Amiloride / hydrochlorothiazide Side Effects

Not all side effects for amiloride / hydrochlorothiazide may be reported. You should always consult a doctor or healthcare professional for medical advice. Side effects can be reported to the FDA here.

For the Consumer

Applies to amiloride / hydrochlorothiazide: oral tablet

In addition to its needed effects, some unwanted effects may be caused by amiloride / hydrochlorothiazide. In the event that any of these side effects do occur, they may require medical attention.

You should check with your doctor immediately if any of these side effects occur when taking amiloride / hydrochlorothiazide:

More common
  • Abdominal pain
  • confusion
  • difficulty breathing
  • irregular heartbeats
  • nausea or vomiting
  • nervousness
  • numbness or tingling in the hands, feet, or lips
  • shortness of breath
  • weakness or heaviness of the legs
Less common
  • Dizziness
  • fainting
  • fast or slow heartbeat
  • labored breathing
  • tightness in the chest
  • wheezing
  • Ankle, knee, or great toe joint pain
  • arm, back, or jaw pain
  • blistering, peeling, or loosening of the skin
  • bloody or black, tarry stools
  • bloody urine
  • burning while urinating
  • burning, crawling, itching, numbness, prickling, "pins and needles", or tingling feelings
  • chest pain, discomfort, or heaviness
  • chills
  • cloudy urine
  • cold sweats
  • coma
  • constipation
  • convulsions
  • cough
  • cracks in the skin
  • decreased awareness or responsiveness
  • decreased frequency or amount of urine
  • diarrhea
  • difficult or painful urination
  • dizziness, faintness, or lightheadedness when getting up from a lying or sitting position suddenly
  • dry mouth
  • fever
  • headache
  • increase in heart rate
  • increased blood pressure
  • increased thirst
  • itching
  • joint pain, stiffness, or swelling
  • lightheadedness
  • loss of appetite
  • loss of heat from the body
  • lower back or side pain
  • muscle pain or cramps
  • pounding heartbeat or pulse
  • rapid breathing
  • red skin lesions, often with a purple center
  • red, irritated eyes
  • red, swollen skin
  • scaly skin
  • severe sleepiness
  • severe stomach pain
  • sore throat
  • sores, ulcers, or white spots in the mouth or on the lips
  • sunken eyes
  • sweating
  • swelling of the face, ankles, hands, fingers, or lower legs
  • troubled breathing
  • unusual tiredness or weakness
  • vomiting of blood or material that looks like coffee grounds
  • weight gain
  • wrinkled skin

If any of the following symptoms of overdose occur while taking amiloride / hydrochlorothiazide, get emergency help immediately:

Symptoms of overdose
  • Drowsiness
  • irritability
  • mood changes
  • pain or weakness in the hands or feet
  • trembling
  • weak pulse

Some of the side effects that can occur with amiloride / hydrochlorothiazide may not need medical attention. As your body adjusts to the medicine during treatment these side effects may go away. Your health care professional may also be able to tell you about ways to reduce or prevent some of these side effects. If any of the following side effects continue, are bothersome or if you have any questions about them, check with your health care professional:

More common
  • Rash
  • weight loss
Less common
  • Leg ache
  • stomach pain
  • Bad taste
  • bloated, full feeling
  • blurred or loss of vision
  • changes in appetite
  • decreased interest in sexual intercourse
  • discouragement
  • disturbed color perception
  • double vision
  • excess air or gas in the stomach or intestines
  • feeling of constant movement of self or surroundings
  • feeling of warmth
  • feeling sad or empty
  • general feeling of discomfort or illness
  • hair loss or thinning of hair
  • hiccups
  • inability to have or keep an erection
  • increased sweating
  • increased urge to urinate during the night
  • indigestion
  • loss in sexual ability, desire, drive, or performance
  • loss of bladder control
  • loss of interest or pleasure
  • muscle spasm
  • night blindness
  • overbright appearance of lights
  • passing of gas
  • redness of the face, neck, arms, and occasionally upper chest
  • seeing halos around lights
  • sensation of spinning
  • sleepiness
  • sleeplessness
  • stomach fullness or discomfort
  • stuffy nose
  • swelling of the breasts or breast soreness in both females and males
  • trouble concentrating
  • trouble sleeping
  • tunnel vision
  • unable to sleep
  • waking to urinate at night

For Healthcare Professionals

Applies to amiloride / hydrochlorothiazide: oral tablet


Cases of severe hyperkalemia associated with paralysis, cardiac arrhythmias, and even death have been reported.

Patients who are at particular risk for thiazide-induced hyponatremia include the elderly, frail women, and those with hypovolemia or who are in the postoperative state. In the latter two cases, antidiuretic hormone levels tend to be elevated, which may contribute to the development of hyponatremia.

Hyperkalemia is more likely in patients with underlying renal dysfunction.

Metabolic side effects are common. Hyperkalemia occurs in 1% to 2% of patients. Hyperkalemia is more likely in women, patients with diabetes (even without signs of diabetic nephropathy), and patients with renal insufficiency. Hyponatremia may occur in up to 20% of patients.

Increases in serum uric acid, total cholesterol, and total triglycerides have been associated with the use of HCTZ. This may be important in some patients at risk for or who have a history of gout or coronary artery disease.


A 50-year-old woman with a history of congestive heart failure developed acute noncardiogenic pulmonary edema within 10 minutes after ingesting HCTZ-amiloride. Inadvertent rechallenge resulted in a recurrence. Subsequent selective skin patch testing revealed an allergy to HCTZ and not to amiloride.

Hypersensitivity reactions to HCTZ-amiloride are rare. A case of allergic pneumonitis and noncardiogenic pulmonary edema has been associated with the use of this drug. Acute pulmonary edema, interstitial cystitis, interstitial nephritis, and anaphylaxis have been associated with the use of HCTZ.


Genitourinary problems include rare complaints of impotence among male patients. Polyuria and urinary frequency have been reported in less than 1% of patients.


Gastrointestinal side effects are unusual. Diarrhea, nausea, constipation, anorexia, and general abdominal pain occur in less than 5% of patients.

Rare instances of pancreatitis and acute cholecystitis have been associated with the use of HCTZ.

Nervous system

Nervous system side effects occur in less than 3% of patients. They include headache, weakness, and fatigue.


Cardiovascular side effects are mainly limited to the increased risk of hyperkalemia-induced arrhythmias in patients at risk for arrhythmias. Angina pectoris, arrhythmias, and orthostatic hypotension have been reported in less than 1% of patients.


Dermatologic side effects associated with hydrochlorothiazide (HCTZ) include isolated cases of subacute cutaneous lupus, erythema annular centrifugum, and acute eczematous dermatitis. Thiazides may induce phototoxic dermatitis.


A 74-year-old woman developed acute renal failure and granulomatous interstitial nephritis during amiloride-HCTZ therapy. Her renal function slightly improved after stopping the drug and after 20 months of oral steroid therapy.

New or worsened renal insufficiency has rarely been associated with each component of this drug. Granulomatous interstitial nephritis has been associated with amiloride-HCTZ.

Disclaimer: Every effort has been made to ensure that the information provided is accurate, up-to-date and complete, but no guarantee is made to that effect. In addition, the drug information contained herein may be time sensitive and should not be utilized as a reference resource beyond the date hereof. This material does not endorse drugs, diagnose patients, or recommend therapy. This information is a reference resource designed as supplement to, and not a substitute for, the expertise, skill , knowledge, and judgement of healthcare practitioners in patient care. The absence of a warning for a given drug or combination thereof in no way should be construed to indicate safety, effectiveness, or appropriateness for any given patient. does not assume any responsibility for any aspect of healthcare administered with the aid of materials provided. The information contained herein is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. If you have questions about the substances you are taking, check with your doctor, nurse, or pharmacist.