Nursing2024 Drug Handbook

844 lamotrigine

PREGNANCY-LACTATION-REPRODUCTION • Drug may increase risk of congenital mal- formations in the first trimester. Use during pregnancy only if potential benefit justifies fetal risk. • Patients should enroll in the North American Antiepileptic Drug Preg- nancy Registry (1-888-233-2334 or www.aedpregnancyregistry.org). • Drug appears in human milk. Use cau- tiously during breastfeeding. Discontinue breastfeeding if infants develop drug toxic- ity. NURSING CONSIDERATIONS Alert: Closely monitor all patients taking or starting AEDs for changes in behavior indi- cating worsening of suicidality or depression. Symptoms such as anxiety, agitation, hostil- ity, mania, and hypomania may be precursors to emerging suicidality. • Don’t stop drug abruptly because this may increase seizure frequency. Instead, taper drug over at least 2 weeks. Boxed Warning Serious rashes, including SJS and TEN, and rash-related death have been reported. Serious rash occurs more fre- quently in children than in adults, when ad- ministered with valproate, or when initial recommended dose or escalation dose is ex- ceeded. Benign rashes may also occur but it’s impossible to predict which rash will become serious or life threatening. Stop drug at first sign of rash, unless rash is clearly not drug- related. Boxed Warning Stopping treatment may not prevent a rash from becoming life-threatening or permanently disabling or disfiguring. Boxed Warning Extended-release form isn’t approved for children younger than age 13. Alert: Drug may cause aseptic meningi- tis. Monitor patient for symptoms such as headache, fever, neck stiffness, nausea, vom- iting, rash, and photophobia. Discontinue drug if no other cause of meningitis is found. • Evaluate patients for changes in seizure ac- tivity. Check adjunct anticonvulsant level. Alert: Monitor patient for HLH (persis- tent fever, hepatosplenomegaly, rash, lym- phadenopathy, neurologic symptoms, cytope- nias, high serum ferritin level, and liver func- tion and coagulation abnormalities). Evalu- ate patient with fever or rash promptly, and discontinue drug if HLH or another serious

Organic cation transporter 2 substrates (dofetilide): May increase lamotrigine or dofetilide plasma level. Don’t coadminister. Strong CYP3A4 inducers (phenytoin, rifam- pin): May decrease lamotrigine level. Use cautiously together; adjust lamotrigine dosage. Valproate : May decrease clearance of lamo- trigine, which increases lamotrigine level; also decreases valproate level. Monitor pa- tient for toxicity. Reduce lamotrigine dosage if added to a multidrug regimen that includes valproic acid. Drug-lifestyle. Sun exposure: May cause photosensitivity reactions. Advise patient to avoid excessive sun exposure. EFFECTS ON LAB TEST RESULTS • May result in false-positive readings in rapid urine drug screens, particularly for phencyclidine. CONTRAINDICATIONS & CAUTIONS • Contraindicated in patients hypersensitive to drug or its components. Alert: Rare, multiorgan hypersensitivity reactions that can be fatal have occurred. Alert: Drug may cause hemophagocytic lymphohistiocytosis (HLH), a rare and life- threatening immune system reaction. • Use cautiously in patients with renal, he- patic, or cardiac impairment. • Drug isn’t recommended for treatment of acute manic or mixed episodes of bipolar dis- order because effectiveness hasn’t been estab- lished. Alert: Use cautiously in patients with struc- tural and functional heart disorders, including HF, valvular heart disease, congenital heart disease, conduction system disease, ventric- ular arrhythmias, cardiac channelopathies, ischemic heart disease, or multiple risk fac- tors for CAD, especially when used in combi- nation with sodium channel blockers (carba- mazepine, phenytoin, topiramate); drug may increase risk of serious or life-threatening ar- rhythmias. Assess whether potential benefits of lamotrigine outweigh risk of arrhythmia for each patient. • Dialyzable drug: 20%. • H Overdose S&S: Ataxia, nystagmus, in- creased seizures, decreased level of con- sciousness, coma, intraventricular conduction delay.

Reactions in bold italics are life-threatening . Interactions may have a rapid onset or a delayed onset .