Thalidomide Disease Interactions

Seizures, including grand mal convulsions, have been reported during post-approval use of thalidomide in clinical practice. Because these events are reported voluntarily from a population of unknown size, estimates of frequency cannot be made. Most patients had disorders that may have predisposed them to seizure activity, and it is not currently known whether thalidomide has any epileptogenic influence. During therapy with thalidomide, patients with a history of seizures or with other risk factors for the development of seizures should be monitored closely for clinical changes that could precipitate acute seizure activity.

In two separate studies involving HIV-seropositive patients, the use of thalidomide was associated with an increase in plasma viral RNA levels. The clinical significance of this finding is unknown. Both studies were published prior to the availability of highly active antiretroviral therapy, or HAART. Until more information is available, the interim recommendation is to measure the viral load after the first and third months of thalidomide treatment and every 3 months thereafter (or as often as indicated by the patient's antiretroviral regimen and clinical status).

The use of thalidomide has been associated with dizziness and orthostatic hypotension. Therapy with thalidomide should be administered cautiously in patients with preexisting hypotension. Rising slowly from a recumbent position is recommended.

The use of thalidomide has been associated with decreased white blood cells counts, including neutropenia. Therapy with thalidomide should be administered cautiously in patients with preexisting neutropenia. Treatment should not be initiated if absolute neutrophil count is below 750/mm3. Monitoring white blood cell count and differential routinely is recommended during treatment.

The use of thalidomide has been associated with the development of peripheral neuropathy, which is sometimes irreversible. Therapy with thalidomide should be administered cautiously in patients with preexisting neuropathy and only after the neuropathy has returned to baseline. Patients should be monitored routinely for early signs of neuropathy including numbness, tingling, pain, or a burning sensation in the hands or feet. If symptoms of drug-induced neuropathy develop, thalidomide should be discontinued immediately.