Pentoxifylline:
Preliminary randomized clinical trial on pentoxifylline (400 mg, TDS for
12 weeks) demonstrated the enhancement of pulmonary gas exchange in COPD
patients. A possible mechanism for these results could have been by the
increase in the cardiac output and mixed venous pO2(Haas et al. 1990). A subsequent trial on
severe ARDS has shown that administration of pentoxifylline with a dose
of 100 mg IV BD for seven days, followed by 400 mg PO TDS, led to the
improvement of the symptoms of the ARDS, suppression of mean TNF levels
and increasing the survival rate
(Montravers et al. 1993).
Furthermore, the efficacy of pentoxifylline in attenuation of acute lung
injury has been shown in animal models such as guinea pigs
(Lilly et al. 1989). It is also well
established that the administration of pentoxifylline at the time of
allergen sensitization airway hyperresponsiveness suppresses the
allergic inflammation and airway hyperresponsiveness in vivo
(Fleming et al. 2001). The observed
bronchodilatory, anti-inflammatory, and immunomodulatory properties
provide further support for suggesting the pentoxifylline as a promising
medicine in severe acute respiratory syndrome (SARS)
(MartÃn et al. 2003).
In a more recent study, pentoxifylline treatment improved ALI-induced by
Infrarenal aortic cross-clamping in the Wistar rat model. The proposed
mechanism involved the phosphorylation of STAT3, leading to the
stimulation of IL-10 production (Li et al.
2016). The beneficial effect of pentoxifylline on lung has been
demonstrated in lung cancer patients. A combination of pentoxifylline
and vitamin E decreased radiation-induced lung toxicity frequency in
lung cancer patients receiving concurrent chemo-radiotherapy
(Misirlioglu et al. 2007). These results
are in line with those that found the preventive efficacy of the
combination, as mentioned earlier in the alleviation of some
radiation-induced side-effects in patients with either breast
(Magnusson et al. 2009) or head and neck
cancer (Sayed et al. 2020). With the
massive evidence of lung involvement in COVID-19 patients,
pentoxifylline may offer a safe and well-tolerated option to treat the
respiratory symptoms in these patients potentially (Figure 1) .