Benadryl and Colestid drug interactions - a phase IV clinical study of FDA data

Summary:

Drug interactions are reported among people who take Benadryl (diphenhydramine hydrochloride) and Colestid (colestipol hydrochloride). Common drug interactions include blood pressure fluctuation among females and agitation among males.

The phase IV clinical study analyzes what interactions people have when they take Benadryl and Colestid. It is created by eHealthMe based on reports of 38 people who take the same drugs from the FDA, and is updated regularly.

What is Benadryl?

Benadryl has active ingredients of diphenhydramine hydrochloride. It is often used in allergies. eHealthMe is studying from 104,956 Benadryl users. Check the latest studies of Benadryl.

What is Colestid?

Colestid has active ingredients of colestipol hydrochloride. It is often used in irritable bowel syndrome. eHealthMe is studying from 2,233 Colestid users. Check the latest studies of Colestid.

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, 02, 2026

38 people who take Benadryl and Colestid together, and have interactions are studied.

Benadryl and Colestid drug interactions.

What are the common drug interactions of Benadryl and Colestid, by gender? *:

female:

Blood pressure fluctuation
Blood pressure increased
Bronchial oedema (build-up of fluid in the bronchia)
Burning sensation
Cachexia (loss of weight)
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)
Chills (felling of cold)
Colitis ulcerative (inflammation of colon with ulcer)
Contusion (a type of hematoma of tissue in which capillaries)
Culture urine positive

male:

Agitation (state of anxiety or nervous excitement)
Anhedonia (inability to experience pleasure from activities usually found enjoyable)
Gait disturbance
Heart rate irregular
Joint swelling
Muscle fatigue (a condition in which muscles cannot exert their normal force)
Muscle spasms (muscle contraction)
Muscular weakness (muscle weakness)
Musculoskeletal stiffness (stiffness of the body's muscles, joints, tendons, ligaments and nerves)
Myalgia (muscle pain)

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

0-1:

n/a

2-9:

n/a

10-19:

n/a

20-29:

Alopecia (absence of hair from areas of the body)
Colitis ulcerative (inflammation of colon with ulcer)
Contusion (a type of hematoma of tissue in which capillaries)
Serum sickness (hypersensitivity reaction that results from the injection of heterologous or foreign protein or serum)
Skin lesion
Therapeutic response delayed (late preventive response)
Type iv hypersensitivity reaction (delayed type hypersensitivity as the reaction takes two to three days to develop)

30-39:

Heart rate increased
Migraine (headache)
Blood pressure fluctuation
Blood pressure increased
Cardiac arrest
Hepatic failure (liver failure)
Hypertension (high blood pressure)
Non-alcoholic steatohepatitis (liver inflammation caused by a build up of fat in the liver)
Septic shock (shock due to blood infection)

40-49:

Myalgia (muscle pain)
Myofascial pain syndrome (a painful condition that affects the muscles and the sheath of the tissue)
Neck pain
Pain
Sinoatrial block
Tremor (trembling or shaking movements in one or more parts of your body)
Visual disturbance
Chest pain
Palpitations (feelings or sensations that your heart is pounding or racing)
Activated partial thromboplastin time prolonged

50-59:

n/a

60+:

Dysphagia (a condition in which swallowing is difficult or painful)
Dizziness
Colon cancer metastatic (cancer of colon spreads to other part of body)
Dehydration (dryness resulting from the removal of water)
Febrile neutropenia (fever with reduced white blood cells)
Hyponatraemia (abnormally low level of sodium in the blood; associated with dehydration)
Immunodeficiency
Lactic acidosis (low ph in body tissues)
Leukopenia (less number of white blood cells in blood)
Muscular weakness (muscle weakness)

What are the existing conditions these people have? *

Rheumatoid Arthritis (a chronic progressive disease causing inflammation in the joints): 8 people, 21.05%
Cataplexy (loss of muscle tone accompanied by full conscious awareness): 6 people, 15.79%
Narcolepsy (brain's inability to regulate sleep-wake cycles normally): 6 people, 15.79%
Hypersensitivity: 5 people, 13.16%
Hypokalemia (low potassium): 4 people, 10.53%
Hypothyroidism (abnormally low activity of the thyroid gland, resulting in retardation of growth and mental development): 3 people, 7.89%
Asthma: 3 people, 7.89%
Depression: 3 people, 7.89%
High Blood Pressure: 3 people, 7.89%
Anaemia (lack of blood): 3 people, 7.89%

* Approximation only. Some reports may have incomplete information.

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