What are the seizure medications that do not cause anemia (iron deficiency)?

From the Guidelines

Levetiracetam, lacosamide, and lamotrigine are the preferred seizure medications that do not significantly impact hepatic metabolizing enzymes and are less likely to cause anemia. These medications are generally preferred when anti-seizure medications are utilized, as stated in the 2022 study published in Neuro-Oncology 1. Levetiracetam is often prescribed at 500-1500 mg twice daily and is generally well-tolerated with minimal blood count effects. Lamotrigine requires slow titration (usually starting at 25 mg daily and gradually increasing) to reduce rash risk but rarely affects blood counts.

Key Points to Consider

• Gabapentin (300-1200 mg three times daily) and pregabalin (75-300 mg twice daily) are also safe regarding hematologic parameters, but the most recent and highest quality study 1 does not specifically mention these medications as preferred options.
• Valproic acid, carbamazepine, phenytoin, and phenobarbital have higher associations with blood disorders including anemia and should be avoided if anemia is a concern.
• Regular follow-up with your neurologist is essential, and blood counts should still be monitored periodically even with these safer medications.
• The choice of anticonvulsant should ultimately be based on seizure type, individual patient factors, and potential drug interactions.

Management of Iron Deficiency Anemia

It's worth noting that if iron deficiency anemia does occur, treatment with iron supplementation, such as ferrous sulphate 200 mg twice daily, can help correct the anemia and replenish body stores, as suggested in the 2011 study published in Gut 1. However, this is not directly related to the choice of seizure medication.

From the FDA Drug Label

The chemical name of levetiracetam, a single enantiomer, is (-)-(S)-α-ethyl-2-oxo-1-pyrrolidine acetamide, its molecular formula is C8H14N2O2 and its molecular weight is 170. 21. Levetiracetam is chemically unrelated to existing antiepileptic drugs (AEDs). Inactive ingredients: colloidal silicon dioxide, corn starch, hydroxypropyl methylcellulose, hypromellose, iron oxide yellow, lactose monohydrate, magnesium stearate, povidone, titanium dioxide, and triacetin.

Seizure medications that do not cause anemia (iron deficiency)

• Levetiracetam does not have direct information in its label about causing anemia.
• Topiramate's label lists anemia as an adverse event, with an incidence of 1% or more in clinical trials, as shown in Table 4: Incidence of Treatment-Emergent Adverse Events in the Monotherapy Epilepsy Trial in Adults
  • Red Blood Cell Disorders Anemia is listed with a percentage, indicating it occurred in the study.

Based on the information provided, Levetiracetam does not have direct information in its label about causing anemia, but Topiramate is associated with anemia as an adverse event. 2 3

From the Research

Seizure Medications that Do Not Cause Anemia

There are several seizure medications that do not cause anemia (iron deficiency) as a side effect. The following medications are considered to be safe in this regard:

• Levetiracetam: This medication is considered to be one of the safest options for patients with epilepsy, with a low risk of anemia 4, 5, 6, 7.
• Lamotrigine: This medication is also considered to be safe, with a low risk of anemia 4, 5, 6, 7.
• Gabapentin: This medication is generally well-tolerated, with a low risk of anemia 4, 5, 8.
• Topiramate: This medication is considered to be safe, with a low risk of anemia 4, 8.
• Zonisamide: This medication is also considered to be safe, with a low risk of anemia 4, 5, 6, 7, 8.

Key Points to Consider

When choosing a seizure medication, it's essential to consider the potential side effects, including the risk of anemia. The following points are crucial to keep in mind:

• Levetiracetam, lamotrigine, gabapentin, topiramate, and zonisamide are all considered to be safe options with a low risk of anemia.
• The risk of anemia is higher with certain medications, such as felbamate, which can cause aplastic anemia and hepatic failure 4.
• It's crucial to monitor patients for signs of anemia, such as fatigue, weakness, and shortness of breath, especially when starting a new medication.
• Patients with a history of anemia or iron deficiency should be closely monitored when taking seizure medications.