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

Summary:

Drug interactions are reported among people who take Flexeril (cyclobenzaprine hydrochloride) and Norflex (orphenadrine citrate). Common drug interactions include fatigue among females and depression among males.

The phase IV clinical study analyzes what interactions people have when they take Flexeril and Norflex. It is created by eHealthMe based on reports of 88 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 Norflex?

Norflex has active ingredients of orphenadrine citrate. It is often used in muscle spasms. eHealthMe is studying from 1,951 Norflex users. Check the latest studies of Norflex.

eHealthMe: drug outcomes in the real world

eHealthMe runs one of the largest post-marketing drug safety studies in the world. We study millions of patients and 5,000 more each day. Our data-driven phase IV clinical trials have been referenced on 800+ peer-reviewed medical publications including The Lancet, Mayo Clinic Proceedings, and Nature. Tools to study our phase IV findings are available to the public, anonymous and free >>>.

On Sep, 03, 2026

88 people who take Flexeril and Norflex together, and have interactions are studied.

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

female:

Fatigue (feeling of tiredness)
Intervertebral disc protrusion (spinal disc protrusion)
Oedema peripheral (superficial swelling)
Injury
Pain in extremity
Arthralgia (joint pain)
Cardiac murmur (an heart sound in valve abnormality)
Deep vein thrombosis (blood clot in a major vein that usually develops in the legs and/or pelvis)
Dizziness
Mental disorder (a psychological term for a mental or behavioural pattern or anomaly that causes distress or disability)

male:

Depression
Anxiety
Weight decreased
Drug dependence
Vomiting
Emotional distress
Headache (pain in head)
Irritability
Nausea (feeling of having an urge to vomit)
Pain

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

0-1:

n/a

2-9:

n/a

10-19:

n/a

20-29:

Depression
Anxiety
Cholelithiasis (the presence or formation of gallstones in the gallbladder or bile ducts)
Crohn's disease (a condition that causes inflammation of the gastrointestinal tract)
Dehydration (dryness resulting from the removal of water)
Drug withdrawal syndrome (interfere with normal social, occupational, or other functioning. are not due to another medical condition, drug use, or discontinuation)
Hypocalcaemia (levels of calcium in blood serum are abnormally low)
Hypokalaemia (low potassium)
Oedema peripheral (superficial swelling)
Paraplegia (paralysis of the legs and lower body)

30-39:

Dyspnoea (difficult or laboured respiration)
Overdose
Pulmonary embolism (blockage of the main artery of the lung)
Asthma
Deep vein thrombosis (blood clot in a major vein that usually develops in the legs and/or pelvis)
Headache (pain in head)
Mental disorder (a psychological term for a mental or behavioural pattern or anomaly that causes distress or disability)
Oedema peripheral (superficial swelling)
Pain in extremity
Drug abuser

40-49:

Depression
Insomnia (sleeplessness)
Tremor (trembling or shaking movements in one or more parts of your body)
Headache (pain in head)
Irritability
Anxiety
Emotional distress
Pain
Acute psychosis (period of mentally unstable behaviour)
Agitation (state of anxiety or nervous excitement)

50-59:

Confusional state
Cough
Death
Dehydration (dryness resulting from the removal of water)
Delirium (wild excitement)
Depression
Diabetes mellitus (diabetes, caused by a deficiency of the pancreatic hormone insulin)
Diabetic ketoacidosis (diabetic ketoacidosis (dka) is high concentrations of ketone bodies)
Diarrhoea
Disorientation (disability in which the senses of time, direction, and recognition of people and places)

60+:

Constipation
Contusion (a type of hematoma of tissue in which capillaries)
Photosensitivity reaction
Stress
Alopecia (absence of hair from areas of the body)
Anaemia (lack of blood)
Application site rash
Arthralgia (joint pain)
Atrioventricular block first degree (heart block first degree)
Blood albumin decreased

What are the existing conditions these people have? *

Pain: 23 people, 26.14%
Depression: 8 people, 9.09%
Rheumatoid Arthritis (a chronic progressive disease causing inflammation in the joints): 7 people, 7.95%
Back Pain: 7 people, 7.95%
Restless Leg Syndrome (a powerful urge to move your legs): 6 people, 6.82%
Migraine (headache): 6 people, 6.82%
High Blood Pressure: 6 people, 6.82%

* Approximation only. Some reports may have incomplete information.

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