Promethazine: A Comprehensive Guide

Summary or Key Points

Promethazine is a medication commonly prescribed for treating allergy symptoms, nausea, vomiting, and motion sickness. It is categorized as an antihistamine and antiemetic drug, useful for both prevention and treatment. Always consult with your healthcare provider for appropriate dosing, and consider telemedicine for quick and convenient consultations.

Names of Medication

US Brand Name: Phenergan (Promethazine)

The ‘generic name’ is the official medical name for the active ingredient in the medicine, which is listed in parentheses.

Pharmacologic Category

Promethazine falls under the pharmacologic categories of Antihistamines and Antiemetics. Other medicines in these categories include diphenhydramine (Benadryl), meclizine (Antivert), and ondansetron (Zofran).

Dosing

Please always consult with your healthcare provider before adjusting your dose. Schedule an appointment with our telemedicine providers for your convenience.

• Allergy symptoms: 25 mg before bedtime or 12.5 mg before meals and at bedtime. Repeat after 2-3 hours if necessary.
• Nausea and Vomiting: 25 mg every 4 to 6 hours as needed.
• Motion Sickness: 25 mg twice daily.

Dosage Forms and Strengths

Promethazine is available in the following forms and strengths:

• Tablets: 12.5 mg, 25 mg, and 50 mg
• Syrup: 6.25 mg/5 mL
• Injection: 25 mg/mL and 50 mg/mL
• Rectal suppository: 12.5 mg, 25 mg, and 50 mg

Administration Instructions

Promethazine can be taken with or without food. For allergies, it is typically taken once daily at bedtime, or occasionally twice daily. For motion sickness, it is typically taken 30 to 60 minutes before travel and again after 8 to 12 hours if needed. For nausea and vomiting, it is taken as needed, usually every 4 to 6 hours.

Adverse Reactions and Side Effects

Promethazine may cause side effects. It’s essential to contact your healthcare provider if any of the following common side effects persist or become severe:

• Drowsiness (common)
• Dizziness (common)
• Constipation (occasional)
• Dry mouth, nose, or throat (occasional)
• Restlessness (rare)

Always remember that you can consult with one of our healthcare providers through telemedicine for immediate assistance. If you experience severe side effects such as hallucinations, slow heartbeat, or uncontrollable movements, seek medical attention immediately.

Drug Interactions

Always consult with your healthcare provider or pharmacist before taking any new medications, including over-the-counter drugs and supplements. Promethazine can interact with several other medications, including sedatives, certain pain medications, muscle relaxants, and drugs for anxiety, depression, and seizures.

Precautions

Before using Promethazine, tell your healthcare provider about any allergies you may have, as well as your medical history, especially of: breathing problems (such as asthma, emphysema), high pressure in the eye (glaucoma), heart disease, high blood pressure, liver disease, stomach/intestinal problems (such as ulcers, blockage), overactive thyroid (hyperthyroidism), difficulty urinating (for example, due to enlarged prostate).

Conclusion

Promethazine can be an effective medication for treating various conditions, such as allergies, nausea, vomiting, and motion sickness. However, as with all medications, it’s important to take it as prescribed and to consult with your healthcare provider if you have any concerns or experience any side effects. Our telemedicine providers are readily available to assist you in understanding and managing your medication effectively and safely.

Contraindications

A contraindication is a condition or factor that serves as a reason to withhold a certain medical treatment due to the harm that it would cause the patient. Promethazine should not be used in the following situations:

• Children younger than two years old – This medication can cause severe respiratory depression.
• Patients with severe asthma or other respiratory issues – Promethazine can exacerbate breathing difficulties.
• People who are allergic to Promethazine or phenothiazines – A severe allergic reaction can occur.

Drug to Drug Interactions

Promethazine can interact with various other medications including:

• Sedatives – such as lorazepam (Ativan), diazepam (Valium).
• Opioid pain or cough relievers – such as codeine, hydrocodone.
• Medications for depression or anxiety – like fluoxetine (Prozac), venlafaxine (Effexor).
• Certain antihistamines – such as diphenhydramine (Benadryl).

Promethazine in Pregnancy

Promethazine should only be used during pregnancy if the benefits to the mother outweigh the potential risks to the unborn baby. Always consult with your healthcare provider if you’re pregnant or planning to become pregnant before taking this medication.

Promethazine while Breastfeeding

Small amounts of Promethazine may pass into breast milk. It’s crucial to discuss the potential risks and benefits with your healthcare provider before taking this medication while breastfeeding.

Estimated Cost of Medication

The estimated cost of a 30-day supply of Promethazine without insurance, using a GoodRX coupon, is approximately $10 for tablets and $15 for syrup.

Possible Alternatives

Before making any changes to your treatment plan, always discuss alternatives with your healthcare provider or one of our telemedicine providers.

• Allergy symptoms – Over-the-counter antihistamines, nasal corticosteroids, or allergen immunotherapy.
• Nausea and Vomiting – Ginger supplements, small frequent meals, or medications like ondansetron (Zofran).
• Motion Sickness – Ginger, staying in the middle of a ship or the front seat of a car, looking at a distant horizon, and medications like meclizine (Antivert).

Recent Updates on Promethazine Research

Current research on Promethazine is exploring its use in treating migraines, in addition to its current indications. Another study is looking at its effects on cognitive function, given the medication’s potential to cause sedation. These studies are ongoing, and patients are advised to consult their healthcare providers or our telemedicine professionals for the most current information.

Brief Legal Disclaimer: This article is for informational purposes only and not intended as medical advice. Always consult a healthcare professional for diagnosis and treatment. Reliance on the information provided here is at your own risk.