Table of Contents  
Year : 2020  |  Volume : 16  |  Issue : 2  |  Page : 83-88

Abuse of parenteral opioid (pentazocine) amongst plastic surgery patients in a tertiary health institution in south-south Nigeria − a case series

1 Department of Surgery, Federal Medical Centre, Asaba, Delta State, Nigeria
2 Department of Surgery, Delta State University Abraka, Delta State, Nigeria

Date of Submission09-Mar-2020
Date of Acceptance07-Aug-2020
Date of Web Publication18-Dec-2020

Correspondence Address:
Dr. I C Ohiaeri
Senior Registrar, Department of Surgery, Federal Medical Centre, Asaba, Delta State
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/njps.njps_4_20

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Introduction: Parenteral opioid abuse is not uncommon amongst patients presenting for plastic surgery care, especially health workers. Pain is the commonest reason for initiating and sustaining the injections. Complications such as lymphedema, cellulitis, ulcers etc. are common sequelae of this psychosocial disorder. Aim: This is to review the pattern of pentazocine abuse; with the objectives of: reviewing the demographics, site, and complications of pentazocine abuse amongst patients presenting to the plastic surgery unit. Materials and Methods: Self-administered questionnaires were used to obtain information by direct interview of the patients. Pentazocine injections were specifically looked at while excluding oral opioids such as tramadol tablets. Results: Most patients (60%) are of SS genotype with pain from vaso-occlusive crisis as the inciting factor. Male: female ratio is 1:4. Forty percent (4 of 10 patients) are health professionals. Lymphedema was a complication in 50% (5 of 10 patients), ulcers in 90% (9 of 10 patients); ten percent (1 of 10) had a pre-existing ulcer before the injection following a road traffic accident (RTA). Upper limbs are affected in 60% and lower limbs in 70 % (one patient had traumatic ulcers on both legs). They all expressed desire to stop when pain ceases but still inject themselves occasionally. Conclusion: Pentazocine abuse is common amongst health professionals and SS genotype patients and can be complicated by lymphedema and associated ulcers when injected into soft tissue. There is a need to periodically evaluate health workers with regards to parenteral opioid abuse in order to ensure safety of patients left under their care.

Keywords: Abuse, parenteral, pentazocine, plastic, surgery

How to cite this article:
Otene C I, Ohiaeri I C, Odatuwa-Omagbemi D O, Enemudo R. Abuse of parenteral opioid (pentazocine) amongst plastic surgery patients in a tertiary health institution in south-south Nigeria − a case series. Nigerian J Plast Surg 2020;16:83-8

How to cite this URL:
Otene C I, Ohiaeri I C, Odatuwa-Omagbemi D O, Enemudo R. Abuse of parenteral opioid (pentazocine) amongst plastic surgery patients in a tertiary health institution in south-south Nigeria − a case series. Nigerian J Plast Surg [serial online] 2020 [cited 2024 Mar 4];16:83-8. Available from:

  Introduction Top

Pentazocine is a mixed agonist-antagonist opioid, a benzmorphinan used for moderate-to-severe pain.[1],[2],[3] As an opioid, it is prone to addiction following prolonged use. It is associated with granulomatous inflammation, vascular thrombosis,[4],[5] dermal fibrosis,[6] lymphedema, myopathy,[7] and necrotizing fasciitis.[1],[8],[9],[10] It acts by cytotoxicity and the stasis from thrombosis creates an enabling environment for infection. Pentazocine is soluble in acidic medium, thus, in the slightly alkaline extracellular fluid, it is precipitated leading to chronic inflammatory reactions,[11] interstitial fibrosis and reduced cutaneous blood flow, with consequent ulceration. For pain management, regular objective reassessment is important to avert addiction.

We present cases of pentazocine addiction and their sequelae among patients that presented to our unit over a 5-year period (June 2014 to May 2019).

  CASE 1 Top

A thirty two year old female nurse, with AA genotype and is not a known diabetic who was placed on pentazocine injection at the ob/gyn clinic for pre-term contraction. She fell at home and pentazocine prescribed in the hospital was used to manage the pain. She subsequently started to use the drug for recreational purposes and stopped on her own volition after about 2 years. She presented with a right leg ulcer (probably pyogenic in origin) of 4 months duration, which healed on out-patient treatment. She was co-managed with the mental health unit.

  CASE 2 Top

A thirty year old single lady, of AA genotype. She has been addicted to pentazocine for 6 years after it was prescribed at a clinic for chronic pain from a left elbow dislocation/fracture following road traffic accident. She presented with a 2-year history of left upper limb ulcer with stiff and deformed left elbow and wrist. Despite combined efforts by psychiatrists, she would often return to pentazocine after apparent rehabilitation. The ulcer healed on out-patient treatment.

  CASE 3 Top

A thirty eight year old female nurse, a known sickler, who presented with bilateral lower limb swelling and generalized post-burn scars of over 8 years duration (lost her husband and two children in the inferno). It was prescribed as analgesia during her wound care at the hospital. Self-injection of pentazocine continued afterwards till she presented to the unit. She developed lower limb lymphedema of 2 years duration, which worsened with injections, with associated renal complications.

  CASE 4 Top

A twenty year old female known sickler who has been receiving pentazocine injection prescribed at the hospital for analgesia during her vaso-occlusive crisis episodes. However, her addiction started 3 years prior to presentation when she started buying the drugs from the pharmacy and injects herself to control pain. She presented with bilateral ulcers on buttock and postero-lateral upper thigh of 3 years duration. She sustained her addiction, sometimes injecting directly into the ulcer.

  CASE 5 Top

A thirty nine year old female unemployed, AS genotype who was given pentazocine prescribed by a doctor in National Youth Service Corps (NYSC) camp for recurrent bone pains 10 months prior to presentation. Her addiction started thereafter as she buys the drugs from pharmacy on self medication. She developed cellulitis and ulcers in left upper limb, both glutei and lower thighs of 9 months duration, which were managed conservatively. She was not willing to stop the addiction. The ulcers worsened leading to necrotizing fasciitis and subsequently had left above-elbow amputation.

  CASE 6 Top

A twenty two year old female known sickler who was given pentazocine prescribed by a doctor in a hospital for pain crisis. She started purchasing the drug from the open drug market and injecting herself 3 years prior to presentation. She presented with left upper limb gangrene of 3 days duration and had above-elbow amputation. Restlessness, insomnia and crave for the injection were her withdrawal symptoms. She was reviewed by the mental health unit but she continued to self inject into her thighs, even after having amputation of the left upper limb. This resulted in thigh ulcerations and muscle fibrosis. She eventually died from complications and bleeding from her thigh ulcers about 4 years later.

  CASE 7 Top

A thirty eight year old female nurse of AA genotype, who commenced pentazocine injections 6 years prior to presentation. This was prescribed for preterm labour at the OB/GYN clinic. However, her addiction started 3 years prior to presentation when she started purchasing the drugs from the open drug market, and injected herself daily into the veins on her forearm, and even into the tissues, when venous access became difficult. She developed lymphedema and ulcers few months later for which she presented. The ulcers were multiple and deep, the largest measured 8 × 6 × 2cm. She was placed on conservative management with elevation, compression bandaging, saline and honey wound dressings, with resultant improvement. Mental health unit reviewed; insomnia, anorexia and restlessness were the withdrawal symptoms she had. She wants to quit but cannot resist the urge [see Figure 1].
Figure 1 Bilateral upper limb lymphedema and cutaneous ulcers

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  CASE 8 Top

A thirty eight year old male commercial motorcycle rider, who is a known sickler, who had bilateral traumatic leg ulcers following road traffic accident of about 4 years duration. Pentazocine was prescribed by a doctor at a general hospital on account of pain at about the time of the trauma incident, but he continued to buy the drug over the counter (OTC) after discharge from the hospital and injected himself weekly on both legs and forearms. He presented with extensive bilateral leg and forearm ulcers, which were managed conservatively with honey wound dressings, surgical debridement, and elevation. He was non-compliant to treatment and later absconded. He had restlessness, insomnia and pain as withdrawal symptoms; was co-managed with the mental health unit see [Figure 3].

  CASE 9 Top

A twenty eight year old male generator technician, a known sickler. who started abusing pentazocine 6 years prior to presentation after it was prescribed at a general hospital on account of vaso-occlusive crisis. He got the drugs via retained prescription, or OTC and injected himself 2-3 times a day into the veins of the forearm. He presented with bilateral upper limb swelling and forearm ulcers of 2 years duration. There was improvement in the condition of the wound following in-patient conservative management. Pain was his only withdrawal symptom and is being co-managed with mental health. He wished to stop the injections if only he was pain-free see [Figure 2].
Figure 2 Left forearm ulcers and lymphedema

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Figure 3 Bilateral leg ulcers

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  CASE 10 Top

A twenty eight year old female of SS genotype, an auxiliary nurse, whose first pentazocine injection was given for vaso-occlusive crisis at the hospital where she worked while in training. She subsequently purchased the drug from patent medicine dealers and the open drug market and injected herself in the thighs and later into both legs, when ulcers developed on the thighs. This abuse started 2 years prior to presentation. She presented with bilateral lower limb swelling (lymphedema) and ulcers, then was discharged during an industrial action and lost to follow-up see [Figure 4],[Figure 5].
Figure 4 Bilateral thigh scars (pentazocine injection sites)

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Figure 5 Bilateral leg ulcers

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  Discussion Top

Pentazocine abuse, as well as local tissue complication(s), is documented in the literature. Iheanacho et al.[12] in Benin city reported three sickle cell disease patients who developed lymphedema from prolonged self-injection with pentazocine. In his study, one of the three patients is a student in a school of health technology. Male: female ratio was 2:1. In another study, Colin et al.[4] in Virginia USA reported a case of necrotizing fasciitis and florid osteomyelitis in a Nigerian female following pentazocine injection into her distal upper extremities, for which the patient had an above wrist amputation. They noted that it was the second case of pentazocine abuse from Nigeria within 6 months of their study.

From our study, all the patients are young between the ages of 20 and 39 years. The male: female ratio is 1:4 (2:8) see [Figure 6]. The sex distribution is probably because the woman would want someone, or in this case, something to comfort them in a turbulent emotional period such as pain. Four of ten (40%) of them are health professionals (nurses to be precise). Most (60%) are of SS genotype, see [Table 1]; vaso-occlusive pain being the most common precipitating factor. This is in tandem with the study by Iheanacho et al.[12] and Olatunji et al.[13], whose patients are all sickle cell disease patients. The lower limbs were the commonest site of injections (70%) as against 60% on the upper limbs (forearm and hands being most common probably from ease of access); some injected into both upper and lower limbs. Two of them first got the drugs during pre-term labour with some relaxing effects.
Figure 6 Sex distribution.

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Table 1 Genotype distribution

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Abuse was sustained by retaining the original prescription, buying from the open market, new prescriptions from doctor-friends and/or over-the-counter as they were known to the dispensers. Withdrawal symptoms include pain (10%), anorexia, insomnia, restlessness.

Fifty percent of the patients presented with lymphedema with associated ulcers (5 of 10 patients) which were equally distributed between the lower limbs and upper limbs. One had necrotizing fasciitis of the legs see [Figure 7]. One (10%) had a pre-existing ulcer from road traffic accident, prior to injection abuse. They all expressed their desire to quit self-injection once pain ceases. One patient actually stopped the injections when the emotional trauma that started the abuse ceased. They were all co-managed with the mental health unit.
Figure 7 Complications.

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They were all managed conservatively with serial surgical and chemical debridement, elevation of the affected limbs and graduated compression bandaging. Two of our patients had upper limb amputation and one died.

  Conclusion Top

Pentazocine abuse is common amongst health professionals and SS genotype patients. It can lead to lymphedema and ulcers when injected into the tissues. Therefore, it is recommended that there should be proper legislation to restrict access or availability of pentazocine over the counter. In addition, there is a need to periodically evaluate health workers with regards to parenteral opioid abuse in order to ensure safety of patients left under their care. It is recommended that alternatives to pentazocine be used as pain relief in sickle cell anemia patients, and that stricter measures be put in place to ensure regulation of purchase outside the hospital facility.

  Limitation of the study Top

Some patients were lost to follow-up. There were missing patient records in some instances.

  Ethical approval Top

Ethical approval was obtained from the Ethics committee of Federal Medical Centre, Asaba, Delta State, Nigeria.


Our appreciation goes to the surgical residents in the plastic surgery unit and the members of the mental health unit that partook in the management of these patients.


This manuscript has been read and approved by all the authors, who have met the requirements for authorship. Each of the authors believes that this manuscript is original and represents honest work.

Authors’ contribution

Dr Otene Cletus I., chief author, did final editing of the manuscript and supervising consultant. Dr Ohiaeri Ikenna C. helped in preparing the manuscript, data collation and analysis. Dr Odatuwa-Omagbemi D.O. helped in data collection and part of the managing team. Dr Enemudo R.E.T. is part of the managing team and data retrieval.

Financial support and sponsorship


Conflicts of interest

There are no conflicts of interest.

  References Top

Callahan TE, Scheaters WP, Hom JK. Necrotizing soft tissue infection masquerading as cutaneous abscess following illicit drug injection. Arch Surg 1998;133:812-9.  Back to cited text no. 1
Edwards C, Whitfield K, Sudhaker S et al. Parenteral substance abuse: reports of chronic pain and coping in adult patients with sickle cell disease. J Nat Med Assoc 2006;98:420-8.  Back to cited text no. 2
Hunter R, Ingram IM. Intravenous pentazocine abuse by a nurse. Lancet 1983;2:227.  Back to cited text no. 3
Colin M, Jonathan I, Frankenhoff J. Injectable pentazocine abuse leading to necrotizing soft tissue infection and florid osteomyelitis. Hand (NY) 2011;6:457-9.  Back to cited text no. 4
Levin MH, Weinstein RA, Nathan C, Sclander RK, Ochman H, Kabina SD. Association of infection caused by Pseudomonas with intravenous abuse of pentazocine mixed with tripelenamine. J Clin Microbiol 1984;20:758-62.  Back to cited text no. 5
Palestine RF, Millins JL, Spigel GT, Schroeter AL. Skin manifestations of pentazocine abuse. J Am Acad Dermatol 1980;2:47-55.  Back to cited text no. 6
Steiner J, Wilkenman A, de Jesus P. Pentazocine-induced myopathy. Arch Neuro 1973;28:408-9.  Back to cited text no. 7
Dunne JH, Johnson WC. Necrotizing skin lesions in heroine injections. Arch Dermatol 1972;105:544-7.  Back to cited text no. 8
Schucher J, Zuduke R, Lynch P. Local changes at the site of pentazocine injection. Arch Dermatol 1971;104:90-91.  Back to cited text no. 9
Wanfield J, Greek K. Cutaneous complications of parenterally administered pentazocine injection. JAMA 1973;226:189-90.  Back to cited text no. 10
Kumar D, Gupta A, Sharma VP, Singh A, Verma AK. Pentazocine induced contractures, Dilemma in management. Indian J Pharmacol 2015;47:451-3.  Back to cited text no. 11
[PUBMED]  [Full text]  
Iheanacho OE, Halim NKD, Enosolease NIE, Awodu OA, Bazuaye GN, Omoh CE et al. Case studies involving bilateral lymphoedema following pentazocine abuse in sickle cell disease patients. Annals of Tropical Pathology 2013;4:47-52.  Back to cited text no. 12
Olatunji PO, Makanjuola AB. Pentazocine abuse amongst sickle cell anemia patients; a report of two cases. African Drug and Alcohol Studies Vignettes 2009;8:59-64.  Back to cited text no. 13


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