Common Adverse Effects of Anti-epileptic Drugs

Common Adverse Effects of Anti-epileptic Drugs

Introduction

Epilepsy is a common condition and it is routinely treated with anti-epileptic drugs (AEDs). It is important to continue AEDs for a long time, even life long in many cases, in order to remain seizure-free. Seizure freedom depends on taking appropriate anti-epileptic drug, at a correct dose and interval, everyday for a long period of time.

When one takes drugs for long time, we need to be aware of the possible side effects. The currently used anti-epileptic drugs have been well studied in clinical trials and data about their safety and possible side effects are well known.

My aim, in this article, is to briefly summarize the common side effects of commonly used AEDs. Early recognition of side effects is important to minimise any harm due to AEDs. 

Side Effects of Phenytoin (Dilantin, Eptoin, etc)

Phenytoin is one of the commonest AED used and also among the oldest drugs. It is used in all age groups.

The main advantage is its availability in injection form; so, it is also used in emergency situations.

The other advantage is that the full dose can be started on day 1 and there is no need to start at low dose and gradually increase the dose (as we need to do with carbamazepine, oxcarbazepine, lamotrigine, etc).

Side effects of phenytoin injection- if injection is rapidly given, it can lead to low blood pressure and cardiac arrest. Also, severe drowsiness can occur.

With the use of phenytoin tablets, the following side effects should be watched for:

• Imbalance while walking,
• blurred vision,
• increased facial hair,
• coarse facies,
• thickening of gum,
• skin rashes. 

Gum hyperplasia due to phenytoin use

Side effects of Carbamazepine (Tegretol, tegrital, mazetol, zeptol, Zen, etc)

Carbamazepine is useful in partial or focal epilepsies and can be used in all age groups. Syrups are available for use in children. However, injection forms are not available, which prevents its use in emergency situations.

Common side effects include:

• Dizziness,
• Drowsiness,
• Imbalance while walking,
• Skin rash,
• Lowering of sodium level (hyponatremia)

The first three side effects can be minimised if carbamazepine is started at a low dose and the dose is gradually increased over a period of days. 

Oxcarbazepine have similar side effects, however, the incidence is lesser than that of carbamazepine. 

Side Effects of Sodium valproate (Depakine, Valparin, Encorate, Valprol, etc)

Sodium valproate is effective in controlling generalised epilepsies, juvenile myoclonic epilepsy (JME), absence seizures, etc. 

Common side effects of valproate include:

• Weight gain,
• Tremors of hands,
• Hair loss,
• Liver toxicity,
• Menstrual irregularities,
• Increased incidence of polycystic ovary disease,
• Pregnancy-related complications.

Sodium valproate should be avoided in patients with liver disease.

Also, it should not be used in women who are pregnant or are planning pregnancy. 

Side Effects of Levetiracetam (Keppra, levipil, levera, etc)

Levetiracetam is a newer AED and is effective in controlling various types of seizures. It is safer than most of the older AEDs. It has injection form, so, it can be used in emergency situations. Also, it is safe in all age groups and can be used in pregnant women too. 

Side effects to be watched for while using levetiracetam are:

• General weakness,
• Sleepiness,
• Aggression and behavioural changes,
• Occasional skin rashes. 

Side Effects of Lamotrigine (Lamictal, lamitor, lametec, etc)

Lamotrigine is also very effective AED, and can be safely used in children as well as pregnant women. 

Side effect to be watched for with lamotrigine use are: 

• Nausea, vomiting, 
• dizziness,
• sleepiness,
• imbalance while walking,
• skin rash

The dose of lamotrigine should be very gradually increased to avoid skin rash.

I hope you find this article useful. Feel free to contact me at the details below. 

Dr Sudhir Kumar MD (Medicine), DM (Neurology)

Senior Consultant Neurologist

Apollo Hospitals, Hyderabad, India.

Email: drsudhirkumar@yahoo.com

Phone: 0091-40-23607777 (to fix appointment for consultation)

online consultation: http://bit.ly/Dr-Sudhir-kumar