Lamotrigine is an antiepileptic drug. It is mainly used to treat epilepsy.
What is lamotrigine?
Lamotrigine is an antiepileptic drug. It is mainly used to treat epilepsy. The antiepileptic drug lamotrigine is one of the most important agents for the treatment of epileptic seizures. It is also suitable for the prevention of depression. Lamotrigine has been approved since 1993 and can be used from the age of 12 years. The drug was developed by the British pharmaceutical company GlaxoSmithKline (GSK). In the 1990s, it also became known that lamotrigine could be used to treat low mood and depression, so the drug was increasingly used as an antidepressant. In 2005, lamotrigine was also launched as a generic drug.
Pharmacologic action
The efficacy of lamotrigine is broad. With the aid of the drug, both simple focal epileptic seizures and complex psychomotor seizures can be treated. The same applies to mixed forms of epilepsy. Neurotransmitters are of central importance for the human nervous system. These are special messenger substances that are responsible for inhibiting or activating the nervous system. The release of the neurotransmitters usually takes place as a result of external circumstances. In this way, appropriate bodily reactions to certain processes such as rest, stress or injury are brought about. However, if a disease of the nervous system occurs, this results in a disturbance of the balance. In most cases, the excitation and inhibition of the nervous system is reduced by brain injury or genetic predisposition. Because the human nervous system is then overexcitable, this can result in epileptic seizures. However, by using lamotrigine, it is possible to reduce hyperexcitability by blocking specific ion channels such as calcium channels or sodium channels within the nerve cells, so that the risk of an epileptic seizure is also reduced. Another beneficial effect of lamotrigine represents the prevention of depression associated with manic-depressive disorders. Thus, lamotrigine has mood-enhancing, sedative, and muscle-relaxing properties. Pain-relieving effects on nerve pain are also attributed to the active ingredient. The transmission of stimuli to the affected nerves within the spinal cord is slowed down. In the human intestine, lamotrigine is rapidly and completely absorbed into the blood. The drug develops its full effect after about 2.5 hours. The substance is broken down in the liver, while its excretion occurs through the kidneys.
Medical use and application
The indications for the use of lamotrigine predominantly include epilepsy. The drug produces seizure freedom in about 40 to 60 percent of all epileptics. The various forms of epilepsy can be treated well with lamotrigine. The drug can also be used to effectively treat Lennox-Gastaut syndrome, which occurs in children. Lamotrigine may be additionally administered to children between 2 and 11 years of age. Alcohol withdrawal is another area of use, provided that this is carried out as an inpatient in a hospital. Lamotrigine is also important for the prevention of depression. The active substance is used when treatment with lithium does not lead to the desired improvement. Other indications for the administration of lamotrigine are Huntington’s disease, Parkinson’s disease, migraine pain and trigeminal neuralgia. Lamotrigine is usually taken orally through tablets. Easier-to-swallow suspensions are also available. In most cases, lamotrigine is taken once a day before or after meals. The same time of day should always be followed. The most appropriate dose varies from patient to patient. Usually, therapy is started with 25 milligrams of lamotrigine a day and the dose is gradually increased to 100 to 200 milligrams as the therapy progresses.
Risks and side effects
Adverse side effects may occur with the use of lamotrigine. These primarily include headache, itching, skin rashes in which spots form, vision problems, dizziness, and increased sexual excitability.Other side effects include fatigue, sleep disturbances, nervousness, nausea, vomiting, diarrhea, tremors, unsteadiness of movement, tics, ataxias, back pain, movement disorders, joint pain, and aggressiveness. Especially in the first few weeks, there is an increased risk of toxic epidermal necrolysis or Stevens-Johnson syndrome. Long-term treatment with lamotrigine may result in bone loss (osteoporosis). Lamotrigine should not be taken at all if the patient suffers from hypersensitivity to the active substance or to carbamazepine or phenytoin. The same applies to restrictions in liver and kidney function. Caution is also advised when taking lamotrigine during pregnancy, as it lowers folic acid levels in pregnant women, which in turn poses a risk of harm to the unborn child. In addition, the active ingredient passes into breast milk and can be transferred to the baby during breastfeeding, so the child’s reactions must be closely monitored. Children younger than two years of age should not receive lamotrigine. Use of the drug for depression is not appropriate until the child reaches the age of 18. Since human reactivity is affected by lamotrigine, active participation in road traffic should be avoided. The same applies to operating complicated machinery. Interactions are also possible due to the intake of lamotrigine. Thus, the effect as well as the side effects of the anitepileptic carbamazepine are increased. Conversely, carbamazepine decreases the beneficial effects of lamotrigine. Furthermore, concomitant use of the drug with other antiepileptic drugs such as phenobarbital, primidone, and phenytoin should be avoided.
