What Kind of Drug is Keppra? The Basics
Keppra is the brand name for the active ingredient levetiracetam. It is officially classified as a pyrrolidine anticonvulsant or antiepileptic drug (AED). Anticonvulsants are medications prescribed to prevent or reduce the severity of seizures in people with epilepsy. Epilepsy is a neurological disorder characterized by abnormal electrical activity in the brain that results in seizures.
Unlike older AEDs, Keppra is considered a second-generation medication. This distinction is important because it often translates to a more favorable side effect profile and fewer drug-drug interactions, though it still has its own set of potential adverse effects.
How Keppra differs from other epilepsy medications
Keppra's classification is partly defined by its unique mechanism of action, which sets it apart from other drugs in the same category. For example, some AEDs work by affecting sodium channels, while others enhance the effects of GABA, a calming neurotransmitter. Keppra’s distinct pharmacology offers an alternative treatment option for patients who may not respond to or tolerate other AEDs. This broad-spectrum efficacy, coupled with its relatively safe profile, has led to its expanded use over the years.
The Mechanism of Action: How Keppra Stabilizes the Brain
The precise mechanism by which levetiracetam works is still under investigation, but significant evidence points to its interaction with a specific protein in the brain.
Targeting the Synaptic Vesicle Protein 2A (SV2A)
The most prominent and well-supported theory is that levetiracetam binds to the synaptic vesicle protein 2A (SV2A). Synaptic vesicles are tiny sacs within nerve cells that store and release neurotransmitters, the chemical messengers that transmit signals between neurons. By binding to SV2A, Keppra modulates neurotransmitter release, thereby helping to stabilize electrical activity and reduce the likelihood of a seizure. This action effectively dampens the abnormal burst firing of neurons without significantly affecting normal neuronal excitability.
Other possible actions
While SV2A binding is the primary suspect, other contributing mechanisms have been observed:
- Inhibition of N-type calcium currents: Keppra may partially inhibit certain calcium channels, which also influences neuronal activity.
- Modulation of GABA and glycine currents: It has been shown to reverse the effects of certain negative modulators on these neurotransmitter systems, although it does not display conventional GABA-enhancing activity like benzodiazepines.
Approved Uses and Formulations
Keppra is approved by the U.S. Food and Drug Administration (FDA) for the treatment of several types of seizures, and it is available in multiple forms to accommodate different patient needs.
FDA-approved indications
- Focal (Partial-Onset) Seizures: Approved for use alone or as an add-on therapy in adults and children as young as one month old.
- Myoclonic Seizures: Used as an add-on therapy in adults and children 12 years and older with juvenile myoclonic epilepsy (JME).
- Primary Generalized Tonic-Clonic (PGTC) Seizures: Used as an add-on therapy in adults and children 6 years and older with idiopathic generalized epilepsy (IGE).
Available formulations
- Immediate-Release (IR) Oral Tablets and Oral Solution: Typically taken twice daily.
- Extended-Release (XR) Oral Tablets: Taken once daily for convenience.
- Oral Tablets for Suspension (Spritam): Dissolvable tablets for patients who have difficulty swallowing pills.
- Intravenous (IV) Injection: Used in hospital settings for short-term treatment when a patient cannot take the medication orally.
Potential Side Effects and Safety Considerations
While generally well-tolerated, Keppra can cause side effects. Awareness of these is important for effective management and patient safety.
Common side effects
- Drowsiness and fatigue
- Dizziness and unsteady walking
- Irritability and aggression (sometimes referred to as “Keppra rage”)
- Headache
- Loss of appetite
Serious side effects
- Behavioral Changes and Suicidal Thoughts: Antiepileptic drugs, including Keppra, can increase the risk of depression, anxiety, agitation, and suicidal thoughts or behavior. Patients and caregivers should monitor for any new or worsening mood changes.
- Severe Skin Reactions (DRESS): A rare but potentially life-threatening reaction called Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS) has been linked to levetiracetam. Symptoms include fever, rash, and injury to internal organs.
- Blood Cell Abnormalities: Keppra can rarely lower blood cell counts, which may increase the risk of infection, bruising, or bleeding.
Comparison of Keppra with other Anticonvulsants
Understanding how Keppra compares to other drugs can help illustrate its place in therapy.
| Feature | Keppra (Levetiracetam) | Gabapentin (Neurontin) | Carbamazepine (Tegretol) | Phenytoin (Dilantin) |
|---|---|---|---|---|
| Drug Class | Pyrrolidine anticonvulsant | GABA analog anticonvulsant | Iminostilbene anticonvulsant | Hydantoin anticonvulsant |
| Mechanism of Action | Binds to SV2A protein, modulating neurotransmitter release | Exact mechanism unclear, but thought to affect voltage-gated calcium channels | Modulates voltage-gated sodium channels | Modulates voltage-gated sodium channels |
| Key Indications | Focal, myoclonic, and tonic-clonic seizures | Focal seizures, nerve pain (e.g., PHN) | Focal, tonic-clonic seizures | Focal, tonic-clonic seizures |
| Side Effect Profile | Somnolence, dizziness, irritability, behavioral changes | Dizziness, sleepiness | Drowsiness, dizziness, nausea, vision problems | Gingival hyperplasia, ataxia, hirsutism |
| Drug Interactions | Minimal pharmacokinetic interactions | Minor interactions | Significant interactions via CYP450 enzymes | Significant interactions via CYP450 enzymes |
| Monitoring Needs | Routine monitoring for mood changes | Generally less intense monitoring for seizures | Regular blood monitoring for therapeutic levels and side effects | Regular blood monitoring for therapeutic levels and toxicity |
| Controlled Substance? | No | Yes, in some states due to potential for misuse | No | No |
Important Safety Warnings and Conclusion
Never stop taking Keppra abruptly without consulting a healthcare provider, as this can lead to an increase in seizure frequency or severity. Your doctor will likely recommend a gradual reduction in dosage to prevent withdrawal seizures. Patients with kidney problems may need a dosage adjustment since the drug is primarily eliminated by the kidneys. The potential for mood and behavioral changes requires close monitoring by patients, families, and healthcare teams. If any severe symptoms appear, such as a rash or fever, seek immediate medical attention.
In conclusion, Keppra is a modern and effective antiepileptic drug with a unique mechanism of action involving the SV2A protein. It represents an important option in the treatment of epilepsy, offering broad-spectrum efficacy with a distinct pharmacological profile compared to older medications. For further information, the FDA provides comprehensive prescribing details and safety warnings on levetiracetam.
