Phenergan 25mg Rectal Suppositories
WARNING: Children:Do not give this drug to a child younger than 2 years of age. It may cause very bad and sometimes deadly breathing problems.Use with care in children 2 years of age and older. Talk with the doctor.Before your child takes this drug, tell the doctor if your child is taking any drugs that can cause breathing problems. There are many drugs that can do this. Ask the doctor or pharmacist if you are not sure. @ COMMON USES: It is used to ease allergy signs.It is used to help motion sickness.It is used to manage pain.It is used to treat sleep problems.It is used to prevent upset stomach and throwing up from surgery.It may be given to you for other reasons. Talk with the doctor.
Drug Class
Antihistamine, Antiemetic, Sedative/Hypnotic
Pharmacologic Class
Phenothiazine derivative, H1-receptor antagonist
Pregnancy Category
Category C
FDA Approved
Jan 1970
DEA Schedule
Not Controlled
Overview
What is this medicine?
Promethazine is a medication used to treat nausea and vomiting, allergic reactions, and to help with sleep or calm you down before or after surgery. It works by blocking certain natural substances in your body that cause these symptoms.
How to Use This Medicine
Taking Your Medication
To use this medication correctly, follow your doctor's instructions and read all the information provided. Use the suppository rectally, and make sure to wash your hands before and after handling it. If the suppository is soft, you can chill it in the refrigerator or run it under cold water to firm it up. Remove the foil wrapper and gently insert the suppository into your rectum, pointed end first, taking care not to handle it excessively.
Storing and Disposing of Your Medication
Store the suppositories in the refrigerator, but do not freeze them. Keep all medications in a safe place, out of the reach of children and pets. When disposing of unused or expired medications, do not flush them down the toilet or pour them down the drain unless instructed to do so. Instead, check with your pharmacist for guidance on the best disposal method, or look into local drug take-back programs.
Missing a Dose
If you take this medication on a regular schedule, take a missed dose as soon as you remember. However, if it's close to the time for your next dose, skip the missed dose and resume your normal dosing schedule. Do not take two doses at the same time or take extra doses. If you take this medication as needed, follow your doctor's instructions and do not take it more frequently than recommended.
To use this medication correctly, follow your doctor's instructions and read all the information provided. Use the suppository rectally, and make sure to wash your hands before and after handling it. If the suppository is soft, you can chill it in the refrigerator or run it under cold water to firm it up. Remove the foil wrapper and gently insert the suppository into your rectum, pointed end first, taking care not to handle it excessively.
Storing and Disposing of Your Medication
Store the suppositories in the refrigerator, but do not freeze them. Keep all medications in a safe place, out of the reach of children and pets. When disposing of unused or expired medications, do not flush them down the toilet or pour them down the drain unless instructed to do so. Instead, check with your pharmacist for guidance on the best disposal method, or look into local drug take-back programs.
Missing a Dose
If you take this medication on a regular schedule, take a missed dose as soon as you remember. However, if it's close to the time for your next dose, skip the missed dose and resume your normal dosing schedule. Do not take two doses at the same time or take extra doses. If you take this medication as needed, follow your doctor's instructions and do not take it more frequently than recommended.
Lifestyle & Tips
- Avoid driving or operating machinery until you know how this medication affects you, as it can cause significant drowsiness.
- Avoid alcohol and other medications that cause drowsiness, as this can worsen sedation and respiratory depression.
- To prevent constipation, drink plenty of fluids and eat fiber-rich foods.
- Use caution in hot weather or during exercise, as this medication can decrease sweating and increase risk of heat stroke.
- Protect your skin from the sun, as promethazine can increase sensitivity to sunlight.
Available Forms & Alternatives
Available Strengths:
Generic Alternatives:
Dosing & Administration
Adult Dosing
Standard Dose:
For nausea/vomiting: 25 mg every 4 to 6 hours as needed. For sedation/allergic reactions: 25 mg at bedtime or 12.5 mg to 25 mg 3 to 4 times daily.
Dose Range:
12.5 - 25 mg
Condition-Specific Dosing:
nausea_vomiting:
25 mg every 4-6 hours as needed
sedation_allergic_reactions:
25 mg at bedtime or 12.5-25 mg 3-4 times daily
Pediatric Dosing
Neonatal:
Contraindicated (due to risk of fatal respiratory depression)
Infant:
Contraindicated (due to risk of fatal respiratory depression)
Child:
For children > 2 years: 0.5 mg/kg/dose every 4 to 6 hours as needed. Maximum 25 mg/dose. Total daily dose should not exceed 1 mg/kg or 50 mg, whichever is less.
Adolescent:
Same as adult dosing for children > 12 years, or 0.5 mg/kg/dose every 4-6 hours as needed, not to exceed 25 mg/dose.
Dose Adjustments
Renal Impairment:
Mild:
Use with caution; dose adjustment may be necessary based on patient response and adverse effects.
Moderate:
Use with caution; dose adjustment may be necessary based on patient response and adverse effects.
Severe:
Use with caution; dose adjustment may be necessary based on patient response and adverse effects. Consider lower initial doses and extended dosing intervals.
Dialysis:
Not well studied; promethazine is highly protein bound, so unlikely to be significantly removed by dialysis. Use with caution.
Hepatic Impairment:
Mild:
Use with caution; dose adjustment may be necessary.
Moderate:
Use with caution; consider lower initial doses and careful monitoring due to extensive hepatic metabolism.
Severe:
Use with caution; consider significant dose reduction and extended dosing intervals due to extensive hepatic metabolism.
Pharmacology
Mechanism of Action
Promethazine is a phenothiazine derivative that acts as a potent H1-receptor antagonist. It also possesses significant anticholinergic (muscarinic), antidopaminergic, and weak alpha-adrenergic blocking activity. Its antiemetic effects are thought to be due to central anticholinergic action and direct depression of the chemoreceptor trigger zone (CTZ). Its sedative effects are due to its H1-receptor blockade and possibly its effects on the reticular activating system.
Pharmacokinetics
Absorption:
Bioavailability:
Variable (due to first-pass metabolism), generally good from rectal route.
Tmax:
2-4 hours (rectal)
FoodEffect:
Not significantly affected by food for rectal administration.
Distribution:
Vd:
131-338 L (large)
ProteinBinding:
Approximately 93%
CnssPenetration:
Yes (readily crosses blood-brain barrier)
Elimination:
HalfLife:
10-14 hours (range 7-19 hours)
Clearance:
Not readily available for rectal route, but generally high due to extensive metabolism.
ExcretionRoute:
Urine (major), feces
Unchanged:
<1% (urine)
Pharmacodynamics
OnsetOfAction:
20-60 minutes (rectal)
PeakEffect:
2-4 hours (rectal)
DurationOfAction:
4-6 hours (antiemetic effect), 6-12 hours (sedative effect)
Safety & Warnings
BLACK BOX WARNING
RESPIRATORY DEPRESSION: Promethazine 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. Caution should be exercised when administering promethazine to pediatric patients 2 years of age and older. A lower dose of promethazine should be used in pediatric patients 2 years of age and older. RISK OF SEVERE CHEMICAL IRRITATION AND TISSUE DAMAGE: The intravenous route of administration is contraindicated in pediatric patients less than 2 years of age. The preferred route of administration is deep intramuscular injection. Subcutaneous or intra-arterial administration is contraindicated. If intravenous administration is used, it should be administered via a large-bore, patent vein, preferably through a central venous catheter, at a concentration not exceeding 25 mg/mL and at a rate not exceeding 25 mg/minute. Tissue damage, including gangrene, has been reported with intravenous administration.
Side Effects
Urgent Side Effects: Seek Medical Help Right Away
Although rare, some people may experience severe and potentially life-threatening side effects while taking this medication. If you notice any of the following symptoms, contact your doctor or seek medical attention immediately:
Signs of an allergic reaction, such as:
+ Rash
+ Hives
+ Itching
+ Red, swollen, blistered, or peeling skin with or without fever
+ Wheezing
+ Tightness in the chest or throat
+ Trouble breathing, swallowing, or talking
+ Unusual hoarseness
+ Swelling of the mouth, face, lips, tongue, or throat
Signs of high or low blood pressure, including:
+ Severe headache
+ Dizziness
+ Passing out
+ Changes in eyesight
Abnormal heart rhythms, such as:
+ Fast or slow heartbeat
Neurological problems, including:
+ Trouble controlling body movements
+ Twitching
+ Changes in balance
+ Difficulty swallowing or speaking
+ Shakiness
+ Trouble moving around
+ Stiffness
Confusion or altered mental state
Feeling nervous or excitable
Hallucinations (seeing or hearing things that are not there)
Mood changes
Ringing in the ears
Seizures
Unexplained bruising or bleeding
Yellowing of the skin or eyes
* Changes in eyesight
Neuroleptic Malignant Syndrome (NMS): A rare but potentially life-threatening condition may occur. Seek medical help immediately if you experience:
+ Fever
+ Muscle cramps or stiffness
+ Dizziness
+ Severe headache
+ Confusion
+ Changes in thinking
+ Fast or irregular heartbeat
+ Excessive sweating
Respiratory Problems: This medication may cause severe and potentially life-threatening breathing problems. Seek medical help immediately if you experience:
+ Slow or shallow breathing
+ Difficulty breathing
Low White Blood Cell Count: This medication may increase the risk of infection due to low white blood cell counts. Seek medical help immediately if you experience:
+ Fever
+ Chills
+ Sore throat
Other Side Effects
Most people experience few or no side effects while taking this medication. However, some common side effects may occur, including:
+ Dizziness
+ Drowsiness
+ Fatigue
+ Weakness
+ Blurred vision
+ Dry mouth
+ Upset stomach or vomiting
+ Trouble sleeping
+ Stuffy nose
If any of these side effects or other symptoms bother you or do not go away, contact your doctor or seek medical attention. You can also report side effects to the FDA at 1-800-332-1088 or online at https://www.fda.gov/medwatch.
Although rare, some people may experience severe and potentially life-threatening side effects while taking this medication. If you notice any of the following symptoms, contact your doctor or seek medical attention immediately:
Signs of an allergic reaction, such as:
+ Rash
+ Hives
+ Itching
+ Red, swollen, blistered, or peeling skin with or without fever
+ Wheezing
+ Tightness in the chest or throat
+ Trouble breathing, swallowing, or talking
+ Unusual hoarseness
+ Swelling of the mouth, face, lips, tongue, or throat
Signs of high or low blood pressure, including:
+ Severe headache
+ Dizziness
+ Passing out
+ Changes in eyesight
Abnormal heart rhythms, such as:
+ Fast or slow heartbeat
Neurological problems, including:
+ Trouble controlling body movements
+ Twitching
+ Changes in balance
+ Difficulty swallowing or speaking
+ Shakiness
+ Trouble moving around
+ Stiffness
Confusion or altered mental state
Feeling nervous or excitable
Hallucinations (seeing or hearing things that are not there)
Mood changes
Ringing in the ears
Seizures
Unexplained bruising or bleeding
Yellowing of the skin or eyes
* Changes in eyesight
Neuroleptic Malignant Syndrome (NMS): A rare but potentially life-threatening condition may occur. Seek medical help immediately if you experience:
+ Fever
+ Muscle cramps or stiffness
+ Dizziness
+ Severe headache
+ Confusion
+ Changes in thinking
+ Fast or irregular heartbeat
+ Excessive sweating
Respiratory Problems: This medication may cause severe and potentially life-threatening breathing problems. Seek medical help immediately if you experience:
+ Slow or shallow breathing
+ Difficulty breathing
Low White Blood Cell Count: This medication may increase the risk of infection due to low white blood cell counts. Seek medical help immediately if you experience:
+ Fever
+ Chills
+ Sore throat
Other Side Effects
Most people experience few or no side effects while taking this medication. However, some common side effects may occur, including:
+ Dizziness
+ Drowsiness
+ Fatigue
+ Weakness
+ Blurred vision
+ Dry mouth
+ Upset stomach or vomiting
+ Trouble sleeping
+ Stuffy nose
If any of these side effects or other symptoms bother you or do not go away, contact your doctor or seek medical attention. You can also report side effects to the FDA at 1-800-332-1088 or online at https://www.fda.gov/medwatch.
Seek Immediate Medical Attention If You Experience:
- Severe drowsiness or difficulty waking up
- Slow or shallow breathing
- Bluish lips or skin
- Confusion or disorientation
- Hallucinations
- Uncontrolled muscle movements (tremors, twitching)
- Difficulty urinating
- Severe constipation
- Yellowing of skin or eyes (jaundice)
Before Using This Medicine
Before Taking This Medication: Important Information to Share with Your Doctor
It is essential to inform your doctor about the following:
Any allergies you have, including allergies to this medication, its components, or other substances, such as foods or drugs. Be sure to describe the allergic reaction and its symptoms.
Certain health conditions, including:
+ Respiratory problems, such as asthma, chronic obstructive pulmonary disease (COPD), or sleep apnea (breathing difficulties during sleep).
+ Liver problems or a history of Reye's syndrome.
Please note that this is not an exhaustive list of potential interactions. To ensure your safety, it is crucial to discuss all of your:
Medications, including prescription and over-the-counter (OTC) drugs, natural products, and vitamins.
Health problems, both current and past.
Before starting, stopping, or modifying the dose of any medication, including this one, consult with your doctor to confirm that it is safe to do so in conjunction with your other medications and health conditions.
It is essential to inform your doctor about the following:
Any allergies you have, including allergies to this medication, its components, or other substances, such as foods or drugs. Be sure to describe the allergic reaction and its symptoms.
Certain health conditions, including:
+ Respiratory problems, such as asthma, chronic obstructive pulmonary disease (COPD), or sleep apnea (breathing difficulties during sleep).
+ Liver problems or a history of Reye's syndrome.
Please note that this is not an exhaustive list of potential interactions. To ensure your safety, it is crucial to discuss all of your:
Medications, including prescription and over-the-counter (OTC) drugs, natural products, and vitamins.
Health problems, both current and past.
Before starting, stopping, or modifying the dose of any medication, including this one, consult with your doctor to confirm that it is safe to do so in conjunction with your other medications and health conditions.
Precautions & Cautions
It is essential to inform all your healthcare providers, including doctors, nurses, pharmacists, and dentists, that you are taking this medication.
Before operating a vehicle or engaging in any activity that requires alertness and clear vision, wait until you understand how this medication affects you.
This drug may interfere with the accuracy of certain pregnancy tests. If you are undergoing pregnancy testing, consult with your doctor.
If you have diabetes, it is crucial to closely monitor your blood sugar levels while taking this medication.
Prior to consuming alcohol, using marijuana or other cannabis products, or taking prescription or over-the-counter medications that may impair your reactions, discuss the potential risks with your doctor.
You may be more susceptible to sunburn while taking this medication. To minimize this risk, avoid exposure to direct sunlight, sunlamps, and tanning beds. Use protective measures such as sunscreen, clothing, and eyewear that provide adequate protection against the sun.
This medication may increase the risk of seizures, particularly in individuals with a history of seizure disorders. Consult with your doctor to determine if you are at a higher risk of experiencing seizures while taking this medication.
If you are 65 years or older, exercise caution when using this medication, as you may be more prone to experiencing side effects.
If you are pregnant, planning to become pregnant, or breastfeeding, inform your doctor. It is necessary to discuss the potential benefits and risks of this medication to both you and your baby.
Before operating a vehicle or engaging in any activity that requires alertness and clear vision, wait until you understand how this medication affects you.
This drug may interfere with the accuracy of certain pregnancy tests. If you are undergoing pregnancy testing, consult with your doctor.
If you have diabetes, it is crucial to closely monitor your blood sugar levels while taking this medication.
Prior to consuming alcohol, using marijuana or other cannabis products, or taking prescription or over-the-counter medications that may impair your reactions, discuss the potential risks with your doctor.
You may be more susceptible to sunburn while taking this medication. To minimize this risk, avoid exposure to direct sunlight, sunlamps, and tanning beds. Use protective measures such as sunscreen, clothing, and eyewear that provide adequate protection against the sun.
This medication may increase the risk of seizures, particularly in individuals with a history of seizure disorders. Consult with your doctor to determine if you are at a higher risk of experiencing seizures while taking this medication.
If you are 65 years or older, exercise caution when using this medication, as you may be more prone to experiencing side effects.
If you are pregnant, planning to become pregnant, or breastfeeding, inform your doctor. It is necessary to discuss the potential benefits and risks of this medication to both you and your baby.
Overdose Information
Overdose Symptoms:
- Severe drowsiness or coma
- Respiratory depression (slow, shallow breathing)
- Hypotension (low blood pressure)
- Tachycardia (fast heart rate)
- Anticholinergic effects (dilated pupils, dry mouth, flushed skin, fever, urinary retention, paralytic ileus)
- Seizures
- Extrapyramidal symptoms (involuntary movements)
- Cardiovascular collapse
What to Do:
Seek immediate medical attention. Call 911 or Poison Control at 1-800-222-1222. Overdose management is supportive, including maintaining airway, breathing, and circulation, and managing symptoms.
Drug Interactions
Contraindicated Interactions
Major Interactions
- Other CNS depressants (e.g., opioids, barbiturates, benzodiazepines, alcohol, tricyclic antidepressants): Additive CNS depression, respiratory depression, profound sedation, coma, death.
- Anticholinergic drugs (e.g., atropine, scopolamine, tricyclic antidepressants): Additive anticholinergic effects (dry mouth, blurred vision, urinary retention, constipation, paralytic ileus).
- QT-prolonging drugs (e.g., antiarrhythmics, certain antipsychotics, macrolide antibiotics): Potential for additive QT prolongation, increasing risk of torsades de pointes.
- Dopamine agonists (e.g., bromocriptine, cabergoline): Promethazine's antidopaminergic effects may antagonize the effects of dopamine agonists.
Moderate Interactions
- Antihypertensives: May cause additive hypotensive effects.
- Epinephrine: Promethazine may reverse the vasopressor effect of epinephrine, leading to a further decrease in blood pressure.
- Antidiabetic agents: Promethazine may mask the warning signs of hypoglycemia.
- Phenytoin: May alter phenytoin metabolism.
Minor Interactions
- Not readily available for minor interactions specific to promethazine.
Monitoring
Baseline Monitoring
Baseline mental status/level of consciousness
Rationale: To assess for pre-existing CNS depression and establish a baseline for monitoring sedative effects.
Timing: Prior to initiation of therapy
Respiratory rate and effort
Rationale: Especially important in pediatric patients and those with respiratory compromise, due to risk of respiratory depression.
Timing: Prior to initiation of therapy
Routine Monitoring
Level of consciousness/sedation
Frequency: Regularly, especially during initial therapy and dose adjustments
Target: Appropriate level of sedation without excessive drowsiness or unresponsiveness
Action Threshold: Excessive sedation, difficulty arousing, or signs of respiratory depression warrant immediate medical attention and dose reduction/discontinuation.
Respiratory status (rate, depth, oxygen saturation if available)
Frequency: Regularly, especially in vulnerable populations (children < 2 years, elderly, those with respiratory disease)
Target: Normal respiratory rate for age, adequate oxygenation
Action Threshold: Bradypnea, shallow breathing, cyanosis, or desaturation require immediate intervention.
Anticholinergic side effects (dry mouth, blurred vision, urinary retention, constipation)
Frequency: Periodically, or as symptoms arise
Target: Minimal to tolerable side effects
Action Threshold: Severe or intolerable anticholinergic effects may require dose reduction or alternative therapy.
Symptom Monitoring
- Excessive sedation or drowsiness
- Dizziness or lightheadedness
- Blurred vision
- Dry mouth
- Urinary retention
- Constipation
- Confusion or disorientation (especially in elderly)
- Restlessness or agitation (paradoxical reaction, especially in children)
- Extrapyramidal symptoms (rare, but possible with higher doses or prolonged use)
- Signs of respiratory depression (slow or shallow breathing, difficulty breathing, bluish lips/skin)
Special Patient Groups
Pregnancy
Category C. Use during pregnancy only if the potential benefit justifies the potential risk to the fetus. Avoid in late pregnancy due to potential for neonatal respiratory depression and extrapyramidal symptoms.
Trimester-Specific Risks:
First Trimester:
Limited data, but generally considered low risk for major malformations based on available human data.
Second Trimester:
Generally considered low risk for major malformations.
Third Trimester:
Potential for neonatal respiratory depression, extrapyramidal symptoms, and irritability if used close to delivery. Avoid use in the third trimester if possible.
Lactation
L3 (Moderate risk). Promethazine is excreted into breast milk. Due to the potential for sedation, irritability, and respiratory depression in the infant, use with caution. Monitor the infant for drowsiness, poor feeding, and respiratory issues.
Infant Risk:
Sedation, irritability, respiratory depression (especially in neonates/preterm infants), anticholinergic effects.
Pediatric Use
Contraindicated in pediatric patients less than 2 years of age due to the potential for fatal respiratory depression. Use with extreme caution in children 2 years and older, using the lowest effective dose. Paradoxical excitation (restlessness, agitation) may occur.
Geriatric Use
Elderly patients are more susceptible to the anticholinergic and sedative effects of promethazine, including confusion, disorientation, urinary retention, and constipation. They are also at increased risk for falls. Use lower initial doses and titrate carefully. Avoid use in elderly patients with dementia or cognitive impairment.
Clinical Information
Clinical Pearls
- Promethazine rectal suppositories are useful when oral administration is not feasible due to severe nausea/vomiting.
- Always confirm patient age before administering promethazine, especially in pediatric patients, due to the black box warning for respiratory depression in children under 2 years.
- Educate patients about the significant sedative effects and the importance of avoiding alcohol and other CNS depressants.
- Monitor for anticholinergic side effects (dry mouth, blurred vision, urinary retention, constipation), especially in the elderly.
- Photosensitivity can occur; advise patients to use sun protection.
- Rarely, extrapyramidal symptoms or neuroleptic malignant syndrome-like reactions can occur, especially with higher doses or prolonged use.
Alternative Therapies
- For nausea/vomiting: Ondansetron (Zofran), Metoclopramide (Reglan), Prochlorperazine (Compazine)
- For allergic reactions: Diphenhydramine (Benadryl), Hydroxyzine (Vistaril, Atarax), Cetirizine (Zyrtec), Loratadine (Claritin)
- For sedation/insomnia: Diphenhydramine, Hydroxyzine, Benzodiazepines (e.g., lorazepam, midazolam - for pre-op sedation)
Cost & Coverage
Average Cost:
Relatively inexpensive per suppository
Generic Available:
Yes
Insurance Coverage:
Tier 1 or 2 (generic)
General Drug Facts
If your symptoms or health issues persist or worsen, it is essential to contact your doctor for further guidance. To ensure your safety, never share your medication with others or take someone else's medication. Some medications may come with an additional patient information leaflet, so it's a good idea to check with your pharmacist. If you have any questions or concerns about this medication, don't hesitate to discuss them with your doctor, nurse, pharmacist, or other healthcare provider. In the event of a suspected overdose, immediately call your local poison control center or seek emergency medical attention. When seeking help, be prepared to provide information about the medication taken, the amount, and the time it happened.