Tranexamic acid has several advantages also when used for simple dental extractions, namely: low cost and ready availability and therefore we recommend this treatment modality.

A 45-year-old man presented to the emergency room with an acute episode of laryngeal spasm. He underwent emergency tracheotomy. He had recurrent episodes of generalised tonic-clonic seizures of 4 years' duration and was on phenytoin sodium 400 mg/day. The frequency of seizures had increased, requiring increasing doses of phenytoin. He had pallor, coarse facial features, gum hyperplasia (fig 1), nuclear cataracts, bilateral extrapyramidal rigidity and carpopedal spasm. Investigations showed macrocytic anaemia; hypocalcaemia, serum calcium 0.5 mmol/l (1.1-1.4 mmol/l); hyperphosphataemia 2.0 mmol/l (1.0-1.4 mmol/l); parathyroid hormone 5 ng/l (10-60 ng/l), 25-hydroxy vitamin D3 30 nmol/l (37.4-200 nmol/l), normal electrocardiogram and phenytoin 22 mg/ml (10-20 mg/ml). A plain cranial computed tomography scan showed bilateral basal ganglia and cortical calcifications (fig 2). In patients with hypoparathyroidism, phenytoin and other microsomal enzyme inducers can accelerate the hepatic inactivation of vitamin D and worsen the hypocalcaemia and its clinical manifestations, including life-threatening manifestations such as acute laryngeal spasm.