Allegra and Questran drug interactions - a phase IV clinical study of FDA data

Summary:

Drug interactions are reported among people who take Allegra (fexofenadine hydrochloride) and Questran (cholestyramine). Common drug interactions include rash among females and abdominal pain among males.

The phase IV clinical study analyzes what interactions people have when they take Allegra and Questran. It is created by eHealthMe based on reports of 99 people who take the same drugs from the FDA, and is updated regularly.

What is Allegra?

Allegra has active ingredients of fexofenadine hydrochloride. It is often used in allergies. eHealthMe is studying from 75,498 Allegra users. Check the latest studies of Allegra.

What is Questran?

Questran has active ingredients of cholestyramine. It is often used in diarrhea. eHealthMe is studying from 4,490 Questran users. Check the latest studies of Questran.

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 Aug, 20, 2026

99 people who take Allegra and Questran together, and have interactions are studied.

What are the common drug interactions of Allegra and Questran, by gender? *:

female:

Rash
Cardiac arrest
Contusion (a type of hematoma of tissue in which capillaries)
Hepatic fibrosis (scarring process that represents the liver's response to injury)
Pyrexia (fever)
Coronary artery atherosclerosis (life-threatening blockages in the arteries of your heart)
Drug dependence
Hepatic steatosis (fatty liver disease)
Respiratory failure (inadequate gas exchange by the respiratory system)
Abdominal pain upper

male:

Abdominal pain
Cholelithiasis (the presence or formation of gallstones in the gallbladder or bile ducts)
Hypocalcaemia (levels of calcium in blood serum are abnormally low)
Dehydration (dryness resulting from the removal of water)
Dyspnoea (difficult or laboured respiration)
Headache (pain in head)
Infection
Renal failure (kidney dysfunction)
Anaemia (lack of blood)
Anaemia of malignant disease

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

0-1:

n/a

2-9:

Cholecystitis acute (rapid infection of gallbladder)
Abdominal pain
Tracheitis (an inflammation of the trachea)
Cholelithiasis (the presence or formation of gallstones in the gallbladder or bile ducts)
Dehydration (dryness resulting from the removal of water)

10-19:

n/a

20-29:

n/a

30-39:

Abdominal pain upper
Anxiety
Biliary colic
Blood pressure increased
Body temperature decreased
Cholecystitis chronic (long lasting infection of gallbladder)
Cholelithiasis (the presence or formation of gallstones in the gallbladder or bile ducts)
Chronic sinusitis (long lasting inflammation of the paranasal sinuses)
Cystic fibrosis (disease of the secretary glands)
Decreased appetite

40-49:

Abdominal pain
Abdominal pain upper
Diarrhoea haemorrhagic (bloody diarrhoea)
Drug ineffective
Dry skin
Dyspnoea (difficult or laboured respiration)
Female genital tract fistula (passage in genital tract of female)
Fungal infection
Oesophageal candidiasis (fungal infection of oesophagus)
Paraesthesia (sensation of tingling, tickling, prickling, pricking, or burning of a person's skin with no apparent long-term physical effect)

50-59:

Cardiac arrest
Dehydration (dryness resulting from the removal of water)
Hepatic fibrosis (scarring process that represents the liver's response to injury)
Pneumonia
Pyrexia (fever)
Rash
Coronary artery atherosclerosis (life-threatening blockages in the arteries of your heart)
Drug dependence
Hepatic steatosis (fatty liver disease)
Respiratory failure (inadequate gas exchange by the respiratory system)

60+:

Abdominal pain
Cholelithiasis (the presence or formation of gallstones in the gallbladder or bile ducts)
Hypertension (high blood pressure)
Renal failure (kidney dysfunction)
Depression
Dyspnoea (difficult or laboured respiration)
Emotional distress
Haemoglobin decreased
Infection
Oedema peripheral (superficial swelling)

What are the existing conditions these people have? *

Multiple Myeloma (cancer of the plasma cells): 15 people, 15.15%
High Blood Pressure: 11 people, 11.11%
Nausea (feeling of having an urge to vomit): 10 people, 10.10%
Pain: 9 people, 9.09%
Gastroesophageal Reflux Disease (a condition in which stomach contents leak backward from the stomach into the oesophagus): 8 people, 8.08%
Depression: 8 people, 8.08%
Multiple Allergies (allergy to multiple agents): 7 people, 7.07%
Insomnia (sleeplessness): 7 people, 7.07%
Stress And Anxiety: 6 people, 6.06%
Osteoporosis (bones weak and more likely to break): 6 people, 6.06%

* Approximation only. Some reports may have incomplete information.

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