[Parkinsonism or Parkinson's disease unmasked by pentoxifylline?]

Pentoxifylline is a synthetic derivative of xantine which stimulates adenosine receptors, inhibit phosphodiesterase and increases cyclic monophosphate adenosine. It is also considered a dopaminergic D1 receptor agonist. Worsening of patients with Parkinson's disease when taking this product has been reported. On the other hand, it is considered that adenosine A2A receptors antagonists have antiparkinsonian properties. Four cases of patients with a mean age of 77 years who developed a rigid akinetic syndrome following therapy with a mean dose of 1100 mg/day of pentoxifylline over a mean period of 32 days are presented. Two of these patients presented clinical characteristics of drug-induced parkinsonism and the other two showed Parkinson's disease. The possibility of pentoxifylline causing an imbalance between D1 and D2 receptor stimulation and producing pharmacologic parkinsonism, or rather, the possibility of pentoxifylline unmasking subclinical Parkinson's disease are discussed.