What is the best course of action for a 36-year-old (y) female (f) patient with obesity, who is taking medication for weight loss, and presents with complaints of head heaviness and headache?

Immediate Evaluation for Idiopathic Intracranial Hypertension (Pseudotumor Cerebri)

This patient requires urgent evaluation for idiopathic intracranial hypertension (IIH), a potentially vision-threatening condition that is strongly associated with obesity and certain weight-loss medications, particularly topiramate-containing combinations like phentermine/topiramate. 1

Critical First Steps

Identify the Specific Weight-Loss Medication

• Determine immediately if the patient is taking phentermine/topiramate (Qsymia), as topiramate is a known cause of acute angle-closure glaucoma and can precipitate headaches through multiple mechanisms including carbonic anhydrase inhibition and decreased bicarbonate levels 1, 2
• If on phentermine alone, headache is a common side effect occurring in up to 15-20% of patients 1
• If on naltrexone/bupropion (Contrave), headache is the second most common side effect after nausea 1
• If on liraglutide or semaglutide (GLP-1 agonists), headache occurs but is less common 1

Perform Targeted Neurological and Ophthalmologic Assessment

• Check visual acuity, visual fields, and perform fundoscopic examination for papilledema - IIH is the most serious cause of headache in this demographic and can cause permanent vision loss 1
• Assess for acute myopia or ocular pain suggesting acute angle-closure glaucoma (specific risk with topiramate) 1
• Measure blood pressure and heart rate, as sympathomimetic agents (phentermine) commonly cause elevated BP and tachycardia, which can manifest as headache 1
• Evaluate for signs of increased intracranial pressure: pulsatile tinnitus, transient visual obscurations, diplopia from sixth nerve palsy 1

Medication-Specific Management Algorithm

If Taking Phentermine/Topiramate:

• Discontinue immediately if any visual symptoms, acute eye pain, or papilledema are present 1, 2
• Obtain urgent ophthalmology consultation for intraocular pressure measurement and dilated fundoscopic exam 1
• Check serum bicarbonate level (topiramate causes metabolic acidosis through carbonic anhydrase inhibition) 1
• If headache is mild without red flags and bicarbonate is normal, consider dose reduction rather than discontinuation 2, 3

If Taking Phentermine Alone:

• Measure blood pressure and heart rate - if elevated (BP >140/90 or HR >100), this is likely the cause 1
• Consider dose reduction from 37.5 mg to 15 mg or 8 mg three times daily 1
• If hypertension is present, phentermine should be discontinued and alternative therapy selected 1

If Taking Naltrexone/Bupropion:

• Headache typically improves with continued use; consider symptomatic treatment with acetaminophen or NSAIDs 1
• Ensure adequate hydration and gradual dose titration 1, 2
• Discontinue only if headache is severe or accompanied by neurological symptoms 1

If Taking GLP-1 Agonists (Liraglutide/Semaglutide):

• Headache is usually transient and resolves within 2-4 weeks 1
• Ensure adequate hydration to prevent dehydration-related headaches 1
• Slow dose titration can minimize this side effect 1, 2

When to Discontinue vs. Continue Medication

Absolute Indications for Immediate Discontinuation:

• Any visual changes or papilledema (suggests IIH) 1
• Acute eye pain or acute myopia (suggests angle-closure glaucoma with topiramate) 1
• Uncontrolled hypertension (BP >160/100) with sympathomimetic agents 1
• Severe, persistent headache unresponsive to analgesics 1

Can Continue with Monitoring:

• Mild headache without red flags that improves with over-the-counter analgesics 1
• Headache occurring within first 2 weeks of initiation (often transient) 1
• Normal neurological and ophthalmologic examination 1

Common Pitfalls to Avoid

Do not assume headache is benign in an obese young woman - this is the classic demographic for IIH, and weight-loss medications (especially topiramate) can unmask or worsen this condition 1. The combination of obesity, female sex, and topiramate creates particularly high risk 1.

Do not continue phentermine in patients with uncontrolled hypertension - sympathomimetic effects can worsen cardiovascular outcomes 1. The American Gastroenterological Association specifically recommends against sympathomimetic agents in patients with cardiovascular disease 1.

Do not miss acute angle-closure glaucoma with topiramate - this can occur within hours to weeks of starting therapy and requires emergency ophthalmologic intervention 1.

Alternative Weight-Loss Medication Selection

If medication must be discontinued due to headache:

• Switch to orlistat (lipase inhibitor) - headache occurs but is less common, and mechanism is peripheral rather than central 1
• Consider GLP-1 agonists (liraglutide 3.0 mg or semaglutide 2.4 mg) - superior weight loss efficacy (10-12% vs 3-5% with other agents) with transient headache that typically resolves 1, 2, 4
• Avoid other sympathomimetic agents if phentermine caused problematic headache 1