Neurobiology and Psychopharmacology. Select two of the following neurotransmitters:
Serotonin
Norepinephrine
Dopamine
Acetylcholine
Glutamate
Melatonin
Histamine
GABA
For each neurotransmitter, please discuss the following: pharmacologic action, the drug class it is most closely linked to, expected outcomes, and potential side effects. Based on this information, which condition would these neurotransmitters be considered for the treatment plan?
Textbook:
https://online.vitalsource.com/reader/books/978113…
Neurobiology, Brain Anatomy, Neurotransmitter Synthesis, and Function
Section 2 of 3
Neurotransmitters are related to how the brain functions and how one feels. The most common neurotransmitters related to mental health are serotonin, norepinephrine, dopamine, acetylcholine, glutamate, and GABA (γ-aminobutyric acid).
Different medications are either agonists, partial agonists, antagonists, or inverse agonists. The neurotransmitter is the agonist. The antagonists are the opposite and are considered neutral. They are the cause of many side effects associated with psychiatric medications. The agonist imitates the action of the intended chemical for that receptor, thus creating a comparable response. The antagonist does the very opposite and elicits no response.
A partial agonist is somewhere in the middle; it is more than an antagonist but less than a full agonist. An inverse agonist is a drug that binds to the same receptor as an agonist but induces a pharmacological response opposite to that of the agonist. A neutral antagonist has no activity in the absence of an agonist or inverse agonist but can block the activity of either. The clinical significance of this action when compared to an antagonist is questionable.
The cytochrome P450 enzyme system is responsible for metabolism of psychiatric medications. Click below to learn more.
CYP1A2+
CYP2D6
+
CYP3A4
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LIGAND-GATED ION CHANNELS
Psychiatric medications can target ligand-gated ion channels. Review the chart below:
Neurotransmitter Ligand-gated ion channel receptor subtype directly targeted Pharmacologic action Drug class Therapeutic action
Acetylcholine α4β2 nicotinic receptors
Partial agonist Nicotinic receptor partial agonist (NRPA) (varenicline) Smoking cessation
GABA GABAA benzodiazepine receptors Full agonist Benzodiazepines Anxiolytic
GABA GABAA non-benzodiazepine PAM sites Full agonist “Z drugs”/hypnotics (zolpidem, zaleplon, zopiclone, eszopiclone) Improve insomnia
Glutamate NMDA NAM channel sites/Mg++ sites Antagonist NMDA glutamate antagonist (memantine) Slowing progression in Alzheimer’s disease
Glutamate
NMDA open channel sites Antagonist PCP (phencyclidine), ketamine Hallucinogen anesthetic
Serotonin 5HT3 Antagonist Antidepressant (mirtazapine)
Unknown; reduce nausea
Serotonin 5HT3
Antagonist Antiemetic Reduce chemotherapy-induced emesis
References
https://online.vitalsource.com/reader/books/978113
Understanding the pharmacologic action, drug class, expected outcomes, and potential side effects of neurotransmitters is crucial in the field of neurobiology and psychopharmacology. Let’s delve into the details of two selected neurotransmitters: serotonin and dopamine.
Serotonin
Pharmacologic Action: Serotonin, also known as 5-hydroxytryptamine (5-HT), is a neurotransmitter that plays a key role in regulating mood, appetite, and sleep. It is involved in various physiological processes, including the modulation of emotions and behavior.
Drug Class: Selective Serotonin Reuptake Inhibitors (SSRIs) are the drug class most closely linked to serotonin. These medications work by increasing the levels of serotonin in the brain by blocking its reabsorption by neurons.
Expected Outcomes: By increasing serotonin levels, SSRIs aim to alleviate symptoms of depression, anxiety, and certain other mental health conditions. The expected outcomes include an improvement in mood, reduction in anxiety, and better regulation of appetite and sleep patterns.
Potential Side Effects: Common side effects of SSRIs may include nausea, insomnia, sexual dysfunction, and weight gain. In some cases, they may also lead to serotonin syndrome, a potentially life-threatening condition characterized by agitation, hallucinations, and rapid heart rate.
Condition for Treatment Plan: Serotonin is considered for the treatment plan of conditions such as major depressive disorder, generalized anxiety disorder, obsessive-compulsive disorder, and panic disorder.
Dopamine
Pharmacologic Action: Dopamine is a neurotransmitter that plays a crucial role in reward-motivated behavior, motor control, and the regulation of emotional responses. It is involved in the brain’s reward system and motor function.
Drug Class: Dopamine receptor agonists are the drug class most closely linked to dopamine. These medications stimulate dopamine receptors in the brain, mimicking the action of dopamine.
Expected Outcomes: By activating dopamine receptors, these medications aim to alleviate symptoms of Parkinson’s disease, restless legs syndrome, and certain other conditions related to dopamine dysregulation. The expected outcomes include improved motor function and reduced symptoms of restless legs syndrome.
Potential Side Effects: Common side effects of dopamine receptor agonists may include nausea, dizziness, hallucinations, and orthostatic hypotension. In some cases, long-term use may lead to dyskinesias, which are involuntary movements.
Condition for Treatment Plan: Dopamine is considered for the treatment plan of conditions such as Parkinson’s disease, restless legs syndrome, and certain types of dystonia.
Understanding the pharmacologic action, drug class, expected outcomes, and potential side effects of neurotransmitters and their associated medications is essential for healthcare professionals involved in the treatment of mental health conditions. It provides valuable insights into the mechanisms of action and potential therapeutic outcomes, enabling informed decision-making in clinical practice.
References:
Stahl, S. M. (2013). Stahl’s essential psychopharmacology: Neuroscientific basis and practical applications. Cambridge University Press.
Sadock, B. J., Sadock, V. A., & Ruiz, P. (2014: 2024 – Essay Writing Service | Write My Essay For Me Without Delay). Kaplan & Sadock’s synopsis of psychiatry: Behavioral sciences/clinical psychiatry. Wolters Kluwer.
