What is this medicine?
DIPHENHYDRAMINE (dye fen HYE dra meen) is an antihistamine. It is used to treat the symptoms of an allergic reaction and motion sickness. It is also used to treat Parkinson's disease.
How should I use this medicine?
This medicine is for injection into a vein or a muscle. It is usually given by a health care professional in a hospital or clinic setting.
If you get this medicine at home, you will be taught how to prepare and give this medicine. Use exactly as directed. Take your medicine at regular intervals. Do not take your medicine more often than directed.
It is important that you put your used needles and syringes in a special sharps container. Do not put them in a trash can. If you do not have a sharps container, call your pharmacist or healthcare provider to get one.
Talk to your pediatrician regarding the use of this medicine in children. While this drug may be prescribed for selected conditions, precautions do apply. This medicine is not approved for use in newborns and premature babies.
Patients over 60 years old may have a stronger reaction and need a smaller dose.
What side effects may I notice from receiving this medicine?
Side effects that you should report to your doctor or health care professional as soon as possible:
allergic reactions like skin rash, itching or hives, swelling of the face, lips, or tongue
changes in vision
confused, agitated, nervous
irregular or fast heartbeat
low blood pressure
trouble passing urine
unusual bleeding or bruising
unusually weak or tired
Side effects that usually do not require medical attention (report to your doctor or health care professional if they continue or are bothersome):
loss of appetite
stomach upset, vomiting
What may interact with this medicine?
Do not take this medicine with any of the following medications:
MAOIs like Carbex, Eldepryl, Marplan, Nardil, and Parnate
This medicine may also interact with the following medications:
barbiturates, like phenobarbital
medicines for bladder spasm like oxybutynin, tolterodine
medicines for blood pressure
medicines for depression, anxiety, or psychotic disturbances
medicines for movement abnormalities or Parkinson's disease
medicines for sleep
other medicines for cold, cough or allergy
some medicines for the stomach like chlordiazepoxide, dicyclomine
What if I miss a dose?
If you miss a dose, take it as soon as you can. If it is almost time for your next dose, take only that dose. Do not take double or extra doses.
Where should I keep my medicine?
Keep out of the reach of children.
If you are using this medicine at home, you will be instructed on how to store this medicine. Throw away any unused medicine after the expiration date on the label.
What should I tell my health care provider before I take this medicine?
They need to know if you have any of these conditions:
asthma or lung disease
high blood pressure or heart disease
pain or difficulty passing urine
ulcers or other stomach problems
an unusual or allergic reaction to diphenhydramine, antihistamines, other medicines foods, dyes, or preservatives
pregnant or trying to get pregnant
What should I watch for while using this medicine?
Your condition will be monitored carefully while you are receiving this medicine. Tell your doctor or healthcare professional if your symptoms do not start to get better or if they get worse.
You may get drowsy or dizzy. Do not drive, use machinery, or do anything that needs mental alertness until you know how this medicine affects you. Do not stand or sit up quickly, especially if you are an older patient. This reduces the risk of dizzy or fainting spells. Alcohol may interfere with the effect of this medicine. Avoid alcoholic drinks.
Your mouth may get dry. Chewing sugarless gum or sucking hard candy, and drinking plenty of water may help. Contact your doctor if the problem does not go away or is severe.