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Microzide Side Effects

Generic name: hydrochlorothiazide

Medically reviewed by Drugs.com. Last updated on Nov 15, 2023.

Note: This document provides detailed information about Microzide Side Effects associated with hydrochlorothiazide. Some dosage forms listed on this page may not apply specifically to the brand name Microzide.

Applies to hydrochlorothiazide: oral capsule, oral tablet.

Serious side effects of Microzide

Along with its needed effects, hydrochlorothiazide (the active ingredient contained in Microzide) may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur while taking hydrochlorothiazide:

Incidence not known

  • back, leg, or stomach pains
  • black, tarry stools
  • bleeding gums
  • blistering, peeling, or loosening of the skin
  • bloating
  • blood in the urine or stools
  • blue lips and fingernails
  • blurred vision
  • burning, crawling, itching, numbness, prickling, "pins and needles", or tingling feelings
  • chest pain or tightness
  • chills
  • clay-colored stools
  • cloudy urine
  • cold sweats
  • confusion
  • constipation
  • cough or hoarseness
  • coughing that sometimes produces a pink frothy sputum
  • coughing up blood
  • cracks in the skin
  • darkened urine
  • decrease in urine-concentrating ability
  • decreased frequency or amount of urine
  • diarrhea
  • difficult, fast, or noisy breathing
  • difficulty with swallowing
  • dizziness, faintness, or lightheadedness when getting up from a lying or sitting position
  • dry mouth
  • fast or irregular heartbeat
  • fever
  • flushed, dry skin
  • fruit-like breath odor
  • general body swelling
  • general feeling of discomfort or illness
  • greatly decreased frequency of urination or amount of urine
  • headache
  • hives, itching, rash
  • increased hunger
  • increased sweating
  • increased thirst
  • increased urination
  • indigestion
  • joint pain, stiffness, or swelling
  • loss of appetite
  • loss of heat from the body
  • lower back or side pain
  • muscle cramps or pain
  • nausea or vomiting
  • nosebleeds
  • numbness, tingling, pain, or weakness in the hands or feet
  • painful or difficult urination
  • pains in the stomach or side, possibly radiating to the back
  • pale skin
  • persistent non-healing sore
  • pink growth
  • pinpoint red spots on the skin
  • puffiness or swelling of the eyelids or around the eyes, face, lips, or tongue
  • red, irritated eyes
  • red skin lesions, often with a purple center
  • red, swollen skin
  • reddish patch or irritated area
  • redness, soreness, or scaly skin
  • seizures
  • shiny bump
  • sore throat
  • sores, ulcers, or white spots on the lips or in the mouth
  • sores, welting, or blisters
  • swelling of the face, fingers, legs, ankles, feet, or lower legs
  • swollen or painful glands
  • tenderness of salivary glands
  • thickening of bronchial secretions
  • trembling
  • trouble breathing
  • unpleasant breath odor
  • unusual bleeding or bruising
  • unusual tiredness or weakness
  • unusual weight loss
  • vomiting of blood
  • weakness and heaviness of the legs
  • weight gain
  • white, yellow or waxy scar-like area
  • yellow eyes or skin

Other side effects of Microzide

Some side effects of hydrochlorothiazide may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects.

Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

Incidence not known

  • cramping
  • decreased interest in sexual intercourse
  • difficulty having a bowel movement (stool)
  • feeling of constant movement of self or surroundings
  • hair loss or thinning of the hair
  • inability to have or keep an erection
  • increased sensitivity of the skin to sunlight
  • loss in sexual ability, desire, drive, or performance
  • muscle spasm
  • redness or other discoloration of the skin
  • restlessness
  • sensation of spinning
  • severe sunburn
  • weakness

Managing side effects (general information)

For healthcare professionals

Applies to hydrochlorothiazide: compounding powder, oral capsule, oral solution, oral tablet.

Metabolic adverse events

Since hydrochlorothiazide (the active ingredient contained in Microzide) may increase total serum cholesterol by 11%, LDL lipoprotein cholesterol by 12%, and VLDL lipoprotein cholesterol levels by 50%, and may reduce insulin secretion, it should be used with caution in diabetic patients and in those with hypercholesterolemia. True glucose intolerance may develop in approximately 3% of patients. It is typically reversible within six months after discontinuation of therapy.

Hyperuricamia may be an important consideration in patients with a history of gout. Hypophosphatasemia and low serum magnesium concentrations may occur, but are usually clinically insignificant except in malnourished patients.[Ref]

Hypersensitivity

There have been approximately 34 known cases of thiazide-induced pulmonary edema, encompassing 52 episodes of pulmonary edema, as of 1991 (per a 1996 review). In some cases, doses as small as 12.5 mg were associated with the development of pulmonary edema. The average time to onset of this adverse reaction is 44 minutes, women carry a relative risk of 9:1, and the average age is 56 years. The mortality rate is 6%. Some experts consider this side effect grossly underreported.[Ref]

Dermatologic

A 67-year-old woman with hypothyroidism, hypercalcemia, depression, and hypertension developed facial erythema, headaches, tremors, confusion and personality changes associated with a new positive ANA and anti-nRNP, and a skin biopsy consistent with lupus erythematosus while taking hydrochlorothiazide (HCTZ), levothyroxine, and amitriptyline. The eruption resolved upon discontinuation of HCTZ, but she later developed a higher ANA titer associated with symptomatic diffuse interstitial pulmonary infiltrates. She was successfully treated with corticosteroids.[Ref]

Renal

Although hydrochlorothiazide has been used to treat nephrogenic diabetes insipidus, a case report in which the drug was believed to have caused this condition has been reported.[Ref]

Cardiovascular

The incidence of premature ventricular contractions as measured by 48-hour ambulatory ECG monitoring is the same in both patients with and without left ventricular hypertrophy despite a similar fall in serum potassium concentrations.[Ref]

Gastrointestinal

Thiazide diuretics may increase serum cholesterol and triglycerides, resulting in increased risk of cholesterol gallstone formation. Reports of bowel strictures associated with thiazide ingestion were reported in the 1960s although these patients were on a combination hydrochlorothiazide-potassium product.[Ref]

Respiratory

Although rare, nearly 40 cases of hydrochlorothiazide-induced noncardiogenic pulmonary edema have been reported including at least two fatalities. Onset of symptoms can occur within minutes (range 10 to 150 minutes) of first exposure to the drug. Associated symptoms include dyspnea, hypoxia, respiratory distress, wheezing, cough, tachypnea, dizziness, nausea, vomiting, diarrhea, and hypotension. Ninety percent of cases have occurred in women at a mean dose of 38.7 mg. Treatment varies, but following discontinuation of hydrochlorothiazide (the active ingredient contained in Microzide) most patients respond, with symptoms resolving in a mean 3.5 days. Rechallenge can result in a more severe reaction, even months to years after the initial exposure. Rechallenge with any thiazide diuretic is not recommended.[Ref]

Immunologic

There are rare case reports of hydrochlorothiazide-induced immune hemolytic anemia. The following illustrates a fatal case:

A 53-year-old man with hypertension developed nausea, vomiting, diarrhea, and progressive anorexia and weakness associated with scleral icterus, anemia with spherocytosis, dark red urine with proteinuria, bilirubinuria, hemoglobinuria, and elevated lactic dehydrogenase levels 18 months after beginning hydrochlorothiazide and methyldopa. Haptoglobin was less than 50 mg per dl. Direct and indirect Coombs tests were positive. The patient died suddenly; autopsy revealed no obvious cause of death, left ventricular hypertrophy, and mild coronary atherosclerosis.[Ref]

Hematologic

Musculoskeletal

Nervous system

Ocular

Genitourinary

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Frequently asked questions

Further information

Microzide side effects can vary depending on the individual. Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Some side effects may not be reported. You may report them to the FDA.

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