Phenergan (Promethazine) Dosage and Side Effects
PHENERGAN is used as an antihistamine, sedative, and anti-nausea drug.
Physicians might combine PHENERGAN with other drugs to help relieve a sudden allergic reaction known as anaphylaxis.
Proper Use of this medication
It’s not necessary to eat before taking PHENERGAN.
- For allergies: take one to four times a day, before meals and/or at bedtime
- For cold symptoms: take every four to six hours
- For motion sickness: 30 to 60 minutes before travelling and again after eight to 12 hours if needed
- For vomiting or to prevent nausea: take every four to six hours
You can also use this medication to reduce anxiety on the night before a surgery, for instance.
You should never take more PHENERGAN than prescribed.
If you feel you have overdosed call poison control or go to the emergency room right away.
Symptoms of an overdose may include:
- Breathing problems
- Loss of consciousness
- Fast heartbeat
- Loss of coordination
- Twisting movements of the hands and feet
Missed Dose of PHENERGAN
If you miss a dose, take it as soon as you remember unless it’s almost time for the next dose.
If that’s the case, skip the missed dose and resume your regular dosing schedule.
Common Side Effects of PHENERGAN
- Dry mouth
- Blurred vision
- Stuffy nose
- Ringing in the ears
- Weight gain
- Impotence or trouble having an orgasm
Serious Side Effects of PHENERGAN
If you notice any of the following, quit taking your medicine and call your doctor right away:
- Restlessness or feeling jittery or agitated
- Twitching or uncontrolled movements of your eyes, lips, tongue, face, legs, or arms
- Uncontrolled shaking
- Problems swallowing or drooling
- Trouble with balance or walking
- Feeling like you might pass out
- Vision problems or increased sensitivity to light
- Pale skin
- Bruising or bleeding easily
- Flu symptoms
- Sore throat
- Nausea/stomach pain
- Skin rash
- Yellowing of the skin or eyes (jaundice)
- Problems with urination
- Joint pain and swelling
- Swollen glands
Other symptoms that necessitate a call to your doctor include:
- Slow heart rate
- Muscle aches and stiffness
- Chest pain
- Unusual thoughts or behavior
- Pale skin color
- Weak pulse
- Slow breathing
Get emergency help if you notice any signs of an allergic reaction such as hives, itching, trouble breathing or swelling of the mouth, face, lips, or tongue.
Warnings and Precautions
The FDA has issued a black-box warning about the use of PHENERGAN hydrochloride in children younger than 2 years because the drug could lead to severe or fatal breathing problems.
Never use PHENERGAN if you are allergic to it or any similar drugs, including:
- Chlorpromazine (Thorazine)
- Fluphenazine (Prolixin)
- Mesoridazine (Serentil)
- Perphenazine (Trilafon)
- Prochlorperazine (Compazine)
- Thioridazine (Mellaril)
- Trifluperazine (Stelazine)
Let your doctor know right away if you have unusual or unexpected side effects to this medication.
PHENERGAN may lead to impaired thinking or reaction time. Drinking alcohol could increase the side effects of this medication.
It’s also possible that serious side effects might result. If you notice twitching, uncontrollable eye movements or uncontrollable movements of your lips, tongue, face, arms, or legs, call your doctor at once.
Let your doctor know if you have or have ever had any conditions that affect the production of blood cells in your bone marrow. It’s also important to alert your healthcare provider of the following conditions:
- An enlarged prostate gland
- Blockage in the passageway between your stomach and intestines
- Blockage in your bladder
- Asthma or other lung diseases
- Sleep apnea
- Heart disease
- Liver disease
If you are planning to give PHENERGAN to your child, it’s important that you discuss your child’s medical history with his/her doctor, listing problems that include vomiting, flu-like symptoms, weakness, listlessness, drowsiness, confusion, aggression, seizures, and yellowing of the skin or eyes.
Tell your pediatrician if your child isn’t drinking normally, appears dehydrated, or has excessive diarrhea or vomiting.
If you are 65 or older, PHENERGAN may not be the safest treatment option for your conditions. Talk to your doctor about other drugs that might be safer.
If you are planning to have any type of surgery, including dental, make sure the physician knows you are using PHENERGAN hydrochloride in advance.
Pregnancy and PHENERGAN
There are no conclusive studies as to how PHENERGAN impacts pregnant women.
However, taking it within two weeks of delivery might affect your newborn’s platelet function. If you become pregnant while taking this drug, tell your doctor right away.
Be sure to let your doctor know if you are pregnant or are planning to become pregnant as well as whether you are breastfeeding.
It’s unknown whether PHENERGAN hydrochloride will pass into breast milk. Talk with your doctor about using PHENERGAN while breastfeeding.
Interactions with this medication
Many medications interact with PHENERGAN.
That’s why it’s important that you provide your doctor with a complete list of all the prescription, non-prescription, and over-the-counter products, vitamins, and herbal supplements you are taking.
PHENERGAN is known to interact with antidepressants, including:
- Amitriptyline (Elavil)
- Amoxapine (Asendin)
- Clomipramine (Anafranil)
- Desipramine (Norpramin)
- Doxepin (Adapin, Sinequan)
- Imipramine (Tofranil)
- ortriptyline (Aventyl, Pamelor)
- Protriptyline (Vivactil)
- Trimipramine (Surmontil)
This drug might also interact with immuno supressants like azathioprine (Imuran) or barbiturates such as phenobarbital (Luminal).
Some treatments might also change the way PHENERGAN affects you, including chemotherapy, epinephrine (Epipen) and ipratropium (Atrovent), and drugs used to treat anxiety, irritable bowel disease, mental illness, motion sickness, Parkinson's disease, seizures, ulcers, or urinary problems.
Monoamine oxidase inhibitors (MAOIs) such as isocarboxazid (Marplan), phenelzine (Nardil), tranylcypromine (Parnate), and selegiline (Eldepryl, Emsam, Zelapar) are also a concern as are narcotics and other pain medication, sleeping pills, and tranquilizers.
In addition, PHENERGAN shouldn’t be used in conjunction with amiodarone (Cordarone), sotalol (Betapace), pimozide (Orap), quinidine, and procainamide because it could increase the risk of abnormal heartbeats.
PHENERGAN also shouldn’t be used with propylthiouracil (PTU) since it can cause low white blood cell counts, increasing the risk of infection.
If you are planning on having an X-ray of your spinal cord (myelography) you should stopping taking this medicine at least 48 hours beforehand and not resume using it until 24 hours after since the dye used in this procedure can increase the risk of seizures.
Other PHENERGAN Interactions
PHENERGAN is known to make you feel sleepy so it’s not a good idea to drive or operate machinery until you know how this medicine affects you.
If you are giving this medicine to your child, you might want to limit his/her activities.
Alcohol can increase the side effects of this drug so talk to your doctor about any restrictions you might need to have while on this medicine.
Since this drug may make your skin more sensitive to sunlight, avoid prolonged exposure to the sun and wear protective clothing and sunscreen when going out.
Other related products
The above information is an educational aid only. It is not intended as medical advice for individual conditions or treatments. Talk to your doctor, nurse or pharmacist before following any medical regimen to see if it is safe and effective for you.