Lamotrigine side effects and contraindications

Lamotrigine side effects

Lamotrigine is a medicine indicated for the treatment of epilepsy and for the prevention of depressive episodes in patients with bipolar disorder. Chemically, it is a synthetic phenyltriazine which is not structurally related to other AEDs.

Noms:

  • Lamotrigine, Lamotriginum PhEur, LTG
  • Nom ATC : N03AX09

Molecule:

C9 H 7 Cl 2 N 5

Metabolism:

The half-life of lamotrigine is 24 to 35 hours. There are no active metabolites. Elimination is mainly hepatic.

Effects:

Lamotrigine has anti-epileptic (anticonvulsant) and mood stabilizing properties. These effects are mainly attributed to the blockage of voltage-gated sodium channels in nerve cells. However, the exact mechanism of action of lamotrigine is not fully explained.

Indications:

  • Epilepsy (especially during so-called focal simple, complex or generalized secondary seizures, also against grand mal)
  • Depressive episodes in patients with bipolar disorders

Notes indications:

  • Against epilepsy, lamotrigine acts in the same way as carbamazepine (another commonly used antiepileptic drug) but is better tolerated.
  • Lamotrigine is usually taken as monotherapy, especially against epilepsy. But the molecule can also be associated with another molecule.

Side effects:

The most common possible side effects are: visual disturbances, fatigue, dizziness, headache, difficulty walking, drowsiness, fatigue, sleep disturbances (sometimes with nightmares), nausea and diarrhea. Lamotrigine can rarely cause a severe rash. Skin disorders (e.g. exanthema) are more common in children and with a rapid increase in the dose. Skin reactions sometimes belong to a severe allergic reaction. A potentially very serious, even fatal, reaction is Stevens-Johnson syndrome. However, this syndrome is rare.

In children lamotrigine may in particular lead to the following typical side effects: vomiting, stomach pain and tremors.

For the full list of side effects, please read the package insert (e.g. Switzerland Lamictal ®).

READ ALSO: METHYLPREDNISOLONE SIDE EFFECTS

Contraindications:

  • History of an allergy to lamotrigine leading to skin disorders.
  • For the full list of contraindications, please read the package insert (e.g. in Switzerland Lamictal ®).

Interactions:

Significant risk of interactions with valproic acid (sodium valproate) , resulting in an increase in the concentration of lamotrigine. Interactions with other drugs or molecules are possible (eg carbamazepine, phenytoin, phenobarbital, contraceptives, etc.).

  • Lamotrigine is conjugated by UDP-glucuronosyltransferases (which is the source of interactions in particular).
  • For the full list of interactions, please read the package insert (e.g. Switzerland Lamictal ®).

Dosage Forms:

Lamotrigine is commercially available as tablets (25, 50, 100 and 200 mg) or dispersible tablets to disintegrate or chew (5, 25, 50, 100 and 200 mg).Dosage:

  • For adults and young people over 12 years of age, the dosage in epilepsy (focal or generalized seizures) as oral monotherapy is as an initiation dose of 25 mg per 24 hours and as a maintenance dose of 50 to 100 mg per 12h.
  • It is advisable to gradually increase the dose, 12.5 mg to 25 mg every 2 weeks until the seizures are under control. High doses should be divided into 2 doses per 24 hours (every 12 hours).
  • During combination therapy, it is essential to carry out an interaction check.

Medicines sold in Switzerland (according to Compendium.ch, status as of October 2021):

Original:

– Lamictal ®

Generics:

  • Lamotrigin Desitin® Tablets 
  • Lamotrigin Desitin® dispersible 
  • Lamotrigin Helvepharm 
  • Lamotrigine Sandoz®, tablets 
  • Lamotrigine-Mepha, Tablets

READ MORE ABOUT: ZIVERDO KIT DESCRIPTION

More Information:

  • Lamotrigine was first marketed in 1994 under the brand name of Lamictal ®. There are now generics.
  • Lamotrigine has established itself as one of the first choice antiepileptics. However, in rare cases dangerous side effects on the skin can occur. It has the advantage that it can be used during pregnancy.
  • It is on the  WHO electronic essential drugs list  (eEML).

Alternatives:

Except for women who are pregnant or who will become pregnant because of a serious risk of malformation to the unborn baby, valproic acid (sodium valproate)may be a good alternative to lamotrigine for certain forms of epilepsy (e.g. atypical epilepsy).

In epilepsy with focal seizures the following molecules are possible effective alternatives: carbamazepine, oxcarbazepine, levetiracetam , gabapentin, lacosamide and topiramate .

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