D -rugs baby ;)

Question 1

Why should hypnotics be reserved for short courses?

Answer 1

Because dependence and tolerance may occur with long term use - 4 weeks max use

Question 2

Indications for hypnotics

Answer 2

To alleviate acute conditions after causal factors have been established e.g. short term insomnia due to shift work / emotional prob / serious medical illness

Question 3

Most commonly used hypnotics

Answer 3

benzodiazepines

Question 4

Mechanism of action for benzodiazepines (hypnotics)?

Answer 4

Benzodiazepines bind to receptor sites that are closely linked to the GABA-A receptor, inducing a conformational change that enhances the action of the inhibitory neurotransmitter GABA

Question 5

What binds to the same receptor as benzodiazepines but isn’t a benzodiazepine?

Answer 5

Zopiclone

Question 6

Examples of hypnotics

Answer 6

Tamezepam - oral at bedtime

Zopiclone - oral at bedtime

Question 7

SE’s hypnotics

Answer 7

Drowsiness
Lightheadedness
Confusion
Ataxia (the loss of full control of bodily movements)
May impair driving next day
Paradoxical increase in anxiety and aggression; adjustment of the dose up or down usually improves the problem
Tolerance may develop within 3-14d

Question 8

Cautions/ contraindications hypnotics and anxiolytics

Answer 8

Contraindicated in: resp depression, acute breathlessness, severe liver disease, myasthenia gravis, sleep apnoea syndrome

Withdrawal symptoms if drug stopped abruptly: anxiety, insomnia, depression, psychosis and convulsions

Elderly pts particularly sensitive - AVOID

Question 9

Why should anxiolytics be reserved for short courses?

Answer 9

As with hypnotics, there is danger of dependence and tolerance following long term use

Question 10

Anxiolytics indications for use

Answer 10

Short term relief in severe anxiety
In panic disorders resistant to antidepressant treatment
IV for short term sedation with medical procedures e.g. colonoscopy
Prevention of the alcohol withdrawal syndrome
Benzodiazepines also used in the acute management of status epilepticus

Question 11

Anxiolytics mechanism of action

Answer 11

Same as for hypnotics: Benzodiazepines bind to receptor sites that are closely linked to the GABA-A receptor, inducing a conformational change that enhances the action of the inhibitory neurotransmitter GABA

Question 12

Most commonly used anxiolytics?

Answer 12

Benzodiazepines

Question 13

Examples of anxiolytics

Answer 13

Diazepam
Lorazepam
Chlordiazepozide
Oxazepam

Question 14

SE’s, cautions/ contraindications anxiolytics

Answer 14

Same as hypnotics

Question 15

Antipsychotics (‘neuroleptics’) mechanism of action

Answer 15

Blockade of CNS dopamine (D2) receptors
Extra info:
There are 3 main dopaminergic pathways in the CNS. The mesolimbic pathway runs between the midbrain and the limbic system/frontal cortex. D2 blockade in this pathway is probably the main determinant of antipsychotic effect.
D2 receptors are also found int he chemoreceptor trigger zone, where blockade accounts for their use in nausea and vomiting

Question 16

Antipsychotics indications

Answer 16

ST - quieten disturbed pts whatever underlying psychopathology e.g. schizophrenia, mania, toxic delirium
LT - management of schizophrenia, intractable hiccup, nausea and vomiting

Question 17

Examples of antipsychotics

Answer 17

Haloperidol
Chlorpromazine
Prochlorperazine

Question 18

SE’s antipsychotics (7)

Answer 18

1. Extrapyramidal effects - movement abnormalities that arise from D2 blockade in the nigrostriatal pathway
2. Acute drowsiness
3. Hypotension
4. Tachycardia
5. Convulsions
6. Antimuscarinic symptoms (dry mouth, constipation, difficulty with micturition, blurred vision)
7. Neuroleptic malignant syndrome (hyperthermia, fluctuation conscious level, muscular rigidity, autonomic dysfunction)

Question 19

Cautions / contraindications antipsychotics

Answer 19

• elderly particularly sensitive
• avoid in dementia as increases stroke and death risk
• use with caution (due to extrapyramidal effects) in parkinsons
  use with caution in: liver disease, renal impairment, CV disease, epilepsy, myasthenia gravis, glaucoma
  Containdication in coma and phaeochromocytoma

Question 20

Drug interactions antipsychotics

Answer 20

Many, refer to BNF. Prominent among these are drugs that prolong the QT interval

Question 21

What are antiepileptics

Answer 21

Drug of choice for seizure type in adults.

Question 22

Examples of antiepileptics

Answer 22

Carbamazepine
Valproate
Phenytoin
Fosphenytoin

Question 23

Carbamazepine (antiepileptic) mechanism of action

Answer 23

Inhibition of repetitive neuronal firing is produced by reduction of transmembrane Na+ influx by use-dependent blockade of Na+ Channels

Question 24

Carbamazepine indications

Answer 24

Drug of choice for simple and complex partial seizures, and for tonic-clonic seizures secondary to a focal discharge

Question 25

SE Carbamazepine

Answer 25

Nausea and vomiting esp in early treatment CNS toxicity leads to double vision, dizziness, drowsiness and ataxia Transient leucopenia is common, esp in early treatment Hyponatraemia caused by potentiation of ADH

Question 26

Contraindications / caustions carbamazepine

Answer 26

- Contraindication in AV conduction abnormalities (unless paced), hx of bone marrow depression, porphyria - Hepatic enzyme induction leading to accelerated metabolism of the oral contraceptive pill (dose should be inc) - Warfarin (reduced anticoagulant effect), - Ciclosporin

Question 27

Valproate (antiepileptic) mechanism of action

Answer 27

Blockade of transmembrane Na+ channels, thus stabilising neuronal membranes

Question 28

Valproate indications

Answer 28

Effective for all forms of epilepsy

Question 29

SE Valproate

Answer 29

``` GI upset (nausea, vomiting, anorexia, abdo pain, acute pancreatitis) Inc appetite and weight gain Transient hair loss Dose related tremor Thrombocytopenia Rarely severe hepatotoxicity ```

Question 30

Cautions / contraindications Valproate

Answer 30

Acute liver disease Porphyria Monitor liver biochemistry 6-monthly in those most at risk of severe liver damage

Question 31

Phenytoin/ Fosphenytoin (antiepileptic) mechanism of action -

Answer 31

inhibit sodium influx across the cell membrane, reduce cell excitability

Question 32

Phenytoin/ Fosphenytoin indications

Answer 32

all forms of epilepsy except absence seizures, but used much less in developed countries Also used in management of status epilepticus and in trigeminal neuralgia

Question 33

SE's Phenytoin/ Fosphenytoin (bloody loads)

Answer 33

IV injection may cause CNS, CV (hypotension, heart block, arrhythmias) and resp depression Other SEs are dose related and include: - impaired brainstem and cerebellar function (nystagmus, double vision, vertigo, ataxia, dysarthria) - chronic connective tissue effects (gum hyperplasia, coarsening of facial features, hirsutism) - skin rashes (withdraw treatment) - folate deficiency - Increased vit D metabolism and deficiency - Blood dyscrasias - Lymphadenopathy - Teratogenic effects

Question 34

Cautions and contraindications Phenytoin/ Fosphenytoin

Answer 34

contraindicated in sinus brachycardia, heart block and porphyria many drug interactions - BNF Highly protein bound and can be displaced by valproate and salicylates, which therefore enhance the effect Induction of hepatic drug-metabolising enzymes and metabolism of warfarin and ciclosporin increased