Tenaxil SR

Tenaxil SR - Precautions | Dosage | Side Effects

This article was medically reviewed by M.Pharm, Marko Tanaskovic on Wed, 22 Jan 2020. To read more about an author, click here.

Tenaxil SR is a medicine that contains an active substance called indapamide. It belongs to the group of antihypertensives (medicines used to treat hypertension). According to the mechanism of action, this drug is classified as a diuretic.

Most of the drug is metabolized by the liver and only 7% of the drug is excreted in the urine in the unchanged form. About 70% of the drug binds to plasma proteins, while the elimination half-life of this drug is 26 hours.

Tenaxil SR is used to treat high blood pressure or retention of fluid or salt due to congestive heart failure.


Tenaxil SR is contraindicated in patients who have anuria (inability to urinate or passage of less than 100 ml of urine in a day) as well as in patients who are allergic or hypersensitive to the active substance indapamide or other drugs/substances from the indoline group.

Several cases of severe hyponatremia (low sodium concentration in the blood) have been reported, followed by hypokalemia (low potassium concentration in the blood), which can lead to severe electrolyte imbalance and severe arrhythmias. The risk of this side effect is higher in elderly women.

It is recommended to monitor the blood electrolyte levels regularly, especially at the beginning of therapy. It is also desirable to start the therapy at low doses and then gradually increase the dose until the therapeutic effect is achieved, with regular monitoring of the electrolytes with each dose increase.

Tenaxil SR may cause an increase in uric acid concentration and should therefore not be used in patients with gout.

Tenaxil SR can affect blood sugar levels and should be used with extra precaution in diabetics.

This medicine should be used with caution in patients who have impaired renal function because of the potential risk of azotemia. Monitoring of renal function is recommended while taking Tenaxil SR.

This medicine should be used with caution in patients with hepatic impairment, as hepatic coma may occur.

This medicine should not be used in patients who have systemic lupus, as it may worsen symptoms in these patients.

Use of Tenaxil SR During Pregnancy and Breastfeeding

Studies in animals, in which doses up to 6000 times higher than those used in humans were used, have shown that Tenaxil SR has no fetotoxic effect and does not affect fertility. However, there are no studies in humans to date to confirm this effect. Therefore, the FDA classifies this medicine in Category B and should not be used during pregnancy unless your doctor thinks that the benefit to the mother is greater than the risk to the fetus.

This medicine should not be used in the case of edema that often occurs in pregnancy.

It is unknown whether this medicine is excreted in breast milk or not, but it is not recommended for use while breastfeeding.


Tenaxil SR is available in potency of 1.25 mg in the form of modified-release tablet. The usual dose in hypertension treatment is one tablet (1.25 mg) per day, preferably to be taken in the morning as soon as you get up.

If the antihypertensive effect of this medicine is not adequate, Tenaxil SR can be combined with other antihypertensives, with electrolyte levels being taken into account.


Tenaxil SR reduces the renal clearance of lithium and therefore slows the elimination of this drug, which can lead to the lithium side effects. Therefore, the concomitant use of these two drugs is not recommended.

Concomitant use with cardiotonic glycosides (such as digoxin) used in the treatment of heart failure should be avoided, because of the increased risk of hypokalemia.

Tenaxil SR should not be used with the following medicines:

  • Aminolevulinic acid - used for the treatment of facial and skull actinic keratoses. Concomitant use may lead to an increased risk of photosensitivity and serious sunlight burns.
  • Arsenic trioxide - a drug used to treat acute promyelocytic leukemia. Concomitant use of these drugs may lead to cardiac arrhythmias.
  • Antiarrhythmic drugs, such as: amiodarone, dofetilide and dronedarone. Concomitant use of these medicines can lead to serious cardiac arrhythmias.
  • Cisapride - a gastrointestinal prokinetic. Concomitant use may lead to arrhythmias.
  • Metformin and other medicines used to treat diabetes. Your dose of diabetes medicine may need to be adjusted if you are taking Tenaxil SR.
  • Calcium supplements. Concomitant use may lead to hypercalcemia.

Tell your doctor about all medicines you are taking.

Adverse Effects

Tenaxil SR might generally cause mild and transient side effects. The following side effects have been reported:

  • Nervousness
  • Abdominal pain
  • Diarrhea
  • Dyspepsia
  • Nausea
  • Electrolyte imbalance (hyponatremia, hypokalemia and hypercalcemia)
  • Low blood platelet count
  • Pancreatitis
  • Dehydration
  • Hyperglycemia
  • Hepatitis
  • Photosensitivity
  • Arrhythmias
  • Allergic reaction

Inform your doctor if you are experiencing any side effect.


  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.