Tiazac and Doxycycline drug interactions - a phase IV clinical study of FDA data

Summary:

Drug interactions are reported among people who take Tiazac (diltiazem hydrochloride) and Doxycycline (doxycycline hyclate). Common drug interactions include dizziness among females and cardiac failure congestive among males.

The phase IV clinical study analyzes what interactions people have when they take Tiazac and Doxycycline. It is created by eHealthMe based on reports of 20 people who take the same drugs from the FDA, and is updated regularly.

What is Tiazac?

Tiazac has active ingredients of diltiazem hydrochloride. It is often used in high blood pressure. eHealthMe is studying from 4,761 Tiazac users. Check the latest studies of Tiazac.

What is Doxycycline?

Doxycycline has active ingredients of doxycycline hyclate. It is often used in acne. eHealthMe is studying from 60,868 Doxycycline users. Check the latest studies of Doxycycline.

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

20 people who take Tiazac and Doxycycline together, and have interactions are studied.

Tiazac and Doxycycline drug interactions.

What are the common drug interactions of Tiazac and Doxycycline, by gender? *:

female:

Dizziness
Fall
Gastrooesophageal reflux disease (stomach contents (food or liquid) leak backwards from the stomach into the oesophagus)
Hyperglycaemia (high blood sugar)
Hyperlipidaemia (presence of excess lipids in the blood)
Hypoacusis (loss of hearing)
Injury
Insomnia (sleeplessness)
International normalised ratio increased
Nasal congestion (blockage of the nasal passages usually due to membranes lining the nose becoming swollen from inflamed blood vessels)

male:

Cardiac failure congestive
Dyspnoea (difficult or laboured respiration)
Renal failure (kidney dysfunction)
Abdominal discomfort
Abdominal pain
Abnormal faeces (abnormal stool)
Acute coronary syndrome (acute chest pain and other symptoms that happen because the heart does not get blood)
Agitation (state of anxiety or nervous excitement)
Anaemia (lack of blood)
Anaemia megaloblastic (disorder of abnormally large red blood cells)

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

0-1:

n/a

2-9:

n/a

10-19:

n/a

20-29:

n/a

30-39:

Anxiety
Emotional distress
Fear
Pain
Renal failure (kidney dysfunction)
Renal impairment (severely reduced kidney function)
Renal injury (kidney injury)
Stress

40-49:

Chronic kidney disease
Renal failure (kidney dysfunction)

50-59:

Back pain
Blood chloride decreased
Blood glucose increased
Bronchitis (inflammation of the mucous membrane in the bronchial tubes)
Cardiac failure congestive
Cardioactive drug level below therapeutic
Cardiomegaly (increased size of heart than normal)
Chronic kidney disease
Confusional state
Cystitis escherichia (inflammation of the wall of the bladder by bacteria escherichia coli)

60+:

Cardiac failure congestive
Dyspnoea (difficult or laboured respiration)
Venous insufficiency (poor circulation of blood caused by damaged or enlarged veins)
Angina pectoris (chest pain due to ischemia of the heart muscle)
Anhedonia (inability to experience pleasure from activities usually found enjoyable)
Anxiety
Arthralgia (joint pain)
Atrial fibrillation (fibrillation of the muscles of the atria of the heart)
Balance disorder
Bronchiectasis (abnormal widening of the bronchi or their branches, causing a risk of infection)

What are the existing conditions these people have? *

Pain: 7 people, 35.00%
Gastroesophageal Reflux Disease (a condition in which stomach contents leak backward from the stomach into the oesophagus): 7 people, 35.00%
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): 5 people, 25.00%
Depression: 4 people, 20.00%
Gout (uric acid crystals building up in the body): 4 people, 20.00%
Nausea (feeling of having an urge to vomit): 4 people, 20.00%
Hyperlipidaemia (presence of excess lipids in the blood): 3 people, 15.00%
High Blood Cholesterol: 3 people, 15.00%
Osteopenia (a condition where bone mineral density is lower than normal): 3 people, 15.00%
Hypothyroidism (abnormally low activity of the thyroid gland, resulting in retardation of growth and mental development): 3 people, 15.00%

* Approximation only. Some reports may have incomplete information.

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