Levetiracetam-induced hyponatremia

Hyponatremia With Anticonvulsant Medications: A Narrative Review

Hyponatremia is an adverse effect of many antiseizure medications (ASMs). It occurs with interference with the normal balance of electrolytes within the body. Various risk factors associated with the development of hyponatremia in patients taking these medications include age, gender, dosage, and combinations with other drugs. ASMs such as carbamazepine (CBZ), oxcarbazepine (OXC), and valproic acid have a higher risk of hyponatremia. Hyponatremia induced by an antiseizure medication can occur through various mechanisms depending on the drug's specific mechanism of action. Hyponatremia can be a potentially fatal side effect. Patients taking these medications need to be monitored closely for the signs and symptoms of hyponatremia. Acute hyponatremia, defined as developing in <48 hours, is more likely to show symptoms than chronic hyponatremia. Signs of acute hyponatremia include delirium, seizures, decerebrate posturing, and cerebral edema with uncal herniation. Chronic hyponatremia, defined as developing in >48 hours, can cause lethargy, dizziness, weakness, headache, nausea, and confusion. Hyponatremia is associated with longer hospital stays and increased mortality. Treatment varies based on the degree of severity of hyponatremia. Choosing a treatment option should include consideration of the drug causing the electrolyte disturbance, the patient's risk factor profile, and the severity of symptoms as they present in the individual patient. Healthcare providers should be aware of hyponatremia as a potential side effect of ASMs, the signs and symptoms of hyponatremia, the different treatment options available, and the potential complications associated with rapid correction of hyponatremia.

Incidence of hyponatremia in patients given levetiracetam vs. phenytoin for early posttraumatic seizure prophylaxis

BACKGROUND

Levetiracetam and phenytoin are comparable for acute posttraumatic seizure(PTS) prophylaxis. Levetiracetam-induced hyponatremia has been reported in non-trauma patients. We studied hyponatremia in posttraumatic intracranial hemorrhage(ICH) patients receiving either drug.

METHODS

Retrospective review of patients with ICH receiving PTS prophylaxis was performed. Patients were categorized by degree of sodium nadir: normal, mild, moderate, or severe, and analyzed by levetiracetam versus phenytoin. Patients were matched 2:1 regarding age and injury severity score(ISS). Incidence and treatment for hyponatremia was examined.

RESULTS

1735 ICH patients received PTS prophylaxis over an 8-year period. After exclusions and matching, there were 282 phenytoin and 564 levetiracetam patients. Age, ISS and initial sodium were comparable between the matched cohorts. There was no clinically significant difference in the rate or degree of hyponatremia. Treatment was more common in levetiracetam patients.

DISCUSSION

There was a small but clinically insignificant difference in the incidence of hyponatremia in traumatic ICH patients receiving levetiracetam vs. phenytoin for PTS prophylaxis. There was an increased rate of intervention for hyponatremia in the levetiracetam group, possibly due to a coincidental preventive paradigm shift.

Levetiracetam and lamotrigine effects as mono- and polytherapy on bone mineral density in epileptic patients

OBJECTIVE

The purpose of this study was to determine the effect of lamotrigine (LTG) and levetiracetam (LEV) as mono- and polytherapy on biochemical markers of bone turnover and bone mineral density in Egyptian adult patients with epilepsy.

METHODS

Forty-eight patients were divided into four groups: two received monotherapy of either LTG or LEV, and the other two groups received polytherapy comprising (valproate [VPA] + LTG or VPA + LEV). Thirty matched healthy participants were included in the study. Participants completed a nutritional and physical activity questionnaire. Biochemical markers of bone and mineral metabolism and bone mineral density of the lumbar spine were measured at baseline and at six months.

RESULTS

In the LEV monotherapy group, the bone formation markers showed a significant decrease in serum alkaline phosphatase and serum osteocalcin levels while the bone resorption marker showed a significant increase in urinary deoxypyridinoline levels. After six months of treatment, bone mineral density showed a significant decrease in all treated groups, while among monotherapy groups, this significant decrease was more prevalent in the LEV monotherapy group compared with the LTG monotherapy group. Furthermore, there was significant negative correlation between urinary deoxypyridinoline levels and bone mineral density in the LEV monotherapy group.

CONCLUSION

Using new generation antiepileptics, LEV monotherapies and polytherapy showed harmful effects on bone but LTG did not.

Differences in associations of antiepileptic drugs and hospitalization due to hyponatremia: A population-based case-control study

PURPOSE

Hyponatremia induced by antiepileptic drugs is common, but detailed evidence is lacking. This can be problematic for the treating neurologist confronted with a patient with severe hyponatremia in need of an alternative drug. The objective of this study was to examine the association between individual antiepileptic drugs and hospitalization due to hyponatremia.

METHODS

This was a register-based case-control study of patients in the general Swedish population. We included 14,359 individuals with a principal diagnosis of hyponatremia and 57,383 matched controls. The association between newly initiated (≤90 days) and ongoing antiepileptic treatment was investigated using multivariable logistic regression adjusting for concomitant drugs, medical conditions, previous hospitalizations and sociaoeconomic factors.

RESULTS

For newly initiated antiepileptic drugs, adjusted ORs (95% CI) for hospitalization due to hyponatremia, compared to controls, were: carbamazepine 9.63 (6.18-15.33); phenytoin 4.83 (1.14-25.76); valproate 4.96 (2.44-10.66); lamotrigine 1.67 (0.70-4.08); levetiracetam 9.76 (4.02-27.59) and gabapentin 1.61 (1.08-2.38). Newly initiated oxcarbazepine treatment was only found in the hyponatremia group and not in controls. Adjusted ORs (CI) for individuals with ongoing treatment ranged from 7.97 (3.70-18.50) for oxcarbazepine to 0.83 (0.64-1.06) for gabapentin.

CONCLUSION

There was a strong association between newly initiated treatment with carbamazepine, oxcarbazepine and levetiracetam, and hospitalization due to hyponatremia. The corresponding association for phenytoin and valproate was moderate. The risk for hyponatremia was lower during ongoing treatment. Lamotrigine and gabapentin had the lowest risk both during initiation and ongoing treatment and may be advantageous in patients at risk of developing hyponatremia.