American Board of Internal Medicine (ABIM) Certification Practice Exam

What is the only reliably effective medication for idiopathic intracranial hypertension?

1. Carbonic anhydrase inhibitors

2. Diuretics

3. Beta-blockers

4. Corticosteroids

The correct answer is: Carbonic anhydrase inhibitors

Carbonic anhydrase inhibitors, such as acetazolamide, are considered the only reliably effective medication for idiopathic intracranial hypertension (IIH). This condition is characterized by increased intracranial pressure without an identifiable cause. The mechanism of action for carbonic anhydrase inhibitors involves reducing the production of cerebrospinal fluid (CSF), thereby decreasing the overall pressure within the cranial cavity. This medication has been shown to alleviate symptoms and improve the condition in numerous clinical studies, making it a primary treatment option for managing IIH. While other options like diuretics, beta-blockers, and corticosteroids may provide some degree of symptom relief in certain contexts, they do not specifically target the underlying pathophysiology of IIH in the same effective manner as carbonic anhydrase inhibitors. Diuretics, for instance, can help reduce fluid retention and may incidentally lower intracranial pressure but are not tailored for IIH management. Beta-blockers and corticosteroids have limited role and effectiveness in the treatment of IIH, often being used in other related conditions or adjunctively rather than as a primary treatment strategy.