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

Summary:

Drug interactions are reported among people who take Zyrtec (cetirizine hydrochloride) and Tapazole (methimazole). Common drug interactions include headache among females and cardiac disorder among males.

The phase IV clinical study analyzes what interactions people have when they take Zyrtec and Tapazole. It is created by eHealthMe based on reports of 44 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 Tapazole?

Tapazole has active ingredients of methimazole. It is often used in hyperthyroidism. eHealthMe is studying from 2,477 Tapazole users. Check the latest studies of Tapazole.

On Jul, 21, 2026

44 people who take Zyrtec and Tapazole together, and have interactions are studied.

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

female:

Headache (pain in head)
Hyperaemia (increase of blood flow to different tissues in the body)
Hypothyroidism (abnormally low activity of the thyroid gland, resulting in retardation of growth and mental development)
Hypoxia (low oxygen in tissues)
Weight decreased
Astrocytoma (tumour of the brain that originate in a particular kind of glial-cells)
Basedow's disease (autoimmune disease where the thyroid is overactive, producing an excessive amount of thyroid hormones)
Bone disorder
Diplopia (double vision)
Disorder of orbit

male:

Cardiac disorder
Cough
Haemorrhage (bleeding)
Lacrimation increased
Ligament sprain (ligament stretched)
Oral pain
Photophobia (extreme sensitivity to light)
Pyrexia (fever)
Urine output increased
Decreased appetite

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

0-1:

n/a

2-9:

Cough
Diarrhoea
Exaggerated startle response
Oral pain
Pyrexia (fever)
Urine output increased

10-19:

Abdominal pain

20-29:

n/a

30-39:

Ageusia (loss of taste functions of the tongue)
Anosmia (partial or complete loss of the sense of smell)
Ankylosing spondylitis (type of arthritis affecting the spine)
Chronic kidney disease
Fatigue (feeling of tiredness)
Hyperparathyroidism secondary (an abnormally high concentration of parathyroid hormone in the blood, resulting in weakening of the bones through loss of calcium-secondary)
Injection site haematoma (localized swelling filled with blood at injection site)
Nephrogenic anaemia (anaemia due to kidney disease)
Rash erythematous (redness of the skin)
Renal failure (kidney dysfunction)

40-49:

Ageusia (loss of taste functions of the tongue)
Anosmia (partial or complete loss of the sense of smell)
Eyelid ptosis (falling of the upper or lower eyelid)
Hypersensitivity
Ventricular tachycardia (rapid heartbeat that originates in one of the lower chambers (the ventricles) of the heart)

50-59:

Sensation of foreign body
Swelling face
Weight increased
Abdominal distension
Constipation
Gastrointestinal pain
Mobility decreased (ability to move is reduced)
Nausea (feeling of having an urge to vomit)

60+:

Weight decreased
Astrocytoma (tumour of the brain that originate in a particular kind of glial-cells)
Lymphoma (cancer that begins in immune system cells)
Mastocytosis (an excessive number of apparently normal mast cells in the skin and, occasionally, in other organs)
Metastasis (spreadable cancer to other organ from origin)
Mouth ulceration (mouth ulcers)
Nasal septum deviation (deviated nasal septum)
Oral disorder (mouth disease)
Oral pain
Osteoarthritis (a joint disease caused by cartilage loss in a joint)

What are the existing conditions these people have? *

Multiple Myeloma (cancer of the plasma cells): 17 people, 38.64%
Urticaria Pigmentosa (skin disease that produces patches of darker skin (lesions) and very bad itching): 13 people, 29.55%
Pain: 7 people, 15.91%
Muscle Spasms (muscle contraction): 4 people, 9.09%
Wheezing (a high-pitched whistling sound made while you breath): 3 people, 6.82%
Thyroid Diseases: 3 people, 6.82%
Nasopharyngitis (inflammation of the nasopharynx): 3 people, 6.82%
Narcolepsy (brain's inability to regulate sleep-wake cycles normally): 3 people, 6.82%
High Blood Cholesterol: 3 people, 6.82%
Gastroesophageal Reflux Disease (a condition in which stomach contents leak backward from the stomach into the oesophagus): 3 people, 6.82%

* Approximation only. Some reports may have incomplete information.

Do you take Zyrtec and Tapazole?

- Personalize this study to your gender, age, symptoms and drugs
- Predict drug outcomes for up to one year with AI
- Get an AI agent to monitor your drugs continuously