Sign in to follow this  
Followers 0
Gurpal

Part 2 ISQ Club - Psychopharmacology

47 posts in this topic

Below are some ISQs from the autumn 2004 exam. The complete paper can be downloaded by clicking here.

1. 5HT3 is an anion channel

2. D1 and D5 receptors belong to same family

3. Donepezil is an anticholinergic drug used in dementia

4. Rivastigmine is a butyrylcholinesterase inhibitor

5. Memantine is a NMDA agonist

6. Olanzapine causes diabetes mellitus only in doses above 20 mg

7. Reboxetine blocks alpha2 receptors

8 .Acamprosate is an NMDA antagonist

9. Clozapine is expected to cause less postural hypotension compared with other antipsychotics when its receptor functions are considered

10. Clozapine antagonises central M4 receptors

11. Fluoxetine increases clozapine levels

12. Tricyclic antidepressants commonly have peripheral neuropathy as a side effect in the elderly

13. Carbamazepine is associated with hypothyroidism

14. The lithium level increases when lithium is given with an ACE inhibitor

15. The lithium level increases when lithium is given with fluoxetine

16. Benzodiazepine withdrawal causes perceptual distortion

Share this post


Link to post
Share on other sites

2. F donepezil is an acetylcholinesterase inhibitor

4 T rivastigmine is a butyrylcholinesterase inhibitor

Share this post


Link to post
Share on other sites

5. Memantine is a NMDA agonist

False

Effect of memantine (NMDA antagonist) on Parkinson's disease: a double-blind crossover randomized study.

Merello M, Nouzeilles MI, Cammarota A, Leiguarda R.

Neurology Department,

Raul Carrea Institute for Neurological Research (FLENI),

Buenos Aires, Argentina.

Clin Neuropharmacol 1999 Sep-Oct;22(5):273-6

Share this post


Link to post
Share on other sites

8 .Acamprosate is an NMDA antagonist

False

Biphasic eect of acamprosate on NMDA but not on GABAA

receptors in spontaneous rhythmic activity from the isolated

neonatal rat respiratory network

Olivier Pierreche , Martine Daoust, Mickae¨l Naassila

GRAP-JE Groupe de Recherche sur l’Alcool et les Pharmacode´

pendances, UFR de Pharmacie, Universite´ de Picardie Jules Verne,

1, rue des Louvels, 80036 Amiens, France

Received 23 October 2003; received in revised form 16 February 2004; accepted 1 March 2004

Abstract

Acamprosate (calcium acetylhomotaurinate) has been shown to be eective in attenuating relapse in human alcoholics. The

precise mechanism for acamprosate has been yet to be determined as there may be multiple sites of action for this drug. We investigated

the mechanism of action of acamprosate on a spontaneous rhythmic activity recorded from hypoglossal nerve rootlet

(XII) in neonatal rat brainstem slices. At 30 lM, acamprosate reversibly increased burst amplitude and reduced burst frequency,

whereas at higher concentrations (100–400 lM) it induced a reversible and concentration-dependent inhibition of this activity.

Interestingly, acamprosate (30 lM) enhanced the eects of low NMDA-induced excitation (1.5 lM), but inhibited higher

NMDA-induced excitation (2.5, 5 lM) by 50–70%, demonstrating a dierential eect on NMDA-induced excitation. Blockade of

GABAA receptors did not aect the increase in amplitude of 30 lM acamprosate and partially abolished the inhibitory eects of

200 lM acamprosate. At 200 lM, acamprosate reduced high NMDA-induced excitation and abolished NMDA-evoked excitatory

tonic phase, suggesting that excitatory eect of low concentrations of acamprosate mainly involved NMDA receptors, while the

inhibitory eects at higher concentration included an increase in GABAA-mediated inhibition with a reduction of NMDAmediated

excitation. Consequently, combined blockade of both receptors abolished all eects of acamprosate tested at all concentrations.

These results show that the eects of acamprosate are mediated via both GABAA and NMDA receptors and suggest

a partial co-agonist role on NMDA receptors, at the level of a spontaneously active network

Share this post


Link to post
Share on other sites

12. Tricyclic antidepressants commonly have peripheral neuropathy as a side effect in the elderly

false

Share this post


Link to post
Share on other sites

QUES. 8) Acamprosate is NMDA agonist

ANS :---FALSE Acamprosate is GABA agonist &

GLUTAMATE antagonist.

hasit

Share this post


Link to post
Share on other sites

QUES 16) BENZODIAZEPINE WITHDRAWAL CAUSES PERCEPTUAL DISTURBANCES.

ANS :----TRUE. 1)Hypersensitivity to stimuli of all kinds eg tinnitus,blurring of vision.

2)Formication ie feeling of things crawling under

the skin.

3)Temporal lobe quality of distorted environmental ralationships eg doors or fireplaces sloping to one side.

4)Frank depersonalisation.

COMPANION TO PSY. STUDIES page 300 &465

Share this post


Link to post
Share on other sites

9. Clozapine is expected to cause less postural hypotension compared with other antipsychotics when its receptor functions are considered

False- Clozapine alpha antagonist which causes hypotension

Ziprazidone newer anti psychotic causes less postural hypotension as no alpha blockade

10. Clozapine antagonises central M4 receptors

False M4 agonist this causes hypersalivation

11. Fluoxetine increases clozapine levels

True CyP 450 inhibition

Share this post


Link to post
Share on other sites

mpant__uk - where is your source for your answer for 10?

- not disagreeing, just like to know

I could only find that clozapine does antagonize M2 receptors, but assumed as M2 & M4 are similar it would antagonize them as well.

(actually i'd forgotten there was a M4 receptor)

Share this post


Link to post
Share on other sites

14 the lithium level increases when given with an ACE inhibitor.

TRUE

BNF

also with

analgesics-diclofenac, ibuprofen

loop diuretics, K-sparing & thiazides

Share this post


Link to post
Share on other sites

stibbles..found the answer in manchester notes for schizophrenia

clozapine has marked anti cholinergic activities-mechanism may be agonist activity at the M4 receptor outweighs antagonism at M1,M2,M3 ans M5 receptors.

Share this post


Link to post
Share on other sites

no 13 carbamazepine asociated w hypothyroidism

false

pubmed and bnf- no evidence found

am i answering all the easy ones???

Share this post


Link to post
Share on other sites

reboxetine blocks alpha 2 receptors

false

no evidence found

Share this post


Link to post
Share on other sites

q.1 5HT3 is an anion channel

False it is a cationic channel

q.13 carbamazepine and hypothyroidism

True (pubmed)

Share this post


Link to post
Share on other sites

i agree 5HT3 is cationic

cant find anything which links carbamazepine to hypothroidism except two months after developing hypersensitivity syndrome

whats the ref?

Share this post


Link to post
Share on other sites

q.1 5HT3 is an anion channel .

FALSE.

5-HT3 receptors are centrally and peripherally occuring ligand gated , cation selective ,ion channels mediating membrane depolarization and neuronal excitation

ion-gated receptors include

1. 5HT3

2. GABAa

3. NMDA, AMPA, Kainate

Serotonin Receptors

There are at least 9 types of 5-HT receptors

5-HT1 : 1A, 1B, 1D, 1E, and 1F

5-HT2 : 2A, 2B, and 2C

5-HT3

5-HT3 receptors are ionotropic, the remainder are metabotropic

5-HT1B and 5-HT1D are presynaptic autoreceptors

Share this post


Link to post
Share on other sites

cabamazepine is associated with hypothyroidism true

Ref: shorter oxford txtbk of psychiatry pg 702

cbz lowers plasma thyroxine concentration, TSH levels are not elevated. clinical hypothyroidism is unusual

this means hypothyroidism can occur!

Share this post


Link to post
Share on other sites

question 15 lithium level increases when given with fluoxetine FALSE

Lithium is not metabolised in the liver.Fluoxetine is an enzyme inhibitor.

OTHERS WHICH CAN INCREASE LITHIUM LEVELS

Diuretics- thiazide

ACE inhibitors --enalapril etc

NSAIDs

Share this post


Link to post
Share on other sites

Dear Dear  ::)

I'm glad the 5HT3 and CBZ-Hypoth controversies have been succesfully resolved by team work  ;)

Indeed cation, indeed associated.

On question  7- Reboxetine does not act on a2, it is a quite selective NA RU inhib.

Ref Fundamentals of clinic psychopharm pag 51

8)

No, I can't sleep these days..

Share this post


Link to post
Share on other sites

6. Olanzapine causes diabetes mellitus only in doses above 20 mg

FALSE

It doesn't CAUSE diabetis. It does increase the likelihood of it, though, and this is dose related.

Any thoughts, fellas?

Ref

J Clin Psychiatry. 2002 Oct;63(10):920-30. Related Articles, Links

Comment in:

J Clin Psychiatry. 2003 Jul;64(7):847-8; author reply 848.

Differential effects of risperidone, olanzapine, clozapine, and conventional antipsychotics on type 2 diabetes: findings from a large health plan database.

Gianfrancesco FD, Grogg AL, Mahmoud RA, Wang RH, Nasrallah HA.

Share this post


Link to post
Share on other sites

8 .Acamprosate is an NMDA antagonist

TRUE

Sorry Peter Pan and DrHasit, but I couldn't help rememberin so and looked it up..

in Fundamentals of Clinical Psycopharmacology (anderson, reid 2002) pag 79

NMDA antagonist and Glu agonist + possily other mechanisms.

Share this post


Link to post
Share on other sites
Sign in to follow this  
Followers 0