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Case 399: Depression and psychopharmacology in rural
general practice
Authors and Affiliations
Professor Cherrie Galletly,
Discipline of Psychiatry,
University of Adelaide, Australia.This case focuses on medication interactions and the difficulties faced
when different practitioners prescribe patients multiple medications. The issue of alternative or
†œherbal†• medications is also considered.
Case Overview
This is expected knowledge for the graduating student.
Learning Objectives
The graduating student should be able to:
describe
the management of depression
understand
identify
the role of medications in management
drug interactions in management
describe
non-pharmacological treatments
Other relevant areas of study may include: - Consideration of drug interactions with complementary
medicines
Question 1 : SC
Question Information:
You have just started working in a rural general practice. A 73 year old woman comes to see you to
renew her prescriptions. She has been taking amitriptyline 100mg nocte for many years, after recurrent
episodes of depression. The most recent episode was 6 months ago.
She mentions that she has recently seen the ophthalmologist. He was concerned about her eyes and
gave her some drops. She forgot to mention that she takes amitriptyline when she saw him, and asks if
this matters.
Question:
What would you be most concerned about in this patient?
Choice 1: Narrow angle glaucoma Score : 1
Choice Feedback:
Correct, tricyclic antidepressants are contraindicated in patients with this condition.
Choice 2: Wide angle glaucoma Score : 0
Choice Feedback:
Wide angle glaucoma is not a contraindication, but a conversation with the opthalomologist would be
wise.
Choice 3: Anticholinergic side effects Score : 1
Choice Feedback:
These do occur with tricyclic antidepressants and are responsible for the effects on the eye.
Choice 4: Macular degeneration Score : -1
Choice Feedback:
This is not a side effect of tricyclic antidepressants.
Choice 5: Corneal opacities Score : -1
Choice Feedback:
Chlorpromazine, a typical antipsychotic, may rarely cause corneal opacities, but this has not been
associated with the use of tricyclic antidepressants.
Question 2 : SC
Question Information:
Your patient has worsening glaucoma and has decided she wants to change to a newer antidepressant
drug. She is obese and does not have much energy so you prescribe fluoxetine 20mg mane.
Question:
Which of the following is the most commonly reported side effect of fluoxetine?
Choice 1: Dry mouth and blurred vision Score : -1
Choice Feedback:
These are anticholinergic side effects seen with the tricyclic antidepressants.
Choice 2: Postural hypotension Score : -1
Choice Feedback:
This is also seen with tricyclics, not the SSRIs.
Choice 3: Nausea, diarrhoea and headache Score : 1
Choice Feedback:
Correct.
Choice 4: Agitation and suicidality Score : 1
Choice Feedback:
This is very rare but can occur in the first few days of treatment, usually in young people.
Choice 5: Personality change Score : 0
Choice Feedback:
Unlikely, although occasionally patients describe a lack of emotional reactivity when they take
antidepressants.
Question 3 : FT
Question Information:
Your patient returns several months later. She has been staying with her daughter in the city. While she
was there she fractured her ankle and it has not healed well. She takes tramadol 100mg bd for the
chronic pain.
She felt more depressed after her injury and saw her daughter†™s GP who increased her fluoxetine to
40mg mane. She also recently consulted her daughter†™s naturopath who gave her Mega St
John†™s Wort 4 tablets daily.
You are seriously worried.
Question:
What is the most likely problem?
Choice 1: null Score : 0
Choice Feedback:
The most likely problem is serotonin syndrome. There is nothing in the information you have to suggest
she has serotonin syndrome, although she is at high risk. Tramadol has some serotonergic activity and
concomitant use with SSRIs can lead to serotonin syndrome.
In addition, St John†™s Wort contains hypericum which is believed to act by inhibiting serotonin
reuptake. This combination of drugs places the patient at high risk of serotonin syndrome.
Serotonin toxicity is characterised by neuromuscular excitation (clonus, hyperreflexia, myoclonus,
rigidity), autonomic stimulation (hyperthermia, tachycardia, diaphoresis, tremor, flushing) and changed
mental state (anxiety, agitation, confusion). Serotonin toxicity can be:
- mild (serotonergic features that may or may not concern the patient);
- moderate (toxicity which causes significant distress and deserves treatment, but is not lifethreatening);
- severe (a medical emergency characterised by rapid onset of severe hyperthermia, muscle rigidity and
multiple organ failure).
Question 4 : SC
Question Information:
Your patient has ceased the St Johns Wort and tramadol. She has been reviewed by the visiting
orthopaedic surgeon and by a physiotherapist and her ankle is much better, so she is managing the
residual pain with paracetamol. She continues on fluoxetine 40 mg daily. She once again goes to stay
with her daughter.
There has been a family crisis †“ the patient†™s 14 year old granddaughter has run away with a
family friend, a man in his 50s. The granddaughter is retrieved and eventually the family settle down
again. In the meantime your patient has been very upset and anxious, so her daughter†™s GP
initiated treatment with alprazolam 2 mg prn. He advised that she would get used to it so she should
increase the dose as needed. She is now taking 12 mg / day. She complains that she feels a bit vague,
she is sometimes confused, and she is worried about the increasing dose.
Question:
You decide to:
Choice 1: Tell her alprazolam is addictive and she must stop it at once Score : -1
Choice Feedback:
This would place her at risk of acute benzodiazepine withdrawal, which can be very serious;
complication include seizures.
Choice 2: Explain that alprazolam has a short half-life, so should be replaced by a longer acting benzodiazepine
such as diazepam, which can then be reduced gradually and ceased Score : 1
Choice Feedback:
This is the best answer. The alprazolam should be replaced by the equivalent dose of diazepam, which
can then be reduced by 1/10 of the dose every 2 weeks.
Choice 3: Explain that alprazolam has a short half-life so she should split the doses through the day Score : -1
Choice Feedback:
This does not address the tolerance and dependence; long term treatment with benzodiazepines tends
to be associated with impaired memory and cognition.
Choice 4: Explain that she is developing tolerance to the current dose so she needs to increase the dose up to 14
mg daily Score : -1
Choice Feedback:
This will simply make the situation worse.
Choice 5: Reduce the alprazolam by 1/10 of the dose every 2 weeks Score : 1
Choice Feedback:
This would also be acceptable but 2 is preferable as the withdrawal from alprazolam is very demanding
for the patient; due to the short half life they feel the alprazolam wear off every few hours and feel as if
they need another dose.
Question 5 : FT
Question Information:
You supervise the patient to gradually reduce and eventually cease the alprazolam. Your patient has
now been taking fluoxetine 40mg for 6 months. She again returns for repeat prescriptions. On
questioning she reports that her mood is flat, she sleeps poorly and she does not enjoy her usual
activities. You arrange a telemedicine consult with the Rural mental Health Service. The psychiatrist
who sees your patient suggests you switch to a dual action antidepressant.
Question:
What does †œdual action antidepressant†• mean?
Choice 1: null Score : 0
Choice Feedback:
Selective serotonin reuptake inhibitors (SSRIs) have become the most popular antidepressants over the
last decade, largely because they have a better side effect profile and are safer in overdose than the
medications that were widely used previously, the tricyclic antidepressants (TCAs) and the monoamine
oxidase inhibitors (MAOIs).
Newer dual-action antidepressants inhibit the reuptake of both serotonin and norepinephrine (SNRIs).
SNRIs include venlafaxine, desvenlafaxine, mirtazapine and duloxetine. Most TCAs are also dual action
but as noted above are rarely used due to the side effects and toxicity.
Question 6 : FT
Question Information:
You choose Duloxetine 60 mg daily as this is generally well tolerated, is not associated with weight
increase, and can help in chronic pain so may assist with the ankle pain.
Your patient is doing well on this and feels much better. She asks what else she can do to ensure she
does not get depressed again. Her daughter has taught her how to use the internet; she asks if there
are any sites you would recommend.
Question:
What suggestions would you make about other measures that might help, including web resources?
Choice 1: null Score : 0
Choice Feedback:
There is some evidence that regular exercise reduces depression. There is also some evidence for the
omega-3 fatty acids (EPA and DHA) and folate as a supplement for (not in place of) antidepressants.
Mindfulness based CBT is effective in chronic depression. It will be hard for her to access this from a
country town, although if there is a visiting psychologist or access via telemedicine this could be
considered.
Sites such as moodgym and crufad provide on-line courses. She can also explore websites such as
BeyondBlue and Blackdog.
Synopsis
This case illustrates the need to take care when prescribing antidepressants or when adding other
medications to antidepressants. The contraindications, adverse effects and potential interactions must
be considered. One of the easiest ways to be aware of potential interactions is to use a program such
as e-mims, ensuring that it is regularly updated. Students need to be able to recognise and to know how
to treat serotonin syndrome.
Nonpharmacological strategies are also important and a good management plan addresses
psychological, social and physical health issues as well as the prescription of antidepressants, if
indicated.
References:
- There is an excellent chapter on psychopharmacology in A Primer of Clinical Psychiatry by David
Castle and Darryl Bassett, (2010), Elsevier. Chapter 14 Biological Therapies, pp 147-188.
- Isbister GK, Buckley NA, Whyte IM (September 2007). Serotonin toxicity: a practical approach to
diagnosis and treatment. Med. J. Aust. 187 (6): 361†“ 5
Some good local websites are:
- www.beyondblue.org.au
- www.blackdoginstitute.org.au
- http://moodgym.anu.edu.au
- www.crufad.com
Support for this case has been provided by the Australian Learning and Teaching Council Ltd, an
initiative of the Australian Government Department of Education, Employment and Workplace
Relations. The views expressed in this case do not necessarily reflect the views of the Australian
Learning and Teaching Council.