Atazanavir
Severe
Database
Drug interaction classified as: synergy
Source: DDInter
Drug reference
Lacosamide
Functionalized amino acid antiepileptic · Epilepsy and other seizure disorders
START
Baseline ECG (PR interval). Check renal function. Assess for cardiac conduction disease. Counsel on dizziness risk (do not drive until stable).
TYPICAL MAX
600mg/day (adults). PR prolongation is dose-dependent—monitor ECG at higher doses.
STOP IF
PR prolongation >200ms, new AV block, syncope, DRESS, severe rash, suicidal ideation.
WATCH
PR interval on ECG at baseline and during titration. Dose-dependent PR prolongation—use caution with other drugs that prolong PR (beta-blockers, calcium channel blockers). Dizziness is most common side effect. IV formulation available for temporary substitution when PO not possible.
CDSCO approvedSchedule HATC N03AX18
KDIGO 2024 + manufacturer label
- ONSET
- 30min · Onset ~30 min
- PEAK
- 2.5h · Tmax 1-4 hours
- t½
- 13h · t½ ~13 hours
- DURATION
- 12h · 12 hours (BID)
EXCRETION
Renal unchanged (~70%)
route + CYP
INTERACTIONS
6 major
SEVERE in our sources
PREGNANCY
Pregnancy registry data suggest no increased major malformation risk; use only if benefit outweighs risk. Folates supplementation recommended.
FDA category + note
Top interactionssee all 12 →
- AtazanavirSevereDatabaseDDInter
- CeritinibSevereDatabaseDDInter
- DolasetronSevereDatabaseDDInter
- SaquinavirSevereDatabaseDDInter
Available in India
86 branded formulations. Look up specific brands in the Drugs workspace.
Mechanism
Selectively enhances slow inactivation of voltage-gated sodium channels (unique mechanism among AEDs), stabilizing hyperexcitable neuronal membranes and inhibiting repetitive neuronal firing. Does not affect fast sodium channel inactivation.
Indications
Focal onset seizures (monotherapy or adjunctive)Focal onset seizures with secondary generalization
Dosing
- Adult
- Monotherapy: 50mg PO BID x 1 week, then 100mg BID x 1 week, then 150mg BID; max 300mg BID (600mg/day). Adjunctive: same titration. IV: same doses infused over 15-60 minutes.
- Pediatric
- ≥4 years: weight-based starting 1mg/kg BID, titrate to 4-6mg/kg BID (max 200mg BID).
- Renal adjustment
- CrCl ≤30: max 300mg/day (reduce by 25%). HD: consider supplemental dose post-HD.
- Hepatic adjustment
- Mild-moderate: max 300mg/day. Severe: contraindicated.
- Geriatric
- Start 25mg BID; slower titration; monitor ECG for PR prolongation.
- Max dose
- 600mg/day (adults); 400mg/day (pediatric)
Pharmacokinetics
Onset
Seizure reduction within days of reaching therapeutic dose
Peak effect
Tmax 1-4 hours (oral); steady-state in 3 days
Duration
12 hours (BID dosing)
Half-life
~13 hours
Bioavailability
~100%
Protein binding
<15%
Metabolism
~30% hepatic (CYP2C9, CYP2C19); 70% excreted unchanged in urine
Excretion
~70% unchanged in urine; ~30% as metabolites
Contraindications
- Hypersensitivity to lacosamide
- Second- or third-degree AV block (known)
- Severe hepatic impairment (Child-Pugh C)
- Known sodium channelopathies with cardiac involvement
Side effects
Common
DizzinessHeadacheNauseaDiplopiaAtaxiaFatigueTremorVertigo
Serious
- PR interval prolongation / AV block
- Severe multi-organ hypersensitivity (DRESS)
- Suicidal ideation
- Syncope
- Bradycardia
Pregnancy & lactation
Pregnancy
Pregnancy registry data suggest no increased major malformation risk; use only if benefit outweighs risk. Folates supplementation recommended.
Lactation
Excreted in breast milk (~milk:plasma ratio 1); infant exposure ~10% of maternal dose. Monitor infant for sedation and poor feeding.
Drug interactions
Ceritinib
Severe
Database
Drug interaction classified as: synergy
Source: DDInter
Dolasetron
Severe
Database
Clinical effect not specified
Source: DDInter
Saquinavir
Severe
Database
Clinical effect not specified
Source: DDInter
Siponimod
Severe
Database
Clinical effect not specified
Source: DDInter
Sodium Oxybate
Severe
Database
Clinical effect not specified
Source: DDInter
Clonazepam
Moderate
Database
Increased risk of CNS adverse effects such as sedation, dizziness, and respiratory depression.
Monitor for increased CNS adverse effects. Consider lower starting doses or slower titration of lacosamide. Dose adjustments may be necessary if adverse effects are intolerable.
Digoxin
Moderate
Database
Lacosamide can cause PR interval prolongation. Concomitant use with other drugs that prolong the PR interval, such as digoxin, may increase this risk, although the clinical significance is generally minor unless pre-existing cardiac conditions are present.
Monitor ECG, especially in patients with pre-existing cardiac conditions or those receiving high doses of lacosamide. Use with caution.
Source: DDInter
Diltiazem
Moderate
Database
Lacosamide can cause PR interval prolongation. Concomitant use with other drugs that prolong the PR interval, such as diltiazem, may increase this risk, although the clinical significance is generally minor unless pre-existing cardiac conditions are present.
Monitor ECG, especially in patients with pre-existing cardiac conditions or those receiving high doses of lacosamide. Use with caution.
Source: DDInter
Fluoxetine
Moderate
Database
Increased plasma concentrations of lacosamide, potentially leading to increased risk of dose-related adverse effects such as dizziness, nausea, vomiting, and cardiac conduction abnormalities (PR interval prolongation).
Monitor for increased lacosamide adverse effects. Consider a lower starting dose or slower titration of lacosamide. Dose adjustments of lacosamide may be necessary.
Source: DDInter
Fluvoxamine
Moderate
Database
Increased plasma concentrations of lacosamide, potentially leading to increased risk of dose-related adverse effects such as dizziness, nausea, vomiting, and cardiac conduction abnormalities (PR interval prolongation).
Monitor for increased lacosamide adverse effects. Consider a lower starting dose or slower titration of lacosamide. Dose adjustments of lacosamide may be necessary.
Source: DDInter
Gabapentin
Moderate
Database
Increased risk of CNS adverse effects such as dizziness, somnolence, and ataxia.
Monitor for increased CNS adverse effects. Consider lower starting doses or slower titration of lacosamide. Dose adjustments may be necessary if adverse effects are intolerable.
Related guidelines
Initial monotherapy for newly diagnosed epilepsy
ILAE · Neurology · 2013
Functional (psychogenic non-epileptic) seizures
AAN · Neurology · 2026
Initial monotherapy for newly diagnosed epilepsy
IAN · Neurology · 2023
Status epilepticus
AAN · Neurology · 2020
Hypertensive disorders of pregnancy
FOGSI · Obstetrics & Gynaecology · 2019
Ask House about Lacosamide
Continue into a citation-backed clinical answer with the drug context already attached.
Sources: KD Tripathi 7e, Goodman & Gilman 14e·Verified: 2026-05-19 · House clinical team·Cockpit curated: 2026-05-19