Lamotrigine Dosage: What You Need to Know

If you’ve been prescribed lamotrigine, the biggest question is probably how much to take. The dose isn’t the same for everyone – it depends on why you’re using it, your age, and any other medicines you’re on. Below you’ll find the most common dosing schedules, how doctors usually start you, and practical tips for staying on track.

Typical Starting Doses and Titration

For epilepsy, doctors often begin with a low dose of 25 mg once a day. The goal is to avoid rash, which is a known side‑effect if the dose jumps too fast. After a week, the dose usually goes up to 50 mg daily. If you tolerate it, the doctor may increase by another 50 mg each week until you reach a maintenance dose of 200–400 mg per day, split into two doses.

When lamotrigine is used for bipolar disorder, the starting dose is even lower – typically 25 mg every other day for the first week, then 25 mg daily for the second week. After that, the dose climbs by 25 mg each week until you reach a typical maintenance dose of 100‑200 mg daily. The slower climb helps keep the rash risk down, especially if you’re also taking valproic acid, which raises lamotrigine levels.

Special Situations and Adjustments

People on valproic acid need only half the usual dose because valproic acid slows lamotrigine’s breakdown. A common regimen is 25 mg twice a week for the first two weeks, then 25 mg daily, and then increase to a maximum of 100‑200 mg per day.

Older adults often start at 25 mg daily and may stay at a lower maintenance dose, especially if they have liver or kidney problems. Children’s doses are calculated by weight – usually 2‑5 mg per kilogram per day, split into two doses.

If you miss a dose, take it as soon as you remember, unless it’s almost time for the next one. In that case, skip the missed dose – don’t double up. Doubling can increase the rash risk.

Always tell your doctor about any new medicines, over‑the‑counter drugs, or supplements. Some antibiotics, oral contraceptives, and certain anti‑epileptics can change how lamotrigine works.

Watch for signs of a rash, especially in the first eight weeks. If a rash appears, stop the medication and call your healthcare provider right away. Early detection can prevent a serious reaction.

In practice, the best way to stay on the right dose is to keep a simple medication log. Write down the dose, the time you take it, and any side effects you notice. Bring the log to each doctor visit – it helps your provider fine‑tune the dose.

Bottom line: start low, increase slowly, and keep an eye on how you feel. Lamotrigine works best when you give your body time to adjust, and when you follow the titration schedule your doctor sets. If anything feels off, reach out to your doctor – dosage tweaks are common and part of safe, effective treatment.