Nimodipine in the treatment of subarachnoid hemorrhage

Intraarterial nimodipine infusion to treat symptomatic cerebral vasospasm after aneurysmal subarachnoid hemorrhage

OBJECTIVE

Cerebral vasospasm leading to cerebral ischemic infarction is a major cause of morbidity and mortality in the patients who suffer with aneurysmal subarachnoid hemorrhage. Despite adequate treatment, some patients deteriorate and they develop symptomatic vasospasm. The objective of the present study was to investigate the efficacy and clinical outcome of intraarterial nimodipine infusion on symptomatic vasospasm that is refractory to hemodynamic therapy.

METHODS

We retrospectively reviewed the procedure reports, the clinical charts and the transcranial doppler, computed tomography and digital subtraction angiography results for the patients who underwent endovascular treatment for symptomatic cerebral vasospasm due to aneurysmal SAH. During the 36 months between Jan. 2005 and Dec. 2007, 19 patients were identified who had undergone a total of 53 procedures. We assessed the difference in the arterial vessel diameter, the blood flow velocity and the clinical outcome before and after these procedures.

RESULTS

Vascular dilatation was observed in 42 of 53 procedures. The velocities of the affected vessels before and after procedures were available in 33 of 53 procedures. Twenty-nine procedures exhibited a mean decrease of 84.1 cm/s. We observed clinical improvement and an improved level of consciousness with an improved GCS score after 23 procedures.

CONCLUSION

Based on our results, the use of intraarterial nimodipine is effective and safe in selected cases of vasospasm following aneurysmal SAH. Prospective, randomized studies are needed to confirm these results.

Subcutaneous administration of nimodipine improves bioavailability in rabbits

We compared subcutaneous and oral methods of nimodipine administration to determine a method of nimodipine administration that maintained serum levels at or above the optimal therapeutic concentration (7 ng/ml). Plasma concentrations of nimodipine were measured in New Zealand White rabbits (2.6-3.9 kg). First, peak plasma concentration (C(max)), time to reach peak plasma concentration (T(max)), and area under the curve (AUC) parameters were calculated and compared between animals receiving oral or subcutaneous nimodipine (5-15 mg/kg). Next, plasma concentrations were measured 24 h after subcutaneous administration of 2.5 mg/kg of nimodipine in healthy animals and animals with experimentally induced SAH. C(max), T(max) and AUC parameters were significantly greater for subcutaneous compared to oral nimodipine administration, irrespective of dose. Mean nimodipine concentrations at 24 h were >7 ng/ml in both healthy animals (12.9 +/- 10.0 ng/ml) and in animals with SAH (11.8 +/- 4.6 ng/ml) that received 2.5 mg/kg of subcutaneous nimodipine. In this model, the subcutaneous method of nimodipine administration consistently maintains plasma levels at or above the optimal therapeutic concentration, whereas oral administration fails to do so.

Experience with nimodipine in aneurysmal subarachnoid haemorrhage

OBJECTIVES

To assess the efficacy of nimodipine in preventing delayed ischaemic deficit in aneurysmal subarachnoid haemorrhage.

DESIGN

A continuous prospective audit of all patients with aneurysmal subarachnoid haemorrhage admitted to the joint neurosurgery units of Prince Henry's and Alfred hospitals, Melbourne. Patients were divided into two groups--135 in the pre-nimodipine group during 1986 to 1989, and 73 in the nimodipine group during 1989 and 1990.

MAIN OUTCOME MEASURES

Outcome was measured according to the Glasgow outcome scale and the incidence of delayed ischaemic deficit was recorded.

RESULTS

A substantial reduction in the overall incidence of poor outcome was observed, from 37% of patients in the non-nimodipine group, to 20% in the nimodipine group (P = 0.022). Delayed ischaemic deficit occurred in 41% and 21% (P = 0.005), and poor outcome due to delayed ischaemic deficit occurred in 18% and 8% (P = 0.09) respectively.

CONCLUSIONS

In our experience, nimodipine appears to have substantially reduced the incidence of delayed ischaemic deficits in patients with aneurysmal subarachnoid haemorrhage, with a resultant improvement in overall patient outcome.