Diclectin Vitamin B6 Content
Each Diclectin tablet contains 10 mg of pyridoxine (vitamin B6) combined with 10 mg of doxylamine succinate. 1, 2, 3
Standard Dosing Regimen
- The American College of Obstetricians and Gynecologists recommends starting with 2 tablets at bedtime on Day 1 (providing 20 mg total pyridoxine), then titrating up based on symptom response 1
- The maximum dose is 4 tablets daily (40 mg total pyridoxine and 40 mg doxylamine), which represents the upper limit of first-line therapy for nausea and vomiting of pregnancy 1, 4
- Most women with moderate to severe symptoms require the full 4-tablet daily dose rather than the commonly underprescribed 2-tablet dose 4
Clinical Context
- This delayed-release formulation (Diclegis in the US, Diclectin in Canada) is recommended as first-line pharmacologic therapy for nausea and vomiting of pregnancy by both the American College of Obstetricians and Gynecologists and the American Gastroenterological Association 1, 3
- The 10 mg pyridoxine per tablet provides therapeutic benefit for pregnancy-related nausea while remaining well below toxicity thresholds (which occur only with chronic intake exceeding 100-300 mg daily) 5
- The oral bioavailability of pyridoxine in Diclectin is approximately 100%, meaning the full 10 mg per tablet is systemically absorbed 2
Important Distinction
- The 10 mg pyridoxine dose in each Diclectin tablet is specifically formulated for nausea and vomiting of pregnancy, not for other indications such as isoniazid-induced neuropathy prevention (which requires 25-50 mg daily) 1, 6
- Standard prenatal multivitamins typically contain less than 25 mg pyridoxine and would not provide adequate supplementation for conditions requiring higher therapeutic doses 6