A patient was on treatment with trifluoperazine for some time. He presents with a complaint of hyperthermia, lethargy and sweating. Needed investigations are -

Hyperthermia, lethargy and sweating in a patient on antipsychotic (trifluoperazine) suggest the diagnosis of the neuroleptic malignant syndrome. The rigidity and hyperthermia found in neuroleptic malignant syndrome contribute to muscle damage and necrosis. This can cause:- Elevated serum creatine kinase (CK) → Serum CK level should be assessed. Assessment of elevated CK level is the most commonly used laboratory investigation for the neuroleptic malignant syndrome. Elevated blood myoglobin (myoglobinemia) and myoglobinuria which can cause renal failure → renal function test should be done. Leucocytosis & thrombocytosis → Hemogram should be evaluated.