FDA Adverse Events Reports (FAERS) Summary for CHLORTHALIDONE

These tables and charts are based on 13,022 total reports for CHLORTHALIDONE (CHLORTHALIDONE) received by the FDA Adverse Event Reporting System (FAERS) from 2004 through April 28, 2026.

This FAERS total includes 12,045 pharmaceutical company-submitted and non-U.S. FAERS reports and 977 U.S. consumer or healthcare provider-submitted MedWatch reports. For a separate summary of the 977 U.S. reports filed via the FDA MedWatch voluntary reporting system, view our FDA MedWatch CHLORTHALIDONE summary report. (See notes section below for explanation of FDA’s mandatory and voluntary reporting system.)

Top 20 Adverse Effects Associated with CHLORTHALIDONE (reported in FAERS Database)

	Side Effect	# of FDA Reports
1	FATIGUE	1013
2	DRUG INEFFECTIVE	967
3	NAUSEA	902
4	DIARRHEA	783
5	PAIN	673
6	DIZZINESS	663
7	HEADACHE	641
8	OFF LABEL USE	633
9	SHORTNESS OF BREATH	624
10	JOINT PAIN	568
11	HIGH BLOOD PRESSURE	502
12	ACUTE KIDNEY INJURY	496
13	LACK OF STRENGTH AND ENERGY (ASTHENIA)	494
14	CHRONIC KIDNEY DISEASE	479
15	RASH	471
16	MALAISE	460
17	FALL	453
18	BLOOD PRESSURE INCREASED	437
19	VOMITING	436
20	ITCHING	411
21	COUGH	402
22	WEIGHT DECREASED	376
23	LOWER LIMBS SWELLING	352
24	HYPONATRAEMIA	345
25	PAIN IN EXTREMITY	345
26	KIDNEY FAILURE	337
27	CONDITION AGGRAVATED	322
28	PNEUMONIA	319
29	CONSTIPATION	316
30	DEATH	314
31	BACK PAIN	301
32	HYPOKALAEMIA	292
33	LOW BLOOD PRESSURE	277
34	DECREASED APPETITE	273
35	FEVER	273
36	PRODUCT DOSE OMISSION ISSUE	272
37	INSOMNIA	268
38	ABDOMINAL PAIN UPPER	264
39	DRUG INTERACTION	260
40	ANXIETY	247
41	WEIGHT INCREASED	244
42	DEHYDRATION	241
43	COVID-19	238
44	FEELING ABNORMAL	237
45	GAIT DISTURBANCE	237
46	URINARY TRACT INFECTION	233
47	ANEMIA	228
48	DRUG HYPERSENSITIVITY	226
49	SWELLING OF LIMBS	226
50	DEPRESSION	209
51	KIDNEY IMPAIRMENT	209
52	MUSCLE PAIN	208
53	MUSCLE SPASMS	207
54	ABDOMINAL DISCOMFORT	205
55	HYPERSENSITIVITY	201
56	COMMON COLD	200
57	CHEST PAIN	196
58	PRODUCT USE IN UNAPPROVED INDICATION	194
59	JOINT SWELLING	191
60	DROWSINESS	191
61	ABDOMINAL PAIN	189
62	BLOOD GLUCOSE INCREASED	183
63	BLOOD POTASSIUM DECREASED	177
64	DRUG INTOLERANCE	177
65	FAINTING	172
66	TREMOR	167
67	MUSCULAR WEAKNESS	162
68	GASTROOESOPHAGEAL REFLUX DISEASE	160
69	NUMBNESS	160
70	PINS AND NEEDLES	160
71	HAIR LOSS	159
72	ATRIAL FIBRILLATION	157
73	HAEMOGLOBIN DECREASED	156
74	INJECTION SITE PAIN	155
75	EXCESS SWEATING	152
76	STROKE	151
77	BLOOD CREATININE INCREASED	148
78	CONFUSIONAL STATE	148
79	ASTHMA	147
80	PRODUCT USE ISSUE	146
81	MUSCULOSKELETAL STIFFNESS	145
82	INAPPROPRIATE SCHEDULE OF PRODUCT ADMINISTRATION	143
83	NEUROPATHY PERIPHERAL	143
84	HOT FLUSH	141
85	HIVES	138
86	WRONG TECHNIQUE IN PRODUCT USAGE PROCESS	132
87	HEART FAILURE	131
88	SKIN REDNESS	131
89	MEMORY IMPAIRMENT	131
90	CONGESTIVE HEART FAILURE	128
91	SINUSITIS	128
92	SWELLING	128
93	PULMONARY EMBOLISM	124
94	INCORRECT DOSE ADMINISTERED	121
95	VISION BLURRED	120
96	KIDNEY FAILURE	119
97	INFLUENZA	116
98	BALANCE DISORDER	114
99	GASTROINTESTINAL DISORDER	114
100	WHEEZING	114

Latest Known Outcomes for Reactions Reported for CHLORTHALIDONE

	Latest Known Outcome for Reported Reactions	Number of Cases
1	Unknown Outcome	7158
2	Patient has not recovered/symtoms have not resolved	3458
3	Patient recovered	3217
4	Patient is recovering/symptoms resolving	1571
5	Patient died	619
6	Patient has recovered but has consequent health issues	81

Search all MedWatch and FAERS by keyword:

CHLORTHALIDONE Total Reports

Male	Female	Unknown	Total
5157	6852	1013	13,022

Top Countries Reporting

	Country	Number of Reports
1	United States	9584
2	Canada	902
3	Brazil	242
4	Germany	181
5	Spain	138
6	Italy	118
7	Portugal	93
8	EU	70
9	Netherlands	66
10	United Kingdom	45

Outcomes for Reports

Serious: 8341
Not Serious: 4677
Note: A serious outcome means the adverse event resulted in death, a life threatening condition, hospitalization, disability, congenital anomaly, or other serious condition.

Top Indications

HIGH BLOOD PRESSURE
Product used for unknown indication
Type 2 diabetes mellitus
HEART FAILURE
Blood pressure measurement

Top Companies Reporting

Safety-Related FDA Updates

THALITONE (CHLORTHALIDONE) Discontinued Drug:
Safety-related Labeling Changes

Have experience (good or bad) with THALITONE? Rate THALITONE at Ask a Patient.

For serious adverse events, report them to the FDA by contacting the drug manufacturer or report directly through the MedWatch voluntary reporting form.

Notes

This report, created by AskaPatient.com, is derived from the cases for CHLORTHALIDONE reported to the United States Food and Drug Administration (FDA) FDA Safety Information and Adverse Event Reporting System (FAERS) and obtained from Open FDA. Data was last updated with reports received through April 28, 2026.

This summary includes ALL reports where the drug is a "primary OR secondary OR suspected interacting" drug. Typically, reports are filed for the most serious type or "event" and do not represent incidental or minor side effects. The majority of these reports are mandatory reports submitted by pharmaceutical companies, who receive complaints from consumers. The reactions, side effects, or "adverse events," represent up to the 20 most frequently occuring events in the database for a drug related to the event. This report also features counts of latest known outcomes associated with reported side effects, but does not provide the specific outcomes for specific adverse events.

Adverse Event Reports are submitted to the FAERS database by pharmaceutical companies (mandatory reporting is required by manufacturers, distributors, or importers). Health care providers such as doctors (voluntary reporting), and patients themselves (voluntary reporting) report to the FDA directly through the MedWatch program. Those MedWatch reports are coded and included in the FAERS database. This report mainly consists of the mandatory reports, because the MedWatch reports are a small percentage (3 - 5%) of total reports. Link to the MedWatch summary report at the top of the page for a summary of the directly reported (voluntary) adverse events for this drug.The number of reports included here might differ somewhat from the number of reports in the downloadable quarterly FAERS reports and in the online FAERS dashboard, due to lags in reporting, drug name differences, duplicates, and other factors. Open FDA states that it only includes the most recent version of a case report. It also adds the disclaimer: "Do not rely on openFDA to make decisions regarding medical care. While we make every effort to ensure that data is accurate, you should assume all results are unvalidated."

FDA uses the "MedDRA" classification system to describe reported adverse reactions. MedDRA is a standardized medical terminology that facilitates sharing of regulatory information internationally. In some cases, "patient friendly" terms for the layman designated by MedDRA have been substituted for medical jargon. Please contact us with questions or comments about this report.