Antidepressants

 Antidepressants: Classification, Doses, Safety, Adverse Effects

Mechanisms & classification

Start dose

Standard dose

Lethality in overdose

Insomnia
and agitation(ii)

Sedation

Nausea or GI effects

Sexual dysfunction

Weight gain

 

mg/day

           

Selective serotonin-reuptake inhibitors (SSRIs)(i)

paroxetine

10-20

20-40

No (unless if combined with other CNS drugs)

++

++

+++

+++

++

sertraline

25-50

50-150

Low

+

- /+

+

+

+(iii)

citalopram

10-20

20-40

No

+++

+++

+++

++

+(iii)

escitalopram

5-10

10-20

No (unless if combined with other CNS drugs)

++

++

+++

++

+(iii)

Mixed or dual-action reuptake inhibitors

duloxetine

30

30-60

Yes (at > 1000 mg)

++

+++

+++

++

+

venlafaxine

37.5-75

75-225

Yes

+++

+++

+++

++

++

Mixed-action newer agents

mirtazapine

30

30-60

Low

- /+

++

- /+

- /+

++

- none  /  + moderate  /  ++ severe  /  +++ very severe

  1. For many persons, SSRI induction may be associated with adverse effects (sexual dysfunction, GI tract, dizziness, anxiety, panic attacks). Commencing at lower doses (i.e. 10, 25 & 10 mg for paroxetine, sertraline and citalopram, respectively) and increasing to the above starting doses after 4 to 7 days if tolerated may reduce such effects
  2. Insomnia is associated with DTG and other INSTI-containing ART regimens and with the use of some antidepressants. Clinicians should be aware when prescribing DTG or other INSTI and antidepressants together
  3. Weight gain may be significant but gradual and insidious