Products
Retigabine was approved in many countries as film-coated tablets since 2011 (Trobalt). In the United States, it is referred to as ezogabine. It was discontinued in 2017.
Structure
Retigabine (C16H18FN3O2, Mr = 303.3 g/mol) is a carbamate that was developed starting from the analgesic flupirtine. The free primary amino group is -glucuronidated (see below).
Effects
Retigabine (ATC N03AX21) has antiepileptic effects and reduces the number of seizures. The effects are due to the opening of potassium channels KCNQ2 and KCNQ3 in neurons in the central nervous system, which stabilizes the membrane potential. Other mechanisms have been described, including enhancement of GABAergic transmission.
Indications
As adjunctive therapy for focal seizures with or without secondary generalization in adults with epilepsy aged 18 years and older. The literature mentions other possible indications for which there is currently no approval, such as nerve pain, resless legs, and migraine.
Dosage
According to the drug label. Retigabine is taken with a meal or independently of meals. Dosing must be gradual and adjusted on an individual basis. Due to its medium-long half-life of 6-10 hours, it is administered three times daily. The maximum daily dose is 1200 mg.
Contraindications
Retigabine is contraindicated in hypersensitivity. For complete precautions, see the drug label.
Interactions
Retigabine is primarily -glucuronidated and converted to a moderately active -acetyl metabolite. CYP450s are involved in metabolism. Interactions are possible with the following: phenytoin, carbamazepine, digoxin, anesthetics (thiopental sodium), and alcohol. Interactions with other antiepileptic drugs are considered unlikely.
Adverse effects
The most common adverse effects include dizziness, fatigue, and exhaustion. Weight gain, psychiatric disorders, visual disturbances, digestive problems, and urinary disorders are common. Other side effects observed include.
