Flexeril and Naproxen sodium drug interactions - a phase IV clinical study of FDA data

Summary:

Drug interactions are reported among people who take Flexeril (cyclobenzaprine hydrochloride) and Naproxen sodium (naproxen sodium). Common drug interactions include nasopharyngitis among females and vomiting among males.

The phase IV clinical study analyzes what interactions people have when they take Flexeril and Naproxen sodium. It is created by eHealthMe based on reports of 100 people who take the same drugs from the FDA, and is updated regularly.

What is Flexeril?

Flexeril has active ingredients of cyclobenzaprine hydrochloride. It is often used in muscle spasms. eHealthMe is studying from 38,308 Flexeril users. Check the latest studies of Flexeril.

What is Naproxen sodium?

Naproxen sodium has active ingredients of naproxen sodium. It is often used in pain. eHealthMe is studying from 11,252 Naproxen sodium users. Check the latest studies of Naproxen sodium.

On Jul, 06, 2026

100 people who take Flexeril and Naproxen sodium together, and have interactions are studied.

Flexeril and Naproxen sodium drug interactions.

What are the common drug interactions of Flexeril and Naproxen Sodium, by gender? *:

female:

Nasopharyngitis (inflammation of the nasopharynx)
Weight increased
Anaemia (lack of blood)
Blood glucose increased
Chest pain
Cholelithiasis (the presence or formation of gallstones in the gallbladder or bile ducts)
Cold sweat
Ingrowing nail
Injury
Joint swelling

male:

Vomiting
Dysphagia (a condition in which swallowing is difficult or painful)
Exostosis (formation of new bone on the surface of a bone)
Joint injury
Musculoskeletal discomfort (discomfort in the body's muscles, joints, tendons, ligaments and nerves)
Nerve compression
Polyarthritis (arthritis which involves 5 or more joints simultaneously)
Spinal osteoarthritis (joint cartilage loss in spine)
Asthenia (weakness)
Cardiac failure congestive

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

0-1:

n/a

2-9:

n/a

10-19:

Anxiety
Grand mal convulsion (a type of generalized seizure that affects the entire brain)
Head injury
Headache (pain in head)
Infusion related reaction
Nausea (feeling of having an urge to vomit)
Rash maculo-papular (red area on the skin that is covered with small confluent bumps)
Tremor (trembling or shaking movements in one or more parts of your body)
Vomiting

20-29:

Arthralgia (joint pain)
Cellulitis (infection under the skin)
Cold sweat
Dizziness
Gastrointestinal disorder (functional problems of gastrointestinal tract)
Hypoaesthesia (reduced sense of touch or sensation)
Ingrowing nail
Injury
Mitral valve incompetence (inefficient heart valve)
Paraesthesia (sensation of tingling, tickling, prickling, pricking, or burning of a person's skin with no apparent long-term physical effect)

30-39:

Alanine aminotransferase increased
Diarrhoea
Dehydration (dryness resulting from the removal of water)
Urinary tract infection
Diabetes mellitus (diabetes, caused by a deficiency of the pancreatic hormone insulin)
Decreased activity
Dizziness
Fasciitis (infection of muscle surrounding tissue)
Fibromyalgia (a long-term condition which causes pain all over the body)
Hunger

40-49:

Anxiety
Upper respiratory tract infection
Bronchitis (inflammation of the mucous membrane in the bronchial tubes)
Fatigue (feeling of tiredness)
Nasopharyngitis (inflammation of the nasopharynx)
Alopecia (absence of hair from areas of the body)
Arthralgia (joint pain)
Depression
Drug hypersensitivity
Gait disturbance

50-59:

Nausea (feeling of having an urge to vomit)
Peripheral swelling
Tachycardia (a heart rate that exceeds the range of 100 beats/min)
Therapeutic response unexpected
Abdominal discomfort
Back injury
Gastrooesophageal reflux disease (stomach contents (food or liquid) leak backwards from the stomach into the oesophagus)
Lumbar spinal stenosis (a medical condition in which the spinal canal narrows and compresses the spinal cord and nerves at the level of the lumbar bone)
Nerve compression
Alanine aminotransferase increased

60+:

Vomiting
Dysphagia (a condition in which swallowing is difficult or painful)
Aphagia (inability or refusal to swallow)
Exostosis (formation of new bone on the surface of a bone)
Joint injury
Musculoskeletal discomfort (discomfort in the body's muscles, joints, tendons, ligaments and nerves)
Nerve compression
Polyarthritis (arthritis which involves 5 or more joints simultaneously)
Asthenia (weakness)
Cerebrovascular accident (sudden death of some brain cells due to lack of oxygen when the blood flow to the brain is impaired by blockage or rupture)

What are the existing conditions these people have? *

Narcolepsy (brain's inability to regulate sleep-wake cycles normally): 22 people, 22.00%
Depression: 15 people, 15.00%
Cataplexy (loss of muscle tone accompanied by full conscious awareness): 14 people, 14.00%
Stress And Anxiety: 13 people, 13.00%
High Blood Pressure: 10 people, 10.00%
Arthritis (form of joint disorder that involves inflammation of one or more joints): 7 people, 7.00%
High Blood Cholesterol: 6 people, 6.00%
Headache (pain in head): 6 people, 6.00%
Gastroesophageal Reflux Disease (a condition in which stomach contents leak backward from the stomach into the oesophagus): 6 people, 6.00%
Diabetes: 6 people, 6.00%

* Approximation only. Some reports may have incomplete information.

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