A presentation on Carbamazepine toxicity performed at CIST COLLEGE, Kathmandu NEPAL

1. Case Study on
Carbamazepine Poisoning
Neeraj Ojha
Yuvraj Kalathoki
7th sem BPHARM

2. INTRODUCTION
Carbamazepine is a commonly prescribed agent for local epilepsy and other non
epileptic conditions such as neuropathic pain ,schizophrenia and bipolar disorder
in the pediatric and adult patients.
It is an anticonvulsant medication used primarily in the treatment of epilepsy and
neuropathic pain.
The first overdose of carbamazepine was reported in 1967,and significant toxicity
occurs at levels higher than 40 mg/L(usual therapeutic levels are 4 to 12 mg/L).
Common etiology for carbamazepine toxicity is coadministration of other
medications.

3. Route of exposure
Ingestion of the drug in large doses (drug overdose).

4. Symptoms /Clinical features
● Drowsiness
● Slurred speech
● Ataxia
● Hallucinations
● Nausea and Vomiting
● Tremors
● Seizures
● Oliguria
● Blurred vision

5. Mechanism of toxicity
Carbamazepine and its active metabolite causes sodium channel
blockade,causing slowed impulses in the brain .<
It binds preferentially to voltage-gated sodium channel in their inactive
conformation, which prevents repetitive and sustained firing of action potential.

6. Etiology of toxicity
Carbamazepine toxicity may result from acute overdose or chronic therapy .<
Therapeutic levels are 4-12 mg/L
Drug drug interaction are known to occur . Vander et al reported a case of
carbamazepine toxicity that occurred after administration of oxybutynin and an
increase in the dose of dantrolene. [9] The combination of these drugs elevated the
level of carbamazepine, leading to toxicity.

7. Treatment and Management
Prehospital care/General management:
● Perform ABCD (Airway, Breathing, Circulation and Disability);
● Obtain intravenous (IV) access
● Place the patient on a cardiac monitor .
● Administer IV fluids if the patient is hypotensive .
● Administer activated charcoal if the patient has intact mental status
and is able to protect the airway .

8. Contd.
Emergency Department care/Specific management for Chronic poisoning:
● Activated charcoal (if presents within 1 hour of ingestion).<
● Gastric lavage; Perform Gastric decontamination by
Diuresis/Dialysis/Haemoperfusion/Peritoneal dialysis;

9. CASE STUDY
Detailed case study
A 40 year male patient was referred to the emergency department of the
hospital.He was admitted due to the ingestion of unknown pharmaceutical agent in
an suicide attempt .THe patient has past medical history of epilepsy treated with
carbamazepine and oxcarbazepine.The patient was in coma ,occasionally
performing involuntary movements with his head arm and legs.

10. Route of exposure
Ingestion was the route through which toxic substance entered into the body.<

11. Subjective detail
● Gender - male
● Age -40 yrs old
● Weight -65kg
● Hospital: XYZ

12. Objective detail
The normal range of carbamazepine is 4-12 mg/L.(therapeutic level).<
The level of carbamazepine in patient was > 20ug/ml.<
The patient was subjected to hemodialysis.The patient underwent a 4 hour
hemoperfusion session followed by a hemodialysis session of 4 hour .

13. Assessment
The patient was diagnosed for the normal carbamazepine levels.<
Hemoperfusion followed by hemodialysis was done to totally clear the high levels
of carbamazepine.( 2 times the process was repeated).

14. Planning
● Gastrointestinal decontamination with activated charcoal is commonly used.
● Hemoperfusion followed by hemodialysis was performed in combination.
● Supportive measures are to be considered.
● Symptomatic treatments are to be performed as soon as the patient reaches
the hospital.

15. Suggestions
1. Study suggests that dialysis techniques can be beneficial in a case of severe
carbamazepine poisoning.<