Lopurin and Efudex drug interactions - a phase IV clinical study of FDA data

Summary:

Drug interactions are reported among people who take Lopurin (allopurinol) and Efudex (fluorouracil). Common drug interactions include dyspepsia among females and fatigue among males.

The phase IV clinical study analyzes what interactions people have when they take Lopurin and Efudex. It is created by eHealthMe based on reports of 60 people who take the same drugs from the FDA, and is updated regularly.

What is Lopurin?

Lopurin has active ingredients of allopurinol. It is often used in gout. eHealthMe is studying from 190,798 Lopurin users. Check the latest studies of Lopurin.

What is Efudex?

Efudex has active ingredients of fluorouracil. It is often used in actinic keratosis. eHealthMe is studying from 1,391 Efudex users. Check the latest studies of Efudex.

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, 01, 2026

60 people who take Lopurin and Efudex together, and have interactions are studied.

What are the common drug interactions of Lopurin and Efudex, by gender? *:

female:

Dyspepsia (indigestion)
Fatigue (feeling of tiredness)
Joint stiffness
Muscle spasms (muscle contraction)
Musculoskeletal stiffness (stiffness of the body's muscles, joints, tendons, ligaments and nerves)
Rash
Skin ulcer
Cough
Death
Immune system disorder

male:

Fatigue (feeling of tiredness)
Cardiac failure congestive
Middle insomnia (difficulty returning to sleep after awakening either in the middle of the night)
Mobility decreased (ability to move is reduced)
Nasopharyngitis (inflammation of the nasopharynx)
Oral pain
Osteoarthritis (a joint disease caused by cartilage loss in a joint)
Pneumonia
Death
Localised infection (infection at the single location)

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

0-1:

n/a

2-9:

n/a

10-19:

n/a

20-29:

n/a

30-39:

n/a

40-49:

n/a

50-59:

Colon cancer
Gastric cancer (stomach cancer)

60+:

Fatigue (feeling of tiredness)
Arthralgia (joint pain)
Mobility decreased (ability to move is reduced)
Nasopharyngitis (inflammation of the nasopharynx)
Oral pain
Osteoarthritis (a joint disease caused by cartilage loss in a joint)
Pain in extremity
Dizziness
Localised infection (infection at the single location)
Nephropathy toxic (damage to kidney due to toxins)

What are the existing conditions these people have? *

Multiple Myeloma (cancer of the plasma cells): 13 people, 21.67%
Chronic Lymphocytic Leukaemia (cancer in which the bone marrow makes too many lymphocytes (a type of white blood cell)): 11 people, 18.33%
Kidney Stones: 7 people, 11.67%
High Blood Pressure: 6 people, 10.00%
Rheumatoid Arthritis (a chronic progressive disease causing inflammation in the joints): 5 people, 8.33%
Primary Myelofibrosis (primary disorder of the bone marrow): 5 people, 8.33%
Polycythaemia Vera (blood disorder in which the bone marrow makes too many red blood cells): 3 people, 5.00%
Face Injury: 3 people, 5.00%

* Approximation only. Some reports may have incomplete information.

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