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chlorthalidone

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Brand names: Thalitone

Thiazide-Like Diuretic Rx

Chlorthalidone is a water pill that helps lower blood pressure and reduce swelling. It works by helping your kidneys remove extra salt and water from your body.

Drug Pricing (NADAC)

Brand Price

$3.55/unit

Generic Price

$0.08/unit

Generic Savings

98%

Generic Available

Yes (16 manufacturers)

Pricing data from NADAC (CMS), effective December 18, 2024. Compare all drug costs →

What it does

This medicine treats high blood pressure, either alone or with other drugs.

Common side effects

Loss of appetite, Upset stomach, Nausea

Key warnings

If you have kidney problems where you aren't producing urine, you should not take this medicine.

How It Works

Chlorthalidone is a diuretic, which means it helps your body get rid of extra fluid. It works by acting on your kidneys to increase the amount of salt and water that you pass in your urine. This helps to lower your blood pressure and reduce swelling.

How to Take It

Take chlorthalidone once a day in the morning with food. Start with a low dose, like 25 mg, and your doctor may increase it to 50 mg or 100 mg if needed. For swelling, you might start with 50 to 100 mg daily, or 100 mg every other day. Follow your doctor's instructions carefully.

Pregnancy & Breastfeeding

Using water pills when you are otherwise healthy during pregnancy is not a good idea and could be risky for you and your baby. If you have swelling during pregnancy, try raising your legs and wearing support hose first. Talk to your doctor before taking this medicine while pregnant.

Missed Dose

If you miss a dose, take it as soon as you remember. If it's almost time for your next dose, skip the missed dose and continue with your regular schedule.

Storage

Store chlorthalidone tablets at room temperature (68° to 77°F) and protect them from light, in a tightly closed container.

Side Effects (from patient reports)

Based on 6,005 FDA adverse event reports.

Tiredness
861
Feeling sick to your stomach
704
The medicine is not working
701
Loose stools
643
Feeling lightheaded
563
Aches
541
Head pain
513
Shortness of breath
509
Using the medicine for something it's not approved for
499
Sudden kidney damage
471

FDA Adverse Event Report Analysis

Detailed analysis of 11,035 reports from the FDA Adverse Event Reporting System (FAERS). Reports span 2004–2025.

Total Reports

11,035

Death-Related Reports

656

Hospitalization Reports

3,583

Top Indication

Product Used For Unknown Indication

Gender Distribution

Female 5,713 (56%)
Male 4,471 (44%)

Age Distribution

0–17 38
18–44 473
45–64 2,757
65–74 2,159
75+ 1,914

Most Reported Adverse Reactions (FAERS)

# Reaction Reports
1 FATIGUE 861
2 NAUSEA 704
3 DRUG INEFFECTIVE 700
4 DIARRHOEA 643
5 DIZZINESS 563
6 PAIN 541
7 HEADACHE 513
8 DYSPNOEA 509
9 OFF LABEL USE 498
10 ACUTE KIDNEY INJURY 471
11 CHRONIC KIDNEY DISEASE 455
12 ARTHRALGIA 432
13 ASTHENIA 420
14 BLOOD PRESSURE INCREASED 388
15 HYPERTENSION 387

Reactions in Death Reports

DEATH 274
COMPLETED SUICIDE 54
ACUTE KIDNEY INJURY 48
PNEUMONIA 43
RENAL FAILURE 39
CHRONIC KIDNEY DISEASE 37
DYSPNOEA 33
HYPOTENSION 33
TOXICITY TO VARIOUS AGENTS 32
FATIGUE 29

Reactions in Hospitalization Reports

ACUTE KIDNEY INJURY 299
NAUSEA 279
FATIGUE 248
DYSPNOEA 238
HYPONATRAEMIA 230
FALL 225
VOMITING 222
DIARRHOEA 217
PNEUMONIA 216
ASTHENIA 200

Source: FDA FAERS (Adverse Event Reporting System) FDA FAERS (Adverse Event Reporting System) Reports are voluntary and do not establish causation

Serious Warnings

If you have kidney problems where you aren't producing urine, you should not take this medicine. Also, if you are allergic to chlorthalidone or other sulfa drugs, avoid this medication.

Known Drug Interactions

moderate azilsartan

7 DRUG INTERACTIONS Renal clearance of lithium is reduced by diuretics, such as chlorthalidone increasing the risk of lithium toxicity ( 7 ) NSAIDS increase risk of renal dysfunction and interfere with antihypertensive effect ( 7 ) Dual inhibition of the renin-angiotensin system: Increased risk of renal impairment, hypotension, and hyperkalemia ( 7 ) Lithium: Increases in serum lithium concentrations and lithium toxicity ( 7 ) 7.1 Non-Steroidal Anti-Inflammatory Agents including Selective Cyclooxygenase-2 Inhibitors (COX-2 Inhibitors) In patients who are elderly, volume-depleted (including ...

Mechanism: These drugs work in different ways to lower blood pressure, which can increase the risk of very low blood pressure and kidney problems.

What to do: Your doctor should monitor your blood pressure and kidney function closely while you are taking these medications.

Chlorthalidone and related drugs may decrease arterial responsiveness to norepinephrine.

Mechanism: Chlorthalidone makes your blood vessels less reactive to norepinephrine. This can make it harder for norepinephrine to raise your blood pressure when needed.

What to do: Your doctor should monitor your blood pressure closely and may need to adjust your medication doses.

In separate single or multiple dose pharmacokinetic interaction studies with chlorthalidone, nifedipine, propranolol, hydrochlorothiazide, cimetidine, metoclopramide, propantheline, digoxin, and warfarin, the bioavailability of fosinoprilat was not altered by coadministration of fosinopril with any one of these drugs.

Mechanism: Taking these medications together does not affect the amount of active medicine that enters your body.

What to do: You can generally take these together without adjusting the dose, though your doctor will monitor your response.

Common Questions

Can I take this with other blood pressure medicines?
Yes, chlorthalidone can be used with other blood pressure medicines.
What should I do if I feel dizzy?
Dizziness can occur. Rise slowly when getting up from a sitting or lying position.
Will this medicine cure my high blood pressure?
Chlorthalidone helps control high blood pressure, but it may not cure it. You may need to take it long-term.
Can I drink alcohol while taking this medicine?
Alcohol can worsen some side effects, like dizziness. Talk to your doctor about alcohol consumption.
Does this medicine affect blood sugar?
Yes, chlorthalidone can increase blood sugar levels, especially in people with diabetes.
Can this medicine affect my potassium levels?
Yes, chlorthalidone can lower your potassium levels. Your doctor may monitor this with blood tests.
How long does it take for this medicine to work?
It may take a few weeks to see the full effect of chlorthalidone on your blood pressure or swelling.
What if I have side effects?
If you have side effects that bother you, contact your doctor.
Can I stop taking this medicine on my own?
Do not stop taking chlorthalidone without talking to your doctor first.
Does this medicine interact with other medications?
Yes, chlorthalidone can interact with other medications. Tell your doctor about all the medicines you take.
What are the common side effects of chlorthalidone?
The most commonly reported side effects of chlorthalidone include Loss of appetite, Upset stomach, Nausea, Vomiting, Cramps. Based on 6,005 FDA adverse event reports. Always consult your healthcare provider about potential side effects.
Does chlorthalidone interact with other medications?
Yes, chlorthalidone has 3 known drug interactions. Notable interactions include azilsartan, norepinephrine, fosinopril. Always inform your doctor about all medications you are taking.
What drug class is chlorthalidone?
chlorthalidone belongs to the Thiazide-Like Diuretic drug class. It requires a prescription (Rx). This medicine treats high blood pressure, either alone or with other drugs.
Is there a generic version of chlorthalidone?
Yes, generic chlorthalidone is available from 16 manufacturers. The generic costs $0.08 per unit compared to $3.55 for the brand version, saving approximately 98%. Pricing is based on NADAC (National Average Drug Acquisition Cost) data from CMS.
Is chlorthalidone safe during pregnancy?
Using water pills when you are otherwise healthy during pregnancy is not a good idea and could be risky for you and your baby. If you have swelling during pregnancy, try raising your legs and wearing support hose first. Always consult your healthcare provider before using any medication during pregnancy or breastfeeding.
Has chlorthalidone been recalled?
There is 1 recall associated with chlorthalidone products. Failed Dissolution Specifications. Check the recalls section below for full details and affected products.

Active Recalls

Class II May 9, 2025

Failed Dissolution Specifications

AvKARE

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What the FDA Data Shows for chlorthalidone

The FDA label for chlorthalidone (sold under brand names such as Thalitone) classifies it as a prescription-only medication in the Thiazide-Like Diuretic class. This medicine treats high blood pressure, either alone or with other drugs. Official labeling lists 12 commonly reported side effects, including Loss of appetite, Upset stomach, Nausea.

Post-market surveillance from the FDA Adverse Event Reporting System (FAERS) captures real-world experience. For this drug, FAERS contains 6,005 voluntary reports. The database also lists 3 documented drug interactions derived from FDA labeling, with the top-flagged interaction rated moderate severity. NADAC pricing from CMS shows a generic unit cost of $0.08 versus $3.55 for the brand — a 98% generic savings.

Report counts do not establish causation — a FAERS entry documents a temporal association, not proof that the drug produced the outcome. Widely prescribed medications naturally accumulate more reports than niche therapies, so raw totals must be interpreted alongside total exposure. Shortage status, recall history (currently 1 recall record on file), and patent information further shape supply and switching decisions. This page summarizes public FDA data for educational purposes only and is not a substitute for professional medical advice — always consult a licensed healthcare provider before starting, stopping, or changing any medication.

Data Sources

Drug labeling: FDA Drug Labels (SPL/DailyMed). Adverse events: FDA Adverse Event Reporting System (FAERS). Pricing: CMS National Average Drug Acquisition Cost (NADAC).

FAERS reports are voluntary and do not establish causation. Drug interactions are derived from FDA labeling and clinical references. Always consult a healthcare professional before making medication decisions.

Last updated: November 24, 2022

All federal data sources used on this page