Venlafaxine and Lamotrigine Dosing Guidelines

Introduction to Venlafaxine Dosing

The American College of Cardiology recommends starting venlafaxine at 37.5 mg once or twice daily, increasing by 75 mg weekly to a target of 150-225 mg/day, with blood pressure monitoring required above 150 mg/day 1
The target dose is 150-225 mg/day for most indications, including depression and neuropathic pain, which demonstrates significantly better efficacy than lower doses in clinical trials 1
Monitor blood pressure at doses exceeding 150 mg/day due to dose-dependent hypertension risk, and exercise caution in patients with pre-existing cardiac disease 1
Always taper gradually—never stop abruptly—to avoid withdrawal syndrome, which is well-documented and can be severe, and reduce dose by approximately 50% per week over at least 2 weeks 1

With enzyme-inducing AEDs (without valproate), lamotrigine requires faster titration and higher doses, including drugs like rifampin, which substantially decreases lamotrigine concentrations 2
Rifamycins (rifampin, rifabutin, rifapentine) substantially decrease lamotrigine levels and may require dose increases with therapeutic drug monitoring 2