In this article, we discuss the potential side effects of the prescription medication Tegretol (Carbamazepine)

White Tablet

Overview

Tegretol (Carbamazepine) is an antiepileptic drug that was first introduced in the late 1960's. It has been hugely beneficial for the treatment of various types of seizures but is well known for it's potential for side effects, both minor and serious. In this article, we will discuss what these side effects are and the how often they occur.


Since Tegretol (Carbamazepine) has been in use for over 40 years, the overall profile of the drug is very well known. While an extremely beneficial and effective drug for many different indications, it can often be difficult to initially start someone on therapy as Tegretol has known difficulties. It typically requires laboratory monitoring to check for appropriate drug levels/effects on blood cells, can change its own metabolism (requiring dose changes) and must be titrated slowly to avoid initial adverse effects.


Side Effects

In addition, it does have the potential for some very serious side effects. Here are some of the major side effects that you need to be aware of:

  • Hyponatremia
  • Bone Marrow Suppression
  • Stevens-Johnson Syndrome
  • Liver Toxicity


Even though these are relatively rare, they are serious and need to be acted upon if they occur. Below we discuss each of these in detail:


Hyponatremia: This refers to low sodium levels in the body and is also known as "water intoxication". Hyponatremia would typically occur during the first 3 months, however, cases of hyponatremia starting more than 1 year after treatment initiation has been reported. Signs and symptoms of hyponatremia include headaches, changes in seizure frequency, mental "cloudiness", confusion and weakness.  Once Tegretol (Carbamazepine) is discontinued, sodium concentrations usually go back to normal within a few days.​


Bone Marrow Suppression: While this isn't common, if it is detected on a blood test, carbamazepine is typically discontinued and blood levels will often return to normal after a few days.


Stevens-Johnson Syndrome: Although rare, if this occurs, it requires the drug be immediately discontinued and medical attention sought. Stevens-Johnson syndrome is a life-threatening skin condition and can be fatal if left untreated. 


Liver Toxicity: Although uncommon, hepatitis and various other hepatic effects have occurred during carbamazepine treatment. Typically you will have your liver enzymes checked via blood tests while you are on therapy.


Here is a list of additional side effects for Tegretol (Carbamazepine) that can occur sorted by incidence:

Common (>10% of patients)

  • ​Ataxia (loss of control of body movements)
  • Drowsiness
  • GI Issues (nausea, constipation etc...)


Uncommon (<10% of patients)

  • ​Lack of energy/weakness
  • Blurred vision
  • Headache
  • ​Itching
  • Dry Mouth
  • Anemia


Rare:

  • ​Hyponatremia
  • Liver Failure
  • Stevens-Johnson Syndrome
  • Suppression of white blood cells
  • Suicidal ideation


Although sedation and lack of energy are possible side effects, when it comes to the anticonvulsant class of medications, Tegretol (Carbamazepine) is typically a preferred option as it has a lower incidence of those effects than others. In addition, nausea, vomiting and sedation are typically problems that occur when therapy first starts and tend to get better as therapy continues.


While the above is not a complete list of possible side effects, it covers many of the serious potential adverse reactions as well as the ones we most encounter in day to day practice.


Do you have any additional questions regarding the side effects of Tegretol (Carbamazepine)? Leave a comment or email us a question and we will be sure to answer it!