Psychiatry pharmacology

Question 1

Imipramine, amitriptyline & doxepin are examples of what class of drugs?

Answer 1

Imipramine, Amitriptyline & Doxepin are examples of Tricyclic antidepressant.

Question 2

What is the MOA of Tricycic antidepressants?

Answer 2

All Tricyclic antidepressants function to increase the presence of monoamines (seritonine, noradrenaline, dopamine) in monoamine neurons.

These mechanisms can include
1. blocking the reuptake pumps,
2. blocking presynaptic receptors that regulate the release of monoamines from the presynaptic neuron.
3. inhibiting monoamine oxidases within the presynaptic neuron (these usually degrade monoamines reuptaken but not yet stored in vesicles),
4. altering the responsiveness of post synaptic receptors.

Question 3

When are tricyclic antidepressants used in the managment of anxiety disorders?

Answer 3

Tricyclics can be used in anxiety disorders as a second line pharmacological treatment option.

SSRI’s and SNRI’s are considered first line treatment for anxiety along with CBT (equally effective to pharmacologial approaches in short term, less effective than CBT in long term).

Anxiolytics (ie benzodiazepines) should be avoided however can be used in refractory cases for short term. Long acting have less addictive potential compared with short acting.

Question 4

What are anxiolytics?

Answer 4

Anxiolytics induce calm in individuals. Examples include:
* Benzodiazepines,
* Non-benzodiazepines (barbituates, buspirone, melatonine, H1 antistamines).

Question 5

What is the MOA of Benzodiazepines?

Answer 5

Binding of Benzodiazapines to their allosteric site on the the GABBA A receptor induces a confirmational change within the receptor that increases the receptors affinity for GABBA, thus increasing the effects of GABBA on the post synaptic neuron; increased influx of Cl- through the GABBA A receptor > causing hyperpolarisation (=less excitatory stimulation of the post synaptic neuron).

Question 6

What are the commons suffix’s for Benzodiazepines?

Answer 6

‘-azapam’ or ‘azolam’ are common suffix’s for Benzodiazepines.
Eg: Diazepam, Tamazepam, Midazolam, Traiazolam

Question 7

Where are the following psychotic drugs secreted…
Lithium, Supiride & Amisulpride?

Answer 7

Renal excretion!
Requires careful monitoring!

Question 8

Clozapine is used for?

Answer 8

Refractory schizoprenia
It has significant side effects:
1. Monitor WBC as neutropenia is a serious side effect.
2. Requires full cardiac work up as can exaggerate arythmias.
3. Metabolic syndrom effects.

Question 9

Neurotransmitter receptors targeted in antipsychotics

Answer 9

Answer 10

Question 11

Treatment of bipolar includes

Answer 11

DO NOT GIVE ANTIDEPRESSANTS TO BIPOLAR TYPE 1 - can bring on mania.

Lithium (drug of choice for mania / Bipolar 1) - also reduces suicide risk.

Antipsychotics

Antiepileptic
Valproate (beware of pregnancy) &
Carbamazepine
Lamotrigine & Quetiapine (Bipolar 2)

Question 12

Anxiety treatments include:

Answer 12

1. SSRI’s first line treatment
2. Gabapentinoids
3. Tricyclics
4. Monoamine Oxidase Inhibitors
5. Short term Benzos

Question 13

Hypnotics and sedative drugs

Answer 13

Melantonin (2mg)
Benzos (3-5 days only) inconjunction with sleep hygine
Z drugs (zolpidem & Zopiclone)

Question 13

Hypnotics and sedative drugs

Answer 13

Melantonin (2mg)
Benzos (3-5 days only) inconjunction with sleep hygine
Z drugs (zolpidem & Zopiclone)

Question 14

What drug can be used to reverse the effects of Benzodiazapines ie in a Benzo overdose?

Answer 14

Flumazenil

Question 15

Delierium Tremens occurs approx 3 days post cessation of alcohol. What treatment is required to manage withdrawl?

Answer 15

CNS depressant drugs such as benzos, analgesic, anticonvulsants and antiemetics.

Question 16

Long term treatment for alcoholism offers three drug options.

Answer 16

1. Acaprosate - acts via GABA & glutamate to reduce cravings.
2. Naltrexone - acts via opoid antagonism by reducing the effects of endogenous opiods theus reducing the cravings.
3. Disulfiram - prevents the use of alcochol by cusing serious unpleasant side effects (blocks alcoholdehydrogenase causing the ‘mother of all hangovers’.

Question 17

Managing the withdrawal from Opoids.

Question 18

Managment of Alzheimers Disease includes..

Answer 18

Cholinesterase inhibitors ie donepezil & rivastgmine (not disease modifying).