⚗️ 1️⃣ Anticholinergic Medications (MOST IMPORTANT)
Mechanism: Block central acetylcholine → impaired attention, memory, processing speed
Clinical pearl: Chronic use in elderly ↑ dementia risk (dose-dependent)
Examples:
- Antihistamines: diphenhydramine, hydroxyzine, chlorpheniramine
- Antidepressants (TCA): amitriptyline, nortriptyline, paroxetine
- Antipsychotics: chlorpromazine, clozapine
- Antispasmodics: oxybutynin, tolterodine
- Antiemetics: promethazine, prochlorperazine
- Muscle relaxants: cyclobenzaprine
🧬 2️⃣ Benzodiazepines
Mechanism: GABAergic sedation → slowed processing, impaired new memory formation
Examples: diazepam, lorazepam, clonazepam, alprazolam
Note: Chronic use may cause “reversible dementia”
💊 3️⃣ Opioids
Mechanism: Sedation, decreased attention/arousal, impaired working memory
High-risk opioids: morphine, hydromorphone, fentanyl, oxycodone, methadone
⚡ 4️⃣ Antiepileptic Drugs (AEDs)
Mechanism: Sedation, slowed psychomotor speed, impaired attention/executive function
High-risk AEDs:
- Topiramate → word-finding difficulty, slowed cognition
- Zonisamide
- Valproate → reversible Parkinsonism + cognitive slowing
- Phenobarbital → significant sedation
- Levetiracetam → irritability/behavioral issues
🧪 5️⃣ Antipsychotics
Mechanism: Dopamine blockade → apathy, executive dysfunction; some anticholinergic effects
Examples: clozapine, olanzapine, quetiapine, chlorpromazine
🌡️ 6️⃣ Antidepressants
- Strong anticholinergics (worst): amitriptyline, imipramine, paroxetine
- Milder effects: SSRIs (esp. high-dose citalopram), SNRIs generally safer
❤️ 7️⃣ Antihypertensives (when overtreated)
Mechanism: Hypoperfusion → confusion in elderly
Culprits: propranolol (lipophilic), clonidine, methyldopa
🩸 8️⃣ Corticosteroids
Mechanism: Mood changes, psychosis, cognitive distortion
Examples: prednisone, dexamethasone
Pearl: “Steroid psychosis” may mimic delirium/dementia
🧴 9️⃣ H2 Blockers (rare)
Examples: cimetidine, ranitidine
Mechanism: Antiandrogen + CNS penetration → confusion in elderly
🧬 10️⃣ Statins (controversial)
Minimal evidence for true dementia risk
Some patients: reversible memory loss, “brain fog”
🦵 11️⃣ Antiparkinsonian Drugs
Examples:
- Amantadine → hallucinations, confusion
- Pramipexole/ropinirole → impulse issues, confusion
- Anticholinergics (trihexyphenidyl, benztropine) → major cognitive burden
🛌 12️⃣ Anesthetics (POCD)
Examples: propofol, sevoflurane, isoflurane
Risk: ↑ with age and frailty
🤧 13️⃣ 1st Generation Antihistamines
Examples: diphenhydramine, doxylamine, hydroxyzine
Note: Sedating + anticholinergic → very common cause of reversible confusion in elderly
