Seizure Medication Safety

May lower seizure threshold at high doses via adrenergic stimulation. Use lowest effective dose; avoid in poorly controlled seizure disorders.

Source: FDA labeling; AES

Mild adrenergic stimulation; lower seizure risk than pseudoephedrine but use with caution in active seizure disorder.

Source: FDA labeling

Lowers seizure threshold, especially at higher doses and in anticholinergic overdose. Prefer cetirizine or loratadine for allergy; melatonin for sleep. Note: 'Unisom' is sold as both diphenhydramine (SleepGels) and doxylamine (SleepTabs) - both are sedating first-generation antihistamines to avoid (see doxylamine entry).

Source: AES; FDA labeling

Sedating first-generation antihistamine, pharmacologically similar to diphenhydramine; can lower the seizure threshold, particularly at high doses or in anticholinergic overdose. Common as Unisom SleepTabs and in nighttime cold/flu combinations (e.g., NyQuil). Prefer melatonin for sleep and a second-generation antihistamine (cetirizine, loratadine, fexofenadine) when an antihistamine is needed.

Source: FDA labeling; AES

At standard OTC antitussive doses (~10-30 mg q4-6h) dextromethorphan does not lower the seizure threshold and is mildly anticonvulsant via NMDA antagonism (even studied for refractory epilepsy) - the preferred OTC cough suppressant in seizure history, though combination-product labels (e.g. promethazine/DXM) still advise caution. The therapeutic window is narrow: high or repeated supratherapeutic doses are paradoxically proconvulsant (facilitated kindling and spontaneous seizures in animal models), and overdose can cause seizures or refractory status epilepticus - relevant since DXM is widely abused and hidden in many combination products. Also serotonergic: contraindicated with MAOIs, with a (rare at therapeutic doses) serotonin-syndrome risk alongside SSRIs/SNRIs that can manifest as clonus/seizures. The DXM/bupropion combination (Auvelity) is contraindicated in seizure disorder - see separate entry.

Source: FDA labeling; AES

No effect on seizure threshold. Safe in seizure history.

Source: FDA labeling

Topical use with minimal systemic absorption; negligible seizure risk at recommended doses and duration (3 days or less).

Source: FDA labeling

Preferred antihistamine in patients with seizure history. Minimal CNS penetration.

Source: AES; FDA labeling

Preferred antihistamine in patients with seizure history. Non-sedating, minimal CNS penetration.

Source: AES; FDA labeling

Preferred antihistamine in patients with seizure history. Does not cross blood-brain barrier.

Source: FDA labeling

First-generation antihistamine with CNS penetration. Lower seizure risk than diphenhydramine but prefer second-generation alternatives.

Source: FDA labeling

Well-documented seizure threshold reduction at toxic levels. Narrow therapeutic index; largely obsolete. Enzyme-inducing AEDs (phenytoin, carbamazepine) accelerate theophylline clearance, complicating dosing.

Source: GINA; AES; FDA labeling

No clinically significant seizure threshold effect. Safe in patients with seizure history.

Source: GINA; FDA labeling

Inhaled route minimizes systemic exposure. No meaningful seizure risk.

Source: GINA; FDA labeling

FDA boxed warning (2020) is for serious neuropsychiatric events (mood changes, agitation, suicidality) - seizures/tremor appear as rare postmarketing adverse events, not as the focus of the box. Overall seizure risk is low. Use with caution and counsel patients on neuropsychiatric symptoms.

Source: FDA labeling (2020 boxed warning); GINA

No clinically significant seizure risk at therapeutic inhaled doses. Safe in seizure history.

Source: GINA; FDA labeling

No seizure threshold effect. Preferred OTC analgesic/antipyretic in seizure history. Standard dosing only - hepatotoxicity at high doses.

Source: FDA labeling

No clinically significant seizure threshold effect at standard OTC doses.

Source: FDA labeling

No clinically significant seizure threshold effect.

Source: FDA labeling

No clinically significant seizure threshold effect at standard doses.

Source: FDA labeling

Well-documented, dose-dependent seizure risk; lowers the threshold even at therapeutic doses, and risk is additive with SSRIs, SNRIs, TCAs, and bupropion. Avoid in seizure disorder. Labeling correction: seizures are a labeled Warning, NOT part of tramadol's boxed warning (the box covers addiction/abuse/misuse, respiratory depression, CYP2D6 ultra-rapid metabolism, neonatal opioid withdrawal, and benzodiazepine/CNS-depressant co-use). The same concern applies to tapentadol (see separate entry).

Source: FDA labeling; AES

Active metabolite normeperidine is a CNS excitant that lowers seizure threshold. Avoid in seizure history; prefer alternative opioids.

Source: FDA labeling; AES

Standard opioids have minimal direct seizure threshold effect at therapeutic doses. Risk increases with overdose or withdrawal. Avoid meperidine, tramadol, and tapentadol (see separate entries).

Source: FDA labeling

Dual mu-opioid agonist and norepinephrine reuptake inhibitor - same mechanistic family as tramadol. The label warns it may lower the seizure threshold and to use caution in patients with seizure disorders. Seizure evidence is less robust than tramadol's, but many clinicians avoid both in epilepsy. Prefer a standard opioid (morphine, oxycodone, hydrocodone) when an opioid is required in seizure history.

Source: FDA labeling; AES

Gabapentin is itself an antiepileptic drug. Safe in seizure history; does not lower seizure threshold.

Source: FDA labeling

Pregabalin is itself an antiepileptic drug. Safe in seizure history.

Source: FDA labeling

Class-wide seizure risk via GABA-A receptor inhibition; FDA boxed warning covers disabling CNS effects (which include convulsions). Use an alternative antibiotic class in seizure history when possible. Drug interaction: ciprofloxacin LOWERS phenytoin levels (reduced AUC, Cmax, and half-life) - documented breakthrough seizures, reported even with ciprofloxacin eye drops; the effect is unpredictable, so monitor phenytoin levels closely. Cipro also raises theophylline and tizanidine levels via CYP1A2 inhibition.

Source: FDA labeling (boxed warning); AES; drugs.com interaction monograph

Highest seizure risk among carbapenems; dose-dependent CNS toxicity. Prefer meropenem or ertapenem when a carbapenem is required in seizure history.

Source: FDA labeling; AES

Lower seizure risk than imipenem, but carbapenems carry a class threshold-lowering warning - risk is low, not zero. Critical AED interaction: meropenem dramatically reduces valproate levels (up to 60-80% reduction) via an unclear mechanism that is NOT overcome by raising the valproate dose. Avoid co-administration with valproate; switch the antibiotic or bridge to an alternative AED. Prefer meropenem or ertapenem over imipenem when a carbapenem is required.

Source: FDA labeling; AES; IDSA

Well-documented and often under-recognized neurotoxicity - encephalopathy, myoclonus, and non-convulsive status epilepticus - especially with renal impairment, supratherapeutic dosing, or in elderly patients. Renally dose-adjust carefully and keep cefepime neurotoxicity on the differential for altered mental status while on therapy. Beta-lactams as a class (also high-dose penicillins) can lower the seizure threshold.

Source: FDA labeling; AES

Neurotoxicity/seizures possible at high doses or prolonged use. Inhibits CYP2C9 - raises phenytoin levels. Monitor phenytoin if co-administered.

Source: FDA labeling; AES

Potent CYP inhibitors - raise levels of phenytoin, carbamazepine, and other CYP2C9/3A4-metabolized AEDs, risking toxicity. Interaction is bidirectional: enzyme-inducing AEDs (phenytoin, carbamazepine, phenobarbital) markedly lower itraconazole/voriconazole levels - antifungal failure risk. Monitor AED levels and antifungal response when starting or stopping azoles.

Source: FDA labeling; AES

CYP3A4 inhibitor - can raise carbamazepine and other AED levels. Monitor for AED toxicity. Prefer azithromycin (minimal CYP interaction).

Source: FDA labeling

Minimal CYP interaction. Preferred macrolide in patients on AEDs.

Source: FDA labeling

Potent CYP3A4/2C9/2C19 inducer - markedly reduces levels of many AEDs (carbamazepine, phenytoin, lamotrigine, valproate). Anticipate need for AED dose increase; monitor levels.

Source: FDA labeling; AES

Inhibits pyridoxine (B6) metabolism - B6 deficiency lowers seizure threshold. Also inhibits phenytoin metabolism (CYP2C9/2C19), raising levels - greatest in slow acetylators; can also raise carbamazepine. Monitor AED levels; supplement B6. INH overdose causes refractory seizures treated with IV pyridoxine gram-for-gram.

Source: FDA labeling

Can displace phenytoin from protein binding and inhibit its metabolism, transiently raising free phenytoin levels. Monitor for phenytoin toxicity.

Source: FDA labeling

Enzyme-inducing AEDs (phenytoin, carbamazepine, phenobarbital) accelerate doxycycline metabolism, reducing its efficacy. May need higher doxycycline dose or alternative antibiotic.

Source: FDA labeling

Dose-dependent seizure risk; FDA-contraindicated in seizure disorder. Risk increases at doses above 450 mg/day. Present in Wellbutrin, Zyban, Contrave (weight-loss combination), AND Auvelity (dextromethorphan-bupropion for depression) - always check ingredients.

Source: FDA labeling (contraindication); AES

Contains bupropion, which is FDA-contraindicated in seizure disorder - the bupropion component (not the dextromethorphan) drives the risk. The label lists seizure disorder as a contraindication and flags added risk factors (severe head injury, CNS tumor, metabolic disturbance, other threshold-lowering drugs). Like Contrave, the brand name hides the bupropion - always check ingredients. Absolute contraindication in seizure history.

Source: FDA labeling (contraindication)

Generally well-tolerated in seizure history. Fluoxetine/paroxetine inhibit CYP2D6/2C19, potentially raising some AED levels. Fluvoxamine is a potent CYP1A2/2C19 inhibitor - can raise carbamazepine and phenytoin levels (toxicity). SIADH risk (especially elderly) - hyponatremia provokes seizures. Monitor sodium in elderly patients.

Source: AES; FDA labeling

Venlafaxine carries dose-dependent seizure risk at higher doses; desvenlafaxine is its active metabolite with the same dose-related risk but minimal CYP interaction; duloxetine and levomilnacipran less so. Venlafaxine/duloxetine inhibit CYP2D6 (desvenlafaxine does not). SIADH/hyponatremia risk similar to SSRIs.

Source: FDA labeling; AES

Seizures reported rarely; lowers threshold less than bupropion or TCAs but use caution in poorly controlled epilepsy, as with all antidepressants. CYP-inducing AEDs (carbamazepine, phenytoin) reduce vortioxetine levels - may need dose increase; SIADH/hyponatremia can itself provoke seizures.

Source: FDA labeling (Trintellix); Maudsley

TCAs lower seizure threshold, especially at high doses or in overdose. CYP2D6 interactions with AEDs. Use lowest effective dose; prefer SSRIs when adequate.

Source: AES; FDA labeling

Highest seizure risk of the TCAs - dose-dependent incidence approaches 1.5-2% above 250 mg/day. Listed separately from other TCAs for this reason. Used for OCD; cap the dose, split dosing, and avoid in poorly controlled epilepsy. CYP2D6 interactions with AEDs.

Source: FDA labeling (Anafranil); AES

Among the most proconvulsant antidepressants - maprotiline has a notably high seizure rate (dose- and duration-dependent, worse with rapid titration) and amoxapine is markedly epileptogenic in overdose. Both are near-obsolete and should be avoided in seizure disorder; safer alternatives exist for nearly every indication.

Source: FDA labeling; AES

Low seizure risk - rarely reported, among the safer antidepressants in seizure history. Main caveats are indirect: sedation and weight gain, and SIADH/hyponatremia (which itself provokes seizures). Reasonable choice when an antidepressant is needed in an epilepsy patient.

Source: FDA labeling (Remeron); Maudsley

Seizures reported in overdose and with hypertensive crises. Greater concern is interactions: tyramine reactions, serotonin syndrome (can manifest with seizures), and required washout periods before/after other serotonergic agents. Rarely used; specialist territory. Indirect risk from autonomic instability.

Source: FDA labeling; AES

Not clearly proconvulsant - ketamine is used to TREAT refractory status epilepticus and leans anticonvulsant; seizure-threshold data in depression dosing is limited, hence caution rather than avoid. The real signal is indirect: sedation, dissociation, and transient blood-pressure spikes (REMS monitoring required). High abuse/diversion potential drives overuse risk.

Source: FDA labeling (Spravato REMS)

Seizures uncommon; low threshold-lowering effect comparable to vortioxetine. CYP3A4 substrate - inducing AEDs (carbamazepine, phenytoin) lower vilazodone levels and may need a dose increase. SIADH/hyponatremia can itself provoke seizures.

Source: FDA labeling (Viibryd)

Highest seizure risk among antipsychotics; dose-dependent. Valproate often added to manage seizure risk. Avoid carbamazepine combination (agranulocytosis risk).

Source: FDA labeling; AES

Lower seizure risk than clozapine; risk increases at high doses. Enzyme-inducing AEDs (carbamazepine) significantly lower quetiapine levels - monitor efficacy.

Source: FDA labeling; AES

Lithium toxicity causes seizures. Narrow therapeutic index - avoid dehydration, NSAIDs, thiazides (raise lithium levels). Monitor levels closely.

Source: FDA labeling; AES

Stimulants may lower seizure threshold. Not contraindicated in well-controlled epilepsy, but monitor seizure frequency when initiating.

Source: FDA labeling; AES

Lower seizure risk than amphetamines but may lower threshold. Can be used in well-controlled seizure disorder with close monitoring.

Source: FDA labeling; AES

Non-stimulant; preferred ADHD option when stimulant risk is concerning in seizure history. Does not meaningfully lower the seizure threshold at therapeutic doses, though seizures have been reported in overdose and the label advises caution in patients at risk for seizures. Guanfacine and clonidine are the most threshold-neutral non-stimulant alternatives.

Source: FDA labeling; AES

No clinically significant seizure threshold effect. Safe in seizure history.

Source: FDA labeling

No clinically significant seizure effect. Preferred OTC sleep aid in patients with seizure history.

Source: FDA labeling; AES

Low seizure risk at sleep doses (25-100 mg). SIADH risk (hyponatremia provokes seizures), especially elderly. Enzyme-inducing AEDs may lower trazodone levels.

Source: FDA labeling

GABA-A agonist; abrupt discontinuation after regular use risks rebound and occasionally seizures. Enzyme-inducing AEDs accelerate metabolism. Use short-term only.

Source: FDA labeling

No known direct seizure threshold effect. CYP3A4 substrate - enzyme-inducing AEDs substantially reduce suvorexant exposure.

Source: FDA labeling

No clinically significant seizure threshold effect. Preferred antiemetic in seizure history.

Source: FDA labeling

Phenothiazine class lowers seizure threshold. Prefer ondansetron or meclizine when possible.

Source: FDA labeling; AES

Dopamine antagonist; may lower seizure threshold. Tardive dyskinesia risk with long-term use.

Source: FDA labeling

Phenothiazine class lowers seizure threshold. Prefer ondansetron in seizure history.

Source: FDA labeling; AES

Minimal seizure threshold effect. Safer antiemetic for motion sickness in seizure history.

Source: FDA labeling

Digoxin toxicity causes neurological effects including seizures. Narrow therapeutic index. Enzyme-inducing AEDs reduce digoxin levels; monitor.

Source: FDA labeling

Potent CYP2C9/3A4 inhibitor - significantly raises phenytoin and warfarin levels. Monitor phenytoin levels and INR closely when starting or stopping amiodarone.

Source: FDA labeling

No clinically significant seizure threshold effect. Generally safe in seizure history.

Source: FDA labeling

CYP3A4 inhibitor - may raise carbamazepine levels significantly. Monitor for carbamazepine toxicity (diplopia, ataxia, dizziness).

Source: FDA labeling

Hypoglycemia is the primary risk - severe hypoglycemia provokes seizures. Risk highest with skipped meals, renal impairment, or elderly patients. Prefer metformin, SGLT2i, or GLP-1 agonists in seizure history when possible.

Source: ADA Standards of Care; FDA labeling

Hypoglycemia risk directly causes provoked seizures. Careful dosing, consistent carbohydrate intake, and patient education critical. Some AEDs (valproate) can affect glucose metabolism.

Source: ADA Standards of Care; FDA labeling

No hypoglycemia risk as monotherapy. No seizure threshold effect. Preferred first-line agent in diabetes with seizure history.

Source: ADA Standards of Care; FDA labeling

Negligible hypoglycemia risk as monotherapy. No seizure threshold effect. Safe in seizure history.

Source: ADA Standards of Care; FDA labeling

Very low hypoglycemia risk as monotherapy. No seizure threshold effect. Safe in seizure history.

Source: ADA Standards of Care; FDA labeling

Enzyme-inducing AEDs (carbamazepine, oxcarbazepine, phenytoin, phenobarbital, topiramate above 200 mg/day) markedly reduce OCP efficacy - contraceptive failure risk. Use barrier method or consider Depo-Provera, LNG-IUD, or copper IUD. Note: estrogen lowers lamotrigine levels.

Source: AES; ACOG; FDA labeling

Less affected by enzyme-inducing AEDs than oral contraceptives; often recommended for women on enzyme-inducing AEDs. Progestogens may have mild anticonvulsant properties.

Source: AES; ACOG

No drug interaction with AEDs. Most reliable contraceptive option for women on enzyme-inducing AEDs.

Source: AES; ACOG

No direct seizure threshold effect. Omeprazole inhibits CYP2C19, may raise some AED levels. Long-term use risks hypomagnesemia - severe hypomagnesemia provokes seizures. Monitor Mg with prolonged PPI use.

Source: FDA labeling

Broad CYP inhibitor (1A2, 2D6, 2C9, 3A4) - can raise levels of many AEDs and other drugs. Prefer famotidine (minimal CYP interaction).

Source: FDA labeling

Minimal drug interactions. Preferred H2 blocker in patients on AEDs.

Source: FDA labeling

Structurally related to TCAs; may modestly lower seizure threshold. Use with caution; prefer methocarbamol or tizanidine.

Source: FDA labeling; AES

Abrupt discontinuation causes severe, life-threatening withdrawal seizures. Never stop abruptly - taper slowly. Intrathecal baclofen withdrawal is a neurosurgical emergency.

Source: FDA labeling; AES

Metabolized to meprobamate (GABA-A modulator); significant abuse potential and seizure risk on withdrawal. Avoid in seizure history.

Source: FDA labeling

Lower seizure risk than cyclobenzaprine or carisoprodol. Use with caution in seizure history.

Source: FDA labeling

No clinically significant seizure threshold effect. Preferred muscle relaxant in seizure history.

Source: FDA labeling

Potent CYP3A4 and P-gp inducer - markedly reduces levels of many AEDs (carbamazepine, phenytoin, lamotrigine). Seizure breakthrough reported. Counsel patients to avoid.

Source: FDA alert; AES

Ginkgotoxin in ginkgo seeds/leaves lowers seizure threshold via pyridoxine (B6) antagonism. Case reports of seizures. Use with caution; avoid concentrated extracts.

Source: FDA; case reports

Older teaching held that EPO lowers the seizure threshold (notably alongside phenothiazines), but this rests on weak, historical case reports and has since been questioned; mechanism unclear. Caution is reasonable, but the evidence is poor.

Source: Case reports (historical); FDA

CBD (Epidiolex) is FDA-approved for seizures and does not lower threshold. However, CBD inhibits CYP2C19/3A4 - can raise clobazam and other AED levels. Monitor for AED toxicity if patient uses CBD products.

Source: FDA labeling; AES

FDA 2015 label update: rare seizures reported in clinical trials and postmarketing, in patients with AND without a prior seizure history (median onset 2-3 weeks after starting). Use cautiously in patients with a history of seizures or other threshold-lowering factors; varenicline also reduces alcohol tolerance. Still more effective than nicotine replacement, so weigh risk/benefit - it is not contraindicated in seizure history.

Source: FDA labeling (2015 seizure warning)

No seizure threshold effect at standard doses. Safe in seizure history.

Source: FDA labeling

CNS stimulant; may lower seizure threshold. Avoid in poorly controlled epilepsy.

Source: FDA labeling

Contains bupropion - FDA-contraindicated in seizure disorder. Brand name obscures the bupropion component; always check ingredients. Absolute contraindication in seizure history.

Source: FDA labeling (contraindication)

Peripheral GI mechanism. No CNS effect; no seizure risk.

Source: FDA labeling

No direct seizure threshold effect. No known AED interactions. Safe in seizure history.

Source: FDA labeling

Topiramate is itself an AED. However, the label warns that ABRUPT discontinuation of Qsymia can provoke seizures even in patients without epilepsy - taper (every-other-day dosing for at least 1 week) rather than stopping cold. Topiramate + valproate combination increases hyperammonemia risk. Phentermine adds mild CNS stimulant caution.

Source: FDA labeling

Enzyme-inducing AEDs (carbamazepine, phenytoin, phenobarbital) increase warfarin metabolism - reduced INR - clot risk. Amiodarone and azoles raise warfarin levels - bleeding risk. Monitor INR closely with any AED change.

Source: FDA labeling; AES

CYP3A4/P-gp substrate - enzyme-inducing AEDs (carbamazepine, phenytoin, phenobarbital, rifampin) reduce apixaban levels approximately 50%. Avoid combination; alternative anticoagulation required if enzyme-inducing AED is necessary.

Source: FDA labeling; AES

CYP3A4/P-gp substrate - same class interaction as apixaban with enzyme-inducing AEDs. Avoid with strong inducers (carbamazepine, phenytoin).

Source: FDA labeling

P-gp substrate (not CYP-dependent). Enzyme-inducing AEDs (carbamazepine, rifampin) reduce dabigatran via P-gp induction. Less affected than factor Xa inhibitors.

Source: FDA labeling

Alcohol withdrawal causes severe seizures (typically 6-48 hours after last drink). Benzodiazepines are first-line for prevention. Chronic alcohol use induces CYP enzymes, lowering AED levels.

Source: AES; ASAM guidelines

Abrupt discontinuation after regular use causes life-threatening withdrawal seizures (onset 1-7 days after cessation). Always taper. Never stop benzodiazepines abruptly in a dependent patient.

Source: AES; FDA labeling

Abrupt withdrawal causes severe seizures (similar timeline to benzodiazepines). Phenobarbital itself is an AED and potent CYP inducer - stopping it affects levels of other co-administered AEDs. Always taper.

Source: AES; FDA labeling

Abruptly stopping any AED risks breakthrough seizures or status epilepticus. Always taper. Patient education critical - never allow a patient to run out of AED medication without a plan.

Source: AES