1.3 EMQs Flashcards
Match each chemical class below with the most appropriate drug from the given list:
- Thienobenzodiazepine
- Dibenzodiazepine
- Substituted benzamides
Olanzapine Clozapine Risperidone Quetipaine Amisulpiride Molindone Loxapine Haloperidol Chlorpromazine Zuclopenthixol Trifuoperazine
Thienobenzodiazepine- Olanzapine;
Dibenzodiazepine- Clozapine;
Substituted benzamides include Amisulpride, Sulpiride.
Dibenzothiazepine- Quetiapine.
Benzisoxazole derivatives include Risperidone;
Thioxanthenes include Flupenthixol and Zuclopenthixol.
Match each chemical class below with the most appropriate drug from the given list:
- Aliphatic phenothiazine
- Butyrophenones
- Piperazine derivatives
- Piperidine derivatives
Quetiapine Ziprasidone Risperidone Quetipaine Thioridazine Molindone Loxapine Haloperidol Chlorpromazine Zuclopenthixol Trifuoperazine
Aliphatic phenothiazine: Chlorpromazine, promazine, and triflupromazine.
Butyrophenones include Haloperidol, Droperidol.
Piperazine derivatives include Trifluoperazine, Fluphenazine, prophenazine.
Piperidine derivatives include thioridazine.
Match each drug below with the most appropriate chemical class from the given list:
- Zopiclone
- Imipramine
- Nortryptyline
- Phenelzine
- Zolpidem
Aliphatic phenothiazine Cyclopyrrolone Tertiary amine Triazolopyridine Butyrophenones Hydrazine derivatives Piperazine derivatives Piperidine derivatives Imidazopyridine Secondary amine
Zopiclone - Cyclopyrrolone
Tertiary amines: Imipramine, Clomipramine, Trimipramine. Amitriptyline, Dothiepin.
Secondary amines include Desipramine, Amoxapine, Nortriptyline and protriptyline.
Hydrazine derivatives include phenelzine and Isocarboxazid (greater hepatotoxicity than non hydrazine compounds such as tranylcypromine )
Zolpidem - Imidazopyridine
Select the mechanism of action for each of the following drugs using the given list:
- Memantine
- Buspirone
- Lofexidine
A. GABA-A agonist B. GABA-B agonist C. MAO-A Inhibitor D. MAO-B Inhibitor E. NMDA receptor antagonist F. 5HT1A partial agonist G. Butyryl-cholinesterase inhibitor H. D-2 receptor partial agonist I. Presynaptic alpha-2 agonist J. 5-HT2 antagonist
Memantine-NMDA receptor antagonist
Buspirone-5HT1A partial agonist
Lofexidine-Presynaptic alpha-2 agonist
Memantine is an antidementia drug which acts through blockade of NMDA glutamate receptors. Unlike ketamine which is a high affinity noncompetitive blocker, memantine is a non competitive blocker with low affinity and binds only to actively open NMDA channels. Its receptor dissociation rate is relatively fast and so it does not accumulate and interfere with normal NMDA activity.
Buspirone is a partial agonist on serotonin 5-HT1A receptors. At presynaptic levels it is mostly a full agonist, which inhibits release of serotonin, with consequent antianxiety effects. Partial agonist action at postsynaptic receptors appears to account for antidepressant activity.
Lofexidine is a presynaptic alpha 2 agonist – leads to reduced central sympathetic tone. Opioid receptors on locus coeruleus projections reduce noradrenergic tone on long-term use. The cellular machinery compensates via up-regulation of adenylate cyclase and maintains normal sympathetic tone in a chronic user. Sudden withdrawal leads to increased adrenergic firing rate (withdrawal symptoms); hence alpha 2 autoreceptor stimulation which reduces central sympathetic tone helps in treating opioid withdrawal
Select one mechanism of action each for the following drugs
- Rivastigmine
- Selegeline
- Diazepam
- Selective norepinephrine re-uptake inhibitor
- Inhibitor of norepinephrine and serotonin re-uptake
- GABA-A agonist
- GABA-B agonist
- MAO-A Inhibitor
- MAO-B Inhibitor
- NMDA receptor antagonist
- 5HT1A partial agonist
- Butyryl-cholinesterase inhibitor
- D-2 receptor partial agonist
- Presynaptic alpha-2 agonist
Rivastigmine - Butyryl-cholinesterase inhibitor
Selegeline - MAO-B Inhibitor
Diazepam - GABA-A agonist
Rivastigmine is a cholinesterase Inhibitor. It acts by inhibiting acetyl cholinesterase enzyme that breaks down acetylcholine centrally. Rivastigmine inhibits both acetyl and butyl-cholinesterase while donepezil and gallantamine are acetyl specific.
Selegiline is a MAOi – selective for the enzyme MAO B at normal therapeutic doses; selectivity is lost when the drug is administered (usually as a patch) at higher doses, leading to some antidepressant action.
Diazepam is a type of benzodiazepine which acts via a specific site called omega site in GABA A complex.
All benzodiazepines are full agonists except clonazepam which is a partial agonist. They facilitate GABA action on GABA-A complex – thus inhibitory neurotransmission via chloride ion flow is facilitated.
Benzodiazepines have no direct agonistic action in the absence of GABA.
A 22-year-old man is admitted in a secure unit following an assault on two policemen. He is very agitated and dehydrated as a result of the long struggle while arresting him. He was given rapid tranquillisation, soon after which he shows signs of hyperthermia, fluctuant BP and rigidity.
- Idiosyncratic reaction
- Dose dependent side effect
- Toxicity
- Time dependent side effect
- Withdrawal effect
- Pharmacokinetic adverse interaction
- Synergistic action
- Nocebo effect
- Pharmacodynamic adverse reaction
Idiosyncratic reaction.
This patient has developed Neuroleptic Malignant Syndrome, which is an idiosyncratic reaction, which can occur at anytime during treatment with neuroleptics.
It consists of tetrad of extreme hyperthermia, severe muscular rigidity and confusion, and autonomic fluctuations (varying BP and pulse rate).
A 40-year-old man on lithium treatment has returned from a trip to Greece where he suffered from traveller’s diarrhoea. He made a good recovery but when he flew back he noticed tremors and soon developed nausea.
- Idiosyncratic reaction
- Dose dependent side effect
- Toxicity
- Time dependent side effect
- Withdrawal effect
- Pharmacokinetic adverse interaction
- Synergistic action
- Nocebo effect
- Pharmacodynamic adverse reaction
Toxicity
This patient has developed signs of lithium toxicity, which occurs in conditions of overdose or dehydration due to vomiting or diarrhoea.
Gastrointestinal symptoms are followed by neurological symptoms.
Immediate stopping of lithium and medical attention is required.
A 45-year-old man is on quetiapine. Due to lack of efficacy and poor compliance he is transferred to risperidone depot. During the transition he was switched to oral risperidone and simultaneous depot administration. He develops a stiff back and some difficulty in rolling over in his bed.
- Idiosyncratic reaction
- Dose dependent side effect
- Toxicity
- Time dependent side effect
- Withdrawal effect
- Pharmacokinetic adverse interaction
- Synergistic action
- Nocebo effect
- Pharmacodynamic adverse reaction
Dose dependent side effect.
This patient has developed dose dependent side effects of risperidone due to cumulative drug use leading to extra pyramidal side effects (stiff back is due to axial dystonia).
Identify the drug that matches each of the following mechanism of action;
- a autoreceptor and selective serotonergic antagonist.
- Serotonin and norepinephrine reuptake inhibitor.
- An inhibitory metabolite of glutamate
- Phosphodiesterase-5 inhibitor
A. Duloxetine B. Fluoxetine C. Mirtazapine D. Lithium E. GABA F. Aspartate G. Sodium monoglutamate H. Glutamate I. Lactate J. Sildenafil
- a autoreceptor and selective serotonergic antagonist - MIRTAZAPINE
Mirtazapine is known as NaSSA – Noradrenergic and specific serotonergic antagonist. 5HT2A antagonism, alpha 2 antagonism, anti histaminic and anti 5HT3 properties are noted with Mirtazapine. Of these, alpha-2 autoreceptor and heteroreceptor (adrenergic receptors on serotonergic neurons) blockade releases noradrenaline and serotonin, respectively, from pre-synaptic neurones.
- Serotonin and norepinephrine reuptake inhibitor - DULOXETINE.
Duloxetine is similar to venlafaxine – a SNRI. It is said to have a better profile for psychosomatic pain and neuropathic pain.
- An inhibitory metabolite of glutamate - GABA.
GABA is the most common inhibitory amino acid neurotransmitter, seen in 60% of the brain synapses. GABA is broken down to glutamate, and then eventually to succinic acid.
- Phosphodiesterase-5 inhibitor - SILDENAFIL
Sildenafil [Viagra] is a Phosphodiesterase-5 Inhibitor, used for the treatment of erectile dysfunction.
Osterloh
A. Sildenafil for erectile dysfunction B. Carbamazepine for mood disorders C. Lithium for mania D. Haloperiol for schizophrenia E. Chlorpromazine for psychosis F. Imipramine for depression G. Clozapine for resistant schizophrenia H. Electroconvulsive therapy
Osterloh - Sildenafil for erectile dysfunction
