IV Buprenorphine



Subutex® abuse presenting to the emergency department: a case series

Chew, HC Hong Kong j. emerg. med. Vol. 14(3) Jul 2007



A case series of four patients who presented to the emergency department following complications of Subutex? abuse. Local complications included deep venous thrombosis, limb ischaemia, and abscess over injection sites. Systemic complications involved epidural abscess and osteomyelitis of the spine.



Patient 1

A 30-year-old Malay female presented in February 2006 with sudden onset of left lower limb swelling with pain and fever (Figure 1). Clinically, she had evidence of deep venous thrombosis which was confirmed on duplex ultrasonography. She admitted injecting Subutex? into her left femoral vein. She was commenced on anticoagulation but subsequently she defaulted follow-up.



Patient 2

A 35-year-old Chinese male developed left hand pain and numbness after injecting his radial artery with Subutex? in May 2006. Clinically, he had developed left hand ischaemia with absent pulses up to the brachial artery (Figures 2 & 3). Duplex ultrasonography confirmed acute thrombosis of the brachial artery. He underwent successful thrombolysis but subsequently discharged himself against medical advice and defaulted follow-up.



Patient 3

A 40-year-old Malay male presented in May 2006 with complaints of fever and lower back pain. He initially denied any intravenous drug use but needle marks were seen over both his arms. Clinically he had a positive straight leg raising test. No neurological deficit was detected. He was admitted for a presumed diagnosis of epidural abscess which was confirmed on magnetic resonance imaging (MRI) of the spine (Figure 4). This was surgically drained and the patient was treated with a prolonged course of intravenous antibiotics.



Patient 4

A 60-year-old Indian male complained of multiple painful skin lesions over both arms and legs in June 2006 (Figures 5a & 5b). Clinically, he had multiple abscesses over the upper limbs and popliteal fossa with needle marks over the areas. He was admitted for incision and drainage of these abscesses but he discharged himself against medical advice the following day.



Discussion (abridged):



...common features of cellulitis, non-healing wounds as well as vascular complications. These are proposed to be a result of the excipients in the preparation of Subutex?, which is meant to be administered sublingually, causing chemical irritation to the vessel wall resulting in poor healing and increased infective and thrombosis rates. The effect of Subutex on the vessel wall has not been studied but the excipients which act as binders to buprenorphine are likely to precipitate local inflammation causing thrombosis or intimal weakening, leading to either vessel occlusion or pseudoaneurysm formation after several injections. This effect can be aggravated by hot or warm injections as a result of the preparation methods as well as inadequate sterility techniques of injection. Local infections result from the use of contaminated preparations and needles. Common bacteria involved are skin organisms such as Staphylococcus and Streptococcus. These infections present in a myriad of ways from simple cellulitis to necrotising fasciitis, which can be life threatening. Delayed presentation may result in increased severity of the infection.7-12 Treatment of such infections usually requires extensive debridement and may result in loss of tissues and poor functional outcome. Complex reconstructive procedures may be required to restore function, and amputation is occasionally required to control the infection. Limb ischaemia or venous thrombosis occurs when a large vessel is injected, either deliberately or inadvertently. The drug itself or other constituents of the tablet cause inflammation, vasospasm and thrombosis. Incompletely dissolved constituents form micro-emboli, which lodge in the microcirculation, causing widespread end-organ ischaemia. Venospasm and venous thrombosis result in outflow obstruction and may cause the acute compartment syndrome. Intermittent decrease in the arterial vasospasm and opening of collateral vessels can precipitate a reperfusion injury, which translates to significant swelling and compartment syndrome. Treatments with antiplatelet drugs, vasodilators, anticoagulation, corticosteroids, thrombolysis, thrombectomy and hyperbaric oxygen therapy have all been tried. Fasciotomy may be required to relieve compartmental pressure. Failure to salvage limbs is frequently attributed to delayed presentation for fear of prosecution and widespread damage to the microcirculation from micro-emboli.7,8 Pulmonary complications of injection drug abuse include pulmonary infections, interstitial pneumonia, pulmonary vascular diseases, septic embolisation and pneumothorax, among others.



Epidural abscess of the spine threatens the spinal cord by both physical compression as well as vascular infarction of the spinal cord. Complications such as motor dysfunction and sensory problems or even paralysis may occur if this is left untreated. The diagnosis is frequently delayed as the initial presentation may be back pain alone or radicular symptoms. The clinical triad of fever, back pain and neurologic deficit is not present in most patients. Early presentations are usually subtle and atypical presentations are not unusual. Intravenous drug abusers belong to a high risk group and hence this medical emergency, which may require urgent surgical decompression and drainage of the abscess as well as intravenous antibiotics, must be suspected in such patients when they present with fever and back pain.





Figure 1. Left lower limb swelling extending to upper thigh caused by deep venous thrombosis of the femoral vein.



Figure 2. Needle marks as a result of intravenous drug use.



Figure 3. Left hand digital ischemia from brachial artery thrombosis following accidental intraarterial injection.



Figure 4. MRI spine showing osteomyelitis of the lumbar spine with epidural abscess over the L5-S1 region.



Figure 5. Abscess formation seen over the skin of both right and left biceps region following injection with contaminated needles.