Choosing an antidepressant - quick tips, dosages, side effects

Citalopram and

Sertraline 

SSRI

Firstline

Reduced risk of toxicity in overdose

Better tolerated than other ADs; better compliance

Fewer interactions; due to shorter half lives; better in those on multiple medications

Effective in the treatment of depression with anxiety

Increased risk of bleeding; consider a PPI in older people and in patients on NSAIDs or aspirin

SSRIs can exacerbate hyponatraemia; especially in the elderly

Citalopram and escitalopram increase the QT interval - avoid with these drugs

Sertraline may result in higher rates of diarrhea

Augmnetned by mirtazipine 

SSRI

Fluoxetine is more commonly used in younger adults; start with 10mg daily for several days

Fluoxetine; lower rates of withdrawal symptoms and suicidal thoughts or behavior 

Paroxetine can be used for pain treatment in patients with depression

Increased likelihood of the person stopping treatment because of side effects

Monitor the elderly more closely for side-effects and start on low dose

Paroxetine; higher rate of withdrawal symptoms such as suicide, higher risk of weight gain an sexual symptoms

Fluoxetine; longer half life and more potential interactions

Avoid in women on tamoxifen

Second line medication if SSRIs have failed

low risk of weight gain

Few interactions

Few side effects

Enhanced efficacy that extends over the entire spectrum of major depression and anxiety disorders; SNRIs may be more effective than SSRIs in resistant or refractory (difficult-to-treat) depression

Increase doses gradually to avoid side effects

Dangerous in overdose

Nausea and vomiting  typically subsides within one week

May increase blood pressure

Duloxetine

SNRI

Used in chronic pain (fibromyalgia, chronic musculoskeletal pain, peripheral neuropathy) as well as depression

Increased likelihood of stopping treatment because of side effects; need to increase the dose more gradually

May increase blood pressure

Serotonin modulator

Less or no effects on sexual dysfunction

no weight gain

safe in renal and hepatic impairment

relatively long half-life, vortioxetine presents a low risk of discontinuation symptoms 

Not usually initiated in primary care - check your local CCG guidelines 

linked with high rates of nausea (typically highest in the first week of treatment). However, in studies, it had no significant effect on body weight in either short-term or longer-term (6 month) research trials accessing weight gain. 

Trazodone

Serotonin modulator

Causes drowsiness, may hep with sleep problems 

May rarely be associated with priapism, a painful and long-lasting erection considered a medical emergency

Mirtazipine

Atypical antidepressants

Can help with sleep at the 15mg dose (sedative properties are lost at higher doses)

Alleviates anxiety 

Low risk of sexual problems

Can be used off licence as a sleeping tablet or to augment treatment with another AD 

Mirtazapine may have a faster onset of action than some other antidepressants

Weight gain & appetite increased 

Atypical antidepressants

Bupropion may be associated with modest weight loss and not associated with sexual dysfunction

May be helpful for depressed patients who feel lethargic or fatigued

Contraindicated in patients with a seizure disorder;

Seizure risk with higher bupropion doses and appears to be a dose-related effect.

Extended-release and sustained-release bupropion formulations have a lower peak blood level and are associated with a lower incidence of seizures 

Bupropion may have a greater effect on potent CYP450 enzyme inhibition (CYP2D6) and lead to drug interactions  

Amitriptyline,
Clomipramine,
Imipramine
and Trimipramine

Tertiary amine TCAs

Can be used at lower doses to help sleep and is also helpful in neuropathic pain, can help detrusor muscle stability and migraines

TCAs are first generation (older) antidepressants and are rarely used as initial treatment

Lower cost agents that can be used second or third line if newer antidepressants such as SSRIs or SNRIs are not effective

Tertiary amines tend to have more bothersome side effects than secondary amines due to anticholinergic effects (e.g., constipation, dry mouth, blurred vision) and more a more sedating effect

Excessive doses of TCAs can lead to cardiac toxicity such as arrhythmias (fast or irregular heart rate), seizures, and orthostatic hypotension, leading to falls and possible injury

Most TCAs are not recommended  for elderly or severely depressed patients at risk for suicide due to the risk for overdose with TCAs

Nortriptyline

Secondary amine TCA

Better tolerated than other TCAs

Isocarboxacis,
Phenelzine,
Selegeline and
Tranylcypromine

MAOIs

Should normally be prescribed only by specialist mental health professionals

May be used for patients with severe depression that does not respond to several other antidepressant treatments first

Phenelzine may cause less insomnia than tranylcypromine.

Tranylcypromine causes less weight gain, sedation, and sexual dysfunction than phenelzine 

Severe side effects

Dietary interactions; high amounts of tyramine such as dried fruits, red wine, cheese, pickles, smoked or processed meats, ripe figs, fava beans. The combination may lead to an increase in blood pressure, headache, nausea and vomiting, confusion, seizures, or death. Avoid tyramine for 2 weeks after discontinuation of a MAOI.

Possibility of serotonin syndrome. Use caution when starting or stopping MAOI treatment to avoid a hypertensive crisis or serotonin syndrome

aripiprazole,
olanzapine,
risperidone and quetiapine

Atypical antipsychotics

Used to treat schizophrenia and bipolar disorder

some atypical (second generation) antipsychotics are approved as an add-on therapy for patients who do not have an optimal response to first-line depression treatment with a single agent.

often combined wit SSRIs

lower doses for unipolar major depression compared to doses for schizophrenia or bipolar depression.

weight gain, blood sugar increases, diabetes, metabolic syndrome and lipid changes (high cholesterol). Patients should be monitored for these effects

All antipsychotics are associated with an increased risk of death when used in elderly people, especially those with dementia-related psychosis, and they are not approved for this use

Do not initiate

Evidence supporting its tolerability relative to other antidepressants is outweighed by the increased cardiac risk and toxicity in overdose

Evidence that it is as effective as traditional antidepressants 

Available to purchase OTC

Unknown interactions

Lack of consistency of dosing in medications available

Should normally be prescribed only by specialist mental health professionals

antihistamines which can help with nightmares in PTSD - start with 1mg nocte and increase by 1mg every month upto 12mg.

Antidepressant

Start dose Adults <65y

Max dose Adults <65y

Start dose Adults >65y

Max dose Adults >65y

Hepatic impairment

Renal Impairment

Citalopram

20mg

40mg

10mg

20mg

20mg

No information available for eGFR less than 20 mL/min; start at reduced dose and titrate slowly

Escitalopram

20mg

5mg

10mg

10mg

Caution if eGFR less than 30 mL/ min: Start at reduced dose and titrate slowly

Sertraline

200mg

50mg

200mg

Reduce dose or increase dose interval in mild to moderate impairment.

Most effective 

Best tolerated

Effective and well tolerated

 Amitriptyline

Escitalopram

Mirtazapine

Paroxetine

Venlafaxine

Vortioxetine

Citalopram

Escitalopram

Fluoxetine

Sertraline

Vortioxetine

Escitalopram

Vortioxetine

Least effective

Least well tolerated

Less effective and poorly tolerated

Fluoxetine

Fluvoxamine

Reboxetine

Trazodone

Amitriptyline

Clomipramine

Duloxetine

Fluvoxamine

Reboxetine

Trazodone

Venlafaxine

Fluvoxamine

Reboxetine

Trazodone