Therapeutic drugs, pt. 1
In this section, we'll cover a collection of therapeutic drugs used to treat some of the conditions we have covered in this course.
1) First, read this article for some historical context: Coal Tar, Dyes, and the Unlikely Origins of Psychotherapeutic Drugs
2) Next, watch these videos:
Antidepressants
Antipsychotics
3) Finally, answer these questions to test your understanding:
1. Ketamine is considered a novel antidepressant; its primary mechanism of action involves the:
- A. serotonin system
- B. dopamine system
- C. acetylcholine system
- D. glutamate system
Show Answer
Correct answer: D
Ketamine and its metabolite norketamine both act at a receptor for the neurotransmitter glutamate called the NMDA receptor. Glutamate is the primary excitatory neurotransmitter in the brain, and ketamine and norketamine act as antagonists at the NMDA receptor, which means that they block the receptor and inhibit activity there.
2. Selective serotonin reuptake inhibitors (SSRIs) are drugs used to treat depression. Their mechanism involves the inhibition of the reuptake of serotonin, which leads to _________ levels of serotonin in the synaptic cleft.
- A. stable/unchanged
- B. decreased
- C. increased
Show Answer
Correct answer: C
Neurotransmitter reuptake is a method neurons use to remove excess neurotransmitters from the synaptic cleft. The inhibition of reuptake leads to higher levels of neurotransmitters in the synaptic cleft. Thus, SSRIs increase serotonin levels in the synaptic cleft, an effect which is either directly or indirectly related to an improvement in the symptoms of depression.
3. Antipsychotic medications have traditionally reduced symptoms by blocking dopamine receptors. However, many newer atypical agents also target which other neurotransmitter receptor?
- A. GABA
- B. norepinephrine
- C. glycine
- D. serotonin
Show Answer
Correct answer: D
Unlike first-generation antipsychotics that mainly block dopamine receptors, many atypical agents also target serotonin receptors. Most act as antagonists, while some newer drugs partially agonize certain serotonin receptors, allowing them to modulate rather than fully block signaling.
4. Xanomeline is a new addition to the antipsychotic drug market, with a unique mechanism compared to other antipsychotics. What receptors does it primarily act on?
- A. dopamine
- B. serotonin
- C. acetylcholine
- D. glutamate
Show Answer
Correct answer: C
Xanomeline (sold as xanomeline-trospium, or Cobenfy) is an acetylcholine receptor agonist. This means that it stimulates acetylcholine receptors (specifically M1 and M4 receptor subtypes). This is unique because most other antipsychotics primarily target dopamine and/or serotonin receptors.
5. Which of the following drugs is considered the first antipsychotic medication and is often credited with launching the modern era of psychopharmacology?
- A. fluoxetine
- B. lithium
- C. chlorpromazine
- D. diazepam
Show Answer
Correct answer: C
Chlorpromazine, introduced in the early 1950s, was the first effective antipsychotic medication and is widely credited with launching the modern era of psychopharmacology. Its ability to reduce symptoms of psychosis revolutionized the treatment of disorders such as schizophrenia and contributed to the movement away from long-term institutionalization of many psychiatric patients.
