Lamictal Drug Interactions

by on May 23, 2012

Lamictal is an anti-epileptic drug used for the treatment of seizure. Like any other medications, taking Lamictal with other drugs can cause unwanted effects. Therefore, it is important to know what drugs can potentially interact with Lamictal.

Medical experts recognize a total of over 500 drugs that can cause drug interactions when taken together with Lamictal. Basically, these medications affect either the metabolism or excretion of Lamictal in the body.

Significant Drug Interactions

Some of the medications that can potentially cause significant negative interactions when combined with Lamictal include the following:

Anticonvulsant Drugs – These medications are used to treat seizures. When taken together with Lamictal, they can either increase or decrease the level of Lamictal in the blood. Carbamazepine, phenobarbital, phenytoin and primidone can decrease the serum levels of Lamictal, possibly causing a reduction in its desired pharmacologic effect. Combining these medications with Lamictal also increases the risk of side effects such as coordination problems, dizziness and vision problems.

Meanwhile, valproic acid can increase the serum levels of Lamictal as well as the risk of side effects. Concomitant use of valproic acid and Lamictal increase the risk of serious skin rash. Patients taking valproic acid together with Lamictal may need a lower dose of Lamictal.

Patients who are taking any of these anticonvulsant drugs may require dose adjustment.

  • carbamazepine (Atretiol, Carbatrol, Tegretol)
  • phenobarbital (Donnatal)
  • phenytoin (Dilantin)
  • primidone (Mysoline)
  • valproic acid (Depakene)

Hormonal Birth Control or Hormone Replacement Therapy: These medications can decrease the amount of Lamictal in the blood, potentially reducing its desired pharmacologic benefits. Use of Lamictal together with hormone replacement therapies and cyclical oral contraceptives that have a “rest week” can result in a sudden increase of Lamictal levels during the inactive pill week. On the other hand, Lamictal can also reduce the effectiveness of the oral contraceptives which can result in unwanted pregnancy. Some healthcare providers recommend using other birth control methods throughout the Lamictal therapy. Discuss with your healthcare provider other possible nonhormonal contraceptive method for your situation.

Some of the birth control products affected by Lamictal include:

  • Hormonal birth control products include pills, patches and rings like Yaz, Yasmin and Seosonique
  • Estrogen

Antihistamines and Anti-Anxiety medications: Concomitant use of Lamictal and any of these medications increases risk of central nervous system side effects especially drowsiness and problems with coordination.

  • cetirizine (Zyrtec)
  • diphenhydramine (Benadryl)
  • alprazolam (Xanax)
  • diazepam (Valium)
  • zolpidem (Ambien)

Antibiotic drugs: Rifampin decreases the amount of Lamictal in the blood, potentially reducing its desired pharmacologic effect. Dose adjustments may be necessary for patients taking Rifampin together with Lamictal.

  • rifampin (Rifadin)

Muscle relaxants, narcotic analgesic (codeine) and alcohol tend to increase the risk of drowsiness, therefore should also be avoided while taking Lamictal.

This medication information does not contain all the drugs that can potentially interact with Lamicta. It is recommended that patients consult their healthcare providers about all the drugs they are taking, including prescription and over-the-counter medications. Also, avoid taking any medication without consulting your healthcare provider.