Dithiazide

Dithiazide - Precautions | Dosage | Effects

This article was medically reviewed by M.Pharm, Marko Tanaskovic on August 12, 2018. To read more about an author, click here.

Dithiazide is a drug containing an active substance called hydrochlorothiazide. According to the mechanism of action, dithiazide is classified as a diuretic group, while it is classified pharmacologically into the group of antihypertensive agents (drugs that lower blood pressure).

How Does Dithiazide Work?

Although this medicine was developed back in 1959, the exact mechanism of its action is still not fully known. What is known is that Dithiazide increases the excretion of sodium and chloride because it changes the electrolyte reabsorption in the distal tubule of the kidneys. Increased sodium excretion leads to increased excretion of water, which reduces the circulatory volume and, consequently, the pressure on the blood vessels.

After taking Dithiazide tablets, the diuretic effect begins after only 2 hours, the maximum is reached after 4 hours and the effects lasts up to 12 hours.

Dithiazide is a drug that is not metabolized and is eliminated almost completely through urine.

Indications

Dithiazide is used in the treatment of hypertension, alone or in combination with other antihypertensives, as well as in the treatment of edema that as associated heart failure, liver cirrhosis, premenstrual tension, certain lung and kidney diseases, or corticosteroid or estrogen derivatives therapy.

Precautions

Dithiazide is contraindicated in patients with anuria (urine output of less than 50 ml over 24 hours) as well as in patients who are allergic to hydrochlorothiazide.

Dithiazide should not be used in patients who have kidney damage, as it can lead to azotemia (a high level of nitrogen or nitrogen-containing compounds in the blood) which can have serious health effects.

Exacerbation of symptoms of lupus erythematosus have been reported in patients taking Dithiazide and it is not recommended to use this medicine in patients with lupus.

Dithiazide can cause angle closure glaucoma, which (if not treated adequately) can lead to permanent vision loss. If you notice eye pain or other visual changes while on Dithiazide, you should contact your doctor immediately.

Like other diuretics, Dithiazide can lead to electrolyte imbalance and hyponatremia (low blood sodium levels), hypokalemia (low blood potassium levels), hypomagnesaemia (low levels of magnesium in the blood) and hypochloremia (low blood chlorine levels). These electrolyte disorders can lead to serious arrhythmias, and patients receiving Dithiazide should be monitored regularly (periodic monitoring of blood electrolyte levels is recommended). The risk of electrolyte imbalance is particularly high in patients who have vomiting or diarrhea while using Diathiazide. If you notice the symptoms of electrolyte imbalance (lethargy, drowsiness, confusion, pain or cramps in the muscles, rapid heartbeat, etc.), you should contact your doctor immediately.

In diabetic patients, blood glucose levels should be carefully monitored when administering Dithiazide, and the dosage of hypoglycemic drugs adjusted. Dithiazide can increase blood glucose levels and lead to hyperglycemia.

Dithiazide should not be used in patients who have liver damage, porphyria, or Adison's disease.

Use of Dithiazide During Pregnancy and Breastfeeding

Dithiazide should not be used during pregnancy, as it passes through the placenta and can damage the fetus.

Dithiazide should not be used in breastfeeding women. If its use is necessary, breastfeeding should be discontinued while taking this medicine.

Interactions

Dithiazide should not be administered concurrently with the following medicines:

  • Phenobarbitone and other barbiturates - medicines used in the treatment of epilepsy.
  • Opioid analgesics used in the treatment of severe pain.
  • Medicines used to treat high cholesterol (colestipol and cholestyramine) therapy. These medicines reduce gastrointestinal absorption of Dithiazide and reduce its effectiveness.
  • Lithium (an antipsychotic drug). Dithiazide reduces lithium excretion via the kidneys, leading to an increased level of lithium in the blood which further increases risk of adverse effects.
  • Non-steroidal anti-inflammatory drugs, such as: diclofenac, indomethacin, ibuprofen, naproxen and others. These drugs are used in the treatment of pain. Concomitant use with these medicines reduces the efficacy of Dithiazide.
  • Cardiac glycosides, such as digoxin. These drugs are used in the treatment of heart failure.
  • Antihistamines, such as: astemizole and terfenadine.
  • Immunosuppressant drugs, such as cyclosporine.

Tell your doctor about all the medicines you are using.

Adverse Effects

Dithiazide may cause the following side effects:

  • Electrolyte imbalance.
  • Electrolyte imbalance.
  • Anorexia.
  • Loss of appetite.
  • Nausea.
  • Vomiting.
  • Constipation.
  • Jaundice.
  • Depression.
  • Interstitial nephritis.
  • Anemia.
  • Blurred vision.
  • Photosensitivity.
  • Increase in blood levels of tryglyceride and cholesterol.
  • Allergic reactions.

Tell your doctor if you notice any side effects.

References

  1. TGA
  2. FDA

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If you have any concerns or questions about your health, you should always consult with a physician or other health-care professional.