Venlafaxine Missed Doses: When to Restart at Lowest Dose
If more than 2 consecutive doses of venlafaxine are missed, consider resuming at the same dose if the patient previously tolerated it well; otherwise, lower the next dose. If 3 or more consecutive doses are missed, restart the titration schedule from the lowest dose. 1
Specific Dosing Algorithm After Missed Doses
1-2 Consecutive Missed Doses
- Resume at the current dose if the patient has demonstrated good tolerance previously 1
- Monitor closely for discontinuation symptoms, which can occur after missing even a single dose 2, 3
More Than 2 Consecutive Missed Doses
- Clinical judgment required to determine whether to continue at the same dose or reduce 1
- If any prior tolerability concerns existed, lower the dose before resuming 1
3 or More Consecutive Missed Doses
- Restart the full titration schedule from the lowest possible dose 1
- This approach minimizes risk of adverse effects while re-establishing therapeutic levels 1
Critical Discontinuation Syndrome Considerations
Severity and Timing of Withdrawal
- Venlafaxine has a short elimination half-life (3-4 hours), making it particularly prone to discontinuation symptoms 4
- Severe withdrawal symptoms can occur within hours of a missed dose, not just days 3
- Symptoms include headache, nausea, fatigue, dizziness, dysphoria, and in severe cases, hallucinations 2
Safety Warning
- Discontinuation symptoms may impair motor and coordination skills to the degree that patients should not drive if doses are missed 3
- Venlafaxine is specifically associated with discontinuation symptoms compared to other SNRIs 1
Formulation-Specific Guidance
Immediate-Release Venlafaxine
- Requires twice- or thrice-daily dosing due to short half-life 1
- More vulnerable to discontinuation symptoms with missed doses 1
Extended-Release Venlafaxine
- Permits once-daily dosing with longer elimination half-life 1
- Still requires slow discontinuation taper when stopping 1
Common Pitfalls to Avoid
- Do not assume patients can simply resume their previous dose after multiple missed doses without assessment 1
- Do not underestimate withdrawal severity—even single missed doses can cause significant symptoms 2, 3
- Do not restart at high doses after 3+ missed doses, as this increases risk of adverse effects including dose-dependent hypertension 4, 5