Psychopharmacology: Mental Disorder Meds

Psychopharmacology Overview

• Psychopharmacology involves the study of medications used to treat mental disorders
• Psychotropic drugs directly impact the central nervous system (CNS), influencing behavior, perception, and thinking

Classes of Psychotropic Medications

• There are main classes of psychotropic medications, antipsychotics, antidepressants, mood stabilizers, anti-anxiety agents and stimulant drugs

Principles Guiding Pharmacologic Treatment

• Drugs should be selected based on their effects on target signs and symptoms
• Medication dosage is often adjusted to the lowest effective level
• Psychotropic drugs need adequate dosages over time before their full effects are realized
• Older clients typically need lower drug dosages to achieve therapeutic effects
• Dosage reduction should be gradual to prevent rebound, recurrence, or withdrawal Follow-up care ensures medication regimen compliance
• Compliance is enhanced when fewer medications are prescribed and taken less frequently each day

Antipsychotic Drugs

• Neuroleptic drugs treat psychosis, schizoaffective disorder, and the manic phase of bipolar disorder
• These drugs act as dopamine receptor blockers
• They treat disorders involving thought processes, helping individuals organize thoughts and respond to stimuli appropriately
• They function as major tranquilizers, altering neuron stimulation and response
• They work by blocking dopamine receptors in the postsynaptic membrane of the brain, antagonizing Dopamine 2, 3, and 4 receptors, thus decreasing dopamine activity
• Used as a primary way to treat schizophrenia
• Other indications include psychosis, bipolar disorder, Tourette's syndrome, severe aggression, and autism
• Typical antipsychotics block dopamine receptors, leading to anticholinergic and antihistamine effects, as well as alpha adrenergic blocking effects
• They prevent stimulation of postsynaptic neurons by dopamine, thereby depressing the reticular activating system (RAS) and limiting the stimuli into the brain
• Atypical antipsychotics block both dopamine and serotonin receptors
• They help alleviate unpleasant neurological effects and depression

Pharmacokinetics of Antipsychotics

• Absorption in the gastrointestinal tract (GIT) varies based on the drug preparation
• Intramuscular (IM) administration results in a 4x higher active dose compared to oral administration
• Caution is advised when switching administration routes
• They are widely distributed in tissues and can be stored and released up to 6 months after discontinuation
• They are metabolized in the liver, where children metabolize them faster than adults, while older adults metabolize them slower Clinical effects may take several weeks, so it's important to continue taking the drugs
• They are excreted in the urine

Contraindications for Antipsychotics

• Conditions exacerbated by dopaminergic blocking effects, like Parkinson's disease, should be avoided due to prolonged QTc intervals and increased risk of Torsade de Point
• Dementia patients are at risk of cardiovascular diseases and death when taking antipsychotics
• Anticholinergic effects can worsen conditions like glaucoma, peptic ulcers, and urinary or intestinal obstruction
• Use is not advised for those with seizure disorders or active alcohol use, as it can cause CNS depression
• Pregnancy, especially in the third trimester, is a contraindication due to extrapyramidal and withdrawal symptoms
• Children under 12 with CNS infection and chicken pox are at risk of dystonia
• Immunosuppressed and cancer patients may experience bone marrow suppression and blood dyscrasias

Adverse Effects of Antipsychotics

• CNS effects: sedation, weakness, tremor, drowsiness
• Extrapyramidal side effects: pseudoparkinsonism, dystonia, akathisia, tardive dyskinesia
• Treatment for extrapyramidal side effects often includes Deutetrabenazine and Valbenazine
• Neuroleptic Malignant Syndrome presents with high grade fever, blood pressure fluctuations, dysrhythmia, and muscle rigidity
• Treatment for Neuroleptic Malignant Syndrome is to immediately stop the medication, cool the patient with ice packs/fluids, and administer antipyretics.
• Dantrolene is used to decrease muscle rigidity, and antiarrhythmic drugs.
• Anticholinergic and cardiovascular effects are possible
• Baseline ECG monitoring is advised during therapy
• Other effects include diabetes mellitus, weight gain, drug reaction with eosinophilia and system symptoms, and respiratory issues like laryngospasm and bronchospasm
• May suppress bone marrow
• Urine discoloration shows a pink to reddish-brown tint.
• Phenothiazines may also cause urine discoloration, including chlorpromazine, fluophenazine, and promethazine

Drug Interactions with Antipsychotics

• Combining antipsychotics with alcohol increases CNS depression
• Combining antipsychotics with anticholinergics raises anticholinergic impacts
• Thioridazine or Ziprasidone taken in combination can cause a prolonged QTc interval and arrhythmia.

Nursing Considerations for Antipsychotics

• Sustained-release capsules should not be crushed or chewed to reduce toxicity
• During parental administration keep patents in the recumbent position because antipsychotics reduce orthostatic hypotension
• It's important to warn patients about adverse effects such as extrapyramidal syndrome and Neuroleptic Malignant Syndrome
• Side effects should be reported to the physician, but the medication should not be stopped abruptly
• Teach patients how to manage or avoid side effects
• Dryness of mouth is eased by drinking non-sugar fluids and eating sugar-free candy Instruct the individual to monitor amount of sleepiness or drowsiness
• Activities dangerous like driving should be avoided
• Teach the patient that if a dose is late, it can be taken if within 3 or 4 hours
• If after this time has passed don't take the medication
• Encourage the patient to create charts and record doses
• Comfort strategies and coping mechanisms should be taught
• Monitor CBC to arrange to discontinue the drug at signs of Bone Marrow Suppression
• Blood glucose level should be monitored during long-term therapy
• Gradual dose reduction prevents withdrawal symptoms
• Provide proper positioning of legs and arms to decrease discomfort of dyskinesia

Antidepressant Drugs Overview

• Antidepressants alter the concentration of neurotransmitters in the brain, making them an effective depression way to treat depression
• Three ways they help: By inhibiting the effects of monoamine oxidase (MAO), this increases neurotransmitter levels in the neuron synaptic cleft, blocking transmitters reuptake from nerves, and regulating receptor sites, accumulating the neurotransmitters and preventing a breakdown

Uses of Antidepressants

• Primary uses include major depressive illness, anxiety disorders, depressed phase of bipolar disorder, and psychotic depression
• Off-label uses encompass chronic pain, migraine headaches, peripheral and diabetic neuropathies, sleep apnea, and panic and eating disorders

Tricyclic Antidepressants (TCA) Characteristics

• These pharmaceuticals reduce the reuptake of norepinephrine and serotonin
• They've got anti-cholinergic properties
• They provide relief and treatment of depression signs and symptoms
• Other indications of use are anxiety and sleep problems
• Enuresis and bed wetting can be managed, used on kids over 6 years old
• Can address chronic and serious pain
• TCAs function by inhibiting presynaptic reuptake of Norepinephrine (NE) and Serotonin (5HT) which increases neurotransmitter availability in the synaptic cleft, increased stimulations of post-synaptic receptors, and ⬆ NE and 5HT levels

Tricyclic Antidepressants (TCA) - Pharmacokinetics

• Absorbed in the gastrointestinal tract (GIT)
• Peak levels are reached in 2 to 4 hours
• They are lipid soluble
• Are metabolized in the liver
• Are excreted in the urine
• Can cross the placenta and pass into human milk

Tricyclic Antidepressants (TCA) - Cautions

• Risk factors including underlying cardiovascular problems
• Conditions that anticholinergic impacts make worse
• Psychosis and paranoia could be worsened
• Contraindicated if the patient suffers symptoms of Manic-depression and the elderly
• Should stay away from the patient with History of seizures/ Hepatic failure, renal failure

Tricyclic Antidepressants (TCA) - Adverse Effects

• CNS: sedation, sleep disturbances, hallucinations, disorientation, difficulty concentrating, weakness, and tremors
• GUT: urinary retention, loss of libido, and changes in sexual functioning
• CVS: orthostatic hypotension, hypertension, tachycardia, arrhythmias, and myocardial infarction
• Anticholinergic: blurred vision and Photophobia

Tricyclic Antidepressants (TCA) - Drug-to-Drug Interactions

• Cimetidine, Fluoxetine, and Ranitidine increase therapeutic and adverse effects:
• Close patient monitoring is needed and dose reductions
• Oral anticoagulants can create problems, high serum levels may develop, risking bleeding and requiring frequent blood tests
• Sympathomimetic Drug and MAOIs should not be taken, this can cause serotonin syndromes

Tricyclic Antidepressants (TCA) - Nursing Considerations

• Warn about risk of depression and suicidal thoughts
• Maintain dose for 4 - 8 weeks for therapeutic effect
• Administer drug at bedtime to combat drowsiness
• Reduce the dose for adverse effects
• Provide comfort measures
• Provide thorough patient teaching
• Offer support and encouragement

Monoamine Oxidase Inhibitors (MAOI) Overview

• MAOI inhibits monoamine oxidase, an enzyme that breaks down biogenic amines such as norepinephrine, dopamine, and serotonin
• Indicated to treat the signs and symptoms of depression in patients who cannot tolerate or do not respond to other safer antidepressants
• Action is to block the breakdown of biogenic amines – NE, Dopamine and 5HT, increasing stimulation of the postsynaptic receptors to cause a relief of depression

Monoamine Oxidase Inhibitors (MAOI) - Pharmacokinetics

• Absorbed in GIT
• Peak levels in 2 to 3 hrs
• Metabolized in the liver
• Excreted in the urine
• Crosses the placenta and in human milk

Monoamine Oxidase Inhibitors (MAOI) - Adverse Effects

• Accumulation of norepinephrine
• Dizziness and Excitement
• GIT Issues
• Hypertensive crisis

Monoamine Oxidase Inhibitors (MAOI) - Drug and Food Interactions

• Other antidepressants including SSRIs risk a hypertensive episode
• Use with sympathomimetic drugs increase effects
• Cannot be taken with tyramine

Selective Serotonin Reuptake Inhibitors (SSRI)

• Blocks 5HT reuptake, first-line therapy for depression
• Treats signs of depression, safe antidepressants

Selective Serotonin Reuptake Inhibitors (SSRI) - Mechanism of Action

• Blocks biogenic amines and 5HT
• Increases postsynaptic receptors, causing stimulation and relief

Selective Serotonin Reuptake Inhibitors (SSRI) - Implications

• Avoid if you hypersensitivity, hepatic failure, or are severely suicidal
• Pregnant or breast feeding

Selective Serotonin Reuptake Inhibitors (SSRI) - Adverse Effects

• GI Effects, Neuro issues and agitation
• Seizures/Coma
• Respiratory problems

Selective Serotonin Reuptake Inhibitors (SSRI) - Nursing Considerations

• Administer drug in the morning
• Comfort/ safety in all actions
• Monitor safety to prevent suicidal attempts

Serotonin-Norepinephrine Reuptake Inhibitors (SNRI)

• Decreases uptake of both serotonin and NE
• Do not have impact dopamine
• Treats major depression

Serotonin-Norepinephrine Reuptake Inhibitors (SNRI) - Nursing Considerations

• Do provide once a day
• Do potential suicide protocols in advance
• Monitor for sexual side effects

Other Antidepressants

• Bupropion is effective in treating depression that cannot respond to other antidepressants
• Mirtazapine antagonizes receptors and histamine

Antidepressants and Time

• SSRIs can be missed after 8 hours
• TCA can only be missed after 3 hours

Mood Stabilizing Drugs Overview

• Mood stabilizers are used in bipolar disorder
• They balance the individual's mood who suffers, low or high

Lithium Carbonate

• Taken in concurrent with diruretics and NSAIDs
• Used frequently in serum level monitoring to alleviate GI effects by drinking with food of milk

Anti-Anxiety Drug Overview

• These calm individuals by depressing the central nervous system (CNS)

Drug Options

• Patients have the option of antidepressants like SSRIs to avoid any sympathetic signs or symptoms

Anxiolytics

• Come in the form of hypnotics
• Barbiturates are an example that help with seizure effects but should not be a main source of use

Benzodiazepines - Cautions

• Should not be taken if allergic
• No grapefruit juice

Benzodiazepines, What to Do

• Flumazenil to reduce symptoms and reverse those from sedation

Stimulant Drug Overview/Mechanism

• For ADHD and Narcolepsy patients
• Help children focus on one main activity with stimulation and dopamine reuptake

Management

• Drug holidays are used to help with children and weight suppression
• Doses should be minimized with anorexia