Antidepressant medication Flashcards
Antidepressant medication
The initial choice of an antidepressant depends on the:
- age and sex of the pt
- side-effect profile.
First-line therapy
Selective serotonin reuptake inhibitors (SSRIs)
Serotonin and noradrenaline reuptake inhibitors (SNRIs)
Serotonin modulator
Selective serotonin reuptake inhibitors (SSRIs)
1). Fluoxetine 20 mg (o) mane
–This dose is usually sufficient for most patients.
–If no response after 2–3 wks,
- ↑ by 20 mg at 2–3 wk intervals to 40–80 mg (o)/d in divided doses.
2) . Sertraline or Fluvoxamine, 50 mg (o)/d, starting dose: can increase up to 200 mg/d
3) . Paroxetine or Citalopram: 20 mg (o) mane; can increase by 10 mg/d every 2–3 wks to 60 mg/d
4) . Escitalopram: 10 mg/d, up to 20 mg
Serotonin and noradrenaline reuptake inhibitors (SNRIs)
Venlafaxine
Desvenlafaxin
Duloxetine
Recommended for major depression where other therapy is inappropriate.
May cause increase in BP and nausea/vomiting.
Duloxetine is also recommended for diabetic peripheral neuropathic pain.
Serotonin modulator
Mirtazapine:
starting dosage 15 mg (o) nocte;
average dose 30–45 mg to maximum 60 mg/d
Second-line therapy
Moclobemide
Selective noradrenaline reuptake inhibitor
Tricyclic antidepressants
Tetracyclic antidepressants
Moclobemide
Moclobemide 150 mg (o) bd
- If no response after 2–3 wks,
- increase by 50 mg/d to max. 300 mg (o) bd.
This is a reversible MAOI,
- which is less toxic than the irreversible MAOIs.
It has minimal interaction with tyramine-containing foodstuffs,
- so that no dietary restrictions are necessary.
Selective noradrenaline reuptake inhibitor
Reboxetine: adult dose 4 mg (o) bd, ↑ if required to 10 mg/d
Tricyclic antidepressants
1). Amitriptyline and imipramine
–the first generation tricyclics
–the most sedating: valuable if marked anxiety and insomnia
–strongest anticholinergic side-effects (e.g. constipation, blurred vision, prostatism)
2). Nortriptyline, doxepin, dothiepin, clomipramine, trimipramine
–less sedating and anticholinergic activity
–nortriptyline is the least hypotensive of the tricyclics
Dosage:
50–75 mg (o) nocte, increasing every 2–3 d to 150 mg (o) nocte by day 7
If no response after 2–3 wks, increase by 25–50 mg/d at 2–3 wk intervals (depending on adverse effects) to 200–250 mg (o) nocte.
Trial for 6 wks.
Tetracyclic antidepressants
Mianserin 30–60 mg (o) nocte↑ to 60–120 mg (o) nocte by day 7
Notes about antidepressants
There is no one ideal antidepressant
The SSRIs are the first-line drugs of choice.
- Other first-line antidepressants are the SNRIs and mirtazapine.
Tricyclics can be given once daily (usu. in the evening)
There is a delay in onset of action 1–2 wks after a therapeutic dose (= 150 mg imipramine at least) is reached
Each drug should have a clinical trial at an adequate dose for at least 4–6 wks before treatment is changed
Swapping from one agent to another, inc. between SSRIs in those not responding, can be beneficial
Do not mix antidepressants
Consider referral if there is a failed (adequate) trial
Full recovery may take up to 6 wks or longer (in those who respond)
Continue Rx at maintenance levels for at least 6–9 mths.
There is a high risk of relapse.
Lifelong treatment may be necessary.
MAOIs are often the drugs of choice for neurotic depression or atypical depression
Serotonin Syndrome
Beware of the dangerous serotonin syndrome;
- agitation
- confusion,
- nausea
- headache
- fever
- tremor
- tachycardia, etc.
It is due to a toxic hyperserotonergic state when switching between antidepressants, esp. with SSRI use.
In the treatment of depression, it is mainly due to an inadequate ‘washout period’—2 wks for most and 6 wks for fluoxetine.
It is usually caused by the combined use of two or more drugs that increase serotonin levels.
These include the antidepressants, e.g.
- SSRIs and MAOIs
- TCAs; selegiline, opioids, illicit drugs, lithium and anti-emetics.
