Contraindications: Bone Marrow Depression, Hypersensitivity, and Concomitant Drugs
- Patients with bone marrow depression or a known hypersensitivity to carbamazepine or tricyclic antidepressants. If patient or immediate family member has history of hypersensitivity, consider benefits and risks and closely monitor for symptoms
- Concomitant use with boceprevir, nefazodone, and delavirdine or other non-nucleoside reverse transcriptase inhibitors
- Use of monoamine oxidase inhibitors (MAOIs) within the past 14 days before beginning carbamazepine treatment
Toxic Epidermal Necrolysis (TEN), Stevens-Johnson syndrome (SJS), HLA-B*1502 Allele, and Aplastic Anemia and Agranulocytosis (see Boxed Warning)
CARNEXIV should generally not be used in patients with moderate or severe renal impairment. Closely monitor patients with renal impairment.
Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS)
DRESS, also known as multiorgan hypersensitivity, has occurred with carbamazepine. These events can be fatal or life-threatening. Advise patients to report signs and symptoms such as fever, rash, lymphadenopathy, and/or facial swelling immediately, and discontinue CARNEXIV if an alternative etiology cannot be established.
Suicidal Behavior and Ideation
Antiepileptic drugs (AEDs), including CARNEXIV, increase the risk of suicidal thoughts or behavior. Monitor patients for the emergence or worsening of depression, any unusual changes in mood or behavior, or suicidal thoughts, behavior, or thoughts of self-harm; and instruct families and caregivers to report behaviors of concern immediately.
Pregnancy Registry and Nursing Mothers
- CARNEXIV can cause fetal harm when administered to a pregnant woman. If used during pregnancy, or if the patient becomes pregnant while taking CARNEXIV, inform the patient of the potential risk to the fetus and carefully consider both the potential risks and benefits of treatment. Encourage patients to call the toll-free number 1-888-233-2334 to enroll in the Pregnancy Registry or visit http://www.aedpregnancyregistry.org/.
- Discontinue CARNEXIV or discontinue nursing, taking into consideration the importance of the drug to the mother.
Abrupt Discontinuation and Seizure Risk
Do not discontinue CARNEXIV abruptly because of the risk of seizures, status epilepticus, and other withdrawal signs/symptoms.
Hyponatremia can result from treatment with CARNEXIV, and in many cases appears to be caused by the syndrome of inappropriate antidiuretic hormone secretion (SIADH). The risk of SIADH appears to be dose-related. Elderly patients and patients treated with diuretics are at a greater risk. Consider discontinuing CARNEXIV in patients with symptomatic hyponatremia.
Carbamazepine has the potential to impair judgment, cognition, motor function, and motor coordination, and it may also cause dizziness, ataxia, and drowsiness. Caution patients about operating hazardous machinery, including automobiles, until they are reasonably certain that carbamazepine does not affect them adversely.
Hepatic effects, ranging from slight elevations in liver enzymes to rare cases of hepatic failure, have been reported, and may progress despite drug discontinuation. Rare instances of vanishing bile duct syndrome have also been reported. Evaluate liver function before and during treatment, particularly in patients with a history of liver disease. Discontinue CARNEXIV based on clinical judgment in the case of active liver disease, or with newly occurring or worsening clinical or laboratory evidence of liver dysfunction or hepatic damage.
Increased Intraocular Pressure
Carbamazepine has mild anticholinergic activity. Consider assessing intraocular pressure before initiating and periodically during therapy in patients with a history of increased intraocular pressure.
Avoid using CARNEXIV in patients with a history of hepatic porphyria, as acute attacks have been reported in such patients and CARNEXIV increases porphyrin precursors in rodents.
Carbamazepine may reduce plasma concentrations of concomitant medications metabolized by CYP1A2, 2B6, 2C9/19 and 3A4; closely monitor carbamazepine levels and make appropriate dose adjustments. CYP3A4 inhibitors can increase plasma carbamazepine levels. CYP3A4 inducers can decrease carbamazepine levels.
The most common adverse reactions with CARNEXIV (incidence ≥2%) were dizziness, somnolence, blurred vision, diplopia, headache, infusion-related reaction, infusion site pain, and anemia. The most common adverse reactions with oral carbamazepine were dizziness, drowsiness, unsteadiness, nausea, and vomiting.
Important Dosing Information
Use of CARNEXIV for more than 7 days has not been studied and is not recommended. At the end of intravenous (IV) replacement therapy, switch patients back to oral carbamazepine at their previous total daily oral dose and frequency as soon as clinically appropriate.
Please see the full Prescribing Information, including Boxed Warning for serious dermatologic reactions and aplastic anemia and agranulocytosis, for complete details.
References: 1. CARNEXIV [package insert]. Deerfield, IL: Lundbeck. 2. Tolbert D, Cloyd J, Biton V, et al. Bioequivalence of oral and intravenous carbamazepine formulations in adult patients with epilepsy. Epilepsia. 2015:56(6):915-923.