I just started phenergan today to control diarrhea/vomiting (daily occurrences). How long will it? Posted on 13-Jul-2023 - Last updated: 13-Jul-2023 ... take for it to become effective? Share this Article Featured questions Expired phenergan. Better than taking nothing and getting extremely ill? Promethazine - Is Phenergan an over the counter drug. What is it mostly used for? Is phenergan useful to treat cough due to common cold? Phenergan - Does phenerghan help with stomach flu? Phenergan - Can you give this to dogs? Is promethazine the same as Phenergan? How long does promethazine stay in your system? What's the difference between Phenergan and Zofran? How often can I take 25mg of phenergan? Can these drugs be used in Thalassemia patients? How does Lupron (leuprolide) work for prostate cancer? What is the consideration to use nifidepine over amlodipine? Related Drugs Fidanacogene Elaparvovec Cerave Anti-Itch (Hydrocortisone topical) Centrum Adult (Multivitamins and minerals) Crovalimab Cyltezo Prefilled Syringe (Adalimumab) Zepbound Pen (Tirzepatide) Mylanta One (Calcium carbonate, magnesium hydroxide, and simethicone) Uretron Ds (Hyoscyamine, methenamine, methylene blue, phenyl salicylate, sodium biphosphate) Medihoney Wound And Burn Dressing (Topical emollients) Lidotrode Libervant (Diazepam (buccal)) Moderna Covid-19 (Covid-19 (6m-11y) vaccine, moderna (2024-2025)) Beqvez (Fidanacogene elaparvovec) Beqvez (Fidanacogene elaparvovec) Beqvez (Fidanacogene elaparvovec)