What Is Diphenhydramine Citrate?

Diphenhydramine citrate is a generic medicine used in several brand name drugs, including Sominex® and Benadryl®. This drug is an antihistamine that works by interfering with histamine, a substance naturally found in the body. It may be used by patients who suffer from allergies, motion sickness, and insomnia, as well as cold symptoms. Sometimes, a doctor may also prescribe it to those who have poor muscle control and balance due to early Parkinson's disease. Diphenhydramine citrate will only help alleviate symptoms, not treat the root cause of the patient's discomfort.

This medicine is available in many different forms, including liquids, dissolving tablets, and regular tablets, as well as powders and dissolving strips. Dissolving medications should be placed on the tongue until they are fully dissolved. Patients taking this drug to treat symptoms of Parkinson's disease will usually be prescribed a dose three to four times daily. Those using it for insomnia may take it 30 minutes prior to bedtime, while those taking it for motion sickness may take it 30 minutes before they expect to experience motion sickness. Patients who suffer from allergies or cold symptoms may use diphenhydramine citrate no more than every four to six hours.

Parents and caregivers who give diphenhydramine citrate to a young child should first consult a pediatrician. It is not recommended for use by those who are younger than four years old. Caution should be used when administering the drug to children who are between the ages of four to 11. A pediatrician can recommend the appropriate dose for a child.

Diphenhydramine citrate may cause some side effects, which should be reported to the physician if they do not go away or become troublesome. Patients may experience nausea, vomiting, and loss of appetite. Constipation, dizziness, and drowsiness have also been reported. Increased chest congestion, dry mouth or nose, and headache may also occur. Muscle weakness, nervousness, and excitement, especially in children, have also been known to occur.

Rarely, more serious side effects may occur, which require immediate medical attention. Patients should call their doctors if they experience ringing in the ears, a pounding or irregular heartbeat, and difficulty urinating. Changes in vision, trouble breathing, and seizures are also possible.

Before using diphenhydramine citrate, patients should disclose their other medical conditions, medications, and supplements. If they are using an over-the-counter brand of this drug, it is recommended that they discuss possible interactions with a pharmacist. Patients who have phenylketonura (PKU) should avoid this product, because some forms of it may contain aspartame. Those with a seizure disorder, lung disease, or asthma may be unable to use this drug. Diphenhydramine citrate may interact with other medicines, including sleeping pills, other cold or allergy drugs, and anxiety or depression medications.