psychiatric drugs

Question 1

SSRI examples

Answer 1

citalopram
fluoxetine
sertraline

Question 2

ssri mechanism

Answer 2

inhibit reuptake of 5-HT by the PREsynaptic neurone, so increase the [5-HT] in the synaptic cleft

Question 3

Side effects of SSRIs

Answer 3

Transient GI disturbance
lower libido
sexual problems

headache
anxiety

Question 4

TCA examples

Answer 4

amitriptyline

imipramine

Question 5

TCA indication

Answer 5

depression
anxiety
OCD
chronic pain
nocturnal enuresis

Question 6

side effects of TCAs

Answer 6

Anticholinergic:
dry mouth
blurred vision
constipation
urinary retention
drowsiness

CVS
postural hypotension
arrhythmias

TOXICITY IN OD
cardiotoxic
resp failure
seizures
convulsions
coma

Question 7

TCA contraindication

Answer 7

recent MI
arrhythmias
Mania is relative

Question 8

MAOI examples

reversible and irreversible

Answer 8

reversible (RIMA): moclobemide

irreversible: phenelezine

Question 9

MAOI side effects

Answer 9

CVS

Neuropsych

Sexual

GI

Hepatic

Question 10

MAOI contraindications

Answer 10

+/- mania
hepatic impairment
cerebrovascular disease
phaeochromocytoma

Question 11

MAOI cautions

Answer 11

Must carry a card indicating that they are taking MAOIS
Foods to avoid: cheese, pickled food, meats, broad beens, yeast extracts
Avoid undercooked food
avoid alcohol
otehr antidepressants not to be prescribed until 2weeks after stopping MAOis

Question 12

LITHIUM indicaitons

Answer 12

BPAD: Maniia
Augments antidepressants in refractory depression
Tx of borderline and impulsive personality disorder
clozipine-related neutropenia, as it increases neutrophil count both acutely and chronically

Question 13

Side effects of lithium

Answer 13

General

1. weight gain
2. fine tremor BUT COARSE tremor in TOXICITY
3. muscle weakness
4. oedema

GI:

1. diarrhoe
2. nausea
3. vomiting
4. metallic taste

renal

1. nephrogenic DI
2. long term -> renal scarring

Endocrine:

1. hypothyroidism&raquo_space; chech TFTs
2. PTH and Ca disturbances

Cardiac:
T wave inversion

PREGNANCY: Ebstein’s anomaly especially in 1st trimester
Haem:
LEUCOCYTOSIS

Question 14

lithium monitoring, toxic levels and Sx

Answer 14

serum levels 12 hPOST-DOSE, keep at 0.6-1.0mmol/l

toxic >1.5mmol/L

GI effects (anorexia, nausea, diarrhoea),

CNS effects (muscle twitching, weakness, ataxia, COARSE tremor);

> 2mmol/l: seizures can progress to death.

Question 15

sodium valproate indications

Answer 15

antiepileptic

mood stabiliser

Question 16

sodium valproate contraindications

Answer 16

acute porphyria, severe liver dysfunction

pregnancy: neural tube and craniofacial defects

Question 17

Sodium vlaproate side effects:

Answer 17

sedation, cerebellar (tremr, ataxia), headache, GI upset, weight gain…

Sodium valproate:
                Nausea is very common (take w food).
Valproate 
Appetite↑, weight gain
Liver failure (watch lft esp. during 1st 6 months)
Pancreatitis
Reversible hair loss (grows back curly)
Oedema
Ataxia
Teratogenicity, tremor, thrombocytopenia
Encephalopathy (due to hyperammonaemia)

rarely suicidal thoughts

Question 18

CARBAMAZEPINE/ indicaitons

Answer 18

Antiepileptic (but NOT absences),
mood stabiliser,
analgesic (neuralgia ( post-herpetic, trigeminal, DM-related);

Question 19

side effects of carbamazepine

Answer 19

leucopenia, diplopia, blurred vision, impaired balance - dizziness, drowsiness, mild generalized erythematous rash, SIADH.

teratogen: neural tube

Question 20

lamotrigine indications

Answer 20

epilepsy (esp partial, 1° or 2° generalised tonic–clonic).

Question 21

lamotrigine side effects

Answer 21

cerebellar symptoms
skin reactions - often severe: SJS
blood disorders: low Hb, Low WCC, low paltelets
N&V

Question 22

warning for patients on lamotrigine

Answer 22

report rash and any flu-like symptoms, signs of infection, bruising. DOn’t stop tablets suddenly

Question 23

phenytoin indications

Answer 23

antiepileptic (blocks Na channels, stabilises neuronal membranes)
status epilepticus, tonic–clonic seizures, partial seizures

Question 24

phenytoin side effecsts

Answer 24

SE (acute): 
dose-dependent: 
drowsiness (also confusion/dizziness), 
cerebellar fx, 
rash (common cause of intolerance and rarely ⇒SJS/TEN), 
N&V, diplopia, 
dyskinesia (esp orofacial). 

If iv, risk of ↓BP, arrhythmias* (esp ↑QTc), ‘purple glove syndrome’ (hand damage distal to injection site), CNS/respiratory depression.

SE (chronic): 
gum hypertrophy, 
coarse facies, 
hirsutism, 
acne, l
ow folate (⇒megaloblastic ↓Hb), 
Dupuytren’s, 
peripheral neuropathy, rickets, osteomalacia. Rarely, blood disorders, hepatotoxicity, 
suicidal thoughts/behaviour.

Question 25

naloxone

Answer 25

opioid receptor antagonist

Question 26

naltrexone

Answer 26

Opioid antagonist: ↓s euphoria of opioids if dependence and ↓s craving and relapse rate in alcoholic withdrawal (opioids thought to mediate alcohol addiction; not licensed for this in UK ).
Use: Opioid and alcohol withdrawal; start >1 wk after stopping
CI: if still taking opioids (can precipitate withdrawal), L (inc acute hepatitis).

Question 27

alcohol detox acute

Answer 27

Chlordiazepoxide usually first line, but diazepam preferred if Hx of seizures (esp if occurred in context of alcohol withdrawal).
• If significant liver failure (↑AST or ALT) - shorteracting benzodiazepines (oxazepam or lorazepam). Only start once acute alcohol intoxication has resolved as benzodiazepines are CId in this state.

Question 28

METHADONE

Answer 28

Opioid agonist: ↓euphoria, long t1/2 (→↓withdrawal symptoms) compared with other opioids.
Use: opioid dependence as aid to withdrawal.
CI/Caution/SE/Interactions: as morphine but levels not ↑by ritonavir, but are by voriconazole and cimetidine and ↑risk of arrhythmias with atomoxetine. Can ↑QTc (caution if FHx of sudden death).
Dose: individual requirements vary widely according to level of previous abuse

Question 29

Consider the following as aids: in alchoholics

Answer 29

• Acamprosate: modulates alcohol withdrawal fx & limits –ve reinforcement of drinking cessation ⇒↓cravings and ↓relapse rate.
• Disulfiram: ⇒unpleasant symptoms if alcohol consumed.
• Naltrexone: ↓s pleasurable fx of alcohol and ↓s craving and relapse rate.

Question 30

• Drugs for rapid tranquilisation of an agitated patient:

Answer 30

Haloperidol, lorazepam, promethazine

Question 31

good for/reasons to choose Antipsychotics

Answer 31

Taking benzodiazepines, elderly (use with caution, esp if ↑ risk of CVA), delirium (non-alcohol withdrawal), psychosis ( hallucinations/ delusions /schizophrenia

Question 32

bad for/reasons to not give Antipsychotics

Answer 32

Antipsychotic-naive, alcohol withdrawal, cardiac disease, movement disorder

Question 33

PROMETHAZINE is what

Answer 33

Sedating antihistamine.
Use: insomnia. Also used iv/im for anaphylaxis and po for symptom relief in chronic allergies.
CI: CNS depression/coma, MAOI w/in 14 days.
Caution: urinary retention, ↑prostate, glaucoma, epilepsy, IHD, asthma, porphyria, pyloroduodenal obstruction, R (↓dose), L (avoid if severe)/P/B/E.
SE: antimuscarinic fx - hangover sedation, headache.
Warn: can ↓ability at driving/skilled tasks.

Question 34

EXTRAPYRAMIDAL EFFECTS of antipsychotics

Answer 34

Abnormalities of movement control arising from dysfunction of basal ganglia.
• Parkinsonism: rigidity and bradykinesia tremor.
• Dyskinesias (abnormal involuntary movements); commonly:
– Dystonia (abnormal posture): dynamic (e.g. oculogyric crisis) or static (e.g. torticollis).
– Tardive (delayed onset) dyskinesia: esp orofacial movements.
– Others: tremor, chorea, athetosis, hemiballismus, myoclonus, tics.
• Akathisia (restlessness): esp after large antipsychotic doses.
All are commonly caused by antipsychotics (esp older ‘typical’ drugs) and are a rare complication of antiemetics (e.g. metoclopramide, rochlorperazine – esp in young women).