last updated 23-05-2024

Drug-induced delirium

Drug-induced delirium

Drug induced delirium occurs frequently in older patients. Particularly in those who are taking more than 5 medicines a day. Delirium is described as a confusional state that is being acutely developed and fluctuating through the day. There is disorganized thinking with at least two of the following:

  • reduced level of consciousness
  • perceptual disturbances
  • isturbances of sleep-wake cycle
  • increased or decreased psychomotor activity
  • disorientation to time, place or person
  • memory impairment

Drugs that are commonly associated with delirium are shown below:

Cardiac agents that cause delirium

  • β-blockers: propranolol
  • Antiarrhythmics: lidocaine, quinidine, amiodarone
  • Central alpha agonists: methyldopa, clonidine
  • Calcium-channel blockers: nifedipine, diltiazem
  • ACE inhibitors: captopril
  • Diuretics: furosemide, hydrochlorothiazide
  • Hypotensive agents: nitroprusside


Anti-infectives that cause delirium

  • β-lactams: penicillin, cephalexin, cefuroxime, ceftazidime, imipenim
  • Quinolones: ofloxacin, norfloxacin, ciprofloxacin, enoxacin
  • Antifungals: ketoconazole, amphotericin B
  • Antivirals: amantadine, zidovudine, zalcitabine, stavudine
  • Other: metronidazole, trimethoprim-sulfamethoxazole, gentamicin, tobramycin

Other medications that cause delirium

  • Analgesics: meperidine
  • Non-steroidal anti-inflammatory: indomethacin, ibuprofen, naproxen
  • Anticonvulsants: phenytoin, primidone, phenobarbital, valproic acid, carbamazepine
  • Anti-Parkinson's agents: levodopa/carbidopa
  • Benzodiazepines: diazepam, triazolam, flurazepam, midazolam
  • H2-antagonists: cimetidine, ranitidine, famotidine
  • Corticosteroids: prednisone, dexamethasone
  • Prokinetic agents: metoclopramide
  • Hemostatics: aminocaproic acid
  • Stimulants: caffeine, pseudoephedrine
  • Sedatives: alcohol

Drugs with anticholinergic side effects are shown in detail in the next slide.