Mental health drugs

Question 1

What kind of drug is amitriptyline?

Answer 1

Tricyclic antidepressant

Question 2

How does amitriptyline work?

Answer 2

Inhibits neuronal uptake of seratonin and noradrenaline from synaptic cleft (leaving more available for neurotransmission)
Block a wide array of receptors (muscarinic, histamine, adrenergic, dopamine etc) - accounts for lots of side effects

Question 3

Name a licenced and unlicensed indication of amitriptyline

Answer 3

Licenced: 2nd line moderate to severe depression when ssri’s ineffective
Unlicenced: neuropathic pain

Question 4

When is amitriptyline contraindicated?

Answer 4

Those at risk of adverse effects: elderly, CVD, constipation, prostatic hypertrophy,

Question 5

What happens when tricyclic antidepressants and monoamine oxidase inhibitors are prescribed together?

Answer 5

Both drugs increase seratonin and noradrenaline levels in the synapse: hypertension: seratonin syndrome

Question 6

List amitriptyline’s side effects (lots!)

Answer 6

Block muscarinic receptors: dry mouth, constipation, urinary retension, blurred vision
Block alpha1 receptors: sedation and hypotension
Cardiac arrhythmias, ECG changes
Convulsions, hallucinations, mania
Overdose: Severe hypotension, arrhythmias, convulsions, coma, respiratory failure, death

Question 7

How do SSRIs work?

Answer 7

Inhibit neuronal reuptake of seratonin from synaptic cleft, so more for transmission (no noradrenaline unlike tricyclic)

Question 8

When are SSRIs indicated? 3

Answer 8

moderate to severe depression first line
panic disorder
OCD

Question 9

When are SSRIs contraindicated

Answer 9

In risk of adverse effects eg peptic ulcer disease and epilepsy
Hepatic impairment

Question 10

What do SSRIs interact with?

Answer 10

MAOIs (seratonin in cleft too)seratonin syndrome
NSAIDs, peptic ulcers or aspirin: need gastroprotection
Drugs that prolong QT interval eg antipsychotics)

Question 11

SSRI side effects:

Answer 11

GI upset, appetite and weigh disturbances
Hypersensitivity
Lower seizure threshold
Seratonin syndrome: autonomic hypersensitivity, altered mental state, neuromuscular excitation

Question 12

How are SSRIs eliminated?

Answer 12

Metabolised in liver, excreted by kidneys

Question 13

What would you tell someone starting on SSRI?

Answer 13

Will take a few weeks to get going
Discuss non medication options
Continue for 6months+ after get better
Dont stop suddenly: GI upset

Question 14

What suffix is used for benzodiazepines?

Answer 14

-pam, eg Diazepam

Question 15

How do benzodiazepines work?

Answer 15

Target GABA receptors, enhancing and facilitating GABA (the main inhibitory neurotransmitter in the brain) to bind to it.

Question 16

Indications for Benzos?

Answer 16

First line for seizures and status epilepticus
First line alcohol withdrawal
Sedation for proceidures
Short term extreme anxiety and insomnia

Question 17

Contraindications for benzos?

Answer 17

Respiratory impairment
Neuromuscular disease
Liver failure (use lorazepam in alcohol withdrawal, least hepatic effect)

Question 18

Benzo interactions:

Answer 18

Additive to other sedating drugs eg Alcohol, opioids

Cytochrome p450 inducers may increase its effects

Question 19

Side effects of Benzos

Answer 19

Drowsiness, sedation, coma

Dependance

Question 20

How are benzos metabolised and eliminated?

Answer 20

cytochrome p450 in liver

Urine

Question 21

Info for someone starting them:

Answer 21

Dangerous!
Dependance!
Don’t drive after taking

Question 22

Name a acetylcholinesterase inhibitor

Answer 22

Donepezil

Question 23

How do acetylcholinesterase inhibitors work?

Answer 23

stop acetylcholinesterase breaking down acetylcholine, so more acetylcholine available in synapse

Question 24

When are aceytlcholinesterase inhibitors indicated?

Answer 24

Alzheimers

Question 25

Name some side effects of donpezil

Answer 25

Diarrhoea
Muscle cramps
fatigue
nausea and vomiting
Insomnia

Question 26

With what is L-dopa always prescribed?

Answer 26

Peripheral dopa decarboxylase inhibitor eg Carbidopa

So its not converted into dopamine outside the brain

Question 27

In parkinsons, where is there a dopamine deficiency?

Answer 27

Nigrostriatal pathway, which links substantia nigra in the midbrain to the corpus striatum in the basal ganglia

Question 28

When should L-dopa be used in caution?

Answer 28

Caution in elderly/psych: hallucinations and confusion

Caution in cardiac patients, risk of hypotension

Question 29

Name some side effects of L-dopa

Answer 29

Nausea, drowsiness, confusion, hallucinations and hypotension

Question 30

Why is it essential that L-dopa is taken at a specific time each day?

Answer 30

Symptoms worsen at the end of the dosage interval, cant be a long time after the drug is due. Called the “on-off” effect

Question 31

What kind of drug is carbemazepine? How does it work?

Answer 31

Anti convulsant
Not completely understood, but it inhibits neuronal sodium channels, stabilising the resting membrane potentials and reducing neuronal exciteability

Question 32

What is the first choice treatment for focal seizures?

Answer 32

Carbemazepine

Question 33

Apart from focal seizures, what what is carbemazepine indicated?

Answer 33

Trigeminal neuralgia

Bipolar, when patients resistant to other meds

Question 34

When is carbemazepine contraindicated? What happens if taken in pregnancy?

Answer 34

Antiepileptic hypersensitivity syndrome
Renal, liver and cardiac disease: can be toxic
Pregnancy: Neural tube defects, cardiac and urinary tract deformities and cleft lip

Question 35

Is carbemazepine a cytochrome P450 inducer, inhibitor or none of these?

Answer 35

Inducer! So it reduces the efficacy of drugs metabolised by it eg warfarin.

Question 36

Name two kinds of drug which reduce the efficacy of carbemazepine

Answer 36

Cytochrome p450 inhibitors (metabolised by cytochrome p450)

Drugs which lower the seizure threshold eg SSRIs, tricyclic antidepressants, tramadol

Question 37

Name some side effects of carbemazepine:

Answer 37

GI upset
Dizziness
Ataxia
Hypersensitivity in 10% Mild macropapular skin rash
Antiepileptic hypersensitivity in 1 in5000
oedema and hyponatraemia