Promethazine
Description
Promethazine is an anti-allergy medicine used to treat the symptoms of allergy. It is also used to prevent and/or control nausea and vomiting due to various conditions such as motion sickness, surgery, etc. It has mild sedative (sleepiness) properties, therefore it is used to make you feel relaxed and sleepy before and after surgery. It works by blocking the action of certain chemicals in your body.
Promethazine can have side effects like dry mouth, blurred vision, headache, constipation, and dizziness. Most of these are temporary and go away on their own. Consult your doctor if these symptoms remain for a long time or worsen. Avoid doing any activity that requires mental focus like driving or operating machines as this medicine can make you feel sleepy.
Promethazine is available in syrup, injection, tablet, and suppository forms. When taken orally, it can be taken with or without food. Take it preferably at bedtime so that the sleepiness does not affect your daily activities. Your dose will be decided by your doctor. Promethazine injections are administered under the supervision of a qualified medical professional in a hospital setting. Promethazine suppositories are usually inserted inside your rectum by nurses. Do not self administer this medicine.
Promethazine is not recommended for use if you are allergic to it, or if you have breathing problems like asthma (a condition in which your airways narrow and swell). Inform your doctor if you have any pre-existing conditions like epilepsy (abnormal brain activity causing fits), heart problems or liver problems as this medicine can further deteriorate your conditions. Inform your doctor if you are taking any other medicines as they can interact with Promethazine.
Promethazine should not be used in children less than 2 years of age. Consult your doctor if you are pregnant, or are breastfeeding.
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Side effects
Major & minor side effects for Promethazine
- Drowsiness
- Headache
- Seizures
- Tremors
- Skin rash
- Loss of strength
- Increased sensitivity of the skin to sunlight
- Excitation
- Dry mouth
- Blurred vision
- Constipation
Uses of Promethazine
What is it prescribed for?
- Allergy
- Sedation
- Nausea and vomiting
- Motion sickness
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Concerns
Commonly asked questions
- Onset of actionThe effect of Promethazine can be observed in 20 minutes when taken orally, rectally, or as an intramuscular injection. It takes around 3 to 5 minutes when administered as an intravenous injection.
- Duration of effectAfter oral administration, the effect of Promethazine lasts for an average duration of 4-6 hours when taken for motion sickness, nausea and vomiting, and allergy. After intravenous administration, the effect of Promethazine lasts for an average duration of 4-6 hours when taken for nausea and vomiting, and allergy. The sleep-inducing effect may last for 2-8 hours after oral and intravenous administration.
- Safe with alcohol?Consumption of alcohol is not recommended during treatment with Promethazine as it may increase the risk of side effects. If you experience symptoms like dizziness or drowsiness, avoid driving or operating machines.
- Is it habit forming?No habit forming tendencies has been reported for Promethazine.
- Usage in pregnancy?Promethazine is not recommended for use in pregnancy as it may harm your developing foetus. This medicine is prescribed by your doctor only when the potential benefits outweigh the risks. Consult your doctor if you are pregnant.
- Usage while breast-feeding?Promethazine is passed into breastmilk. Therefore, this medicine is not recommended for use while breastfeeding. All the risks and benefits should be discussed with your doctor before taking this medicine.
Allergy
Promethazine is not recommended for use if you have a known allergy to it. Consult your doctor if you experience worsening of your symptoms such as skin rash, redness/swelling (anywhere in your body), hives (itchy and painful eruptions), breathing difficulty, etc.
Asthma
Asthma is a condition affecting the airways leading to your lungs. The airways become narrow and may produce extra mucous (thick slippery fluid) making it difficult to breathe. Promethazine is not recommended for use if you have asthma or any respiratory problems as this medicine can increase the production of mucous which can obstruct your airway tubes.
Central nervous system depression
Promethazine is not recommended for use in people who are in a coma, or have severe central nervous system depression (reduced brain activity). This medicine can further depress brain activity and respiration functions in such conditions.
Use in children below 2 years of age
Promethazine is not recommended in children below 2 years as it may cause slow and ineffective breathing.
Warnings for special population
Pregnancy
Promethazine is not recommended for use in pregnancy as it may harm your developing foetus. This medicine is prescribed by your doctor only when the potential benefits outweigh the risks. Consult your doctor if you are pregnant.
Breast-feeding
Promethazine is passed into breastmilk. Therefore, this medicine is not recommended for use while breastfeeding. All the risks and benefits should be discussed with your doctor before taking this medicine.
General warnings
Driving or operating machines
Promethazine should be used with caution as it may cause drowsiness or dizziness. Avoid performing activities that require mental alertness like driving vehicles and operating machines if you experience any of these symptoms.
Use in children
Promethazine is not recommended for use in children less than 2 years of age. Use this medicine with caution in children above 2 years of age as it may cause breathing difficulty.
Hypotension
Promethazine should be used with caution as it may cause a fall in your blood pressure. This risk is especially higher if you have heart problems. Your doctor may frequently monitor the functioning of your heart during treatment with this medicine.
Missed Dose
ORAL FORMS: Take the missed dose of Promethazine as soon as you remember. However, skip the missed dose if it is time for the next dose. Do not double the dose to make up for the missed one.
INJECTION FORM: The likelihood of missing a dose of Promethazine is less as it is administered in a hospital/clinic.
Overdose
ORAL FORMS: Seek emergency medical treatment in case of an overdose of Promethazine.
INJECTION FORMS: As Promethazine is administered in the hospital setting by a qualified healthcare professional, the likelihood of an overdose is very low. However, emergency medical treatment will be initiated by your doctor if an overdose is suspected.
All drugs interact differently for person to person. You should check all the possible interactions with your doctor before starting any medicine.
Interaction with Alcohol
Description
Concurrent use of ethanol and phenothiazines may result in additive CNS depression and psychomotor impairment.
Instructions
Consumption of alcohol is not recommended during treatment with Promethazine as it may increase the risk of side effects. If you experience symptoms like dizziness or drowsiness, avoid driving or operating machines.
Interaction with Medicine
Escitalopram
Escitalopram
Propranolol
Propranolol
Tramadol
Tramadol
Fosphenytoin
Fosphenytoin
Verapamil
Verapamil
Acebutolol
Acebutolol
Mifepristone
Mifepristone
Gatifloxacin
Gatifloxacin
Amiodarone
Amiodarone
Chlorpheniramine
Chlorpheniramine
Quinidine
Quinidine
Metformin
Metformin
Disease interactions
Heart diseases
Promethazine should be used with caution if you have heart problems. This medicine can cause low blood pressure, increase in heart rate, alteration in the electrical signals in your heart, etc., and may worsen your condition. Your doctor may closely monitor the functioning of your heart during treatment with this medicine.
Impaired liver function
Promethazine should be used with caution if you have liver problems as it may lead to the accumulation of unused medicine in your blood and increase the risk of side effects. Your doctor may suggest tests to closely monitor your liver function while you are taking this medicine.
Impaired kidney function
Promethazine is filtered by your kidneys and removed from your body via urine. Promethazine should be used with caution if you have kidney problems as an already damaged kidney will not be able to eliminate the medicine properly. This can lead to increased levels of unused medicine in your blood. Your doctor may suggest tests to closely monitor your kidney function during treatment with this medicine.
Seizure disorders
Promethazine should be used with caution if you have seizures (abnormal and uncontrolled electrical activity in the brain causing uncontrolled jerking of the body) as it can increase your likelihood of triggering a seizure, particularly at high doses.
Heart diseases
Promethazine should be used with caution if you have heart problems. This medicine can cause low blood pressure, increase in heart rate, alteration in the electrical signals in your heart, etc., and may worsen your condition. Your doctor may closely monitor the functioning of your heart during treatment with this medicine.
Impaired liver function
Promethazine should be used with caution if you have liver problems as it may lead to the accumulation of unused medicine in your blood and increase the risk of side effects. Your doctor may suggest tests to closely monitor your liver function while you are taking this medicine.
Impaired kidney function
Promethazine is filtered by your kidneys and removed from your body via urine. Promethazine should be used with caution if you have kidney problems as an already damaged kidney will not be able to eliminate the medicine properly. This can lead to increased levels of unused medicine in your blood. Your doctor may suggest tests to closely monitor your kidney function during treatment with this medicine.
Seizure disorders
Promethazine should be used with caution if you have seizures (abnormal and uncontrolled electrical activity in the brain causing uncontrolled jerking of the body) as it can increase your likelihood of triggering a seizure, particularly at high doses.
Food interactions
Information not available.
Lab interactions
Information not available.
ORAL FORMS: Take Promethazine as instructed by your doctor. Do not break, crush or chew the tablets. For syrups and suspension shake the bottle well before use.
Promethazine is used for short-term treatment only. Talk to your doctor if your symptoms do not improve after few days. Make sure you check the expiry date before taking the medicine.
For motion sickness, take the first dose 30 to 60 minutes before you start travelling.
Avoid activities that require mental focus while taking this medicine. Promethazine can cause dizziness so try standing up slowly to avoid feeling dizzy. Do not drink alcohol while taking Promethazine as it can make you feel more sleepy.
Promethazine can make your skin sensitive to the sun. Cover your skin and/or use sunscreen whenever you are going out to avoid any skin irritation.
SUPPOSITORY: Wash your hands before and after inserting Promethazine. Remove the wrapper without breaking the suppository. Moisten the tip of the suppository and carefully insert it well up into the rectum. Follow all the usage instructions given on the label/package insert.
INJECTIONS: Promethazine injections are administered by a qualified healthcare professional in a hospital or clinic. Do not self administer.
Miscelleneous
How it works
Promethazine is an anti-allergic medicine.
When your body is exposed to an allergen (pollen, animal dander, house dust, etc.), it produces a chemical called histamine. Promethazine works by blocking the action of histamine, thereby relieves allergic symptoms. It may also cause sleepiness and helps to control pain.
It also works directly on several areas of your brain to prevent nausea/vomiting and help you feel more relaxed.
Legal Status
Classification
Category
Antihistamines
Schedule
Schedule G
Medicines.org.uk. 2021. Sominex Tablets - Summary of Product Characteristics (SmPC) - (emc). [online] Available at: < [Accessed 8 September 2021].
Drugs, H., 2021. Promethazine: MedlinePlus Drug Information. [online] Medlineplus.gov. Available at: < [Accessed 8 September 2021].
Dailymed.nlm.nih.gov. 2021. PROMETHAZINE HYDROCHLORIDE SYRUP, USP 6.25 mg/5 mL. [online] Available at: < [Accessed 9 August 2021].
Accessdata.fda.gov. 2021. [online] Available at: < [Accessed 28 September 2021].
Information on this page was last updated on 21 Oct 2021
Disclaimer
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