| Recommended Dose and Dosage Regimen | The recommended starting dose of lamotrigine for epilepsy in adults is usually 25 mg once daily for two weeks, then increased to 50 mg once daily for two weeks. The dosage may then be titrated upwards by 25-50 mg every 1-2 weeks based on response and tolerability, up to a maintenance dose of 100-200 mg daily. For bipolar disorder, the initial dose is typically 25 mg once daily, with subsequent increases up to 200-400 mg daily as tolerated. Follow your healthcare provider’s instructions regarding dosing. |
| Frequency of Administration | Lamotrigine is usually taken once daily. |
| Route of Administration | Lamotrigine is administered orally in the form of tablets or chewable dispersible tablets. |
| Mechanism of Action (MOA) | Lamotrigine’s mechanism of action involves modulation of voltage-gated sodium channels, leading to stabilization of neuronal membranes and inhibition of excessive neuronal firing. It may also modulate glutamate release and inhibit calcium channels. |
| Pharmacokinetics (PK) | Lamotrigine is well absorbed after oral administration, with peak plasma concentrations reached in 1.4 to 4.8 hours. It undergoes hepatic metabolism primarily via glucuronidation. The half-life ranges from 25 to 33 hours and is shortened by enzyme-inducing medications. |
| Pharmacodynamics (PD) | Lamotrigine’s pharmacodynamic effects include inhibition of neuronal excitability, modulation of neurotransmitter release, and potential neuroprotective properties. |
| Pathophysiology | Lamotrigine is used in the treatment of epilepsy, including partial seizures, generalized seizures, and seizures associated with Lennox-Gastaut syndrome. It is also indicated for the maintenance treatment of bipolar disorder to delay the occurrence of mood episodes (depression, mania, hypomania, mixed episodes) in adults. |
| Primary Indications | Epilepsy: Partial seizures, generalized seizures, Lennox-Gastaut syndrome. Bipolar disorder: Maintenance treatment to delay mood episodes. |
| Contraindications | Contraindications include hypersensitivity to lamotrigine or its components, history of serious skin reactions (e.g., Stevens-Johnson syndrome, toxic epidermal necrolysis) with lamotrigine, and concomitant use with valproate unless benefits outweigh risks. Use caution in patients with hepatic impairment. |
| Purpose of Taking Medication | Lamotrigine is used to control seizures in epilepsy and to stabilize mood in bipolar disorder, thereby reducing the frequency and severity of mood episodes. |
| Usage Instructions | Take lamotrigine exactly as prescribed by your healthcare provider. It may be taken with or without food. The dosage should be titrated gradually to minimize the risk of serious skin reactions. |
| Precautions and Care | Patients should be monitored for signs of hypersensitivity reactions, especially during the initial months of treatment. Dose adjustments may be necessary in patients with hepatic impairment. Abrupt discontinuation should be avoided to prevent seizure recurrence. |
| Dietary Considerations | There are no specific dietary restrictions associated with lamotrigine use. Maintain a balanced diet unless otherwise advised by your healthcare provider. |
| Missed Dose | If a dose of lamotrigine is missed, take it as soon as you remember, unless it is close to the time for your next dose. Do not double the dose to catch up. |
| Possible Side Effects | Common side effects include dizziness, headache, drowsiness, nausea, vomiting, and rash. Serious but rare side effects may include severe skin reactions (Stevens-Johnson syndrome, toxic epidermal necrolysis), blood disorders, and mood changes. |
| Storage and Disposal | Store lamotrigine at room temperature away from light and moisture. Keep out of reach of children. Dispose of unused or expired medication according to local regulations. |
| Overdose or Emergency | In case of overdose, seek emergency medical attention or contact a poison control center immediately. Symptoms may include dizziness, blurred vision, nausea, vomiting, and seizures. |
| Monitoring and Laboratory Tests | Monitoring parameters may include serum lamotrigine levels, liver function tests, and complete blood counts, especially during dose titration and in patients at higher risk of adverse effects. Regular follow-up with healthcare providers is recommended. |
