Diclectin therapy for nausea and vomiting of pregnancy: effects of optimal dosing

(1) To quantify rates of suboptimal use of pyridoxine hydrochloride-doxylamine (Diclectin); and (2) to study responses to optimal doses of Diclectin in women previously taking a suboptimal dose.

Women who called the Motherisk NVP helpline, and were taking only Diclectin (vitamin B6 10 mg and doxylamine 10 mg), were enrolled in the study and assessed for the severity of nausea and vomiting of pregnancy (NVP) with the Motherisk-PUQE (pregnancy-unique quantification of emesis and nausea) scoring system. Their Diclectin doses were subsequently increased according to body weight and individual symptoms. A follow-up phone call occurred within 1 to 3 weeks after the intervention, at which time the overall PUQE score was repeated, along with individual scoring of symptoms of nausea, vomiting, and retching.

Sixty-eight women were enrolled and completed the study. Despite moderate to severe NVP, defined by the validated PUQE scoring system, most women (50/68) were receiving 2 tablets a day of Diclectin instead of the recommended dose of 4 tablets a day. Following a mean doubling of the dose to 4 tablets a day, there was a significant decrease in length of nausea (from 4 to 3 hours, P < 0.001), frequency of vomiting (from mean 1.6 to 1.3 a day, P = 0.02), and overall PUQE score (from mean 7.5 to 6.1, P < 0.001).

Women suffering from NVP are often given subtherapeutic doses of Diclectin. Women should receive a dosage according to their body weight and severity of their symptoms.