Xipamide is a sulfonamide diuretic drug marketed by Eli Lilly under the trade names Aquaphor (in Germany) and Aquaphoril (in Austria). It is used for the treatment of oedema and hypertension.
Mechanism of action
Like the structurally related thiazide diuretics
, xipamide acts on the kidneys to reduce sodium
reabsorption in the distal convoluted tubule. This increases the osmolarity in the lumen, causing less water to be reabsorbed by the collecting ducts. This leads to increased urinary output. Unlike the thiazides, xipamide reaches its target from the peritubular side (blood side).
Additionally, it increases the secretion of potassium in the distal tubule and collecting ducts. In high doses it also inhibits the enzyme carbonic anhydrase which leads to increased secretion of bicarbonate and alkalizes the urine.
Unlike with thiazides, only terminal renal failure renders xipamide ineffective.
Xipamide is used for
After oral administration, 20 mg of xipamide are resorbed quickly and reach the peak plasma concentration of 3 mg/l within an hour. The diuretic effect starts about an hour after administration, reaches it speak between the third and sixth hour, and lasts for nearly 24 hours.
One third of the dose is glucuronidized, the rest is excreted directly through the kidney (1/3) and the faeces (2/3). The total plasma clearence is 30-40 ml/min. Xipamide can be filtrated by haemodialysis but not by peritoneal dialysis.
Initially 40 mg, it can be reduced to 10-20 mg to prevent a relapse.
The lowest effective dose is 5 mg. More than 60 mg have no additional effects.
- more than 1/10 of all patients
- hypokalaemia, which can lead to nausea, muscular weakness or cramps, and ECG abnormities
- 1/100 to 1/10
- 1/1000 to 1/10,000
- less than 1/10,000
Not recommended combinations
- Xipamide lowers the renal clearence of lithium which can lead to lithium intoxication. (This interaction is classified as medium.)
Combinations requiring special precautions
The product information requests special precautions for these combinations:
Contraindications not included in the product information
- Xipamide can reduce the effect of antidiabetics. (Classified as minor.)