Diphen and Horizant drug interactions - a phase IV clinical study of FDA data

Summary:

Drug interactions are reported among people who take Diphen (diphenhydramine hydrochloride) and Horizant (gabapentin enacarbil). Common drug interactions include chronic kidney disease among females and sinusitis among males.

The phase IV clinical study analyzes what interactions people have when they take Diphen and Horizant. It is created by eHealthMe based on reports of 70 people who take the same drugs from the FDA, and is updated regularly.

What is Diphen?

Diphen has active ingredients of diphenhydramine hydrochloride. It is often used in insomnia. eHealthMe is studying from 115,432 Diphen users. Check the latest studies of Diphen.

What is Horizant?

Horizant has active ingredients of gabapentin enacarbil. It is often used in restless leg syndrome. eHealthMe is studying from 2,051 Horizant users. Check the latest studies of Horizant.

On Jul, 11, 2026

70 people who take Diphen and Horizant together, and have interactions are studied.

What are the common drug interactions of Diphen and Horizant, by gender? *:

female:

Chronic kidney disease
Concussion (short loss of normal brain function in response to a head injury)
Disability
Drug ineffective
Fall
Fibula fracture
Gastrointestinal disorder (functional problems of gastrointestinal tract)
Inflammation
Infusion site haemorrhage (bleeding from infusion site)
Middle ear effusion (fluid in middle ear)

male:

Sinusitis (inflammation of sinus)
Infection
Dermatitis (inflammation of the skin resulting from direct irritation by an external agent or an allergic reaction to it)
Erythema (redness of the skin)
Fall
Intervertebral discitis (infection in the intervertebral disc space)
Multiple-drug resistance
Oedema (fluid collection in tissue)
Osteomyelitis (infection of bone)
Pseudomonas infection (pseudomonas infection is caused by a bacterium, pseudomonas aeruginosa)

What are the common drug interactions of Diphen and Horizant, by age (0-1 to 60+)? *:

0-1:

n/a

2-9:

n/a

10-19:

n/a

20-29:

Blood urine present
Drug hypersensitivity
Fall
Haemorrhage (bleeding)
Nephrolithiasis (calculi in the kidneys)
Pain
Pleurisy (inflammation of the pleurae, which causes pain when breathing)
Rib fracture

30-39:

Fibula fracture
Morning sickness (sickness in morning during pregnancy)
Asthenia (weakness)
Blood pressure decreased
Cervical radiculopathy (disturbance of nerve function that causes pain in the upper body)
Disturbance in attention
Fatigue (feeling of tiredness)
Gastrointestinal haemorrhage (bleeding gastrointestinal tract)
Hepatitis (inflammation of the liver)
Hypophagia (reduced food intake)

40-49:

Sinusitis (inflammation of sinus)
Accident
Cellulitis (infection under the skin)
Chest discomfort
Concussion (short loss of normal brain function in response to a head injury)
Contusion (a type of hematoma of tissue in which capillaries)
Inflammation
Infusion site pruritus (severe itching at infusion site)
Infusion site rash
Knee arthroplasty

50-59:

Sinusitis (inflammation of sinus)
Upper respiratory tract infection
Infection
Seasonal allergy (allergic condition due to certain season)
Infusion site rash
Staphylococcal infection (an infection with staphylococcus bacteria)
Arthropathy
Autoimmune disorder (a condition in which the immune system attacks the body's normal substances and tissue)
Cellulitis (infection under the skin)
Cystitis (inflammation of the wall of the bladder)

60+:

Pain
Dyspnoea (difficult or laboured respiration)
Migraine (headache)
Muscle spasms (muscle contraction)
Nasopharyngitis (inflammation of the nasopharynx)
Neuralgia (pain in one or more nerves)
Obstruction
Pelvic pain
Sinusitis (inflammation of sinus)
Weight fluctuation

What are the existing conditions these people have? *

Immunodeficiency Common Variable: 32 people, 45.71%
Narcolepsy (brain's inability to regulate sleep-wake cycles normally): 15 people, 21.43%
Cataplexy (loss of muscle tone accompanied by full conscious awareness): 12 people, 17.14%
Primary Immunodeficiency Syndrome: 5 people, 7.14%

* Approximation only. Some reports may have incomplete information.

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