Common use

Phenergan is a well-established antihistamine and antiemetic medication with a broad range of therapeutic applications that has been trusted by healthcare professionals for decades. The active ingredient in Phenergan is promethazine, a first-generation antihistamine belonging to the phenothiazine class. Promethazine works by decreasing the effects of histamine, a chemical your body releases in response to allergens and other irritants, while also acting on the central nervous system to provide additional anti-nausea and sedative effects.

Phenergan is widely prescribed to treat different types of allergy symptoms, including itching, runny nose, sneezing, itchy or watery eyes, hives, and itchy skin rashes, making it a comprehensive allergy medication for multiple allergic conditions. Beyond its role as an antihistamine, Phenergan is one of the most effective medications for preventing and controlling nausea and vomiting — whether caused by surgery, illness, or other medical treatments. It is also a proven treatment for motion sickness, helping travelers avoid the uncomfortable symptoms of travel-related nausea and dizziness. As a sedative, promethazine is frequently used as a pre-operative or post-operative aid to help patients relax and sleep, and it can be combined with pain medications for enhanced comfort during recovery. When you buy Phenergan online, you gain access to a versatile medication that addresses allergies, nausea, motion sickness, and sleep difficulties. Phenergan generic versions containing promethazine offer the same proven efficacy and safety profile at a more affordable price. If you need to buy promethazine for reliable anti-nausea relief, allergy medication, or vomiting treatment, Phenergan is a time-tested choice that delivers consistent results.



Dosage and direction

Take Phenergan orally with or without food or milk. If stomach upset occurs, it is best to take this medication with food to minimize gastrointestinal discomfort.

For treating allergy symptoms: the recommended dose for adults is 25 mg taken before bedtime. If needed, the dose may be repeated within two hours. Some patients may benefit from taking 12.5 mg before meals and 25 mg at bedtime for more comprehensive allergy medication coverage throughout the day.

For preventing and treating motion sickness: the recommended dose is 25 mg taken 30 to 60 minutes before travel, then repeated every 8 to 12 hours as needed. For best results, take the first dose at least 30 minutes before departure.

For anti-nausea and vomiting treatment: the recommended dose for adults is 12.5 mg to 25 mg taken every 4 to 6 hours as needed. Your doctor will determine the most appropriate dose based on the severity of your symptoms.

As a sedative for sleep: 25 to 50 mg at bedtime, as directed by your physician.

Note: this instruction is presented here for informational review only. It is essential to consult with your doctor before starting any new medication. Your healthcare provider will help you determine the optimal dose and schedule to achieve the best results for your specific needs.



Precautions

Do not administer Phenergan to patients in a comatose state. Avoid consuming alcohol while taking promethazine, as the combination can cause extreme drowsiness and dangerous central nervous system depression. Promethazine may increase your sensitivity to sunlight — wear sunscreen and protective clothing when exposed to the sun to help prevent sunburn and reduce the risk of heat stroke.

Phenergan should not be used during pregnancy, while planning to become pregnant, or while breastfeeding without consulting your doctor first. Promethazine passes into breast milk and may cause unwanted effects in nursing infants. Exercise particular caution when driving, operating heavy machinery, or performing activities that require alertness, as this sedative medication can significantly impair your reaction time and judgment. Elderly patients should use Phenergan with extra caution due to increased sensitivity to anticholinergic and sedative side effects.



Contraindications

Phenergan is strictly contraindicated in children under 2 years of age due to the risk of fatal respiratory depression. Phenergan is also contraindicated in comatose states, and in individuals known to be hypersensitive to promethazine or to other phenothiazines. Additionally, this drug is contraindicated for the treatment of lower respiratory tract symptoms, including asthma, as it may thicken bronchial secretions and impair mucociliary function.



Possible side effect

Serious side effects may include an allergic reaction: hives; difficulty breathing; swelling of your face, lips, tongue, or throat. Seek immediate emergency medical attention if any of these occur. Other potentially serious side effects include:

twitching or uncontrollable movements of your eyes, lips, tongue, face, arms, or legs;

tremor (uncontrolled shaking), drooling, trouble swallowing, problems with balance or walking;

feeling restless, jittery, or agitated;

high fever, stiff muscles, confusion, sweating, fast or uneven heartbeats, rapid breathing (neuroleptic malignant syndrome);

feeling like you might pass out;

seizure (convulsions);

pale skin, easy bruising or bleeding, fever, sore throat, flu symptoms;

decreased night vision, tunnel vision, watery eyes, increased sensitivity to light;

hallucinations, agitation;

nausea and stomach pain, skin rash, and jaundice (yellowing of the skin or eyes);

urinating less than usual or not at all;

joint pain or swelling with fever, swollen glands, muscle aches, chest pain, vomiting, unusual thoughts or behavior, and patchy skin color; or

slow heart rate, weak pulse, fainting, slow breathing (breathing may stop).



Less serious side effects may include:

dizziness, drowsiness, anxiety;

blurred vision, dry mouth, stuffy nose;

ringing in your ears;

weight gain, swelling in your hands or feet;

impotence, trouble having an orgasm; or

constipation.

If you experience any of these side effects, stop using Phenergan and tell your doctor as soon as possible. Also consult with your healthcare provider about any side effect that seems unusual or concerning.



Drug interaction

Phenergan has significant interactions with numerous medications, including:

lithium (Eskalith, Lithobid);

anticholinergic drugs such as atropine (Atreza, Sal-Tropine), belladonna (Donnatal, and others), benztropine (Cogentin), dimenhydrinate (Dramamine), methscopolamine (Pamine), or scopolamine (Transderm-Scop);

blood pressure medications such as guanadrel (Hylorel), guanethidine (Ismelin), propranolol (Inderal), and others;

blood thinners such as warfarin (Coumadin);

bronchodilators such as ipratropium (Atrovent) or tiotropium (Spiriva);

bladder or urinary medications such as oxybutynin (Ditropan, Oxytrol), solifenacin (Vesicare), and others;

MAO inhibitors such as isocarboxazid (Marplan), tranylcypromine (Parnate), phenelzine (Nardil), selegiline (Eldepryl, Emsam);

medicines to treat Parkinson's disease, restless leg syndrome, or pituitary gland tumor (prolactinoma);

medicines for stomach ulcer or irritable bowel syndrome, such as dicyclomine (Bentyl), glycopyrrolate (Robinul), hyoscyamine (Anaspaz, Cystospaz, Levsin, and others), mepenzolate (Cantil), or propantheline (Pro-Banthine).

Also note that an interaction between two medications does not always mean that you must stop taking one of them. Consult with your doctor about how any interactions are being managed or should be managed. Always provide your healthcare provider with a complete list of all medications you are currently taking.



Missed dose

If you forgot to take your dose of Phenergan at the scheduled time, take it as soon as you remember. However, if it is close to the time for your next dose, skip the missed dose and continue with your regular schedule. Do not take double or extra doses. Resume your usual dose the next day at the same regularly scheduled time.



Overdose

Symptoms of a Phenergan overdose may include: severe drowsiness, dizziness, dry mouth, large (dilated) pupils, flushing, nausea, vomiting, shallow breathing, and fainting. Promethazine overdose can be life-threatening, particularly in children. If you suspect an overdose, contact emergency medical services immediately.



Storage

Store Phenergan at room temperature between 59-77 degrees F (15-25 degrees C) away from direct light and moisture. Keep away from children and pets. Do not use after the expiration date printed on the packaging.



Disclaimer

We provide only general information about medications which does not cover all directions, possible drug interactions, or precautions. Information on this site cannot be used for self-treatment or self-diagnosis. Any specific instructions for a particular patient should be agreed upon with your health care adviser or doctor in charge of the case. We disclaim reliability of this information and any mistakes it could contain. We are not responsible for any direct, indirect, special, or other indirect damage as a result of any use of the information on this site and also for consequences of self-treatment.