From the Guidelines
Improvement in headaches from Diamox (acetazolamide) 500mg twice daily for idiopathic intracranial hypertension (IIH) typically begins within 1-2 weeks, though some patients notice relief within a few days, as supported by the consensus guidelines on management 1. Most patients experience significant headache reduction within 4-6 weeks of consistent treatment.
Key Points to Consider
- Diamox works by reducing cerebrospinal fluid production, which lowers intracranial pressure and relieves the headaches associated with IIH.
- It's essential to take the medication consistently and not stop abruptly.
- Patients should stay well-hydrated while on Diamox, as it can cause dehydration and electrolyte imbalances.
- Common side effects include tingling in hands and feet, altered taste (especially for carbonated beverages), fatigue, and increased urination.
- If headaches don't improve after 4-6 weeks, or if they worsen at any point, patients should contact their healthcare provider as their dosage may need adjustment or an alternative treatment approach might be necessary, considering the use of migraine therapies in IIH patients with migraine headaches may be useful 1.
Additional Considerations
- Regular follow-up appointments are crucial to monitor progress and adjust treatment as needed.
- Patients with IIH often have coexisting migrainous headaches superimposed on the headaches secondary to raised intracranial pressure, and failure to optimize the ICP may render the migrainous headache difficult to treat 1.
- Alternative therapeutic strategies, such as topiramate, zonisamide, candesartan, or venlafaxine, may be considered in patients with migraine, but caution must be observed when selecting drugs that could increase weight or exacerbate depression 1.
From the FDA Drug Label
The dosage employed in the treatment of chronic simple (open-angle) glaucoma ranges from 250 mg to 1 g of acetazolamide per 24 hours, usually in divided doses for amounts over 250 mg. In treatment of secondary glaucoma and in the preoperative treatment of some cases of acute congestive (closed-angle) glaucoma, the preferred dosage is 250 mg every four hours, although some cases have responded to 250 mg twice daily on short-term therapy
The FDA drug label does not answer the question.
From the Research
Improvement in Headaches with Diamox
- The provided studies do not specifically mention when headaches improve after starting Diamox (acetazolamide) 500mg BID for idiopathic intracranial hypertension.
- However, studies 2, 3, 4, 5 discuss the efficacy of acetazolamide in treating idiopathic intracranial hypertension, with improvements in visual fields and decreased cerebrospinal fluid pressure.
- Study 5 mentions that the average time to achieve maximum study dosage of acetazolamide was 13 weeks, but it does not specifically address headache improvement.
- Study 3 found a statistically significant 67% increase in the likelihood of improvement at 6 months compared to the baseline with the administration of acetazolamide, but it does not provide information on headache improvement timeline.
Relevant Studies
- Studies 2, 3, 4, 5 are relevant to the treatment of idiopathic intracranial hypertension with acetazolamide, but they do not provide specific information on headache improvement timeline.
- Study 6 is not relevant to the treatment of idiopathic intracranial hypertension with acetazolamide, as it discusses the effect of ventricular extrasystoles on idioventricular rhythm in patients with complete heart block.