Rehman Muhammad Abd Ur, Mohammed Maaz Uddin, Mannan Muhammad Abdul, Salem Waleed
Clinical Fellow Medical Toxicology, Hamad Medical Corporation, Qatar.
Clinical Pharmacist, Emergency Department, Hamad Medical Corporation, Qatar.
Toxicol Rep. 2025 May 27;14:102055. doi: 10.1016/j.toxrep.2025.102055. eCollection 2025 Jun.
Lower back pain is among the top ten reasons patients visit the emergency department (ED). Tizanidine, a centrally acting alpha-2 adrenergic receptor agonist, is commonly prescribed for managing spasticity in patients with cerebral or spinal injuries. It is also used as an effective treatment for nonspecific lower back pain. One of the most critical and life-threatening causes of lower back pain is abdominal aortic dissection, particularly in patients with hypertension. Nifedipine, a 1,4-dihydropyridine calcium channel blocker (CCB), is a widely used oral antihypertensive and antianginal agent. It lowers systemic vascular resistance and dilates coronary arteries by inhibiting calcium ion (Ca²⁺) entry into the smooth muscle cells of small arteries (arterioles), thereby reducing systemic blood pressure and improving myocardial oxygen delivery. We report a compelling case of a male patient presenting to the ED with high blood pressure and lower back pain. Shortly after the administration of tizanidine and nifedipine, his blood pressure dropped significantly within an hour. Initially suspected to be a ruptured abdominal aortic dissection, the cause was later identified as a drug-drug interaction. The synergistic effects of tizanidine and nifedipine resulted in a rapid and critical drop in blood pressure. The Drug Interaction Probability Scale (DIPS) score of 4 suggests the hypotensive episode was possibly caused by a drug interaction. This case also highlights the importance of point of care ultrasound (POCUS) and repeated examinations in excluding life-threatening conditions like aortic rupture.
下背痛是患者前往急诊科就诊的十大原因之一。替扎尼定是一种中枢作用的α-2肾上腺素能受体激动剂，常用于治疗脑损伤或脊髓损伤患者的痉挛。它也被用作非特异性下背痛的有效治疗药物。下背痛最危急且危及生命的原因之一是腹主动脉夹层，尤其是在高血压患者中。硝苯地平是一种1,4-二氢吡啶类钙通道阻滞剂（CCB），是一种广泛使用的口服抗高血压和抗心绞痛药物。它通过抑制钙离子（Ca²⁺）进入小动脉（微动脉）的平滑肌细胞来降低全身血管阻力并扩张冠状动脉，从而降低全身血压并改善心肌氧输送。我们报告了一例令人关注的病例，一名男性患者因高血压和下背痛前往急诊科就诊。在给予替扎尼定和硝苯地平后不久，他的血压在一小时内显著下降。最初怀疑是腹主动脉夹层破裂，后来发现原因是药物相互作用。替扎尼定和硝苯地平的协同作用导致血压迅速且严重下降。药物相互作用概率量表（DIPS）评分为4表明低血压发作可能是由药物相互作用引起的。该病例还强调了床旁超声（POCUS）和反复检查在排除主动脉破裂等危及生命情况方面的重要性。
