Dexamethasone thrombocytopenia

Uses w/ cisplatin in nonresectable mesothelioma NSCLC Action Antifolate antineoplastic Dose 500 mg/m IV over 10 min q3wk hold if CrCl <45 mLAnin give w/ vit Bi2 (1000 meg IM q9wk) folic acid (350-1000 meg PO daily) start 1 wk before dexamethasone 4 mg PO bid x 3 start 1 d before each Rx Caution [D, -] w/ renal/hepatic/ BM impair Contra Component sensitivity Disp IV SE Neutropenia, thrombocytopenia, N/V/D, anorexia, stomatitis, renal failure, neuropathy, fevCT, fatigue, mood changes, dyspnea, anaphylactic Rxns Interactions t Effects W/ NSAIDs, probenecid d/t decreased pemetrexed EMS Monitor for S/Sxs of Infxn OD May cause profound BM suppression, mucous membrane irritation, D, and rash symptomatic and supportive... 

Lenalidomide, a derivative of thalidomide, was introduced in 2004. Patients with multiple myeloma stage II/III, who have undergone at least one previous treatment can be treated with bortezomib or with lenalidomide in combination with dexamethasone. There is good oral absorptin with peak plasma levels at 0.5-4 hours. Lenalidomide is maily eliminated by the kidneys with a half-life of circa 3-9 hours. Teratogenicity cannot be excluded. Side effects include thrombosis, pulmonary embolus, and hepato-toxicity, as well as bone marrow toxicity resulting in neutropenia and thrombocytopenia. 

Severe and life-threatening agranulocytosis in 2 patients and thrombocytopenia in 6 other patients " have been attributed to the concurrent use of phenytoin and cimetidine. Severe skin reactions have also been reported in 3 patients treated with phenytoin, cimetidine, and dexametha-sone after resection of brain tumours, which resolved on discontinuing phenytoin. See also Corticosteroids + Phenytoin , p.l059 for the effects of dexamethasone on phenytoin levels. 

Bortezomib In a retrospective medical record review of six adults with relapsed multiple myeloma who received intravenous bortezomib + oral dexamethasone, three who also took itraconazole had new or worsening peripheral neuropathy and grade 4 thrombocytopenia [13 ]. One patient who took lansoprazole alone and two who did not take itraconazole or lansoprazole had no such reactions. The authors noted that itraconazole inhibits CYP3A4 and lansoprazole inhibits CYP2C19. 

The results of various clinical trials indicated that the incidence of adverse events was similar in the aprepitant group compared with the group which received only standard regimen of ondansetron and dexamethasone. The most commonly observed side effects with aprepitant treatment were asthenia, hiccups, diarrhea, gastritis, elevation in fiver function tests, and dizziness. There are also reports of thrombocytopenia and dehydration. 

A 57-year-old woman developed a diffuse rash and thrombocytopenia with platelets as low as 20,000 per gL on a combination of phenytoin and dexamethasone [137 ]. The combination of these two drugs may worsen phenytoin-induced thrombocytopenia. 

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