| Stepwise Approach to Nausea and Vomiting During Pregnancy (From ACOG) |
| Step 1: Vit B6 (pyridoxine) 25mg PO q6-8h |
| Step 2: Vit B6 + Doxylamine 12.5mg (half a tablet of 25mg of Unisom) PO q6-8h; OR Diclegis (Doxylamine 10mg + Vit B6 10mg) 2 tabs qhs, maximum 4 tabs (1tab AM, 1 tab PM, 2 tabs at bedtime) |
| Step 3: Vit B6 + Doxylamine q6-8h PLUS promethazine (Phenergan) 12.5-25mg q4h PO or per rectum, or dimenhydrinate 50-100mg q4-6h PO or per rectum. |
| Step 4: 1. If sufficiently hydrated, add Metoclopramide (Reglan) 5-10mg q8h IM or PO, or Promethazine 12.5mg IM, or trimethobenzamide (Tigan) 200mg q6-8h per rectum. 2. If dehydrated, give IV fluid. For prolonged vomiting, consider IV nutrients, e.g. banana bag (thiamine 100mg, folic acid 1mg, multivitamins, and +- Magnesium Sulfate 2g). Add promethazine 12.5-25mg IV q4h, or dimenhydrinate IV q4-6h or Metoclopramide 5-10mg IV |
| Step 5: Add methylprednisolone 16mg q8h PO or IV (beware of association between corticosteroids and oral cleft when used during the first 10 weeks of gestation), or Ondansetron (Zofran) 8mg IV q12 |
Ondansetron: 4-8mg PO QD or TID; classified as category B; a serotonin 5-HT3 receptor antagonist.
A.Doxylamine (Unisom) and pyridoxine (vitamin B6) =First-line treatment for nausea and vomiting in pregnancy according to ACOG
Mild cases of nausea and vomiting can be controlled with lifestyle and dietary changes. It is recommended that patients eat frequent small meals consisting of dry and bland foods, avoid spicy and fatty foods, eat high-protein snacks, and eat crackers in the morning before rising. If the nausea and vomiting are not controlled with dietary modifications, the first-line treatment is vitamin B6, 10–25 mg, and doxylamine, 12.5 mg, 3–4 times per day.
The other antiemetics (see below) can also be used in pregnancy, but vitamin B6 and doxylamine should be tried first because of the balance of safety and efficacy.
A.Doxylamine (Unisom) and pyridoxine (vitamin B6)
B.Ondansetron (Zofran)
C.Prochlorperazine
D.Promethazine (Phenergan)
E.Metoclopramide (Reglan)