The Efficacy of Administration of Papaverine Administration by Different Routes for the Treatment of Experimental Acute Cerebral Vasospasm

Objective: To compare the effect of papaverine (PPV) by different routes of administration for the treatment of experimental acute cerebral vasospasm. Methods: A rabbit model of acute cerebral vasospasm induced by autologous blood injected into the basilar and prepontine cistern was used . The PPV (2 mg/kg) was injected either by an intravenous (IV), intra- arterial (A), intra-cisternal (IC), or combination of intra-arterial and intra-cisternal (IA + IC) routes. Basilar artery diameters were measured before and after vasospasm was induced and after PPV treatment. Results: Induction of vasospasm reduced basilar artery diameters by more than 50% in all animals. Compared to artery diameters before vasospasm, diameters after PPV treatment via the IV route were only reduced by 0.5+/-4.7%. Other reductions in the diameter included 29.1+/-10.4%, about 1.8+/-3.1%, and about 26.7+/-8.4% in the IA, IC, and IA + IC groups, respectively. However, IA administration of PPV caused obvious side effects. Conclusion: Intra-arterial application of the PPV was the most effective way to treat vasospasm in this study. The efficacy of IC route in our study did not confirm the results of prior study. The possibility of side effects of PPV via the IA route should be considered before clinical application. (C) 2002 Published by Elsevier Science Ltd