Pysch SI Session: Week 10

What is the main mechanism of action of benzodiazepines?

What is the main mechanism of action of benzodiazepines?

Increase the likelihood that a chloride channel is open (not the duration of how long it is open for) and they positively modulate GABA on the GABA receptor

Which drug will increase the duration of a chloride channel being open?

Barbiturates

What are the main SARS for benzodiazepines?

1. Position 2 C=O (carbonyl) critical for activity

2. Position 5-phenyl group leads to increased activity

3. Ring A should be an aromatic ring for increased activity

What is true regarding midazolam’s relationship with pH?

pH can affect the solubility of midazolam

• More water soluble at pH < 4, more lipid soluble at pH > 4

Which enzyme metabolizes midazolam?

CYP3A4

Hydroxyzine is metabolized using CYP___ enzyme leading to active metabolite __________.

CYP3A4; cetirizine

Does hydroxyzine’s active metabolite cross the BBB?

Naur. Cetirizine is non sedating and does not cross the BBB

What are some treatment options for anxiety disorders?

1. 5-HT antidepressants (SSRIs, SNRI)

2. Beta Blocker

3. Antihistamine

4. Benzodiazepines

5. 5HTA partial agonists (buspirone)

6. 2nd generation antipsychotics (off label)

True or False: Careful tapering of benzos is critical to avoid withdrawal symptoms?

True

True or False: Triazoloam is a benzo with a short half life that does not accumulate in the body

True

True or false: Discontinuing a long acting benzo abruptly will lead to significant withdrawal symptoms

False: They stay longer in the body and the withdrawal symptoms are less severe

What are the short half life benzodiazepines?

Triazolam and oxazepam

What are the intermediate half-life benzodiazepines?

Temezepan, alprazolam, lorazepam, estazolam

What’s the nemonic to remember the short and intermediate benzos?

TOTALE

• Triazolam, oxazepam, temezepan, alprazolam, lorazepam, and estazolam

What benzodiazepines can come in a parenteral formulation?

Diazepam, chlordiazepoxide, lorazepam, and midazolam

Which benzo can be given intramuscularly?

Lorazepam

Oxazepam is (more or less) likely to be abused due to (hydrophobic or hydrophilic nature)

Less; hydrophilic

• The more hydrophilic something is the less likely it is to cross the BBB

Which benzodiazepines are best to avoid in the elderly and why?

Diazepam because it is longer acting

Which one has better therapeutic effects for GAD: SSRI/SNRIs or buspirone?

SSRI/SNRIs

Is Clomipramine (Anafranil) anticholinergic?

Yeth, it is a TCA (cant see cant spit, cant pee cant shit)

What is the standard/best treatment for PTSD?

Psychotherapy (group therapy)

I personally need this but my psychiatrist is pissing me off

What is the number one phobia for most people and the current recommended treatment?

Public speaking, propanolol

I LOVE propranolol it makes me feel so yummers and it prevents my migraines

What is the main ligand for GABAa receptor?

The pentameric ligand gated chloride channel GABA receptor

True or False: Patients with alcohol use disorder cannot tolerate high doses of benzodiazepines?

Fwalse: Alcohol also acts on the GABA receptor (this is an example of cross-tolerance). GABA receptors are now constantly being stimulated by alcohol and you become tolerant

• Alcoholism is bad, my uncle Trino is an alcoholic and his son committed suicide so he finally stopped drinking but that didnt last long so basically he wouldn’t really benefit from taking a benzo