Pentazocine-induced contractures: Dilemma in management
Pentazocine is a commonly used synthetic opioid analgesic for moderate to severe pain secondary to various conditions. Complications of parenteral opioid abuse including localized ulcerations, abscess, indurations, and sclerosis are well-documented.

Published in the Indian Journal of Pharmacology, the authors present a rare case of drug abuse due to pentazocine (Fortwin) in a 32-year-old female, who had severe myogenic contractures of her knee joints.

A 32-year-old female patient presented with the complaints of inability to stand erect and walking in equinus both sides along with stiffness of knees and ankles in our outpatient facility. She was nondiabetic and normotensive. She gave the history of chronic abuse of self-administered injection pentazocine (up to two ampoules [60 mg]/day intramuscularly) over a period of 2 years.

She was apparently well 8 years back, when she developed pain in abdomen. Pain was acute in onset and colicky in nature. It was too severe to be reduced by oral medications, so she was advised pentazocine injections intramuscularly by a local physician for relief of pain. She took the unsupervised injections intramuscularly over anterior thigh and calf on both sides. Gradually she developed stiffness at both knee and ankle joints followed by contractures.

On general examination, her cardiopulmonary and neurological examination showed no abnormality except stiffness of both knee and ankle joints. On local examination of both lower limbs, tone of musculature gave feeling of abnormal woody hardness with shining skin over thigh and calf muscles.

Multiple small healed abscesses scars were seen. Active and passive movement restriction was observed in both knees and ankles. Her feet were in equinus; more severe on right side and few degrees (10-15°) of dorsiflexion was seen on either side but unable to come to neutral position.

She was unable to squat and sit cross-legged. There was 60° flexion contracture at right knee joint and 80° at left knee joint. Tendoachillis was tight on both sides. Both hips showed secondary flexion deformities

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