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Zonisamide vs Keppra

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Zonisamide Details

Keppra Details

Comparative Analysis

Zonisamide Prescription Information

Keppra Prescription Information

Zonisamide Side Effects

Keppra Side Effects

Safety Information

Cost Analysis

Market Analysis



For patients with epilepsy or other types of seizure disorders, certain drugs that alter the concentrations of compounds in the brain that are linked to neuronal excitability can help in stabilizing seizure activity and managing symptoms. Zonisamide and Keppra are two such drugs that are prescribed for seizures. They each impact different pathways in the brain, but both have anti-epileptic effects in patients with seizure disorders. Zonisamide is a sulfonamide anticonvulsant and carbonic anhydrase inhibitor, affecting voltage-sensitive sodium channels and calcium channels while also increasing GABA neurotransmission. Keppra, on the other hand, is classified as an antiepileptic drug (AED) with a unique mechanism which binds to SV2A synaptic vesicle protein affecting neurotransmitter release.

Zonisamide vs Keppra Side By Side

Brand NameZonegranKeppra
ContraindicationsShould not be taken with Carbonic Anhydrase Inhibitors (CAIs).No specific contraindications mentioned other than the general caution against mood or behavior issues exacerbation.
CostFor the brand name, about $130 for 30 capsules of 100 mg. For the generic, approximately $1.10 to about half that amount per day.For the brand name, around $850 for 60 tablets of 500 mg. For the generic, daily costs range between $0.44 and $1.76.
Generic NameZonisamideLevetiracetam
Most Serious Side EffectSerious psychiatric symptoms including confusion, hallucinations, or suicidal thoughts.Increased risk of suicidal thoughts or behavior.
Severe Drug InteractionsInteracts with alcohol and certain over-the-counter medicines.Less likely to interact with co-administered medication due to its unique mechanism.
Typical DoseStarts from 100 mg/day, ramping up to 300-400 mg/day as needed. Maximum dosage should not exceed 600 mg/day.Starts at 500 mg twice daily, can be increased to 1000 mg twice daily after two weeks, up to a maximum of 3000 mg/day.

What is Zonisamide?

Zonisamide (the generic name for Zonegran) and Levetiracetam (Keppra) are both anticonvulsant medications, which represented a significant advancement from the first class of anti-seizure drugs. Zonisamide was first approved by the FDA in 2000. It works by reducing abnormal electrical activity in the brain, thus helping to prevent seizures. This medication is commonly prescribed for the treatment of partial seizures and generalized tonic-clonic seizures.

Like Prozac's selective influence on serotonin, Zonisamide specifically targets sodium and calcium channels without substantially affecting GABA receptors, resulting in it having fewer side effects than other antiepileptic drugs that have stronger effects on these other pathways.

On the other hand, Keppra also effectively reduces epileptic seizures but acts through a different mechanism - it binds to synaptic vesicle protein SV2A which is believed to result in the suppression of seizure activity. The choice between these two medications often depends upon individual patient factors including side effect profiles, co-existing conditions, and potential interactions with other drugs.

What conditions is Zonisamide approved to treat?

Zonisamide is approved for the treatment of several forms of epilepsy:

  • Partial seizures, also known as focal onset seizures
  • Generalized tonic-clonic seizures (in combination with other antiepileptic drugs)
  • Seizures associated with Lennox-Gastaut syndrome (in combination with other antiepileptic drugs)

How does Zonisamide help with these illnesses?

Zonisamide acts to control seizures by reducing the abnormal electrical activity in the brain. It does this by blocking sodium and calcium channels, which are involved in nerve signals that lead to seizures. This reduces the likelihood of a seizure occurring and helps stabilize neuronal firing. Calcium plays an important role in muscle contractions, neurotransmission, and cell viability; by inhibiting these channels, Zonisamide limits over-excitation and excessive signaling.

On the other hand, Keppra (levetiracetam) also works to prevent seizures but it operates differently than Zonisamide. While its exact mechanism is not fully understood yet, it's believed that levetiracetam influences GABAergic transmission through binding to SV2A protein found on synaptic vesicles – this essentially aids in modulating neural cell activity.

Both drugs can be effective for managing epilepsy but their different modes of action mean they might work better for different individuals or types of seizures.

What is Keppra?

Keppra is a brand name for levetiracetam, an antiepileptic drug that works by decreasing abnormal excitement in the brain. It was first approved by the FDA in 1999. Unlike zonisamide, Keppra doesn't inhibit carbonic anhydrase and therefore does not have a diuretic effect or cause kidney stones, which are potential side effects of zonisamide. Levetiracetam also lacks enzyme induction properties seen with many other antiepileptic drugs, meaning it's less likely to interact with other medications. Though its mechanism of action is not fully understood yet, it appears to work differently from all currently available antiepileptic drugs such as Zonisamide. Keppra can be beneficial for patients who do not respond well to other epilepsy treatments due to its unique mechanism of action and different side-effect profile.

What conditions is Keppra approved to treat?

Keppra is an anticonvulsant medication that has been approved for the treatment of various types of seizures, including:

  • Partial onset seizures
  • Myoclonic seizures in patients with juvenile myoclonic epilepsy
  • Primary generalized tonic-clonic seizures.

This makes it a versatile option for managing different forms of epilepsy.

How does Keppra help with these illnesses?

Levetiracetam, commonly known as Keppra, is an anticonvulsant medication which plays crucial roles in inhibiting neuronal hypersynchronization. It does this by modulating neurotransmitter release through its effect on synaptic vesicle protein SV2A in the brain. This action helps to reduce seizures and manage epilepsy symptoms.

Keppra works differently from many other anticonvulsants as it doesn't interact significantly with GABA or glutamate pathways directly implicated in seizure activity. Instead, its unique mechanism of action makes it a useful choice when patients do not respond well to more "typical" antiepileptic drugs (such as Zonisamide), or it may be combined with these medications for more effective control of epileptic symptoms. Its generally good tolerability profile also adds to its appeal for use across varying age groups and types of epilepsy.

How effective are both Zonisamide and Keppra?

Both Zonisamide and Levetiracetam (Keppra) have well-documented histories of success in managing seizure disorders, with their initial FDA approvals occurring within a few years of each other. These medications act on different aspects of neuronal functioning which may make them suitable for different types of seizures or patient populations. The effectiveness of Zonisamide and Keppra was directly compared in several clinical trials; the two drugs exhibit similar efficacy in controlling seizures while also showing comparable safety profiles.

A 2011 systematic review noted that Zonisamide effectively reduces seizure frequency even from the first weeks of treatment, has an acceptable side effect profile when compared to many other antiepileptic drugs, and is generally well-tolerated across diverse patient populations including children and adults alike. This report shares that Zonisamide has gained widespread adoption as an adjunct therapy for epilepsy worldwide due to its broad spectrum action against both focal-onset and generalized onset seizures.

Similarly, a 2013 meta-analysis indicated that Keppra seems more effective than placebo at reducing seizure frequency amongst patients with refractory epilepsy. Although often prescribed as an add-on treatment like zonisamide, Keppra still holds firm ground as a first-line monotherapy especially following its demonstrated efficacy in treating newly diagnosed epilepsy cases without causing significant psychiatric adverse effects unlike some other antiepileptics. Nonetheless, because it's unique mechanism devoid of hepatic metabolism or protein binding interaction makes it less likely to interact with co-administered medication thus making it particularly useful for multiple drug therapy regimens where polypharmacy can be problematic.

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At what dose is Zonisamide typically prescribed?

Oral dosages of Zonisamide typically start from 100 mg/day, but medical studies have suggested that for most people affected by seizures, a ramp-up to 300-400 mg/day may be needed. For children and adolescents, the starting dose is usually around 1mg/kg per day. In either population group, dosage can be increased gradually every two weeks if there is no response or if seizures persist. The maximum dosage of Zonisamide should not exceed 600 mg/day under any circumstances.

At what dose is Keppra typically prescribed?

Keppra treatment typically commences at an initial dosage of 500 mg twice daily. Depending on the patient's response, this can be increased to 1000 mg twice daily after a span of two weeks. Subsequent dose adjustments should also be based on clinical response with increments of 1000 mg/day every two weeks up to a maximum recommended dose of 3000 mg/day. This is divided into two doses spread approximately 12 hours apart and may be tested if there is no significant improvement in seizure control or if side effects are present. As always, it's important to follow your healthcare provider’s guidance regarding any medication adjustment.

What are the most common side effects for Zonisamide?

Potential side effects of Zonisamide may include:

  • Sleepiness/drowsiness
  • Loss of appetite, anorexia
  • Nausea and vomiting
  • Diarrhea or constipation
  • Dizziness or lack of coordination
  • Mood swings, irritability, depression
  • Difficulty concentrating or remembering things
  • Weight loss

On the other hand, Keppra's (Levetiracetam) common side effects encompass:

  • Sleepiness/drowsiness
  • Weakness (asthenia)
  • Infection
  • Lack of energy/fatigue
  • Agitation/nervousness/anxiety
  • Nasopharyngitis/upper respiratory tract infection/sinusitis
  • Somnolence/insomnia
  • Headache/migraine
  • Hypersensitivity/rash.

Always discuss potential side effects with your healthcare provider when deciding between medications.

abstract image of a patient experiencing side effect

Are there any potential serious side effects for Zonisamide?

Zonisamide and Keppra are both used to treat seizures, but they do have different side effect profiles. Here's what you should know:

  • Zonisamide can sometimes cause serious psychiatric symptoms including confusion, hallucinations, or suicidal thoughts. If you notice these changes in mood or behavior while taking zonisamide, reach out to your doctor immediately.
  • An allergic reaction is rare with either drug but could occur. Symptoms may include hives; difficulty breathing; swelling of your face, lips, tongue or throat.
  • Both medications could potentially affect vision so if you experience any blurred vision, eye pain or swelling seek medical attention promptly.
  • Zonisamide can sometimes cause a decrease in sweating which might lead to an increase in body temperature (fever). This is particularly important for children as it can lead to heat stroke.
  • Side effects that require immediate medical attention include signs of metabolic acidosis such as rapid breathing, irregular heartbeat and unusual tiredness.

Keppra has its own unique considerations:

  • A small number of people who use keppra may become suicidal. Keep watch for mood swings or other new signs of depression while using this medication.
  • It's also possible that keppra could cause coordination problems – muscle weakness and unsteadiness on the feet are worth bringing up with your healthcare provider.

Remember - always consult a healthcare professional before making decisions about medication management!

What are the most common side effects for Keppra?

Keppra, an anticonvulsant often used to manage epilepsy, can have the following side effects:

  • Fatigue or drowsiness
  • Dizziness and coordination problems
  • Behavioral changes such as mood swings, hostility or agitation
  • Headache
  • Loss of appetite leading to weight loss
  • Nausea and vomiting
  • Sore throat and other symptoms similar to a cold
  • Muscle weakness.

It's important to note that while these are possible side effects, not everyone who takes Keppra will experience them. Each individual reacts differently to medication.

Are there any potential serious side effects for Keppra?

While Keppra is generally safe and well-tolerated, it can cause some serious side effects in rare cases. Please be aware of the following potential adverse reactions:

  • Signs of a severe allergic reaction such as skin rash, itching or hives; swelling of your face, lips or tongue; difficulty breathing or swallowing
  • Increased risk of suicidal thoughts or behavior
  • Unexpected seizures despite medication
  • Unusual changes in mood like agitation, aggression, anger, anxiety, apathy, depression or hostility
  • Problems with muscle movement including tremor and coordination difficulties
  • Changes in vision such as blurred vision and seeing double
  • Irregular heartbeat that feels either too fast or too slow
  • Extreme fatigue and lack of energy.

If you notice any of these symptoms while taking Keppra, contact your healthcare provider immediately.

Contraindications for Zonisamide and Keppra?

Both Zonisamide and Keppra, similar to other anticonvulsant medications, may exacerbate mood or behavior issues in some individuals. If you notice your symptoms worsening, or an increase in suicidal ideation, thoughts, or behavior while taking these drugs, please seek immediate medical help.

Neither Zonisamide nor Keppra should be taken if you are using Carbonic Anhydrase Inhibitors (CAIs). It's crucial to inform your physician about all the medications you are currently taking; CAIs will need a period of approximately 1-2 weeks to clear from your system before starting either Zonisamide or Keppra to prevent dangerous interactions. It's also important to note that both these drugs can interact with alcohol and certain over-the-counter medicines so always discuss any substance use with your doctor.

How much do Zonisamide and Keppra cost?

For the brand name versions of these drugs:

  • The price of 60 tablets of Keppra (500 mg) averages around $850, which works out to $14–$28/day, depending on your dose.
  • The price of 30 capsules of Zonisamide (100 mg) averages about $130, working out to approximately $4.33/day.

Thus, if you are in the higher dosage range for Keppra (i.e., 2000 mg/day or higher), then brand-name Zonisamide is less expensive on a per-day treatment basis. Please note that cost should not be a primary consideration in determining which of these drugs is right for you.

For the generic versions, costs are significantly lower:

  • Levetiracetam (the active ingredient in Keppra), available in packs from 30 up to 120 tablets with approximate daily costs ranging between $0.44 and $1.76 at doses from 500mg to 2000mg per day.

  • Zonisamide comes typically packed as either a set of thirty or sixty capsules with prices varying between different locations and sellers but generally resulting in an average daily expense ranging from approximately $1.10 down to roughly half that amount when purchased as larger quantities.

Despite the difference in cost, both medications have their own unique benefits and potential side effects; therefore it's important to consult with your healthcare provider before deciding based solely on price.

Popularity of Zonisamide and Keppra

Zonisamide and levetiracetam, often known by the brand name Keppra, are both used as anticonvulsants in the treatment of epilepsy.

In 2020, an estimated 3 million prescriptions were written for zonisamide in the US. Zonisamide accounted for approximately 5% of all antiepileptic drug prescriptions last year. It is a sulfonamide anticonvulsant that has been growing in popularity since its approval by the FDA in 2000.

Levetiracetam (Keppra) was prescribed to about 8.2 million people in the USA during that same period. Accounting for nearly 15% of all antiepileptic medication prescriptions, it is one of the most commonly used drugs within this category. Its prevalence has remained steady over recent years with only slight growth noted since its introduction almost two decades ago.


Both Zonisamide and Keppra (levetiracetam) are effective medications used for the management of epilepsy, with a long-standing record of usage backed by multiple clinical studies and meta-analyses that demonstrate their effectiveness over placebo treatments. They share similar mechanisms of action in reducing seizures but differ somewhat in terms of their pharmacokinetics.

Zonisamide works primarily by blocking sodium channels and inhibiting carbonic anhydrase. It can be prescribed alone or as part of combined therapy for treating partial seizures, both in adults and children aged 6 years and above.

Keppra works differently, binding to synaptic vesicle protein SV2A to exert its effects. It is commonly chosen as a first-line treatment due to its proven efficacy across different types of seizures, including myoclonic, tonic-clonic, and partial onset ones.

Both Zonisamide and Levetiracetam are available in generic form which represents significant cost savings especially for patients who must pay out-of-pocket. Starting any new anti-epileptic drug requires careful titration under medical supervision so that the body has time to adjust gradually without triggering adverse side effects or breakthrough seizures.

The side effect profile varies between these two drugs but they are generally well-tolerated; common side effects include dizziness, fatigue or weakness. However it's worth noting that less common but serious potential side effects such as mood changes should be reported immediately to healthcare providers.