Trihexyphenidyl Hydrochloride

Anticholinergic toxicity and neuroleptic malignant syndrome (NMS) are common toxidromes in medical emergencies. However, their co-occurrence, resulting in a dual toxidrome, is rare and presents significant diagnostic and therapeutic challenges. We present the case of a 23-year-old young male with polysubstance dependence, admitted following combined trihexyphenidyl and risperidone toxicity. He was diagnosed with a dual toxidrome of anticholinergic storm and NMS. Treatment of NMS included lorazepam and bromocriptine. Due to the unavailability of physostigmine, the preferred antidote for anticholinergic syndrome, intrathecal neostigmine was administered. The patient subsequently recovered and was discharged. This case highlights the complexity of managing dual toxidromes and the need for alternative therapeutic strategies in resource-limited settings.

Thrust manipulation is one of the most commonly used techniques for managing musculoskeletal pain in clinical practice. This involves the application of a high-velocity, low-amplitude force directed to the joints with the intent of achieving joint cavitation. This current case report describes a female in her mid-20s who presented with excessive bilateral and involuntary hand muscle contractions after bilateral thrust manipulation. Dystonia appeared both at rest and during voluntary movements but was aggravated by actions such as finger flexion or spreading and disappeared during sleep. A diagnosis of complex regional pain syndrome (CRPS) type I combined with dystonia was made. Prednisolone administered between 2 and 5 weeks after symptom onset significantly reduced CRPS symptoms, but intramuscular botulinum toxin injection 5 weeks after symptom onset was ineffective at controlling her symptoms. Seven weeks after symptom onset, the patient was administered 2 mg trihexyphenidyl oral twice a day, 2.5 mg diazepam oral twice a day and 5 mg baclofen oral three times a day for 1 month and this significantly reduced dystonia, but complete resolution was not achieved. Clinicians should be aware that dystonia is a rare complication of thrust manipulation.