Optimizing anti-seizure medication management and adherence in epilepsy care
March 10, 2026
Adherence involves shared decision-making between patients and healthcare providers, considering individual circumstances, treatment priorities, medication preferences, and lifestyle factors when selecting the most suitable anti-seizure therapy.
Epilepsy is a chronic neurological disorder characterized by recurrent, unprovoked seizures caused by abnormal electrical activity in the brain. It can affect people of all ages. It carries a significant global burden, has a profound impact on quality of life, and is often associated with stigma and discrimination.
Management strategies include anti-seizure medications, which remain the mainstay of treatment, as well as lifestyle modifications, surgery for selected cases, vagus nerve stimulation, and other therapeutic approaches. Anti-seizure medications (ASMs) “Anti-seizure medications are also known as anti-epileptic drugs (AEDs). The terminology has now shifted to anti-seizure medications because the aim is to control key symptoms, namely seizures, including in patients who do not yet have a formal diagnosis of epilepsy,” explains Elaine Ho Swee Wen, Lead Clinical Pharmacist, Sunway Medical Center, Sunway City, at the International Epilepsy Day symposium, Enhancing Epilepsy Awareness and Improving Care in Malaysia. There are currently more than 30 anti-seizure medications available on the market, with additional drugs undergoing research and seeking authorization from the FDA. These medications are proven to be effective for up to two-thirds of people diagnosed with epilepsy. For many patients, treatment is often lifelong. Common anti-seizure medications include Carbamazepine (Tegretol), Valproate (Epilim), Phenytoin (Dilantin), Levetiracetam (Keppra), Lamotrigine (Lamictal), and Topiramate (Topamax), among others. One of the more recent additions is Fenfluramine. Treatment selection Treatment selection for patients is highly personalized because anti-seizure medications have different mechanisms of action, making the process complex. The effectiveness of each medication depends on the patient’s circumstances, how the drug works, how dosing frequency affects the patient’s daily life, and the overall safety and tolerability for each individual. There are multiple sources of variability in response to anti-seizure medications. These may include the formulation of the medication, such as tablets or syrups. Pharmacological interactions are also important considerations. These include drug-drug interactions, drug-disease interactions, and drug-food interactions. Such factors can create challenges for patients with comorbidities and may affect adherence to the recommended medications and treatment plans. Other contributing factors include disease progression, body weight, sex, maturation, genetics, and seizure type. The primary goals of treatment are to prevent breakthrough seizures, reduce hospitalizations, lower the risk of injury and mortality, and improve quality of life, since there is no absolute guarantee that epilepsy can be cured. Compliance versus adherence What, then, is the difference between compliance and adherence? “When I first started as a young pharmacist trainee, we often referred to drug compliance. Our role as pharmacists has evolved since then. In the past, we were often the individuals standing behind the counter receiving prescriptions from doctors. We would simply relay the doctor’s instructions—for example, to take 500 milligrams twice a day, morning and night—to the patient. It was a passive role for the patient, where we provided instructions and they were expected to follow them exactly,” shares Elaine. In this model, compliance focuses on patients strictly following instructions, even when they face barriers and challenges. Adherence, on the other hand, reflects a shared decision-making process between the patient and the healthcare provider. The patient’s circumstances, priorities, medication preferences, and lifestyle factors are taken into account when selecting the most suitable anti-seizure medication. “We may not be able to cure the disease, but we can help patients improve their quality of life through medication and treatment. An agreement is made during the clinic appointment, and the patient’s behavior is expected to align with that plan. Adherence is therefore defined as the extent to which a person’s behavior corresponds with taking medications as recommended by healthcare providers. It can also be evaluated in terms of non-adherence or suboptimal adherence.” For example, a medication may need to be taken in the morning and at night. However, if the patient experiences drowsiness in the morning that interferes with concentration and daily functioning, they may choose to take the medication only at night. This situation would be considered suboptimal adherence. Barriers to treatment Adhering to treatment can be challenging for patients with epilepsy. Barriers may include affordability and accessibility of medications. Some medications may be available in government hospitals but not in private hospitals, or vice versa. In some cases, non-adherence may be unintentional. In other cases, patients may intentionally decide not to take the medication or to discontinue the recommended treatment. A survey conducted in the United States found that the most common barriers affecting medication adherence among patients with epilepsy include difficulty remembering to take medications, side effects, access issues, medications that do not adequately control seizures, and the perception that the medication may not be necessary. Side effects Side effects may be idiosyncratic, meaning they are acute, early-emergent reactions often associated with unknown mechanisms. If a new medication is introduced and the patient develops a reaction, a causal relationship may be established with that specific drug. However, these reactions can also be complex because they may occur at any time. Some anti-seizure medications have inhibitory effects on the nervous system, resulting in side effects such as drowsiness and sleepiness. These symptoms may occur at the start of treatment but can also develop after long-term use. Long-term effects may include bone disorders associated with carbamazepine. Severe cutaneous adverse reactions (SCAR) may also occur, including Stevens-Johnson syndrome, drug-induced hypersensitivity syndrome, and toxic epidermal necrolysis (TEN). These reactions are associated with medications such as carbamazepine, phenytoin, and phenobarbital. Risk factors include genetic links associated with HLA-A and HLA-B genes, as well as cytochrome P450 enzymes involved in the metabolism of certain medications used in epilepsy treatment. These genetic associations are more prevalent in Asian populations. Other idiosyncratic allergic mechanisms may include myelosuppression, pancytopenia, and hepatic dysfunction. Dose-dependent effects The inhibitory effects of anti-seizure medications on the nervous system may lead to dose-dependent side effects such as drowsiness, nausea, dizziness, nystagmus, and psychiatric symptoms. These side effects can affect a patient’s ability to continue or adhere to prescribed medications. Drug-drug interactions also play an important role. Some medications act as enzyme inducers or inhibitors of cytochrome P450 or other metabolizing enzymes. These interactions affect pharmacokinetics and pharmacodynamics, influencing how the body processes medications and the likelihood of side effects. Such interactions can alter drug metabolism and bioavailability, thereby affecting both the effectiveness of the medication and the side effects experienced by the patient. Combining anti-seizure medications can also create challenges. Drugs such as Carbamazepine, Phenytoin, Phenobarbital, and Primidone are enzyme inducers. When introduced as part of drug therapy, they may reduce serum concentrations and increase the clearance of co-administered anti-seizure medications, potentially reducing the efficacy of the accompanying treatment. For example, a patient may initially be treated with Phenytoin but experience suboptimal seizure control. Carbamazepine may then be introduced as an adjunct therapy in hopes of improving seizure control. However, drug-drug interactions may complicate the prediction of treatment response and the availability of drug levels in the patient. Routine drug monitoring is not always strongly advocated because clinical response and side effects do not always correspond directly to medication levels. Beyond combination therapy, drug interactions with other medications remain an important concern. A detailed drug history and overall patient history are essential because dose adjustments may be necessary. Long-term effects Certain anti-seizure medications are associated with long-term metabolic effects. Valproate, Gabapentin, and Perampanel may cause weight gain, whereas Topiramate and Zonisamide may lead to weight loss. Long-term treatment with Carbamazepine and Phenytoin has been associated with osteoporosis. Specific issues for girls and women Teratogenicity is a major concern in epilepsy treatment. Many anti-seizure medications have been shown to increase the likelihood of major congenital malformations. Valproate, in particular, has been associated with neurodevelopmental effects in children born to mothers who have taken the medication long term. Regulatory controls were initially introduced for women but have more recently been expanded. There are also emerging concerns regarding potential paternal effects related to medication exposure and possible neurodevelopmental implications for children. For these reasons, contraception and pre-conception planning are extremely important for patients diagnosed with epilepsy. Drug-drug interactions may also occur between anti-seizure medications and contraceptives, which can affect the effectiveness of birth control. Risks during pregnancy Pregnancy presents additional challenges in epilepsy management. If anti-seizure medications are discontinued, patients may experience loss of seizure control. Conversely, switching to another medication may introduce uncertainty regarding treatment response. Dosing can also be difficult during pregnancy because significant pharmacokinetic changes occur during pregnancy and the postpartum period. Which anti-seizure medication is considered safe during pregnancy? None can be considered completely safe. There is no definitive “green light” for any anti-seizure medication. Pharmacovigilance studies indicate that medications such as Valproic Acid carry a higher risk, followed by Phenytoin, Phenobarbital, and Primidone. In comparison, Levetiracetam is considered to have a relatively lower risk. Accessibility and cost Medication shortages remain a significant and ongoing global issue. Switching between branded and generic medications can also create problems. The neuroscience community has expressed concerns not only about changing treatments but also about switching brands. Although regulatory standards require generic medications to achieve a defined level of bioequivalence to the originator drug, variations are permitted within an acceptable range. In some cases, a difference of around 10 percent in bioavailability may occur. For certain patients, even this variation may be clinically significant. Some patients have experienced a loss of seizure control after switching brands, despite having been stable for many years. Cost and insurance restrictions, systemic barriers, and a lack of continuity in treatment assessment remain ongoing concerns. Patients may also worry about long-term effects of medications, including depression and anxiety. Stigma, fear of lifelong medication, and concerns about chronic illness can also affect treatment acceptance. It is often difficult to determine whether these psychological effects are related to the underlying condition, associated with the diagnosis of epilepsy, or caused by medication side effects. Stigma remains a significant issue, especially for children. Children who require medication at school may face questions from their peers about why they need to take these drugs. If a seizure occurs in public, it can appear dramatic to those who are unfamiliar with the condition. People who lack awareness may struggle to understand the situation or appreciate its significance. |
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