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Promethazine (Oral)

Generic name: promethazine [ proe-METH-a-zeen ]
Brand names: Phenergan, Promacot
Drug classes: Antihistamines, Phenothiazine antiemetics

Medically reviewed by Drugs.com. Last updated on Apr 30, 2023.

Oral route(Tablet;Syrup;Solution)

Promethazine hydrochloride should not be used in pediatric patients less than 2 years of age because of the potential for fatal respiratory depression. Postmarketing cases of respiratory depression, including fatalities, have been reported with use of promethazine in pediatric patients less than 2 years of age. A wide range of weight-based doses of promethazine have resulted in respiratory depression in these patients. Caution should be exercised when administering promethazine to pediatric patients 2 years or age and older. It is recommended that the lowest effective dose of promethazine be used in pediatric patients 2 years of age and older and concomitant administration of other drugs with respiratory depressant effects be avoided .

Uses for promethazine

Promethazine is used to relieve or prevent the symptoms of hay fever, allergic conjunctivitis (inflammation of the eye), and other types of allergy or allergic reactions. It works by preventing the effects of a substance called histamine, which is produced by the body. Histamine can cause itching, sneezing, runny nose, and watery eyes. It can sometimes close up the bronchial tubes (air passages of the lungs) and make breathing difficult .

Promethazine is also used to prevent and control motion sickness, nausea, vomiting, and dizziness. In addition, it may be used to help people go to sleep and control their pain or anxiety before or after surgery or other procedures .

Promethazine may also be used for other conditions as determined by your doctor .

This medicine is only available with your doctor's prescription .

Before using promethazine

In deciding to use a medicine, the risks of taking the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For this medicine, the following should be considered:

Allergies

Tell your doctor if you have ever had any unusual or allergic reaction to this medicine or any other medicines. Also tell your health care professional if you have any other types of allergies, such as to foods, dyes, preservatives, or animals. For non-prescription products, read the label or package ingredients carefully.

Pediatric

Appropriate studies have not been performed on the relationship of age to the effects of promethazine in the pediatric population. Safety and efficacy have not been established in children below 2 years of age. Caution should be used when this medicine is given to children 2 years of age and older .

Geriatric

Insufficient information is available on the relationship of age to the effects of promethazine in geriatric patients. However, elderly patients may be more sensitive to the side effects of this medicine (such as confusion and severe drowsiness) than in younger adults, and are more likely to have age-related heart or blood vessel disease, liver problems, and kidney disease, which may require adjustment of dosage in patients receiving promethazine .

Breast Feeding

There are no adequate studies in women for determining infant risk when using this medication during breastfeeding. Weigh the potential benefits against the potential risks before taking this medication while breastfeeding.

Interactions with Medicines

Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. When you are taking this medicine, it is especially important that your healthcare professional know if you are taking any of the medicines listed below. The following interactions have been selected on the basis of their potential significance and are not necessarily all-inclusive.

Using this medicine with any of the following medicines is not recommended. Your doctor may decide not to treat you with this medication or change some of the other medicines you take.

Using this medicine with any of the following medicines is usually not recommended, but may be required in some cases. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.

Using this medicine with any of the following medicines may cause an increased risk of certain side effects, but using both drugs may be the best treatment for you. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.

Interactions with Food/Tobacco/Alcohol

Certain medicines should not be used at or around the time of eating food or eating certain types of food since interactions may occur. Using alcohol or tobacco with certain medicines may also cause interactions to occur. Discuss with your healthcare professional the use of your medicine with food, alcohol, or tobacco.

Other Medical Problems

The presence of other medical problems may affect the use of this medicine. Make sure you tell your doctor if you have any other medical problems, especially:

Proper use of promethazine

This medicine can be taken with food or a glass of water or milk to lessen stomach irritation if necessary.

Dosing

The dose of this medicine will be different for different patients. Follow your doctor's orders or the directions on the label. The following information includes only the average doses of this medicine. If your dose is different, do not change it unless your doctor tells you to do so.

The amount of medicine that you take depends on the strength of the medicine. Also, the number of doses you take each day, the time allowed between doses, and the length of time you take the medicine depend on the medical problem for which you are using the medicine.

Missed Dose

If you miss a dose of this medicine, take it as soon as possible. However, if it is almost time for your next dose, skip the missed dose and go back to your regular dosing schedule. Do not double doses.

Storage

Store the medicine in a closed container at room temperature, away from heat, moisture, and direct light. Keep from freezing.

Ask your healthcare professional how you should dispose of any medicine you do not use.

Do not keep outdated medicine or medicine no longer needed.

Keep out of the reach of children.

Precautions while using promethazine

It is very important that your doctor check your progress at regular visits to make sure this medicine is working properly. Blood tests may be needed to check for unwanted effects .

This medicine may affect blood sugar levels. If you notice a change in the results of your blood or urine sugar tests or if you have any questions, check with your doctor .

This medicine may cause some people to become dizzy, lightheaded, drowsy, or less alert than they are normally. Even if taken at bedtime, it may cause some people to feel drowsy or less alert on arising. Make sure you know how you react to this medicine before you drive, use machines, or do anything else that could be dangerous if you are not alert .

This medicine will add to the effects of alcohol and other CNS depressants (medicines that make you drowsy or less alert). Some examples of CNS depressants are antihistamines or medicine for hay fever, other allergies, or colds; sedatives, tranquilizers, antidepressants, or sleeping medicine; prescription pain medicine or narcotics; barbiturates; medicine for seizures; muscle relaxants; or anesthetics, including some dental anesthetics. Check with your medical doctor or dentist before taking any of the above while you are taking this medicine.

Check with your doctor right away if you have symptoms of pale or blue lips, fingernails, or skin; difficult or troubled breathing; irregular, fast, slow, or shallow breathing; or shortness of breath. These could be signs of a condition called respiratory depression .

Check with your doctor right away and stop taking your medicine (if directed by your doctor) if you have muscle stiffness, fever, difficult or fast breathing, seizures, fast heartbeat, increased sweating, loss of bladder control, unusually pale skin, or tiredness or weakness. These may be symptoms of a serious condition called neuroleptic malignant syndrome (NMS) .

Before you have any medical tests, tell the medical doctor in charge that you are taking this medicine. The results of some tests may be affected by this medicine .

This medicine may cause dryness of the mouth. For temporary relief, use sugarless candy or gum, melt bits of ice in your mouth, or use a saliva substitute. However, if your mouth continues to feel dry for more than 2 weeks, check with your medical doctor or dentist. Continuing dryness of the mouth may increase the chance of dental disease, including tooth decay, gum disease, and fungus infections .

This medicine may make your skin more sensitive to sunlight. Use a sunscreen when you are outdoors. Avoid sunlamps and tanning beds .

This medicine controls nausea and vomiting. For this reason, it may cover up some of the signs of overdose caused by other medicines or the symptoms of encephalopathy or Reye's syndrome. This will make it difficult for your doctor to diagnose these conditions. Make sure your doctor knows that you are taking this medicine .

Side Effects of promethazine

Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Stop taking this medicine and get emergency help immediately if any of the following effects occur:

Rare

- Symptoms of neuroleptic malignant syndrome; two or more occur together; most of these effects do not require emergency medical attention if they occur alone

Check with your doctor immediately if any of the following side effects occur:

Incidence not known

Symptoms of overdose

Some side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

Incidence not known

Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.

Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.

Commonly used brand name(s)

In the U.S.

Available Dosage Forms:

Therapeutic Class: Gastrointestinal Agent

Pharmacologic Class: Antihistamine

Chemical Class: Aliphatic

Frequently asked questions

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.