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

Summary:

Drug interactions are reported among people who take Flexeril (cyclobenzaprine hydrochloride) and Unisom (doxylamine succinate). Common drug interactions include dyspepsia among females and anxiety among males.

The phase IV clinical study analyzes what interactions people have when they take Flexeril and Unisom. It is created by eHealthMe based on reports of 40 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 Unisom?

Unisom has active ingredients of doxylamine succinate. It is often used in insomnia. eHealthMe is studying from 3,875 Unisom users. Check the latest studies of Unisom.

On Jul, 10, 2026

40 people who take Flexeril and Unisom together, and have interactions are studied.

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

female:

Dyspepsia (indigestion)
Anaemia (lack of blood)
Bone disorder
Bone pain
Bronchitis (inflammation of the mucous membrane in the bronchial tubes)
Bursitis (inflammation of a bursa, typically one in the knee, elbow, or shoulder)
Chest pain
Conjunctivitis (pink eye)
Decreased interest
Dyspnoea (difficult or laboured respiration)

male:

Anxiety
Apnoea (suspension of external breathing)
Bundle branch block left (absence of transmission of electric impulses from the atrioventricular (av) bundle of his to the left ventricle)
Cardiomegaly (increased size of heart than normal)
Cardiomyopathy (weakening of the heart muscle)
Cerebral atrophy (decrement in size of brain)
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)
Cervical cord compression (compression of spinal cord at site of cervical vertebrae)
Chills (felling of cold)
Cholelithiasis (the presence or formation of gallstones in the gallbladder or bile ducts)

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

0-1:

n/a

2-9:

n/a

10-19:

Drug toxicity

20-29:

Convulsion (muscles contract and relax rapidly and repeatedly, resulting in an uncontrolled shaking of the body)

30-39:

Biliary colic
Brain oedema (excess accumulation of fluid in the intracellular or extracellular spaces of the brain)
Cholecystitis (infection of gallbladder)
Cholecystitis chronic (long lasting infection of gallbladder)
Cholelithiasis (the presence or formation of gallstones in the gallbladder or bile ducts)
Completed suicide (act of taking one's own life)
Contusion (a type of hematoma of tissue in which capillaries)
Gallbladder injury
Mental disorder (a psychological term for a mental or behavioural pattern or anomaly that causes distress or disability)
Pulmonary oedema (fluid accumulation in the lungs)

40-49:

Headache (pain in head)
Pain
Sinusitis (inflammation of sinus)
Anxiety
Depression
Anaemia (lack of blood)
Bone disorder
Bone pain
Bronchitis (inflammation of the mucous membrane in the bronchial tubes)
Bursitis (inflammation of a bursa, typically one in the knee, elbow, or shoulder)

50-59:

Atelectasis (partial or complete collapse of the lung)
Atrial fibrillation (fibrillation of the muscles of the atria of the heart)
Axonal neuropathy (dysfunction of axon nerves)
Barrett's oesophagus (barrett's oesophagus is a disorder in which the lining of the oesophagus (the tube that carries food from the throat to the stomach) is damaged by stomach acid and changed to a lining similar to that of the stomach)
Bone disorder
Bone lesion (bone with abnormalities. bone lesions can result from growth formations, infections, or injuries)
Bone pain
Bone swelling
Bronchial secretion retention
Bronchitis chronic (inflammation of the mucous membrane in the bronchial tubes- chronic)

60+:

Anaemia (lack of blood)
Anxiety
Bone pain
Bronchial secretion retention
Bronchitis chronic (inflammation of the mucous membrane in the bronchial tubes- chronic)
Bundle branch block left (absence of transmission of electric impulses from the atrioventricular (av) bundle of his to the left ventricle)
Cardiomegaly (increased size of heart than normal)
Cardiomyopathy (weakening of the heart muscle)
Cerebral atrophy (decrement in size of brain)
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? *

Multiple Myeloma (cancer of the plasma cells): 13 people, 32.50%
Pain: 5 people, 12.50%
Sleep Disorder: 4 people, 10.00%
Premenstrual Syndrome: 4 people, 10.00%
Dysmenorrhea (painful menstruation): 4 people, 10.00%
Depression: 3 people, 7.50%
Diabetes: 3 people, 7.50%
Gastroesophageal Reflux Disease (a condition in which stomach contents leak backward from the stomach into the oesophagus): 3 people, 7.50%
Hot Flush (sudden feelings of heat): 2 people, 5.00%
Bipolar Disorder (mood disorder): 2 people, 5.00%

* Approximation only. Some reports may have incomplete information.

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