202409222330
Status:
Tags: Neuro, pharmacology
Anti-epileptic drugs
Common ADR: hypoNa, dLFT, ↓plt, leukopenia
An electrocardiogram should be routinely performed given the common finding of Brugada-type ST changes and J wave abnormalities that are often associated with sodium channel blocking AEDs
| Mechanism of action | Drug | Effect on drug metabolism | Adverse effects |
|---|---|---|---|
| Sodium channel effects | Carbamazepine | Potent CY2P, UGT and P-gp inducer | Hyponatraemia, leucopenia, cardiac conduction abnormalities |
| Eslicarbazepine | Mixed inducer and inhibitor | Hyponatraemia, increased PR interval, deranged LFTs | |
| Oxcarbazepine | Mixed inducer and inhibitor | Hyponatraemia, rare cause of Steven–Johnson syndrome | |
| Phenytoin | Potent CY2P and UGT-glucuronidation inducer | Rash, gingival hypertrophy, decreased bone density | |
| Lacosamide | Minor CYP2C19 inhibitor | PR prolongation, potential interaction with other AEDs | |
| Zonisamide | None | Weak carbonic anhydrase inhibitor, nephrolithiasis, cognitive and psychiatric adverse effects | |
| Lamotrigine | Minor inducer of own metabolism (UGT) | Somnolence, rash, hypersensitivity reactions, aseptic meningitis | |
| Modulation of GABA activity | Clobazam | Moderate inhibitor CYP2D6 | Somnolence, dysarthria, mood changes |
| Phenobarbital | Potent enzyme inducer | Osteomalacia, Dupuytren's contracture, megaloblastic anaemia (rare) | |
| Glutamate receptor blockade | Perampanel | None significant but can affect hormonal contraceptives | Neuropsychiatric effects |
| Calcium channel blockade | Ethosuximide | None | Nausea, vomiting, sleep disturbance |
| Multiple mechanisms of action | Valproate | Mixed inhibitor and inducer CYP group | Metabolic syndrome, thrombocytopenia, coagulation disorders, hepatotoxicity |
| Topirimate | Minor CYP3A4 inducer, minor CYP2C19 inhibitor | Weight loss, paraesthesia, metabolic acidosis | |
| Primidone | Potent enzyme inducer | Osteopenia, QT interval changes, deranged LFTs | |
| Other mechanisms of action | Levetiracetam | None | Neuropsychiatric effects |
| Brivaracetam | Weak inhibitor | Irritability, anxiety, hypersensitivity reactions | |
| Gabapentin | None | Sedation, weight gain | |
| Cannabidiol | Likely moderate inducer CYP450 | Somnolence, vomiting, abnormal LFTs |