Promethazine hydrochloride 25g tablets are used to treat an allergic reaction and symptoms associated with it including rashes, itching and runny nose.


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Frequently Asked Questions

What is the mechanism of action of Promethazine? 

Promethazine acts by preventing certain cells in your body from emitting a substance called histamine. When you’re allergic to something, such as pollen, dander, mold, or chemicals, histamine is excessively produced.

This medicine promotes drowsiness and aids pain management by blocking the production of histamine. This is due to the fact that histamine helps the regulation of wakefulness, keeping you alert and your senses heightened.

This medication also works to lessen the activation of the portion of your brain that causes you to vomit.

What are some of the advantages of taking Promethazine? 

The main benefit of promethazine is that it prevents and treats nausea and vomiting produced by motion sickness. It can also be used for the treatment of allergy symptoms such as rashes, itching, and a runny nose. It may be used to make you sleepy or calm before and after surgery. It can also improve the effectiveness of certain opioid pain medications (like meperidine). It can sometimes be used for a short amount of time to cure a runny nose caused by a cold. 

Who shouldn’t take Promethazine? 

Promethazine is safe for most adults and children over the age of two. However, there are some circumstances in which promethazine should not be used. It should be avoided by people who have a history of promethazine or other phenothiazine sensitivities. 

Also, speak to your doctor if you have any of the following conditions to ensure that promethazine is safe for you:

  • Asthma
  • COPD
  • Sleep apnea or a breathing problem
  • Intolerances to sulfites
  • History of seizures
  • A weakened immune system (bone marrow depression)
  • Glaucoma
  • Swollen prostate or urinary problems
  • Ulceration or blockage of your stomach
  • Heart and blood pressure
  • Low blood calcium concentrations (hypocalcemia)

Before you start taking it and each time you get a refill, read the Patient Information Leaflet if one is available. Consult your doctor or pharmacist if you have any concerns about taking promethazine. If you’ve ever experienced a major adverse effect while taking promethazine or another phenothiazine, tell your doctor.

You should stop taking promethazine a few days before your allergy test appointment since it can affect your test results. Inquire at the clinic where you’ll be having your allergy test.

How do you take Promethazine? 

Because second-generation antihistamines like Allegra (fexofenadine) and Claritin (loratadine) are available over-the-counter and cause less sleepiness, they are preferred over promethazine for the treatment of seasonal allergies or allergic conjunctivitis. Promethazine should be considered if these second-generation antihistamines do not work. 

The same goes for the use of promethazine to treat morning sickness or motion sickness. Only use promethazine if other options have failed to alleviate nausea symptoms. Other options for cough and cold relief should be considered by your doctor or pharmacist, such as drinking enough water, using a humidifier, or utilizing saline nasal drops/spray.

Take this medication by mouth, 2 to 4 times daily, with or without food, as advised by a medical professional. The first dose of promethazine for motion sickness should be given 30 to 60 minutes before you start traveling. To avoid getting drowsy during the day, take this medication once daily in the evening for allergies. If you’re taking this medication in liquid form, use a special measuring device/spoon to accurately measure the dose. 

In a hospital environment, Promethazine is given under the supervision of a doctor. Before surgery, you could be given promethazine the night before or right before the procedure. For further information on how to use your product safely, consult your doctor or pharmacist.

Want To Know More About Promathezine?

The dose is influenced by your age, health condition, and response to treatment. The dosage for children may also be determined by their weight. Do not use this medication in larger amounts or more frequently than prescribed.

Promethazine can be found in these strengths:

  • Tablets of 12.5 mg, 25 mg, and 50 mg doses
  • 12.5 mg, 25 mg, and 50 mg suppository doses
  • 25 mg/ml and 50 mg/ml injectable solutions
  • Syrup from maple trees (6.25 percent in 5 mL)

The dosage will vary based on the condition you’re treating:

  • Take 20 to 50 mg at night for short-term insomnia.
  • Hay fever – 10mg twice a day to 20mg three times a day is typical.
  • Hives – 10mg twice a day to 20mg three times a day is typical.
  • Preventing travel sickness – 25mg taken 1 to 2 hours before a short journey or 25mg the night before a long journey
  • Treating travel sickness – take 25 mg as soon as possible and 25 mg the same evening
  • For morning sickness and vertigo, the dose may vary from 25 mg to 25 mg four times a day.

Promethazine is mixed with other chemicals to treat cough and cold symptoms; the recommended dose is determined by the type of drug you’re taking.

Promethazine might cause allergic reactions in certain people. Tell your doctor or pharmacist if you have any of the following symptoms:

  • Have had an allergic reaction to promethazine or any other medication in the past 
  • Have primary angle-closure glaucoma
  • You’re having trouble urinating
  • Suffer from epilepsy or another medical disease that causes convulsions
  • You have a lactose or sorbitol sensitivity or inability to digest specific sugars.
  • You shouldn’t consume alcoholic beverages of any kind. Because some liquid promethazine products contain a trace amount of alcohol, check the contents and labeling carefully.
  • You’re trying to conceive a child. Promethazine may interfere with home pregnancy tests. Instead, talk to your doctor about getting a blood test if you think you’re pregnant.

Promethazine should be avoided or used with caution in a variety of situations. Even if it isn’t technically prohibited, it may be dangerous for some people. Listed below are a few of the issues to be aware of. 

  • When used with alcohol or any nervous system depressant, the sedative effects of the medication can be amplified.
  • Patients who are undergoing chemotherapy or receiving any other treatment that inhibits bone marrow should use promethazine with caution. The number of white blood cells in their body could drop dramatically as a result of this.
  • Anticholinergic drugs, which suppress the effects of acetylcholine, and monoamine oxidase inhibitors (MAOIs) can increase the risk of unwanted side effects.

In some cases, a dose adjustment or drug substitution may be necessary. To avoid interactions, always tell your doctor about any medications you’re taking, whether they’re prescription, over-the-counter, nutritional, herbal, or recreational.

It’s not a good idea to stop taking any chronic medication, especially MAOIs without first visiting your doctor. Withdrawal symptoms and other unpleasant effects may occur as a result of this.

Promethazine, like any other medication, can cause side effects, especially in the early phases of treatment. Milder side effects usually fade away as the body adjusts to the medication. Serious cases may necessitate the discontinuation of treatment.


Promethazine has a long list of potential adverse effects, which include:

  • Drowsiness
  • Disorientation
  • Double eyesight or hazy vision
  • Dizziness
  • Fatigue
  • Vomiting or nausea
  • Stuffiness in the nose
  • Xerostomia is a term used to describe a condition in which (dry mouth)
  • Tinnitus is a type of ringing in the ears (ringing in the ears)
  • Photosensitivity is the ability to respond to light (increased sensitivity to sunlight)
  • Nervousness and giddiness
  • Euphoria
  • Insomnia
  • Tremors
  • Palpitations in the heart


Promethazine can occasionally induce severe adverse effects that necessitate rapid medical intervention. These are some of them:

  • Bradypnea (slow breathing)
  • Bradycardia (slowed heartbeat)
  • Tachycardia (rapid heartbeat)
  • Angioedema (swelling of the tissues beneath the skin)
  • Cyanosis (bluish skin, lips, toes, or fingers)
  • Jaundice (yellowing of the skin or eyes)
  • Rashes or hives
  • Hallucinations
  • Seizures
  • Rigidity of muscles
  • Tardive dyskinesia (involuntary movements, such as the sudden upward turning of the eyes, twisting of the head to one side, or jutting of the tongue)

These symptoms could indicate a medication reaction, liver damage, respiratory depression, or a disorder called neuroleptic malignant syndrome. None of these warning signs should be overlooked. Even non-fatal problems like tardive dyskinesia may become permanent.

If you have symptoms of respiratory depression (slow breathing, loss of breath, or bluish skin), neuroleptic malignant syndrome (fever and muscle rigidity), or anaphylaxis (hives, wheezing, rapid heart rate, or swollen face or tongue), call 999 immediately. These illnesses can be lethal if not treated right away.

If you’re experiencing side effects from taking this medication, here’s what to do:

  • Drowsiness during the day – this normally passes 12 hours after a dose. If you’re feeling this way, don’t drive or operate any tools or machinery.
  • If you’re feeling dizzy or unsteady on your feet or having difficulties concentrating, stop doing what you’re doing and sit or lie down until you feel more comfortable and talk to your pharmacist or doctor. If the feeling persists or is bothering you, stop taking the medicine and consult a pharmacist or your doctor.
  • If you have a headache, make sure you get plenty of rest and drink lots of water. If your headaches continue for more than a week or are severe, see your doctor.

If you’re taking it for the prevention of travel sickness, take it as soon as you remember. If you’re taking it for a different condition, skip it and resume your regular schedule.

Do not take more than two doses at once. Never take two doses to make up for a missing one.

Setting an alarm to remind you of your doses can help if you forget them frequently. You could also seek advice from your pharmacist on how to remember to take your medicine in the future.

Promethazine overdose can be fatal.

If you take too much, you may have the following side effects:

  • Extreme tiredness
  • Have a rapid, irregular, or pounding heartbeat (palpitations)
  • Have difficulty breathing

In severe circumstances, you may lose consciousness or experience convulsions, necessitating hospitalization.

If your child takes too much promethazine, they may experience the following side effects:

  • Walk shakily or stumble 
  • Have erratic movements, particularly in their hands and feet
  • Have hallucinations
  • Have irregular heartbeat

 Serious consequences

If you experience any of the symptoms listed below, contact your doctor straight away.

  • The color of your skin or the whites of your eyes may indicate that you have liver disease.
  • Muscle rigidity or tremors or peculiar motions of the face or tongue
  • Bruising or bleeding that isn’t quite right

True Medical is a safe place to buy Promethazine online. Before your order is filled, you must first have an online consultation with an independent pharmacist. They’ll determine if Promethazine is the best drug for your medical condition.