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Diltiazem Side Effects

The most commonly reported side effects of diltiazem include dyspnoea, fatigue, and diarrhoea, based on 92,591 FDA adverse event reports from 2004 to 2025. 4.3% of reports found the drug to be ineffective.

Diltiazem side effects

Percentages show how often each reaction appears relative to total reports for diltiazem.

1
Dyspnoea6.8%6,259
2
Fatigue5.5%5,058
3
Diarrhoea4.6%4,241
4
Nausea4.4%4,068
5
Drug Ineffective4.3%3,996
6
Headache4.0%3,697
7
Dizziness3.9%3,583
8
Pain3.8%3,510
9
Fall3.8%3,488
10
Pneumonia3.6%3,366
11
Death3.6%3,357
12
Off Label Use3.5%3,261
13
Asthenia3.1%2,911
14
Atrial Fibrillation3.1%2,863
15
Hypotension3.1%2,842

These are voluntary reports and do not establish that diltiazem caused these reactions.

Report severity

74.3%Serious68,816 reports
41.8%Hospitalizations38,727 reports
15.5%Fatal14,392 reports

Seriousness is determined by the reporter, not by OpenClaim.

Diltiazem drug interactions

Other drugs that appear in adverse event reports alongside diltiazem. Drugs flagged as a suspected cause appear in the first column. Drugs taken at the same time but not suspected appear in the second.

Also suspected

1
Adalimumab3.7%3,432
2
Lenalidomide3.5%3,224
3
Aspirin3.1%2,915
4
Apixaban3.1%2,889
5
Acetaminophen3.1%2,870
6
Prednisone3.0%2,821
7
Treprostinil3.0%2,772
8
Omeprazole2.8%2,604
9
Rivaroxaban2.8%2,583
10
Dabigatran-etexilate-mesylate2.7%2,539
11
Etanercept2.4%2,249
12
Metoprolol2.3%2,144
13
Furosemide2.3%2,141
14
Tiotropium-bromide2.2%2,015
15
Pantoprazole-sodium2.1%1,932

Taken alongside

1
Aspirin19.0%17,631
2
Furosemide17.8%16,457
3
Acetaminophen14.4%13,366
4
Atorvastatin-calcium13.3%12,272
5
Levothyroxine-sodium13.0%12,020
6
Albuterol12.8%11,814
7
Metoprolol12.4%11,452
8
Ergocalciferol11.7%10,800
9
Omeprazole11.2%10,411
10
Lisinopril9.5%8,750
11
Warfarin9.1%8,430
12
Prednisone9.1%8,386
13
Metformin8.9%8,284
14
Fluticasone8.8%8,156
15
Pantoprazole-sodium8.3%7,711

Co-occurrence in adverse event reports does not establish a drug interaction. Patients often take multiple medications, and these lists reflect prescribing patterns rather than causal relationships. Consult a healthcare provider about potential drug interactions.

Who reports diltiazem side effects

58.4% of diltiazem adverse event reports involve female patients and 35.2% involve male patients. The largest age group is elderly at 62%. These figures reflect who reports side effects, not underlying risk.

Sex

Female58.4%
Male35.2%
Unknown6.4%

Age group

< 20.2%
2–110.1%
12–170.2%
18–6437.2%
65+62.2%

What is diltiazem used for

Conditions and purposes for which patients were taking diltiazem when the adverse event was reported.

Abdominal DiscomfortAccidental Drug Intake By ChildAccidental ExposureAccidental Exposure To ProductAccidental OverdoseAcidosisAcute Coronary SyndromeAcute Myocardial InfarctionAddison^s DiseaseAdverse EventAfibAggressionAgranulocytosisAllergic SinusitisAnal Fissure

Showing 15 of 703 indications

Diltiazem brand names and reporting trend

Diltiazem is sold under brand names including Cardizem Cd, Teczem.

Brand names

Cardizem Cd122
Teczem34

Quarterly reports (20042025)

20052010201520202025

An upward trend reflects increased FAERS reporting overall, not necessarily increased risk.

Taking diltiazem with another medication?

Ask OpenClaim about your specific drug combination. Get a sourced report using FDA data, drug labels, and medical literature.