drugs are an "initiating event" and that eventual therapeutic effectiveness results when neurons respond more slowly, making serotonin available at the synapses. ## Antidepressant Drugs: Side Effects - **Selective Serotonin Reuptake Inhibitors:** Have fewer side effects compared to the cyclic compounds. Enhanced serotonin transmission can lead to several common side effects, such as anxiety, agitation, akathisia, nausea, insomnia, and sexual dysfunction, specifically diminished sexual drive or difficulty achieving an erection or orgasm. In addition, weight gain is both an initial and ongoing problem during antidepressant therapy, although SSRIs cause less weight gain than other antidepressants. Taking medications with food usually can minimize nausea. Akathisia is usually treated with a beta-blocker, such as propranolol or a benzodiazepine. Insomnia may continue to be a problem even if the client takes the medication in the morning, a sedative-hypnotic or low-dosage trazodone may be needed. Less common side effects include sedation, sweating, diarrhea, hand tremor, and headaches. Diarrhea and headaches can usually be managed with symptomatic treatment. Sweating and continued sedation most likely indicate the need for a change to another antidepressant. - **Cyclic Antidepressants:** Have more side effects than do SSRIs and the newer miscellaneous compounds. The individual medications in this category vary in terms of the intensity of side effects, but generally side effects fall into the same categories. The cyclic antidepressants block cholinergic receptors, resulting in anticholinergic effects, such as dry mouth, constipation, urinary hesitancy or retention, dry nasal passages, and blurred near vision. More severe anticholinergic effects such as agitation, delirium, and ileus may occur, particularly in older adults. Other common side effects include orthostatic hypotension, sedation, weight gain, and tachycardia. Clients may develop tolerance to anticholinergic effects, but these side effects are common reasons that clients discontinue drug therapy. Clients taking cyclic compounds frequently report sexual dysfunction similar to problems experienced with SSRIs. Both weight gain and sexual dysfunction are cited as common reasons for noncompliance. - **Monoamine Oxidase Inhibitors (MAOIs):** The most common side effects of MAOIs include daytime sedation, insomnia, weight gain, dry mouth, orthostatic hypotension, and sexual dysfunction. The sedation and insomnia are difficult to treat and may necessitate a change in medication. Of particular concern with MAOIs is the potential for a life-threatening hypertensive crisis if the client ingests food that contains tyramine or takes sympathomimetic drugs. Because the enzyme MAO is necessary to break down the tyramine in certain foods, its inhibition results in increased serum tyramine levels, causing severe hypertension, hyperpyrexia, tachycardia, diaphoresis, tremulousness, and cardiac dysrhythmias. Drugs that may cause potentially fatal interactions with MAOIs include SSRIs, certain cyclic compounds, buspirone, dextromethorphan, and opiate derivatives, such as meperidine. The client must be able to follow a tyramine-free diet. Studies are currently underway to determine whether a selegiline transdermal patch would be effective in treating depression without the risks of dietary tyramine and orally ingested MAOIs. - **Other Antidepressants:** Nefazodone, trazodone, and mirtazapine commonly cause sedation. Both nefazodone and trazodone commonly cause headaches. Nefazodone can also cause dry mouth and nausea. Bupropion, venlafaxine, and desvenlafaxine may cause loss of appetite, nausea, agitation, and insomnia. Venlafaxine may also cause dizziness, sweating, or sedation. Sexual dysfunction is much less common with the novel antidepressants, with one notable exception: trazodone can cause priapism, a sustained and painful erection that necessitates immediate treatment and discontinuation of the drug. Priapism may also result in impotence. ## Antidepressant Drugs: Client Teaching - Inform clients about the types of side effects that may occur, and encourage clients to report such problems to the physician instead of discontinuing the medication. - Teach clients methods of managing or avoiding unpleasant side effects and maintaining the medication regimen. - Drinking sugar-free fluids and eating sugar-free hard candy eases dry mouth. - The client should avoid calorie-laden beverages and candy because they promote dental caries, contribute to weight gain, and do little to relieve dry mouth. - Methods to prevent or relieve constipation include exercising and increasing water and bulk-forming foods in the diet. - Stool softeners are permissible, but the client should avoid laxatives. - The use of sunscreen is recommended because photosensitivity can cause the client to sunburn easily. - Clients should monitor the amount of sleepiness or drowsiness they feel. - They should avoid driving and performing other potentially dangerous activities until their response times and reflexes seem normal. - If the client forgets a dose of antipsychotic medication, he or she can take the missed dose if it is only 3 or 4 hours late. - If the dose is more than 4 hours overdue or the next dose is due, the client can omit the forgotten dose. - The nurse encourages clients who have difficulty remembering to take their medication to use a chart, and to record doses when taken, or to use a pillbox that can be prefilled with accurate doses for the day or week. ## Mood-Stabilizing Drugs - Used to treat bipolar disorder by stabilizing the client's mood, preventing or minimizing the highs and lows that characterize bipolar illness, and treating acute episodes of mania. - Lithium is the most established mood stabilizer. - Some anticonvulsant drugs, particularly carbamazepine and valproic acid, are effective mood stabilizers. - Other anticonvulsants, such as gabapentin, topiramate, oxcarbazepine, lamotrigine, and clonazepam, are also used for mood stabilization. - Clonazepam is included in the discussion of antianxiety agents. ## Mood-Stabilizing Drugs: Mechanism of Action - Although lithium has many neurobiologic effects, its mechanism of action in bipolar illness is poorly understood. - Lithium normalizes the reuptake of certain neurotransmitters such as serotonin, norepinephrine, acetylcholine, and dopamine. - It also reduces the release of norepinephrine through competition with calcium and produces its effects intracellularly rather than within neuronal synapses; it acts directly on G-proteins and certain enzyme subsystems. - Lithium is considered a first-line agent in the treatment of bipolar disorder. - The mechanism of action for anticonvulsants is not clear because it relates to their off-label use as mood stabilizers. - Valproic acid and topiramate are known to increase the levels of the inhibitory neurotransmitter GABA. - Valproic acid and carbamazepine are thought to stabilize mood by inhibiting the kindling process. ## Mood-Stabilizing Drugs: Dosage - Lithium is available in tablet, capsule, liquid, and sustained-release forms, no parenteral forms are available. The effective dosage of lithium is determined by monitoring serum lithium levels and assessing the client's clinical response to the drug. Daily dosages generally range from 900 to 3,600 mg. More importantly, the serum lithium level should be about 1 mEq/L. Serum lithium levels of less than 0.5 mEq/L are rarely therapeutic, and levels of more than 1.5 mEq/L are usually considered toxic. ## Mood-Stabilizing Drugs: Client Teaching - For clients taking lithium and the anticonvulsants, monitoring blood levels periodically is important. - The time of the last dose must be accurate so that plasma levels can be checked 12 hours after the last dose has been taken. - Taking these medications with meals minimizes nausea. - The client should not attempt to drive until dizziness, lethargy, fatigue, or blurred vision has subsided. ## Antianxiety Drugs (Anxiolytics) - Used to treat anxiety and anxiety disorders, insomnia, obsessive-compulsive disorder, depression, posttraumatic stress disorder, and alcohol withdrawal. - Antianxiety drugs are among the most widely prescribed medications today. A wide variety of drugs from different classifications have been used in the treatment of anxiety and insomnia. - Benzodiazepines have proved to be the most effective in relieving anxiety and are the drugs most frequently prescribed. - Benzodiazepines may also be prescribed for their anticonvulsant and muscle relaxant effects. - Buspirone is a nonbenzodiazepine often used for the relief of anxiety and therefore is included in this section. - Other drugs such as propranolol, clonidine, and hydroxyzine, that may be used to relieve anxiety are much less effective and are not included in this discussion. ## Antianxiety Drugs: Mechanism of Action - Benzodiazepines mediate the actions of the amino acid GABA, the major inhibitory neurotransmitter in the brain. - Because GABA receptor channels selectively admit the anion chloride into neurons, activation of GABA receptors hyperpolarizes neurons and thus is inhibitory. - Benzodiazepines produce their effects by binding to a specific site on the GABA receptor. - Buspirone is believed to exert its anxiolytic effect by acting as a partial agonist at serotonin receptors, which decreases serotonin turnover. ## Antianxiety Drugs: Table |Generic (Trade) Name | Daily Dosage Range | Half-Life (h) | Speed of Onset | |---|---|---|---| | **Benzodiazepines** | | | | | Alprazolam (Xanax) | 0.75-1.5 | 12-15 | Intermediate | | Chlordiazepoxide (Librium) | 15-100 | 50-100 | Intermediate | | Clonazepam (Klonopin) | 1.5-20 | 18-50 | Intermediate | | Clorazepate (Tranxene) | 15-60 | 30-200 | Fast | | Diazepam (Valium) | 4-40 | 30-100 | Very fast | | Flurazepam (Dalmane) | 15-30 | 47-100 | Fast | | Lorazepam (Ativan) | 2-8 | 10-20 | Moderately slow | | Oxazepam (Serax) | 30-120 | 3-21 | Moderately slow | | Temazepam (Restoril) | 15-30 | 9.5-20 | Moderately fast| | Triazolam (Halcion) | 0.25-0.5 | 2-4 | Fast | | **Nonbenzodiazepine** | | | | | Buspirone (BuSpar)| 15-30 | 3-11 | Very slow |