"It only takes one bad apple to spoil the bunch, and the same may be true of certain proteins in the brain. Studies have suggested that just one rogue protein (in this case, a protein that is misfolded or shaped the wrong way) can act as a seed"...
Clinical Studies Experience
Since clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice. The following table presents the frequency of adverse reactions which occurred during the administration of 58 courses of high dose methotrexate 12 grams/m²followed by levoleucovorin rescue for osteosarcoma in 16 patients age 6-21. Most patients received levoleucovorin 7.5 mg every 6 hours for 60 hours or longer beginning 24 hours after completion of methotrexate.
Table 2: Adverse Reactions
|Body System/Adverse Reactions||Number (%) of Patients with Adverse Reactions
|Number (%) of Courses with Adverse Reactions
(N = 58)
|All||Grade 3+||All||Grade 3+|
|Stomatitis||6 (37.5)||1 (6.3)||10 (17.2)||1 (1.7)|
|Vomiting||6 (37.5)||0||14 (24.1)||0|
|Nausea||3 (18.8)||0||3 (5.2)||0|
|Diarrhea||1 (6.3)||0||1 (1.7)||0|
|Dyspepsia||1 (6.3)||0||1 (1.7)||0|
|Typhlitis||1 (6.3)||1 (6.3)||1 (1.7)||1 (1.7)|
|Dyspnea||1 (6.3)||0||1 (1.7)||0|
|Skin and Appendages|
|Dermatitis||1 (6.3)||0||1 (1.7)||0|
|Confusion||1 (6.3)||0||1 (1.7)||0|
|Neuropathy||1 (6.3)||0||1 (1.7)||0|
|Renal function abnormal||1 (6.3)||0||3 (5.2)||0|
|Taste perversion||1 (6.3)||0||1 (1.7)||0|
|Total number of patients||9 (56.3)||2 (12.5)|
|Total number of courses||25 (43.1)||2 (3.4)|
The incidence of adverse reactions may be underestimated because not all patients were fully evaluable for toxicity for all cycles in the clinical trials. Leukopenia and thrombocytopenia were observed, but could not be attributed to high dose methotrexate with levoleucovorin rescue because patients were receiving other myelosuppressive chemotherapy.
Since adverse reactions from spontaneous reports are provided voluntarily from a population of uncertain size, it is not always possible to estimate reliably their frequency or establish a causal relationship to drug exposure. Spontaneously reported adverse reactions collected by the WHO Collaborating Center for International Drug Monitoring in Uppsala Sweden have yielded seven cases where levoleucovorin was administered with a regimen of methotrexate. The events were dyspnea, pruritus, rash, temperature change and rigors. For 217 adverse reactions (108 reports) where levoleucovorin was a suspected or interacting medication, there were 40 occurrences of “possible allergic reaction.”
Read the Levoleucovorin (levoleucovorin) Side Effects Center for a complete guide to possible side effects
Folic acid in large amounts may counteract the antiepileptic effect of phenobarbital, phenytoin and primidone, and increase the frequency of seizures in susceptible children. It is not known whether folinic acid has the same effects. However, both folic and folinic acids share some common metabolic pathways. Caution should be taken when taking folinic acid in combination with anticonvulsant drugs.
Preliminary human studieshave shown that small quantities of systemically administered leucovorin enter the CSF, primarily as its major metabolite, 5-methyltetrahydrofolate (5-MTHFA). In humans, the CSF levels of 5-MTHFA remain 1-3 orders of magnitude lower than the usual methotrexate concentrations following intrathecal administration.
levoleucovorin increases the toxicity of 5-fluorouracil [see WARNINGS and PRECAUTIONS].
Last reviewed on RxList: 3/31/2008
This monograph has been modified to include the generic and brand name in many instances.
Additional Levoleucovorin Information
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