Dyazide tablets contain Hydrochlorothiazide and Triamterene. It is a combination of two diuretic drugs and is used in patients with hypertension and edema or excess fluid in the body. It is associated with electrolyte abnormalities and dehydration.

Hydrochlorothiazide and triamterene Uses:

• Hypertension and edema:

  • Not recommended for initial treatment but recommended when hypertension and edema treated by hydrochlorothiazide have caused hypokalemia, or when the development of hypokalemia needs to be avoided.

Dyazide (Hydrochlorothiazide and Triamterene) Dose in Adults

Dyazide (Hydrochlorothiazide and Triamterene) Dose in the treatment of Hypertension and edema: Oral:

• Hydrochlorothiazide 25 mg/triamterene 37.5 mg: 1 to 2 tablets/capsules once daily
• Hydrochlorothiazide 25 mg/triamterene 50 mg: 1 to 2 capsules once daily
• Hydrochlorothiazide 50 mg/triamterene 75 mg: 1 tablet daily

Use in Children:

Not indicated.

Pregnancy Risk Factor C

• This product has not been used in animal reproduction studies.
• Talk to individual agents.

Use during breastfeeding:

• Breast milk excrets thiazide diuretics; triamterene excretion is unknown.
• It is not advised to breastfeed
• Talk to individual agents.

Dose in Kidney Disease:

• There are no dosage adjustments provided in the manufacturer’s labeling.
• Not recommended in CrCl<10ml.
• Contraindicated in patients with anuria, acute kidney injury, chronic renal failure, or significant renal impairment.

Dose in Liver disease:

There are no dosage adjustments provided by the manufacturer’s although it is advised to use with caution and monitor for precipitation of hepatic encephalopathy.

Side effects of Dyazide (Hydrochlorothiazide and Triamterene):

• Cardiovascular:

  • Angina Pectoris
  • Cardiac Arrhythmia
  • Necrotizing Angiitis
  • Orthostatic Hypotension
  • Tachycardia

• Central Nervous System:

  • Anxiety
  • Depression
  • Dizziness
  • Fatigue
  • Glossopyrosis
  • Headache
  • Insomnia
  • Paresthesia
  • Restlessness
  • Vertigo

• Dermatologic:

  • Skin Photosensitivity
  • Skin Rash
  • Urticaria

• Endocrine & Metabolic:

  • Acidosis
  • Diabetes Mellitus
  • Glycosuria
  • Hypercalcemia
  • Hyperglycemia
  • Hyperkalemia
  • Hyperuricemia
  • Hypochloremia
  • Hypokalemia
  • Hypomagnesemia
  • Hyponatremia

• Gastrointestinal:

  • Abdominal Pain
  • Anorexia
  • Constipation
  • Diarrhea
  • Dysgeusia
  • Gastric Distress
  • Nausea
  • Pancreatitis
  • Sialadenitis
  • Stomach Cramps
  • Tongue Discoloration (Bright Orange)
  • Vomiting
  • Xerostomia

• Genitourinary:

  • Impotence
  • Urine Discoloration
  • Urine Sedimentation Abnormality

• Hematologic & Oncologic:

  • Agranulocytosis
  • Aplastic Anemia
  • Hemolytic Anemia
  • Leukopenia
  • Megaloblastic Anemia
  • Purpura
  • Thrombocytopenia

• Hepatic:

  • Abnormal Liver Function Tests
  • Jaundice

• Hypersensitivity:

  • Anaphylaxis

• Neuromuscular & Skeletal:

  • Exacerbation Of Systemic Lupus Erythematosus
  • Lupus-Like Syndrome (Subacute
  • Cutaneous)
  • Muscle Cramps
  • Weakness

• Ophthalmic:

  • Transient Blurred Vision
  • Xanthopsia

• Renal:

  • Acute Renal Failure
  • Increased Blood Urea Nitrogen
  • Increased Serum Creatinine
  • Interstitial Nephritis
  • Nephrolithiasis

• Respiratory:

  • Dyspnea
  • Hypersensitivity Pneumonitis
  • Pulmonary Edema
  • Respiratory Distress

• Miscellaneous:

  • Fever

Contraindications to Dyazide (Hydrochlorothiazide and Triamterene):

• Hypersensitivity to triamterene, hydrochlorothiazide and sulfonamide-derived medications, or any component in the formulation
• anuria;
• Acute and chronic renal insufficiency, or severe renal impairment.
• Patients who are receiving potassium-sparing diuretics or potassium-containing substitutes for salts or potassium supplements (except in severe hypokalemia)
• preexisting hyperkalemia

Notice: 

• Although the FDA-approved product labeling says that this medication is contraindicated with other sulfonamide-containing drug classes, the scientific basis of this statement has been challenged.

Warnings and precautions

• Electrolyte disturbances:

  • Hydrochlorothiazide can cause electrolyte imbalances such as:
    • Hypokalemia
    • Hypochloremic alkalosis
    • hyponatremia

• Gout

  • Hydrochlorothiazide may trigger gout in some patients, especially those with a history or chronic renal disease.
  • Doses greater than 25 mg pose a higher risk.

• Hyperkalemia: [US Boxed Warning]:

  • Triamterene may cause hyperkalemia. Patients who have renal disease, diabetes (even if they don't show signs of impairment), the elderly and the seriously ill are at higher risk.
  • Serum potassium levels must be monitored closely at certain intervals especially in patients first receiving hydrochlorothiazide/triamterene, when dosages are changed, or with any other cause that may influence renal function.
  • Avoid potassium-containing salt substitutes, potassium-rich diets and other drugs that may cause hyperkalemia. 
  • Some exceptions to hypokalemia can be made by closely monitoring serum potassium levels in severe cases.
  • Hyperkalemia can be treated with drugs that should be stopped immediately
  • Critically ill patients may develop respiratory or metabolic acidosis. This may lead to rapid elevations of serum potassium concentrations.

• Hypersensitivity reactions

  • Hydrochlorothiazide may cause hypersensitivity reactions.
  • Patients who have a history of asthma or allergy are more likely to develop it.

• Ocular effects

  • Patients with acute transient myopia or acute angle-closure vision glaucoma may experience hydrochlorothiazide.
  • Treatment should be stopped immediately for patients experiencing severe visual impairments.
  • If uncontrolled intraocular pressure persists after discontinuation of treatment, additional treatments may need to be administered.
  • A history of penicillin allergy or sulfonamide allergy are major risk factors.

• Photosensitivity

  • Photosensitivity can occur.

• Allergy to sulfonamide ("sulfa")

  • FDA approved many medications that contain sulfonamides. Patients with an allergy to sulfonamides are advised not to use them.
  • Cross-reactivity is possible between members of the same group (e.g., two antibiotics sulfonamides).
  • Crossreactivity concerns have been raised for all compounds with the sulfonamide structural (SO NH). These drugs are also known as sulfa drug.
  • A better understanding of allergic mechanisms suggests that cross-reactivity between non-antibiotic sulfonamides (Brackett 2004, Johnson 2005, Slatore 2004, Tornero 2004) may not be possible.
  • Cross-reactions due to antibody production (anaphylaxis), are less likely to occur when using non-antibiotic sulfonamides.
  • T-cell-mediated (type IV), reactions (eg maculopapular skin rash) are less understood. It is difficult to exclude this possibility based on current knowledge.
  • Some clinicians will choose to avoid these classes in cases of Stevens-Johnson syndrome/TEN or other severe reactions.

• Diabetes:

  • Patients with diabetes mellitus or prediabetes should be cautious. It can cause a decrease in glycemic control.

• Hepatic impairment

  • Patients with severe hepatic impairment should be cautious
  • Avoid electrolyte imbalances and acid/base imbalances in progressive or severe liver disease. This could lead to hepatic emboli/coma.

• Hypercalcemia:

  • Patients with hypercalcemia should avoid Thiazide diuretics as they can decrease renal calcium excretion.

• Hypercholesterolemia:

  • Thiazides have been linked to impaired cholesterol and triglyceride levels. Patients with high or moderate cholesterol should not take thiazides.

• Kidney stones

  • Triamterene should be used with caution in patients suffering from renal stones.

• Parathyroid disease

  • Long-term use of Thiazide diuretics can reduce calcium excretion.
  • Parathyroid gland pathologies such as hypophosphatemia and hypercalcemia can be caused by prolonged exposure to the drug.
  • Before testing for parathyroid function, it is important to stop taking thiazides.

• Renal impairment

  • Hydrochlorothiazide and hydrochlorothiazide may have combined effects on the kidneys, including azotemia in those with impaired renal function.
  • In severe renal disease, avoid hydrochlorothiazide (ineffective).
  • Triamterene can cause hyperkalemia in patients suffering from renal impairment.

• Systemic lupus erythematosus (SLE):

  • SLE activation or exacerbation may be caused by hydrochlorothiazide.

Monitoring parameters:

• Monitor blood pressure,
• serum electrolytes, BUN, creatinine, liver function tests,
• signs of hyperkalemia

How to administer Dyazide (Hydrochlorothiazide and Triamterene)?

• Administer without regard to meals.

Mechanism of action of Dyazide (Hydrochlorothiazide and Triamterene):

Hydrochlorothiazide:

• Reduces sodium reabsorption through the distal tubules, resulting in increased excretion of sodium, water, as well as potassium ions and hydrogen ions.

Triamterene

• Blocks epithelial sodium channels within the late distal convoluted tube (DCT), and collecting duct, which in turn blocks sodium reabsorption from lumen. 
• This reduces intracellular sodium and decreases the function of Na+/K+ATPase.
• It also results in potassium retention, decreased calcium, magnesium and hydrogen excretion. 
• The natriuretic/diuretic and antihypertensive effects of sodium are generally weak because of the limited sodium uptake capacity within the DCT/collecting conduit.

See individual agents.

International Brand Names of Hydrochlorothiazide and triamterene:

• Dyazide
• Maxzide
• Maxzide-25
• Anjal
• Apo-triazide
• Dezide
• Diuracet-K
• Dyazide
• Dyberzide
• Dytenzide
• Dytide H
• Hidronol T
• Hydrene
• Maxzide
• Prestole
• Renezide
• Thiazide T
• Triampur Compositum
• Triazide
• Turfa

Hydrochlorothiazide and triamterene Brand Names in Pakistan: