Zyrtec and Simcor drug interactions - a phase IV clinical study of FDA data

Summary:

Drug interactions are reported among people who take Zyrtec (cetirizine hydrochloride) and Simcor (niacin; simvastatin). Common drug interactions include dizziness among females and flushing among males.

The phase IV clinical study analyzes what interactions people have when they take Zyrtec and Simcor. It is created by eHealthMe based on reports of 67 people who take the same drugs from the FDA, and is updated regularly.

What is Zyrtec?

Zyrtec has active ingredients of cetirizine hydrochloride. It is often used in allergies. eHealthMe is studying from 114,619 Zyrtec users. Check the latest studies of Zyrtec.

What is Simcor?

Simcor has active ingredients of niacin; simvastatin. It is often used in high blood cholesterol. eHealthMe is studying from 11,604 Simcor users. Check the latest studies of Simcor.

On Jul, 17, 2026

67 people who take Zyrtec and Simcor together, and have interactions are studied.

What are the common drug interactions of Zyrtec and Simcor, by gender? *:

female:

Dizziness
Drug dependence
Faeces discoloured
Gastroenteritis viral (inflammation of stomach and intestine caused by virus infection)
Gastrooesophageal reflux disease (stomach contents (food or liquid) leak backwards from the stomach into the oesophagus)
Haematochezia (passage of stools containing blood)
Hiatus hernia (hernia resulting from the protrusion of part of the stomach through the diaphragm)
Hyperparathyroidism secondary (an abnormally high concentration of parathyroid hormone in the blood, resulting in weakening of the bones through loss of calcium-secondary)
Ill-defined disorder
Melaena (the passage of black, tarry stools)

male:

Flushing (the warm, red condition of human skin)
Feeling hot
Arthralgia (joint pain)
Asthenia (weakness)
Haemorrhagic disorder (bleeding disorder)
Hernia (hernia happens when part of an internal organ or tissue bulges through a weak area of muscle)
Abdominal distension
Abdominal pain
Back pain
Blood glucose increased

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

0-1:

Flushing (the warm, red condition of human skin)
Gallbladder pain
Nausea (feeling of having an urge to vomit)
Vomiting

2-9:

n/a

10-19:

n/a

20-29:

Fatigue (feeling of tiredness)
Haematochezia (passage of stools containing blood)
Hepatitis a antibody positive
Hepatitis b core antibody positive
Hepatitis b surface antibody positive
Inflammatory bowel disease
Melaena (the passage of black, tarry stools)
Rash generalised (rash on most of body parts)
Abdominal pain upper
Alanine aminotransferase increased

30-39:

Arthralgia (joint pain)
Flushing (the warm, red condition of human skin)
Myalgia (muscle pain)
Osteonecrosis of jaw (death of bone of jaw)
Paraesthesia (sensation of tingling, tickling, prickling, pricking, or burning of a person's skin with no apparent long-term physical effect)

40-49:

Flushing (the warm, red condition of human skin)
Paraesthesia (sensation of tingling, tickling, prickling, pricking, or burning of a person's skin with no apparent long-term physical effect)
Pruritus (severe itching of the skin)
Blood glucose increased
Abdominal discomfort
Headache (pain in head)
Nausea (feeling of having an urge to vomit)
Erythema (redness of the skin)
Feeling hot
Back pain

50-59:

Flushing (the warm, red condition of human skin)
Paraesthesia (sensation of tingling, tickling, prickling, pricking, or burning of a person's skin with no apparent long-term physical effect)
Erythema (redness of the skin)
Pruritus (severe itching of the skin)
Abdominal distension
Abdominal pain
Hepatic enzyme increased
Hepatitis (inflammation of the liver)
Pleural effusion (water on the lungs)
Swelling

60+:

Flushing (the warm, red condition of human skin)
Skin burning sensation
Blood creatinine increased
Blood iron decreased
Blood uric acid increased
Buccal mucosal roughening
Cheilitis (infection of lips)
Oral pain
Paraesthesia (sensation of tingling, tickling, prickling, pricking, or burning of a person's skin with no apparent long-term physical effect)
Stomatitis (inflammation of mucous membrane of mouth)

What are the existing conditions these people have? *

High Density Lipoprotein Decreased: 13 people, 19.40%
Low Density Lipoprotein Increased (cholesterol increased in blood): 11 people, 16.42%
Hypersensitivity: 8 people, 11.94%
Hyperlipidaemia (presence of excess lipids in the blood): 6 people, 8.96%
High Blood Pressure: 5 people, 7.46%
Seasonal Allergy (allergic condition due to certain season): 4 people, 5.97%

* Approximation only. Some reports may have incomplete information.

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