Amiloride HCl is usually well tolerated and, except for hyperkalemia (serum potassium levels greater than 5.5 mEq liter - see WARNINGS), 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 amiloride HCl 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 amiloride HCl). 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 amiloride HCl and these adverse reactions, some of which have been reported only rarely.
| Incidence > 1% | Incidence ≤ 1% |
| Body as a Whole | |
| Headache* | Back pain |
| Weakness | Chest pain |
| Fatigability | Neck/shoulder ache |
| Pain, extremities | |
| Cardiovascular | |
| None | Angina pectoris |
| Orthostatic hypotension | |
| Arrhythmia | |
| Palpitation | |
| Digestive | |
| Nausea/anorexia* | Jaundice |
| Diarrhea* | GI bleeding |
| Vomiting* | Abdominal fullness |
| Abdominal pain | GI disturbance |
| Gas pain | Thirst |
| Appetite changes | Heartburn |
| Constipation | Flatulence |
| Dyspepsia | |
| Metabolic | |
| Elevated serum potassium levels ( > 5.5 mEq per liter)** | None |
| Skin | |
| None | Skin rash |
| Itching | |
| Dryness of mouth | |
| Pruritus | |
| Alopecia | |
| Musculoskeletal | |
| Muscle cramps | Joint pain |
| Leg ache | |
| Nervous | |
| Dizziness | Paresthesia |
| Encephalopathy | Tremors |
| Vertigo | |
| Psychiatric | |
| None | Nervousness |
| Mental confusion | |
| Insomnia | |
| Decreased libido | |
| Depression | |
| Somnolence | |
| Respiratory | |
| Cough | Shortness of breath |
| Dyspnea | |
| Special Senses | |
| None | Visual disturbances |
| Nasal congestion | |
| Tinnitus | |
| Increased intraocular pressure | |
| Urogenital | |
| Impotence | Polyuria |
| Dysuria | |
| Urinary frequency | |
| Bladder spasms | |
| Gynecomastia | |
| *Reactions occurring in 3% to 8% of patients treated with amiloride HCl. (Those reactions occurring in less than 3% of the patients are unmarked.) **See WARNINGS. |
|
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