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Journal of
eISSN: 2373-4396

Cardiology & Current Research

Case Report Volume 6 Issue 4

Atrial Fibrillation and Unresponsiveness with Muscadol - A Case Report

Ayesha Parveen, Waleed Awad Salem, Abeer Kaled, Robert J Hoffman, Rawan Salameh

Department of Emergency Medicine, Hamad Medical Corporation, Qatar

Correspondence: Ayesha Parveen, Department of Emergency Medicine, Hamad Medical Corporation, Doha, Qatar

Received: September 20, 2016 | Published: September 26, 2016

Citation: Parveen A, Salem WA, Kaled A, Hoffman RJ, Salameh R (2016) Atrial Fibrillation and Unresponsiveness with Muscadol - A Case Report. J Cardiol Curr Res 6(4): 00216. DOI: 10.15406/jccr.2016.06.00216

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Muscadol is a combination medication containing paracetamol 450 mg and orphenadrine citrate 35 mg used in the treatment of muscle spasms. The Paracetamol component is intended to provide analgesia, and the orphenadrine is an anticholinergic muscle relaxant. The adverse effects of paracetamol as well as orphenadrine individually are well described. Here we describe an uncommon adverse event- atrial fibrillation with unresponsiveness occurring in association with initiation of Muscadol treatment for osteoporosis.

Case Description

An 89 year old woman with no previous comorbidities other than osteoporosis was brought to our ED by ambulance after she was found unresponsive for about 30 minutes at home. There was no witnessed seizures or abnormal movements. Her physical examination included: GCS 15, T 37°C, HR 130-140/minute, BP 120/ 80mmHg, RR 16/minute, and pOx 99% on room air. Her cranial nerves were normal, pupils 6 mm and reactive, mucous membranes moist, bowel sounds present, and dry skin. Her 12-lead ECG demonstrated atrial fibrillation (which was a new finding compared to her old ECG). The patient was subsequently evaluated as a case of TIA secondary to atrial fibrillation. Her lab assays including complete blood count, electrolytes, renal function test were normal. Noncontrast brain CT revealed nothing indicating ischemia or hemorrhage. Upon reviewing her medication profile it was found that the patient was recently started on Muscadol (paracetamol 450mg/orphenadrine 35mg) for osteoporosis 7 days prior to the event. Consultations to cardiology and neurology service were obtained, and these included additional investigations of echocardiogram, the result of which was normal. At 4 hours after presentation, the patient was treated with Metoprolol 25mg orally and no further doses of muscadol were given. In 72hrs the patient reverted back to sinus rhythm, and she was discharged from the hospital.


The physiologic mechanism for orphenadrine to cause atrial fibrillation is uncertain, but action as an anticholinergic agent is a possible explanation. A recent study of 484 people taking orphenadrine found atrial fibrillation in 12 of them (2.48%). Of these 100% of them were female and 85.71% were >60 years. Although many conditions and medications can cause atrial fibrillation, Muscadol or any drug containing orphenadrine should be used with the understanding that atrial fibrillation is a recognized adverse event. In General drugs that increase or decrease adrenergic or vagal activity, such as sympathicomimetics, parasympathicomimetics, and their inhibitors, may be able to cause AF, especially in susceptible patients with a history of cardiovascular disease (disease is the substrate, drug is the trigger), but also in “healthy” patients. These drugs represent a substantial part of cardiovascular, respiratory, and central nervous system medications [1-5]. Check Table for some of the examples

Drug Class

Representative Drugs

Anti-inflammatory drugs


High dose


Anti-convulsions drugs


Dopamine agonist












** Note: This list is not conclusive just examples.


The risk of orphenadrine-associated atrial fibrillation is greatest in elderly females above 60 years of age. In our case, the atrial fibrillation was easily reversed by cessation of the drug and use of a beta blocker


  1. Wolf PA, Abbott RD, Kannel WB (1991) Atrial fibrillation as an independent risk factor for stroke: the Framingham study. Stroke 22(8): 983-988.
  2. Chugh SS, Blackshear JL, Shen WK, Hammill SC, Gersh BJ (2001) Epidemiology and natural history of atrial fibrillation: clinical implications. J Am Coll Cardiol 37(2): 371-378.
  3. Gupta AK, Maheshwari A, Tresch DD, Thakur RK (2002) Cardiac arrhythmias in the elderly. Cardiac Electrophysiol Rev 6(1-2): 120-128.
  4. MacMahon JR (1974) Letter: Atrial fibrillation and sympathomimetics. J Pediatr 84(4): 613.
  5. Van der Hooft CS, Heeringa J, van Herpen G, Kors JA, Kingma JH, et al. (2004) Drug-Induced Atrial Fibrillation. J Am Coll Cardiol 44(11): 2117-2124.
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©2016 Parveen, et al. This is an open access article distributed under the terms of the, which permits unrestricted use, distribution, and build upon your work non-commercially.