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

Summary:

Drug interactions are reported among people who take Diphen (diphenhydramine hydrochloride) and Tapazole (methimazole). Common drug interactions include dysgeusia among females and anaemia among males.

The phase IV clinical study analyzes what interactions people have when they take Diphen and Tapazole. It is created by eHealthMe based on reports of 18 people who take the same drugs from the FDA, and is updated regularly.

What is Diphen?

Diphen has active ingredients of diphenhydramine hydrochloride. It is often used in insomnia. eHealthMe is studying from 115,432 Diphen users. Check the latest studies of Diphen.

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, 14, 2026

18 people who take Diphen and Tapazole together, and have interactions are studied.

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

female:

Dysgeusia (disorder of the sense of taste)
Chronic obstructive pulmonary disease (a progressive disease that makes it hard to breathe)
Influenza
Drug ineffective
Hypothyroidism (abnormally low activity of the thyroid gland, resulting in retardation of growth and mental development)
Abdominal pain upper
Back pain
Diarrhoea
Retching (strong involuntary effort to vomit)
Tachycardia (a heart rate that exceeds the range of 100 beats/min)

male:

Anaemia (lack of blood)
Anal ulcer
Drug ineffective
Dyspepsia (indigestion)
Dyspnoea exertional (breathlessness or shortness of breath)
Escherichia infection (bacterial infection by escherichia coli)
Haematuria (presence of blood in urine)
Haemorrhoids (a swollen vein or group of veins in the region of the anus)
Hepatomegaly (abnormal enlargement of the liver)
Intestinal ischaemia (decreased supply of oxygenated blood to the intestines)

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

0-1:

n/a

2-9:

n/a

10-19:

n/a

20-29:

Anal ulcer
Atelectasis (partial or complete collapse of the lung)
Blood culture positive
Colonic perforation (a hole in the colon)
Escherichia infection (bacterial infection by escherichia coli)
Hepatomegaly (abnormal enlargement of the liver)
Intestinal ischaemia (decreased supply of oxygenated blood to the intestines)
Neutropenia (an abnormally low number of neutrophils)
Pleural effusion (water on the lungs)
White blood cell count decreased

30-39:

n/a

40-49:

Dysgeusia (disorder of the sense of taste)
Drug ineffective
Hypothyroidism (abnormally low activity of the thyroid gland, resulting in retardation of growth and mental development)
Tachycardia (a heart rate that exceeds the range of 100 beats/min)
Hypersensitivity
Pruritus (severe itching of the skin)
Rash
Swelling
Decreased appetite
Depression

50-59:

Pericardial effusion (fluid around the heart)
Completed suicide (act of taking one's own life)
Overdose

60+:

Abdominal pain upper
Back pain
Proctitis (inflammation of the rectum and anus)
Rash maculo-papular (red area on the skin that is covered with small confluent bumps)
Chronic obstructive pulmonary disease (a progressive disease that makes it hard to breathe)
Diarrhoea
Influenza
Retching (strong involuntary effort to vomit)
Anaemia (lack of blood)
Clostridium difficile colitis (inflammation of colon by clostridium difficile bacteria infection)

What are the existing conditions these people have? *

Arrhythmias (irregular heartbeat): 3 people, 16.67%
Rheumatoid Arthritis (a chronic progressive disease causing inflammation in the joints): 2 people, 11.11%
Basedow's Disease (autoimmune disease where the thyroid is overactive, producing an excessive amount of thyroid hormones): 2 people, 11.11%
Drug Hypersensitivity: 2 people, 11.11%
Swelling: 1 person, 5.56%
Headache (pain in head): 1 person, 5.56%
Atrial Fibrillation/flutter (atrial fibrillation and flutter are abnormal heart rhythms in which the atria, or upper chambers of the heart, are out of sync with the ventricles): 1 person, 5.56%
Cancer Pain: 1 person, 5.56%
Chest Pain: 1 person, 5.56%
Constipation: 1 person, 5.56%

* Approximation only. Some reports may have incomplete information.

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