when should antidepressants be used
- for moderate-severe depression psychomotor and physiological changes such as loss of appetite and sleep disturbance
- should not be routinely used in mild depression, psychological therapy first line
when would electroconvulsive treatment be suitable to treat depression
antidepressants can take 2 weeks before they start to have an effect, can use electroconvulsive treatment in patients with severe depression where this delay (2 weeks) may be hazardous or intolerable
what side effects may occur during the first few weeks of starting antidepressants
there is an increased risk of agitation, anxiety, and suicidal ideation.
which class of antidepressants is first-line for treating depression and why
SSRIs because they are:
- better tolerated and are safer in overdose than other classes of antidepressants
- less sedating (than Tricyclic antidepressants)
- have fewer cardiotoxic effects (than Tricyclic antidepressants)
- can be used in unstable angina or who have had a recent myocardial infarction
which class of antidepressants has dangerous interactions with food
monoamine oxidase inhibitors (MAOI)
why should st johns wort not be prescribed or recommended to treat mild depression
- St John’s wort can induce drug metabolising enzymes which causes interactions with conventional drugs including antidepressants.
- The amount of active ingredient varies between different preparations of St John’s wort and switching from one to another can change the degree of enzyme induction
- if a patient stops taking St John’s wort, the concentration of interacting drugs may increase, leading to toxicity
once a person is in remission due to taking antidepressants, do they stop taking the antidepressants
no, should be continued at the same dose for at least 6 months (about 12 months in the elderly, those with anxiety or 2 years if they have recurrent depression)
what symptoms may indicate a person has hyponatraemia from taking antidepressants
hyponatraemia can be caused by all antidepressants but more often SSRIs
symptoms of hyponatremia:
drowsiness, confusion, or convulsions while taking an antidepressants
which patients have a higher risk of suicidal thoughts and behaviour linked to taking antidepressants
- children
- young adults
- patients with a history of suicidal behaviour
when is it most important to monitor patients for suicidal thoughts and behaviours when they are taking antidepressants
- at the start of treatment
- if dose is changed
what may cause Serotonin syndrome (or serotonin toxicity) in a patient taking antidepressants
- the initiation of antidepressants
- dose escalation
- overdose of a serotonergic drug
- adding a new serotonergic drug to treatment
- replacement of one serotonergic drug by another without allowing a long enough washout period in-between, particularly when the first drug is an irreversible MAOI or a drug with a long half-life
what are the symptoms of Serotonin syndrome (or serotonin toxicity) in a patient taking antidepressants
3 categories of symptoms:
- neuromuscular hyperactivity (such as tremor, hyperreflexia, clonus, myoclonus, rigidity)
- autonomic dysfunction (tachycardia, blood pressure changes, hyperthermia, diaphoresis, shivering, diarrhoea)
- altered mental state (agitation, confusion, mania).
how do you treat Serotonin syndrome (or serotonin toxicity)
stop the serotonergic medication and supportive care; specialist advice should be sought.
name some examples of SSRIs
- sertraline
- citalopram
- escitalopram
- fluoxetine
- paroxetine
what is the next step in treatment if a patient doesn’t respond to initial treatment with an SSRI
may require an increase in the dose, or switching to a different SSRI or Mirtazapine (a tetracyclic antidepressant)
- Other second-line choices include lofepramine, moclobemide, and reboxetine.
which antidepressants are used for severe forms of depression
tricyclic antidepressants and venlafaxine (serotonin and noradrenaline re-uptake inhibitors SNRI)
when would you treat generalised anxiety disorder with antidepressants
- if the patient has chronic anxiety (of longer than 4 weeks’ duration) and has been offered psychological treatment before starting antidepressant
- note acute anxiety generally involves the use of a benzodiazepine or buspirone hydrochloride. a patient may also be taking a antidepressant + benzodiazepine whilst waiting for antidepressant to take effect*
which antidepressants can be used to treat generalised anxiety disorder
- an SSRI such as escitalopram, paroxetine, or sertraline [unlicensed]
- Duloxetine and venlafaxine (serotonin and noradrenaline reuptake inhibitors (SNRIs)) are also recommended
- note if a patient can’t tolerate both SSRI and SNRI, pregabalin can be used*
which class of drugs are used to treat panic disorders, Obsessive-compulsive disorder, post-traumatic stress disorder, and phobic states such as social anxiety disorder
SSRIs e.g sertraline, citalopram, escitalopram, fluoxetine, paroxetine
name some examples of Tricyclic antidepressants which have sedative properties
- amitriptyline ,
- clomipramine
- dosulepin
- trazodone
- trimipramine
note agitated and anxious patients tend to respond best to the sedative compounds
give some examples of Tricyclic antidepressants that are less sedating
imipramine hydrochloride, lofepramine, and nortriptyline
note withdrawn and apathetic patients will often obtain most benefit from the less sedating ones
which class of antidepressants causes antimuscarinic side-effects and cardiotoxicity in overdose
Tricyclic antidepressants
- examples of antimuscarinic side effect include: dry mouth, blurred vision, hot + flushed skin, urinary retention*
which 2 antidepressants Tricyclic antidepressants are NOT recommended for treatment in depression and why
Amitriptyline hydrochloride and dosulepin hydrochloride
They are not recommended in depression because they are particularly dangerous in overdose. if they are given, it is by a specialist
why can most tricyclic antidepressant drugs be given once daily
because they have a long half life
note this is why the use of modified-release preparations is unnecessary
