Diclegis vs. Phenergan

Zofran (ondansetron) and Phenergan (promethazine HCI) are used to prevent and treat nausea and vomiting after surgery.

Zofran is also used to treat nausea and vomiting due to cancer chemotherapy.

Phenergan is also used to treat nausea and vomiting related to motion sickness, and to treat allergic symptoms such as rash, itching, and runny nose.

The brand name Phenergan is discontinued in the U.S. Phenergan is available as a generic drug.

Zofran and Phenergan belong to different drug classes. Zofran is an antiemetic (anti-nausea and vomiting) and selective 5-HT3 receptor antagonist and Phenergan is an antihistamine.

Side effects of Zofran and Phenergan that are similar include dizziness, drowsiness, constipation, and blurred vision.

Side effects of Zofran that are different from Phenergan include diarrhea, headache, fever, lightheadedness, weakness, tiredness, rash, and muscle spasm.

Side effects of Phenergan that are different from Zofran include anxiety, dry mouth, stuffy nose, ringing in your ears, weight gain, swelling in your hands or feet, impotence, and trouble having an orgasm.

Both Zofran and Phenergan may interact with antidepressants, narcotics, and seizure medications.

Zofran may also interact with arsenic trioxide, tacrolimus, tramadol, antibiotics, anti-malaria medications, heart rhythm medicines, medicine to prevent or treat nausea and vomiting, medicines to treat psychiatric disorders, and migraine headache medicines.

Phenergan may also interact with cold or allergy medicines, sedatives, sleeping pills, muscle relaxers, anxiety medicines, lithium, atropine, belladonna, benztropine, dimenhydrinate, methscopolamine, scopolamine, blood pressure medications, blood thinners, bronchodilators, bladder or urinary medications, MAO inhibitors, medicines to treat Parkinson's disease, restless leg syndrome medications, medicines to treat pituitary gland tumor, or medicines to treat stomach ulcer or irritable bowel syndrome.

Side effects of Diclegis include:

• sleepiness,
• drowsiness,
• dizziness,
• stomach upset,
• diarrhea,
• constipation,
• headache,
• trouble sleeping (insomnia),
• blurred vision,
• shortness of breath,
• palpitations,
• fast heart rate, vertigo,
• bloating,
• fatigue,
• irritability,
• malaise,
• numbness and tingling,
• anxiety, nightmares,
• difficulty urinating,
• itching, or
• rash

Diclegis should be used with caution, especially with respect to activities that require complete mental alertness.

Common side effects of Phenergan include:

• drowsiness,
• dizziness,
• anxiety,
• blurred vision,
• dry mouth,
• stuffy nose,
• ringing in your ears,
• weight gain,
• swelling in your hands or feet,
• impotence,
• trouble having an orgasm, or
• constipation.

Diclegis (doxylamine succinate and pyridoxine hydrochloride) is an antiemetic (anti-nausea and vomiting) agent used to treat nausea and vomiting in pregnant women.

Phenergan (promethazine HCI) is an antihistamine used to treat nausea and vomiting related to certain conditions (e.g., motion sickness, before/after surgery). Phenergan is also used to treat allergic symptoms such as rash, itching, and runny nose. The brand name Phenergan is discontinued in the U.S. Phenergan is available as a generic drug.

Severe drowsiness can occur when using Diclegis with other sedative medications. Diclegis interacts with monoamine oxidase inhibitors (MAOIs), or alcohol and other CNS depressants (such as hypnotic sedatives and tranquilizers). Tell your doctor all medications and supplements you use. Diclegis is intended for use in pregnant women. Women should not breastfeed while using Diclegis.

Phenergan may interact with cold or allergy medicine, sedatives, narcotics, sleeping pills, muscle relaxers, seizure medications, antidepressants, anxiety medicines, lithium, atropine, belladonna, benztropine, dimenhydrinate, methscopolamine, scopolamine, blood pressure medications, blood thinners, bronchodilators, bladder or urinary medications, MAO inhibitors, medicines to treat Parkinson's disease, restless leg syndrome medications, medicines to treat pituitary gland tumor, or medicines to treat stomach ulcer or irritable bowel syndrome. Tell your doctor all medications and supplements you use. Phenergan Tablets and Suppositories should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus. It is not known whether Phenergan is excreted in human milk. Because of the potential for serious adverse reactions in nursing infants from Phenergan Tablets and Suppositories, a decision should be made whether to discontinue nursing or to discontinue the drug, taking into account the importance of the drug to the mother.

Diclegis are available as delayed-release tablets containing 10 mg doxylamine succinate and 10 mg pyridoxine hydrochloride. Patients should take two tablets of Diclegis at bedtime. If nausea and vomiting is not controlled with two tablets, the dose may be increased to a maximum of four tablets daily. Diclegis should not be used by women with sensitivities to any ingredient in Diclegis.

The dose of Phenergan to treat allergies is 25 mg taken before retiring. The adult dose of Phenergan to treat motion sickness is 25 mg taken twice daily. The dose of Phenergan for the active therapy of nausea and vomiting in children or adults is 25 mg.