Who should not take acetazolamide? Essential Safety Precautions

October 10, 2025 •

3 min read

Acetazolamide is a widely used medication, but its use is strictly contraindicated in patients with marked liver disease or certain severe electrolyte imbalances. Understanding who should not take acetazolamide is crucial for preventing dangerous side effects and ensuring patient safety.

Quick Summary

Acetazolamide is unsafe for individuals with severe kidney or liver disease, specific electrolyte imbalances, or a history of sulfonamide allergy. Avoid high-dose aspirin while on this medication to prevent dangerous interactions.

Key Points

Severe Organ Dysfunction: Individuals with severe kidney disease, liver cirrhosis, or adrenal gland failure should not take acetazolamide.
Electrolyte Imbalances: Pre-existing low sodium (hyponatremia), low potassium (hypokalemia), or hyperchloremic acidosis are contraindications.
Sulfa Allergy: Patients with a history of severe allergic reactions to sulfonamides should avoid acetazolamide.
High-Dose Aspirin Interaction: Concomitant use with high-dose aspirin is extremely dangerous and can cause severe toxicity.
Pregnancy and Breastfeeding: Use during pregnancy should be carefully considered, and the drug is not recommended while breastfeeding due to potential infant risks.
Respiratory Issues: Caution is needed for patients with severe lung problems like COPD, as the drug can worsen acidosis.
Chronic Glaucoma: Long-term use in chronic noncongestive angle-closure glaucoma is contraindicated.

Absolute Contraindications: When Acetazolamide is Forbidden

Acetazolamide is contraindicated in certain medical conditions due to the risk of serious complications. These include severe kidney disease, as the drug is primarily eliminated by the kidneys and can accumulate to toxic levels. Severe liver disease, particularly cirrhosis, is also a contraindication as it increases the risk of hepatic encephalopathy. Patients with adrenal gland failure or severe, uncorrected low sodium (hyponatremia) or potassium (hypokalemia) should not take acetazolamide, as it can worsen these conditions. Hyperchloremic acidosis is another contraindication because acetazolamide promotes bicarbonate excretion. Individuals with a history of severe allergic reactions to sulfonamides should avoid this medication due to the potential for cross-reactivity.

Important Precautions: Cases for Caution and Discussion

Drug Interactions to Avoid or Monitor Closely

Several medications can interact with acetazolamide. It is vital to inform a healthcare provider of all current medications and supplements.

High-Dose Aspirin: Concurrent use is dangerous and can lead to severe metabolic acidosis and neurological issues. This combination should be avoided.
Phenytoin and Primidone: Acetazolamide can increase levels of these anti-seizure drugs, raising toxicity risk.
Lithium: Acetazolamide may increase lithium excretion, potentially reducing its effectiveness.
Other Carbonic Anhydrase Inhibitors: Combining with other inhibitors like topical dorzolamide is not advised due to increased systemic side effects.

Considerations for Pregnant or Breastfeeding Individuals

Pregnancy: Acetazolamide is a Category C drug. It should only be used if the benefits outweigh risks, based on animal studies. Discussion with a healthcare provider is necessary.
Breastfeeding: The drug is present in breast milk. A decision must be made to either stop the medication or discontinue nursing, considering the mother's needs and potential infant risk.

Respiratory Conditions

Use with caution in individuals with severe respiratory problems like COPD, as it can worsen metabolic acidosis.

Chronic Glaucoma Treatment

Long-term use is contraindicated in chronic noncongestive angle-closure glaucoma because it can mask the disease's progression.

Understanding the Risks: Acetazolamide vs. Alternative Medications


Feature	Acetazolamide	Dexamethasone	Furosemide (Diuretic)
Primary Mechanism	Carbonic anhydrase inhibitor; promotes bicarbonate excretion.	Corticosteroid; reduces cerebral edema and inflammation.	Loop diuretic; increases excretion of water and electrolytes.
Typical Use	Glaucoma, altitude sickness, certain seizures.	Severe altitude illness (AMS, HACE).	Edema due to congestive heart failure, liver, or kidney disease.
Use in Kidney Disease	Contraindicated in marked disease; dose reduction necessary for moderate impairment.	Does not rely on kidney clearance; can be an alternative.	Used for renal conditions, but requires careful monitoring.
Sulfa Allergy Risk	Potential, though low risk, of cross-reactivity with antibiotic sulfonamides. Avoid in severe cases.	Not a sulfonamide; no risk of cross-reactivity.	Sulfonamide-based, but cross-reactivity risk is low.
Key Drug Interactions	High-dose aspirin, certain anti-seizure medications, lithium.	Many, including certain antibiotics, antifungals, and NSAIDs.	Digoxin, lithium, NSAIDs, risk of hypokalemia.
Benefit for Acclimatization	Speeds up acclimatization process.	Provides rapid symptom relief; no acclimatization.	No effect on altitude acclimatization.

Conclusion

Acetazolamide is effective but not suitable for everyone. It should not be taken by individuals with pre-existing kidney disease, liver cirrhosis, severe electrolyte imbalances, or a history of severe sulfa allergies. Caution is advised for those with respiratory issues, or who are pregnant or breastfeeding. A dangerous interaction exists with high-dose aspirin. Always provide a complete medical history and list of all medications to your healthcare provider to ensure safe treatment and explore alternatives if needed.

For more information on high-altitude travel and related medication considerations, refer to authoritative sources like the Centers for Disease Control and Prevention guidelines for clinicians.

Frequently Asked Questions

While acetazolamide is a sulfonamide derivative, cross-reactivity with antibiotic sulfonamides is less common. However, if you have a history of a severe allergic reaction to sulfa drugs, particularly something like Stevens-Johnson syndrome, acetazolamide is contraindicated.

No, acetazolamide is not safe for people with marked kidney disease or dysfunction. Since the drug is eliminated almost entirely by the kidneys, impairment can lead to toxic buildup and severe side effects.

Taking high-dose aspirin with acetazolamide can cause a severe drug interaction, leading to serious metabolic acidosis, lethargy, confusion, and potentially coma or death. This combination should be strictly avoided.

Acetazolamide is contraindicated in patients with liver cirrhosis because it can decrease the clearance of ammonia, which significantly increases the risk of developing hepatic encephalopathy.

Acetazolamide should be used with great caution during pregnancy, and only if the potential benefit outweighs the potential risk to the fetus, as animal studies have shown teratogenic effects. A healthcare provider must be consulted.

Acetazolamide can cause significant electrolyte imbalances. It is contraindicated in patients with pre-existing low sodium (hyponatremia) and low potassium (hypokalemia).

Yes, alternatives exist for altitude sickness. Dexamethasone is an option for rapid symptom relief, and Ibuprofen can also be effective for prevention, though potentially less so than acetazolamide.