Valtor

Monotherapy & adjunctive therapy in the treatment of complex partial seizures that occur either in isolation or in association w/ other types of seizures. Sole & adjunctive therapy in the treatment of simple & complex absence seizures, & adjunctively in multiple seizure types including absence seizures.

Monotherapy for complex partial seizures, or conversion to monotherapy Adult & childn ≥10 yr Initially 10-15 mg/kg daily, increased by 5-10 mg/kg wkly. Adjunctive therapy 10-15 mg/kg daily may be added to the regimen, & may be increased by 5-10 mg/kg wkly. Give in divided doses if total daily dose exceeds 250 mg. Simple & complex absence seizures Initially 15 mg/kg daily, increased at 1 wk intervals by 5-10 mg/kg daily. Max dose: 60 mg/kg daily. Give in divided doses if total daily dose exceeds 250 mg.

May be taken with or without food: Patients who experience GI irritation may benefit by taking w/ food.

Hypersensitivity. Mitochondrial disorders caused by mutations in mitochondrial DNA polymerase γ (POLG; eg, Alpers-Huttenlocher syndrome) & childn <2 yr suspected of having POLG-related disorder. Urea cycle disorders (UCD). Porphyria. Not to be administered to patients w/ hepatic disease or significant hepatic dysfunction. Use in prophylaxis of migraine in pregnant women.

Discontinue use in case of suspected multiorgan hypersensitivity reaction; in presence of suspected or apparent significant hepatic dysfunction or signs of brain atrophy; diagnosed pancreatitis; increased ammonia. Consider discontinuing use if hypothermia develops. Thrombocytopenia. Patients w/ prior history of hepatic disease; at risk of hepatotoxicity; hereditary neurometabolic syndromes caused by mutations in the gene for mitochondrial POLG eg, Alpers-Huttenlocher syndrome. Closely monitor patients for appearance of symptoms of serious or fatal hepatotoxicity. Perform LFTs prior to therapy & at frequent intervals thereafter, especially during the 1st 6 mth. Consider evaluation for UCD prior to initiation of therapy in patients w/ history of unexplained encephalopathy or coma, encephalopathy associated w/ a protein load, pregnancy-related or postpartum encephalopathy, unexplained mental retardation, or history of elevated plasma ammonia or glutamine, those w/ cyclical vomiting & lethargy, episodic extreme irritability, ataxia, low BUN, protein avoidance, those w/ family history of UCD or of unexplained infant deaths (particularly males), those w/ other signs or symptoms of UCD. Monitor for emergence or worsening of depression, suicidal thoughts or behavior, &/or any unusual changes in mood or behavior. Reports of inhibition of the secondary phase of platelet aggregation, & abnormal coagulation parameters (eg, low fibrinogen); platelet counts & coagulation tests are recommended prior to initiating therapy & at periodic intervals. Monitor for platelet count & coagulation parameters prior to planned surgery. May lead to false interpretation of urine ketone test. Reports of altered thyroid function tests. Interpretation of results from regular monitoring of viral load in HIV infected patients receiving valproate or when following cytomegalovirus infected patients clinically. Hyperammonemia w/ or w/o encephalopathy w/ topiramate. Concomitant use w/ carbapenems eg, ertapenem, imipenem, meropenem. Not to be taken by patients w/ fructose intolerance, glucose & galactose malabsorption, or sucrose-isomaltase insufficiency. Patients w/ DM. May be harmful to the teeth. Contains methylhydroxybenzoate which may cause allergic reactions (possibly delayed). Do not engage in hazardous activities eg, driving an automobile or operating dangerous machinery. Hepatic dysfunction. Women of childbearing potential should use effective contraception during treatment. May produce teratogenic effects. Pregnancy & lactation. Extreme caution in childn & only use as sole agent. Elderly.

Headache, asthenia, fever, back & chest pain, malaise; tachycardia, HTN, palpitation; nausea, vomiting, abdominal pain, diarrhea, anorexia, dyspepsia, constipation, increased appetite, flatulence, hematemesis, eructation, pancreatitis, periodontal abscess; thrombocytopenia, ecchymosis, petechia; wt gain & loss, peripheral edema, increased SGOT & SGPT; myalgia, twitching, arthralgia, leg cramps, myasthenia; somnolence, tremor, dizziness, diplopia, amblyopia/blurred vision, ataxia, nystagmus, emotional lability, abnormal thinking, gait & dreams, amnesia, nervousness, depression, anxiety, confusion, paresthesia, hypertonia, incoordination, personality disorder; flu syndrome, infection, bronchitis, rhinitis, pharyngitis, dyspnea, sinusitis, increased cough, pneumonia, epistaxis; rash, pruritus, dry skin, alopecia; tinnitus, taste perversion, abnormal vision, deafness, otitis media; urinary incontinence & frequency, vaginitis, dysmenorrhea, amenorrhea.

Clearance may be increased w/ drugs that affect level of expression of hepatic enzymes, particularly those that elevate levels of glucuronosyltransferases eg, ritonavir. Doubled clearance w/ phenytoin, carbamazepine, & phenobarb (or primidone). Decreased protein binding & inhibition of metabolism w/ aspirin at antipyretic doses in ped patients. Reduced serum conc w/ carbapenems eg, ertapenem, imipenem, meropenem. Mean peak conc may be increased w/ felbamate. Oral clearance may be increased w/ rifampin. Decreased plasma clearance of amitriptyline & decreased net clearance of nortriptyline. Decreased serum levels of carbamazepine. May induce absence status w/ clonazepam in patients w/ history of absence type seizures. Inhibited metabolism of diazepam; ethosuximide; phenobarb; primidone; phenytoin. Increased t½ of lamotrigine. Hyperammonemia w/ & w/o encephalopathy, & hypothermia w/ topiramate. Increased unbound fraction of tolbutamide; warfarin. Decreased clearance of zidovudine in patients who were seropositive for HIV.

Anticonvulsants

N03AG01 - valproic acid ; Belongs to the class of fatty acid derivatives antiepileptic.

Rx