Antidepressants and Anxiolytics Quiz

Central Nervous System Medications

• Presented by Elizabeth Cohen, PharmD BCPS
• Objectives include reviewing mechanisms of action and adverse effects of commonly used CNS agents.
• Identifying important counseling points for patients prescribed CNS agents.
• Developing an optimal psychotropic regimen considering patient and medication specific characteristics.
• Summarizing clinically significant drug interactions, key monitoring parameters, and contraindications for CNS agents.

Neurotransmitters

• GABA and Glycine are major inhibitory neurotransmitters in the CNS.
• Glycine is primarily found in the spinal cord and brainstem.
• GABA is present throughout the CNS.
• Glutamate is a major excitatory neurotransmitter in the CNS.
• Glutamate interacts with several receptors: AMPA (all neurons), KA (hippocampus, cerebellum, spinal cord), and NMDA (all neurons in CNS).
• NMDA receptors are a key pharmacological target of glutamate.
• Serotonin (5-HT) has many pathways originating from the raphe or midline region of the pons/upper brainstem.
• Serotonin plays a role in perception, mood, anxiety, pain, and temperature regulation
• Norepinephrine (NE) is an α₁, α₂, β₁ agonist with little β₂ activity.
• NE is found in the locus caeruleus (LC) or lateral tegmental area.
• NE impacts vasoconstriction, tachycardia, increased cardiac output, peripheral resistance, and hypertension.
• Dopamine (DA) has various pathways with different functions:
  • Mesocortical: Important for higher-order cognitive functions.
  • Mesolimbic: Involved in the reward pathway.
  • Nigrostriatal: Regulates movement.
  • Tuberoinfundibular: Regulates prolactin.
• Acetylcholine (ACh) interacts with muscarinic and nicotinic receptors, having both excitatory and inhibitory effects.
• Presynaptic nicotinic receptors regulate glutamate, 5-HT, GABA, DA, and NE release in the CNS.
• ACh is hydrolyzed through acetylcholinesterase (AChE).
• AChE inhibitors (e.g., neostigmine, physostigmine, donepezil) increase ACh levels.

Cholinergic Effects/Toxidrome

• Cholinergic activation causes various effects (DUMBELS):
  • Diarrhea, Urination, Miosis (constricted pupils), Bronchoconstriction/bradycardia, Emesis (vomiting), Lacrimation (tearing), Salivation/sweating.
• Anticholinergic effects have the opposite actions (ACHOES) -Dry mouth, blurred vision, confusion, constipation, urinary retention.

CNS & Psychiatric Medications

• Overview of medications:
  • Antidepressants
  • Antipsychotics
  • Mood Stabilizers
  • Anxiolytics

Antidepressants

• Treatment of Major Depressive Disorder (MDD) includes pharmacotherapy, psychotherapy, and somatic therapies.
• Pharmacotherapy effectiveness is generally comparable across antidepressant classes.
• Treatment decisions consider comorbid conditions, anticipated side effects, and patient preference.
• Antidepressants carry a black box warning for increased risk of suicidal thinking and behavior in young adults (18-24), with major depressive disorder and other psychiatric disorders in short-term studies.
• Selective serotonin reuptake inhibitors (SSRIs), Serotonin/norepinephrine reuptake inhibitors (SNRIs), atypical antidepressants, Tricyclic antidepressants (TCAs), and Monoamine oxidase inhibitors (MAOIs).

Antipsychotics

• Dopamine pathways in the brain are a target of antipsychotics.
• Blockade of dopamine receptors can result in adverse effects, including worsening negative symptoms, increased prolactin release, or extrapyramidal symptoms (EPS)
• First-generation antipsychotics (FGAs) are potent D2 receptor antagonists and have various side effects and a higher risk of EPS.
• Second-generation antipsychotics (SGAs) block D2 and 5-HT2A receptors.
• SGAs have a lower risk of EPS but other potential side effects exist.
• Clozapine is a SGA reserved for treatment-resistant cases; registration with a REMS program is required and frequent blood monitoring is necessary.

Mood Stabilizers

• Lithium is a monovalent ion, almost entirely eliminated by the kidneys.
• Lithium has a narrow therapeutic index and toxicity can occur at doses above 1.2 mEq/L.

Anxiolytics

• Benzodiazepines (BDZs) bind to the gamma subunit of the GABAA receptor.
• BDZs alter the frequency of channel opening, increasing chloride ion conductance and inhibiting action potentials.
• Alternative anxiolytics, such as hydroxyzine, gabapentin, pregabalin, and buspirone, have different mechanisms of action and potential side effects.

Additional Notes

• Many drug interactions and potentially serious adverse effects are possible, consult with a physician or pharmacist.
• Detailed information regarding specific drugs and their uses often includes detailed information on dosage, mechanism of action, potential side effects, and various other parameters on an individual level.

Test your knowledge on various antidepressants and anxiolytics with this quiz. Explore key features, mechanisms of action, and adverse effects of medications like mirtazapine, bupropion, and duloxetine. This quiz is perfect for students in pharmacology or mental health courses.