Side Effects of Acetazolamide (Diamox)
Acetazolamide (Diamox) commonly causes paresthesias, taste disturbances, polyuria, and fatigue, with side effects being dose-dependent and more severe at higher doses. 1
Common Side Effects
- Paresthesias (tingling sensations): Most common side effect with a number needed to harm of only 2.3 patients 1
- Dysgeusia (taste disturbances): Metallic taste or altered taste perception 1
- Polyuria (increased urination): Due to its diuretic effect 1
- Fatigue/drowsiness: Significantly impacts quality of life 1, 2
Neurological Side Effects
- Vertigo/dizziness 3
- Confusion (more common with higher doses) 2
- Headache (paradoxically, though used to treat certain headache conditions) 4
- Depression and cognitive slowing (particularly noted when used for idiopathic intracranial hypertension) 4
Gastrointestinal Side Effects
Serious Side Effects
- Kidney stones: Requires monitoring, especially with prolonged use 3
- Metabolic acidosis: Due to its mechanism as a carbonic anhydrase inhibitor 3
- Electrolyte imbalances: Particularly potassium abnormalities 5
- Blood dyscrasias: Rare but serious hematologic complications 3
- Stevens-Johnson syndrome: Severe cutaneous adverse reaction 3
- Anaphylactic reactions: Potentially fatal in patients with sulfonamide allergies 6
Dose-Dependent Effects
The risk of side effects increases with higher doses of acetazolamide:
- Paresthesias risk increases significantly with doses above 600 mg/day 1
- Taste disturbances show clear dose-dependence 1
- Fatigue tends to worsen at higher doses, though the relationship is not as strong 1
Special Considerations
Drug Interactions
- Caffeine: Patients taking acetazolamide should limit caffeine intake due to potential interactions that could worsen side effects 3
- Other diuretics: Avoid combining with other diuretics due to increased risk of dehydration and electrolyte imbalances 3
Contraindications
Acetazolamide is contraindicated in patients with:
- Kidney stones
- Sulfa allergy (due to risk of cross-reactivity and potential anaphylaxis) 6
- Severe hepatic or renal disease
- Adrenocortical insufficiency
- Hyperchloremic acidosis
- Aplastic anemia
- Sickle cell disease 3
Monitoring Recommendations
Overdose Management
In case of overdose:
- No specific antidote exists
- Treatment should be symptomatic and supportive
- Monitor electrolytes (particularly potassium) and blood pH
- Administer bicarbonate to correct acidosis
- Dialysis may be considered in severe cases, especially with concurrent renal failure 5
The side effect profile of acetazolamide often limits its therapeutic use, making it important to use the lowest effective dose possible to minimize adverse effects 1. Modified-release formulations may help reduce plasma concentration fluctuations and decrease the incidence of certain side effects 2.