Page 57 - Demo

CONTINUING PROFESSIONAL DEVELOPMENT
MEDICATION REVIEW
• Rivastigmine patch not being applied to an area that prevented resident from removing the patch.
• Risedronate being sucked (but not experiencing any adverse effects).
• Suboptimal diabetes control shown
by blood glucose levels tending to be high (~10 mmol/L), with no episodes of hypoglycaemia reported.
• No recent international normalised ratio (INR) results.
• No treatment of hyperlipidaemia.
• Patient experiencing falls, so there was
a need to review all medicines that increase falls risk.
There were multiple issues identified by the pharmacist conducting this RMMR. We will focus on serotonin discontinuation syndrome following the abrupt switch of antidepressants.
Anxiety and depression in dementia
Behavioural symptoms, including anxiety and depression, frequently coexist in dementia. It is important to clarify the type of dementia that has been diagnosed as the likeliness of a particular behavioural symptom varies in the different dementias (see Table 2).1 Mrs LC had a diagnosis of mixed dementia – both Alzheimer’s disease and vascular dementia.
The presence of depression can contribute to cognitive decline, so recognition and treatment is important. Diagnosis of depression in dementia can be difficult because both conditions share decreases
in initiative, motivation, socialisation and interest in self or other people. As depression in dementia can be difficult to diagnose, the Cornell Scale for Depression in Dementia can be useful in assessment. Selective serotonin re-uptake inhibitors (SSRIs) are the first-line drug treatment for depression in dementia. SSRIs can also be beneficial where anxiety
is a symptom. Mirtazapine (a tetracyclic antidepressant) has a role where depression is associated with insomnia.2
Antidepressants seem to be less effective
in persons with a diagnosis of dementia. The benefits of treatment with sertraline or mirtazapine were compared to placebo in individuals with depression and Alzheimer’s disease in an English study.3 This study showed that there was no difference
in the reduction of depression scores between the placebo group and sertraline
or mirtazapine. However, there were more adverse effects in the mirtazapine and sertraline groups than in placebo. The authors recommended psychosocial interventions as first-line treatment, with antidepressants started in 3 months for non-responders, used earlier according to risk or severity.3
Abrupt discontinuation of
antidepressants
Abrupt cessation of an antidepressant may result in discontinuation or withdrawal syndrome in an estimated 20% of patients that have taken these medicines for
6 weeks or more.4 SSRIs, monoamine oxidase inhibitors (MAOIs), tricyclic antidepressants, venlafaxine, mirtazapine, trazodone and duloxetine have all been associated with this syndrome. Higher doses of antidepressants are more likely to cause withdrawal syndromes when therapy ceases. The proposed mechanism for SSRIs is that abrupt withdrawal causes a lack of serotonin in the synapse, which causes the postsynaptic receptors to remain down- regulated.4 Other neurotransmitter systems such as noradrenaline, dopamine and gamma-aminobutyric acid (GABA) may also be affected.4
Symptoms that have been linked to SSRI withdrawal are shown in Table 3. Serotonin noradrenaline re-uptake inhibitors (SNRIs) are associated with similar symptoms. Tricyclic antidepressant withdrawal symptoms include nausea, headache, abdominal pain, diarrhoea, lethargy, anxiety and vivid dreams.5 Irreversible MAOIs must be withdrawn cautiously
as discontinuation can cause agitation, irritability, mood disorders, dreams,
cognitive impairment and sometimes psychoses and delirium.5
An essential counselling point for patients
is that they continue therapy beyond the initial remission phase, as maintenance therapy is important. Patients may decide to stop antidepressants without consulting a healthcare professional after initial remission of their symptoms, and may lack awareness that antidepressants should be discontinued gradually. A group particularly at risk of discontinuing their medicines abruptly
is pregnant females, who are reluctant
to take medicine for fear of harming the fetus. Patients should be advised that their mental health may deteriorate and they
may feel unwell if their medicine is not stopped gradually. All patients should be advised to discuss with their GP first before stopping antidepressants so that they may be managed appropriately.4
Switching antidepressants
Switching from one antidepressant to another is clinically justified when the initial drug does not achieve remission, when there are untreated symptoms
or when there are problematic adverse effects. Abrupt discontinuation of an antidepressant should be avoided during switching so that the patient does not suffer from either withdrawal symptoms (see Table 3), or a relapse in their mental state, i.e. return of anxiety and depression.
The severity of withdrawal symptoms varies according to the antidepressant stopped. Venlafaxine and paroxetine are associated with the most severe withdrawal effects.5 A systematic review of sertraline withdrawal identified eight case reports of withdrawal symptoms.6
Table 2. Behavioural symptoms associated with different dementias
Type of dementia
Symptom
Alzheimer’s disease
Apathy, agitation, depression, anxiety, irritability Delusions and hallucinations are less common
Dementia with Lewy bodies
Visual hallucinations, delusions, depression, REM sleep behaviour disorder
Vascular dementia
Apathy, depression, delusions
Dementia associated with Parkinson’s disease
Visual hallucinations, delusions, depression, REM sleep behaviour disorder
Frontotemporal dementia
Apathy, disinhibition, elation, repetitive behaviours, appetite or eating changes
Progressive supranuclear palsy
Apathy, disinhibition
Corticobasal degeneration
Depression
Adapted from McKeith1
Australian Pharmacist January 2017 I ©Pharmaceutical Society of Australia Ltd. 55