What psychotropic drugs are contraindicated in patients with glaucoma?

Psychotropic Drugs Contraindicated in Glaucoma Patients

Tricyclic antidepressants, benzodiazepines, topiramate, and phentermine are contraindicated in patients with glaucoma due to their potential to precipitate acute angle-closure glaucoma or worsen intraocular pressure. 1, 2

Mechanism of Risk

The risk of psychotropic medications in glaucoma patients primarily relates to their potential to:

1. Induce angle-closure glaucoma - Particularly in anatomically predisposed patients with narrow angles
2. Elevate intraocular pressure (IOP) - Worsening existing glaucoma
3. Cause other ocular adverse effects - Including mydriasis, accommodation problems, and retinopathy

Specific Contraindicated Medications

1. Tricyclic Antidepressants (TCAs)

• Mechanism: Anticholinergic effects cause mydriasis (pupil dilation) that can precipitate angle closure 1
• Risk level: High - when patients with narrow angles are given TCAs, they appear to experience induction of glaucomatous attacks 1
• Examples: Amitriptyline, imipramine, nortriptyline

2. Topiramate

• Mechanism: Can cause an allergic-type reaction displacing structures of the lens and ciliary body 1
• Risk level: High - frequently associated with significant ocular symptoms including acquired myopia and angle-closure glaucoma 1

3. Benzodiazepines

• Mechanism: May affect eye movements and potentially worsen glaucoma 3, 1
• Risk level: Moderate to high - should be avoided in patients diagnosed with glaucoma 3
• Examples: Diazepam, lorazepam, clonazepam

4. Phentermine

• Mechanism: Sympathomimetic effects can increase IOP
• Risk level: High - explicitly contraindicated in glaucoma according to FDA labeling 2

5. First-Generation Antipsychotics (at high doses)

• Mechanism: Can cause mydriasis and anticholinergic effects
• Risk level: Moderate - especially chlorpromazine and thioridazine at high doses over prolonged periods 1
• Concern: Can cause lenticular opacifications and retinopathy with long-term use

Medications Requiring Caution

1. Selective Serotonin Reuptake Inhibitors (SSRIs)

• Risk level: Low to moderate - may lead to an added risk of developing angle-closure glaucoma, but only in predisposed eyes 1
• Current evidence: Best evidenced as having no association with glaucoma among psychotropics 3

2. Second-Generation Antipsychotics

• Risk level: Variable - ziprasidone requires special attention 3
• Monitoring: Close ophthalmological follow-up recommended

3. Carbamazepine

• Risk level: Variable - case reports of IOP elevation 4
• Monitoring: May require IOP monitoring, especially in pseudoexfoliative glaucoma patients

Clinical Approach to Psychotropic Medication in Glaucoma Patients

1. Determine glaucoma type:

   • Open-angle glaucoma - fewer medication restrictions
   • Angle-closure glaucoma or narrow angles - higher risk with anticholinergic medications

2. Assess anatomical risk factors:

   • Shallow anterior chamber
   • Narrow angles
   • Pseudoexfoliation

3. Medication selection algorithm:

   • First-line options: SSRIs and SNRIs (lowest risk)
   • Second-line options: Second-generation antipsychotics (except ziprasidone)
   • Avoid if possible: TCAs, benzodiazepines, topiramate, phentermine

4. Monitoring recommendations:

   • Baseline ophthalmological examination before starting high-risk medications
   • Regular IOP monitoring for patients on moderate-risk medications
   • Immediate ophthalmological evaluation for any visual symptoms

Important Caveats

• Patients with open-angle glaucoma generally have fewer medication restrictions than those with angle-closure glaucoma
• Individual susceptibility varies significantly - some patients may tolerate medications that are theoretically contraindicated
• The risk of untreated psychiatric illness must be weighed against potential ocular risks
• All glaucoma patients on psychotropic medications should be under strict ophthalmological supervision 3

Warning Signs Requiring Immediate Attention

• Sudden vision changes
• Eye pain or headache
• Halos around lights
• Nausea and vomiting with eye pain
• Redness of the eye

These symptoms may indicate acute angle-closure glaucoma, which is a medical emergency requiring immediate ophthalmological intervention.