Successful recovery after accidental overdose of cyclophosphamide

Complete recovery of a cyclophosphamide overdose after vincristine administration in a dog

“…In our dog, the dose was lower and it did not present any signs compatible with cardiomyopathy and pulmonary oedema, neither the other cases described previously in the literature 11–14 . In humans, fulminant cardiac toxicity is associated with high‐dose cyclophosphamide at 60 mg/kg for 4 days 15 . This fact should be taken into account in dogs that have been overdosed with cyclophosphamide, especially if the overdose is severe.…”

“…In human medicine, cyclophosphamide overdoses has also occurred, the complications being more severe and affecting other additional organs such as heart and lungs. 15,16 The pulmonary changes are usually secondaries to the cardiomyopathy. 22 All these changes are produced by the metabolites, especially by acrolein.…”

“…In the other cases published in the past, the cumulative dose was higher but over a longer period of time (21 days) the dose intensity was decreasing. 13,15 When the overdose was detected, it was unreported if vincristine could add some synergism to cyclophosphamide in terms of increase in the toxicities. What had been reported was that both drugs could be administered simultaneously, but to avoid marked toxicity the cyclophosphamide dose tend to be decreased slightly.…”

“…These timings were similar to the ones in the other cases reported, and thrombocytopenia was also the last parameter getting within normal range. 13,15 Therefore, in our patient we opted for classic management as described in the literature. [11][12][13][14][15] Neutropenia following chemotherapy administration is a well-characterised adverse event in both human and veterinary oncology.…”

“…[11][12][13][14] The same management is performed in human medicine, but more severe consequences have been reported, and cyclophosphamide can also produce cardiac and pulmonary effects. 15,16 In veterinary medicine, gastrointestinal toxicity (anorexia, diarrhoea, vomiting), sterile haemorrhagic cystitis and myelosuppression are the possible clinical adverse events associated with cyclophosphamide when used at a therapeutical dosage. 6,17 The same adverse events are seen when an overdose happens, but with higher severity.…”