MIDAMOR (amiloride) is usually well tolerated and except for hyperkalemia (serum potassium levels greater than 5.5 mEq per liter † see BOXED WARNING), significant adverse effects have been reported infrequently. Minor adverse reactions were reported relatively frequently (about 20%) but the relationship of many of the reports to amiloride HCl is uncertain and the overall frequency was similar in hydrochlorothiazide treated groups. Nausea/anorexia, abdominal pain, flatulence, and mild skin rash have been reported and probably are related to amiloride. Other adverse experiences that have been reported with amiloride are generally those known to be associated with diuresis, or with the underlying disease being treated.

The adverse reactions for MIDAMOR (amiloride) listed in the following table have been arranged into two groups: (1) incidence greater than one percent; and (2) incidence one percent or less. The incidence for group (1) was determined from clinical studies conducted in the United States (837 patients treated with MIDAMOR (amiloride) ). The adverse effects listed in group (2) include reports from the same clinical studies and voluntary reports since marketing. The probability of a causal relationship exists between MIDAMOR (amiloride) and these adverse reactions, some of which have been reported only rarely.

** Reactions occurring in 3% to 8% of patients treated with MIDAMOR (amiloride) . (Those reactions occurring in less than 3% of the patients are unmarked.)
*** See BOXED WARNING.

Causal Relationship Unknown: Other reactions have been reported but occurred under circumstances where a causal relationship could not be established. However, in these rarely reported events, that possibility cannot be excluded. Therefore, these observations are listed to serve as alerting information to physicians.

• Activation of probable pre-existing peptic ulcer
• Aplastic anemia
• Neutropenia
• Abnormal liver function

Read the Midamor (amiloride) Side Effects Center for a complete guide to possible side effects »

When amiloride HCl is administered concomitantly with an angiotensin-converting enzyme inhibitor, the risk of hyperkalemia may be increased. Therefore, if concomitant use of these agents is indicated because of demonstrated hypokalemia, they should be used with caution and with frequent monitoring of serum potassium. (See WARNINGS.)

Lithium generally should not be given with diuretics because they reduce its renal clearance and add a high risk of lithium toxicity. Read circulars for lithium preparations before use of such concomitant therapy.

In some patients, the administration of a non-steroidal anti-inflammatory agent can reduce the diuretic, natriuretic, and antihypertensive effects of loop, potassium-sparing and thiazide diuretics. Therefore, when MIDAMOR (amiloride) and non-steroidal anti-inflammatory agents are used concomitantly, the patient should be observed closely to determine if the desired effect of the diuretic is obtained. Since indomethacin and potassium-sparing diuretics, including MIDAMOR (amiloride) , may each be associated with increased serum potassium levels, the potential effects on potassium kinetics and renal function should be considered when these agents are administered concurrently.

Last reviewed on RxList: 5/19/2008
This monograph has been modified to include the generic and brand name in many instances.