* '''Day 1:''' reduce dosage of doxepin to 50 mg/day.
* '''Day 3:''' reduce dosage of doxepin to 25 mg/day.
* '''Day 8:''' stop administration of doxepin.
| start =
* '''Day 1:''' simultaneously start administration of citalopram/escitalopram in a normal dosage of 20 mg/day, resp. 10 mg/day.* '''Day 8:''' stop administration of doxepin and continue administration of citalopram/escitalopram.
| info =
* Occurrence of serotonin syndrome is theoretically possible, so caution is necessary.
* Citalopram/escitalopram is a weak inhibitor of CYP2D6, which metabolizes doxepin.
}}