How do I switch from nighttime to daytime dosing of Prostiq (paroxetine)?

Switching Paroxetine from Nighttime to Daytime Dosing

Simply take your next scheduled dose in the morning instead of at night—no gradual transition or dose adjustment is needed. 1

Recommended Approach

The switch can be made immediately by skipping the nighttime dose and resuming with the morning dose the following day. This direct transition is safe because:

• Paroxetine has a 21-24 hour elimination half-life, which provides continuous coverage even with a timing shift 2, 3
• The medication should be given as a single daily dose, and timing flexibility is built into its pharmacokinetic profile 3

Rationale for Morning Dosing

Morning administration is the preferred timing for paroxetine based on sleep architecture considerations:

• Morning dosing increases slow-wave sleep, which is less disruptive to overall sleep quality compared to nighttime dosing 1
• Paroxetine disturbs normal sleep patterns by reducing REM sleep time and lengthening REM latency when taken at night 4
• The American Family Physician recommends addressing insomnia through sleep hygiene measures or adjunctive medications rather than nighttime dosing, as paroxetine will likely worsen sleep quality when taken at night 1

Practical Execution

To make the switch:

1. Skip the nighttime dose on day 1
2. Take the regular dose the following morning 3
3. Continue morning dosing thereafter as a single daily dose 3

The 24-hour half-life ensures therapeutic levels are maintained during this transition without requiring dose overlap or tapering 2.

Common Pitfalls to Avoid

• Do not take both a nighttime and morning dose during the transition—this would constitute a double dose given the once-daily regimen 3
• Do not gradually shift the timing over several days—the pharmacokinetics support an immediate switch 2
• If insomnia persists after switching to morning dosing, address it through sleep hygiene or adjunctive treatment rather than reverting to nighttime dosing 1