Drug Uses PHENERGAN is very useful in treating allergy symptoms, including hives and nasal congestion. It is used to prevent and control pain and nausea during and after surgery, motion sickness and it works by blocking the sites where histamine acts. Usage Following the dosage instructions of your doctor is the best way to use any medication. If you are unsure or do not remember the instructions then you may read the medicine label for more detailed information. You may choose to take PHENERGAN with a meal to avoid an upset stomach or without one. Please take it by mouth. It is very important that you complete the dosage schedule and do not interrupt it in between without seeking prior consultation from your doctor. Taking your medication at the same time each day is a tried and tested method to avoid missing any doses. Drug Class and Mechanism PHENERGAN falls under henothiazine antihistamine and it works by blocking the sites where histamine acts. Missed Dose Despite your best attempts at remembering, if you still miss out on a dose, then take it as soon as you remember about it. But keep in mind that you will have to adjust your next dose by spacing it out by 4 to 5 hours. If this is not possible, then the best thing to do would be to skip the missed dose and continue with your normal dosage schedule. Never try to compensate for the missed dose by taking a double dose together. It may cause adverse effects. Storage Store PHENERGAN at room temperature(read medicine label if unsure). Always keep it in a cool dark place that is not directly exposed to sources of heat or moisture and sunlight. Protect it from kids and pets.