A Patient's Guide to Phenergan

Phenergan, also prescribed as promethazine and Phen-Tuss, is an oral medication. It has several uses and is only available by prescription. It is important that this medication be used exactly as directed to help avoid potentially dangerous effects and interactions.

Uses

This drug is classified as an antihistamine and works to relieve a patient’s symptoms by blocking the histamine produced by the body when it is having an allergic reaction. It is often used short-term to help alleviate a runny nose caused by the common cold and to treat allergic reaction symptoms, such as itching, rash, and runny nose. It is also used to help alleviate and prevent vomiting and nausea that can occur before or after surgery and for motion sickness. Other uses include being administered prior to surgery to help calm the patient and to help certain narcotic pain medications work better and faster.

Administration

How this medication is taken depends on what it is being taken for. When taken for motion sickness, the patient should take it 30-60 minutes prior to traveling and it can be repeated every 8-12 hours if needed. This medication is taken before bedtime when taken for allergies. When taken for surgery, it is either administered just before and after surgery or the night before.

Side Effects

The most common side effects of Phenergan include drowsiness, constipation, dry mouth, dizziness, and blurred vision. Some patients may experience excitability instead of drowsiness. The serious side effects include lack of coordination, vision changes, severe dizziness, weakness, ringing ears, painful urination, fainting, decreased urination, slow heartbeat, shaking, mental changes, restlessness, mood changes, and involuntary movements. The very serious side effects include slow breathing, increased sweating, shallow breathing, irregular heartbeat, signs of infection, fast heartbeat, severe abdominal pain, seizures, persistent vomiting, very high fever, persistent nausea, severe muscle stiffness, bleeding easily, dark urine, bruising easily, yellow eyes, and yellow skin.

Contraindications

All patients should discuss their current medical conditions with their doctors prior to starting this medication to avoid contraindications. Conditions that may be contraindicated include breathing and lung problems, urination problems, immune system or blood problems, sun sensitivity related to other medications, narrow-angle glaucoma, stomach problems, heart disease, bowel problems, high blood pressure, seizure, nervous system disorders, diabetes, and liver disease.

Drug Interactions

Patients taking certain other medications may have to avoid this medication to avoid drug interactions. These include epinephrine for hypotension, sibutramine, metrizamide, cough medicine, anticholinergics, cold medicine, tricyclic antidepressants, cancer chemotherapy, tramadol, guanethidine, theophylline, guanadrel, phenothiazines, other antihistamines, MAO inhibitors, medications that may increase a patient’s seizure risk, isoniazid, bupropion, anti-seizure drugs, psychiatric medications, sleep medications, narcotic pain killers, anti-anxiety drugs, and muscle relaxers.

Risks and Warnings

This medication should not be taken by children that are two years of age or younger. If it is taken by children of this age, they may experience potentially fatal respiratory depression, even in normal doses. Pregnant women should use extreme caution with this medication, as should those who are breastfeeding.

Resources

RxList. (2010). Phenergan. Retrieved on January 16, 2010 from RxList: https://www.rxlist.com/phenergan-drug.htm