Easily reversible hypoxemia and hypotension induced by nimodipine

The effect of nimodipine on pulmonary function in artificially ventilated patients with aneurysmal subarachnoid hemorrhage

Background

Nimodipine is routinely administered in patients with aneurysmal subarachnoid hemorrhage (aSAH). However, the effect of nimodipine on oxygen exchange in the lungs is insufficiently explored.

Methods

The study explored nimodipine medication in artificially ventilated patients with aSAH. The data collection period was divided into nimodipine-dependent (ND) and nimodipine-independent (NID) periods. Values for arterial partial pressure of oxygen (PaO₂) and fraction of inspired oxygen (FiO₂) were collected and compared between the periods. Patients were divided in those with lung injury (LI), defined as median Horowitz index (PaO₂/FiO₂) ≤40 kPa (≤300 mmHg), and without and in those with lower respiratory tract infection (LRTI) and without.

Results

A total of 53 out of 150 patients were artificially ventilated, and in 29 patients, the Horowitz index could be compared between ND and NID periods. A linear mixed model showed that during ND period the Horowitz index was 2.3 kPa (95% CI, 1.0–3.5 kPa, P<0.001) lower when compared to NID period. The model suggested that in the presence of LI, ND period is associated with a decrease of the index by 2.8 kPa (95% CI, 1.2–4.3 kPa, P<0.001). The decrease was more pronounced with LRTI than without: 3.4 kPa (95% CI, 0.8–6.1 kPa) vs. 2.1 kPa (95% CI, 0.7–3.4 kPa), P=0.011 and P=0.002, respectively.

Conclusions

In patients with LI or LRTI in the context of aSAH, pulmonary function may worsen with nimodipine treatment. The drop of 2 to 3 kPa of the Horowitz index in patients with no lung pathology may not outweigh the benefits of nimodipine. However, in individuals with concomitant lung injury, the effect may be clinically relevant.

Hypoxemia associated with nimodipine in a patient with an aneurysmal subarachnoid hemorrhage

PURPOSE

A case of probable nimodipine-induced hypoxemia in a patient undergoing treatment for aneurysmal subarachnoid hemorrhage (SAH) is reported.

SUMMARY

A 62-year-old man hospitalized for SAH developed symptoms of respiratory distress on several occasions within days of initiation of nimodipine therapy (60 mg every four hours, with three doses withheld during intubation for intracranial surgery). Several hours after extubation (on hospital day 5), the patient had rapidly worsening tachypnea and declining arterial oxygen saturation (SPO2) despite increased oxygen delivery by mask, necessitating reintubation. When a nurse noted that the declines in SPO2 occurred soon after nimodipine administration, the patient's respiratory and hemodynamic functions were closely monitored after a single dose of nimodipine via nasogastic tube; the monitoring results supported the suspicion that nimodipine's vascular effects were a causal or contributory factor in the hypoxemia episodes. With subsequent fractionated dosing (30 mg every two hours), the patient completed the prescribed 21-day course of nimodipine therapy. Using the rating scale of Naranjo et al., this case was assigned a score of 7, indicating a probable pulmonary adverse reaction to nimodipine. As nimodipine is commonly used in cases of SAH to reduce delayed neurologic deficits due to persistent cerebral vasospasm, clinicians should be mindful of its potential hypoxemic effects in vulnerable patients.

CONCLUSION

A patient with aneurysmal SAH developed hypoxemia associated with the administration of nimodipine. Hypoxemia is a known complication of treatment with other vasodilatory agents, particularly in patients who have concomitant pulmonary disease.

Treatment for calcium channel blocker poisoning: a systematic review

CONTEXT

Calcium channel blocker poisoning is a common and sometimes life-threatening ingestion.

OBJECTIVE

To evaluate the reported effects of treatments for calcium channel blocker poisoning. The primary outcomes of interest were mortality and hemodynamic parameters. The secondary outcomes included length of stay in hospital, length of stay in intensive care unit, duration of vasopressor use, functional outcomes, and serum calcium channel blocker concentrations.

METHODS

Medline/Ovid, PubMed, EMBASE, Cochrane Library, TOXLINE, International pharmaceutical abstracts, Google Scholar, and the gray literature up to December 31, 2013 were searched without time restriction to identify all types of studies that examined effects of various treatments for calcium channel blocker poisoning for the outcomes of interest. The search strategy included the following Keywords: [calcium channel blockers OR calcium channel antagonist OR calcium channel blocking agent OR (amlodipine or bencyclane or bepridil or cinnarizine or felodipine or fendiline or flunarizine or gallopamil or isradipine or lidoflazine or mibefradil or nicardipine or nifedipine or nimodipine or nisoldipine or nitrendipine or prenylamine or verapamil or diltiazem)] AND [overdose OR medication errors OR poisoning OR intoxication OR toxicity OR adverse effect]. Two reviewers independently selected studies and a group of reviewers abstracted all relevant data using a pilot-tested form. A second group analyzed the risk of bias and overall quality using the STROBE (STrengthening the Reporting of OBservational studies in Epidemiology) checklist and the Thomas tool for observational studies, the Institute of Health Economics tool for Quality of Case Series, the ARRIVE (Animal Research: Reporting In Vivo Experiments) guidelines, and the modified NRCNA (National Research Council for the National Academies) list for animal studies. Qualitative synthesis was used to summarize the evidence. Of 15,577 citations identified in the initial search, 216 were selected for analysis, including 117 case reports. The kappa on the quality analysis tools was greater than 0.80 for all study types.

RESULTS

The only observational study in humans examined high-dose insulin and extracorporeal life support. The risk of bias across studies was high for all interventions and moderate to high for extracorporeal life support. High-dose insulin. High-dose insulin (bolus of 1 unit/kg followed by an infusion of 0.5-2.0 units/kg/h) was associated with improved hemodynamic parameters and lower mortality, at the risks of hypoglycemia and hypokalemia (low quality of evidence). Extracorporeal life support. Extracorporeal life support was associated with improved survival in patients with severe shock or cardiac arrest at the cost of limb ischemia, thrombosis, and bleeding (low quality of evidence). Calcium, dopamine, and norepinephrine. These agents improved hemodynamic parameters and survival without documented severe side effects (very low quality of evidence). 4-Aminopyridine. Use of 4-aminopyridine was associated with improved hemodynamic parameters and survival in animal studies, at the risk of seizures. Lipid emulsion therapy. Lipid emulsion was associated with improved hemodynamic parameters and survival in animal models of intravenous verapamil poisoning, but not in models of oral verapamil poisoning. Other studies. Studies on decontamination, atropine, glucagon, pacemakers, levosimendan, and plasma exchange reported variable results, and the methodologies used limit their interpretation. No trial was documented in humans poisoned with calcium channel blockers for Bay K8644, CGP 28932, digoxin, cyclodextrin, liposomes, bicarbonate, carnitine, fructose 1,6-diphosphate, PK 11195, or triiodothyronine. Case reports were only found for charcoal hemoperfusion, dialysis, intra-aortic balloon pump, Impella device and methylene blue.

CONCLUSIONS

The treatment for calcium channel blocker poisoning is supported by low-quality evidence drawn from a heterogeneous and heavily biased literature. High-dose insulin and extracorporeal life support were the interventions supported by the strongest evidence, although the evidence is of low quality.

Human cardiotoxic drugs delivered by soaking and microinjection induce cardiovascular toxicity in zebrafish

Cardiovascular toxicity is a major challenge for the pharmaceutical industry and predictive screening models to identify and eliminate pharmaceuticals with the potential to cause cardiovascular toxicity in humans are urgently needed. In this study, taking advantage of the transparency of larval zebrafish, Danio rerio, we assessed cardiovascular toxicity of seven known human cardiotoxic drugs (aspirin, clomipramine hydrochloride, cyclophosphamide, nimodipine, quinidine, terfenadine and verapamil hydrochloride) and two non-cardiovascular toxicity drugs (gentamicin sulphate and tetracycline hydrochloride) in zebrafish using six specific phenotypic endpoints: heart rate, heart rhythm, pericardial edema, circulation, hemorrhage and thrombosis. All the tested drugs were delivered into zebrafish by direct soaking and yolk sac microinjection, respectively, and cardiovascular toxicity was quantitatively or qualitatively assessed at 4 and 24 h post drug treatment. The results showed that aspirin accelerated the zebrafish heart rate (tachycardia), whereas clomipramine hydrochloride, cyclophosphamide, nimodipine, quinidine, terfenadine and verapamil hydrochloride induced bradycardia. Quinidine and terfenadine also caused atrioventricular (AV) block. Nimodipine treatment resulted in atrial arrest with much slower but regular ventricular heart beating. All the tested human cardiotoxic drugs also induced pericardial edema and circulatory disturbance in zebrafish. There was no sign of cardiovascular toxicity in zebrafish treated with non-cardiotoxic drugs gentamicin sulphate and tetracycline hydrochloride. The overall prediction success rate for cardiotoxic drugs and non-cardiotoxic drugs in zebrafish were 100% (9/9) as compared with human results, suggesting that zebrafish is an excellent animal model for rapid in vivo cardiovascular toxicity screening. The procedures we developed in this report for assessing cardiovascular toxicity in zebrafish were suitable for drugs delivered by either soaking or microinjection.

Intravenous magnesium versus nimodipine in the treatment of patients with aneurysmal subarachnoid hemorrhage: a randomized study

OBJECTIVE

The prophylactic use of nimodipine in patients with aneurysmal subarachnoid hemorrhage reduces the risk of ischemic brain damage. However, its efficacy seems to be rather moderate. The question arises whether other types of calcium antagonists offer better protection. Magnesium, nature's physiological calcium antagonist, is neuroprotective in animal models, promotes dilatation of cerebral arteries, and has an established safety profile. The aim of the current pilot study is to evaluate the efficacy of magnesium versus nimodipine to prevent delayed ischemic deficits after aneurysmal subarachnoid hemorrhage.

METHODS

One hundred and thirteen patients with aneurysmal subarachnoid hemorrhage were enrolled in the study and were randomized to receive either magnesium sulfate (loading 10 mg/kg followed by 30 mg/kg daily) or nimodipine (48 mg/d) intravenously until at least postoperative Day 7. Primary outcome parameters were incidence of clinical vasospasm and infarction. Secondary outcome measures were the incidence of transcranial Doppler/angiographic vasospasm, the neuronal markers (neuron-specific enolase, S-100), and the patients' Glasgow Outcome Scale scores at discharge and after 1 year.

RESULTS

One hundred and four patients met the study requirements. In the magnesium group (n = 53), eight patients (15%) experienced clinical vasospasm and 20 (38%) experienced transcranial Doppler/angiographic vasospasm compared with 14 (27%) and 17 (33%) patients in the nimodipine group (n = 51). If clinical vasospasm occurred, 75% of the magnesium-treated versus 50% of the nimodipine-treated patients experienced cerebral infarction resulting in fatal outcome in 37 and 14%, respectively. Overall, the rate of infarction attributable to vasospasm was virtually the same (19 versus 22%). There was no difference in outcome between groups.

CONCLUSION

The efficacy of magnesium in preventing delayed ischemic neurological deficits in patients with aneurysmal subarachnoid hemorrhage seems to be comparable with that of nimodipine. The difference in their pharmacological properties makes studies on the combined administration of magnesium and nimodipine seem promising.