This case involves a 68-year-old male with multiple medical conditions who developed altered mental status and occasional jerking movements. He was on several medications that could potentially cause drug-induced encephalopathy, including antibiotics, anticonvulsants, antidepressants, and opioids. The document outlines different medication classes and specific drugs that can cause reversible encephalopathy, focusing on their mechanisms and management approaches. It emphasizes that drugs and dehydration are often the most treatable causes, and provides counseling advice on giving information to caregivers to help manage delirium.

1. Patama Gomutbutra MD
Case management
Drug induced
encephalopathy
Palliative care for pharmacist
14-15th march 2016

2. Outline
• Case demonstration
• Drug induced encephalopathy
• Care giver counselling

3. Case
• Male 68 yo UD DM, HT, Spinal canal stenosis
• Consult because alteration of conscious with
occasional jerking movement
• Admited to ICU 6 months ago due ruptured
abdominal aorta then off and on infection
• later developed ESRD on HD 3 times/weeks

4. • Current medication (selected) :
– Meropenem IV for UTI ESBL
– Gabapentin 300 mg PO
Tramadol 1 tab q 8 hrs
for his back pain
– Fluoxetin for his depression
– Dilantin 100 mg IV q 8 hrs
because his jerking movement seizure

5. • Physical exam
– Concious: E4VTM5 stuporous , occuasional
spontaneous eye opening but not follow command
– Pupil : 3 mm RTLBE
– Ocular : roving eyes, no eye deviation, no nystagmus
– Movement : equal movement, non-rhythmic jerking
movment of distal hands, stimulus sensitive
– Meningeal irritation signs : stiffneck all directions
Kernig’s sing negative
– Respiration along ventilator
– Reflex : 1+ all, BBK negative both

7. Goal of care
• “Minimal pain”
• Full medication
• His family refuse lumbar puncture or any
invasive procedure including CPR

8. Approach delirum
Appendix 1

9. D-E-L-I-R-I-U-M nmemonic
• Most of delirium caused by multifactorial
– Drugs and dehydration * The most potential reversible
– Electrolyte and Endocrine
– Low blood flow and Low oxygen (include anemia)
– Infection and Inflammation
– Retention urine
– Impact feces
– Uncontroled pain
– Mental disorientation
Lawlor PG, Arch Intern Med. 2000 Mar 27;160(6):786.

10. Drug induced encephalopathy
– Common
• Anti-cholinergic (appendix 2)
• Dopaminergic
• Steroid
• Opioid
– Uncommon
• Serotoninergic
• Antimicrobial
• Antiepileptic

11. Serotoninergic
• serotonin syndrome
– limbic : agitation
– striatum : tremor , clonus, rigidity : legs> hands
– Autonomic instability
– GI hypermotility
• Mild anxiety like -> Sever sepsis like
• Symptom may develop eariest as 6 hrs
• Reverse after 24 hrs discontinue
• Antidote:
cyproheptadine via NG 12 mg then 2 mg q 2 hrs
maintanance8 mg q 6 hrs

12. Tramadol & Fluoxetine
drug interaction

13. Antimicrobial drug
• Metronidazole
• Cephalosporin *
• Carbapenem *
• Linezolid
• Acyclovir
• Isoniazid
* associate with non-convulstive status epilepticus

14. Antibiotics
• Metronidazole
– Dose related : more than 2 g/day
– Bilateral symmetrical vasogenic edema
of cerebellar dentate and pons
– Reversible : symptom 2 wks to 3 months after
discontinue

15. Iqbal A. Ann Indian Acad Neurol. 2013 Oct-Dec; 16(4): 569–571.
ReversibleReversible

16. Antiviral
• Acyclovir
– Adjust to renal dose
(Appendix 3)
– Reversible symptom after 48-72 hrs after dose
adjusted

17. Antiepileptic
• Phenytoin
– Hypoalbumin
• Valporate
– Hypoalbumin
– Liver decompensation
• Levetriazetam
– Renal impairment

18. Antiepileptic
• Valporate
• Hyperammonia : level >40
– CSF ammonia may high in the normal level serum
ammonia
– Inhibit glutamate uptake by astrocyte
• Rx by lactulose to reduce ammonia absorb by
intestine.

19. Care giver advise
• Give them information ‘sens of controllable’
– Delirium is not ‘Permanent psychosis’
– Tell them basic advise
“D-E-L-I-R-I-U-M”
– Reorientation protocol
• Remind patient - time place person
• Less confusional environment
• Sleep wake adjustment

20. Take home message
• Drugs and dehydration is the most potential
reversible cause of encephalopathy
• Medication involve Ach, DA and Serotonin
should be precaution
• Giving information to care giver may be
important than medication

21. Reference
• Comprehensive review with references of drug
induce encephalopathy:
http://cdn.intechopen.com/pdfs-wm/35733.pdf

22. Appendix 1

23. Appendix 2
PL Detail-Document, Drugs with Anticholinergic Activity. Pharmacist’s Letter/Prescriber’s
Letter. December 2011.

27. Dose adjustment for Acyclovir
Encephalitis dose :
CrCl > 50 : 500 mg (10mg/kg) IV q 8 hrs
25-50 : 500 mg (10mg/kg) IV q 12 hrs
10-25 : 500 mg (10mg/kg) IV q 24 hrs
< 10 : 150 mg (5 mg/kg) IV q 24 hrs
give after HD on dialysis day
HD -> 60% decrease dose
Herpes zoster dose:
CrCl >25 : 800 mg PO q 4 hrs -5 times a day
10-25 : 800 mg PO q 8 hrs
< 10 : 800 mg PO q 12 hrs
Appendix 3