Case Report International Journal of Comprehensive and Advanced Pharmacology, April-June,2017;2(2):68-69 68 Carbamazepine induced secondary hyperparathyroidism: A rare clinical entity Tarun Sharma 1 , Aradhna Sharma 2 , Dinesh Kansal 3,* , Himani Prajapati 4 1 Assistant Professor, 2 Senior Resident, 3 Professor & HOD, 4 Pharmacovigilance Associate, Dept. of Pharmacology, Dr. RPGMC, Tanda, Himachal Pradesh *Corresponding Author: Email: dinesh.kansal56@gmail.com Abstract Antiepileptic drugs (AEDs) are associated with altered bone metabolism and decreased bone density thereby increasing the risk of fractures several folds. This is a unique case report of a young 34 year old female diagnosed as a case of partial epilepsy two years back, was on carbamazepine (CBZ) therapy (300 mg SR twice a day). The seizures were fully controlled but she presented with gradual pure motor weakness involving proximal muscles over the duration of one year. There was a pentad of weakness, raised alkaline phosphatase (ALP), hypocalcaemia, hypophosphatemia and raised parathyroid hormone PTH. On dechallenge by tapering the doses of carbamazepine and starting newer antiepileptic there was marked improvement in the weakness. It has been found that epilepsy itself increases the risk of seizures and also anti-epileptics alter the bone metabolism by various mechanisms. Therefore while starting the antiepileptic in young patients for long term, high levels of suspicion should be kept in mind in view of altered calcium metabolism and even the first sign should not be missed. This patient presented with inability to walk and on evaluation was found to have secondary hyperparathyroidism. The pentad of weakness, raised ALP, hypocalcaemia and increased PTH in a patient on carbemazapine can easily lead to diagnosis. Keywords: Carbamazepine; Adverse drug reaction; Hyperparathyroidism Introduction Adverse drug effects of an anticonvulsant therapy on calcium metabolism is a known entity. We present a rare case report of a patient on chronic carbamazepine therapy, presented with inability to walk and on evaluation were found to have secondary hyperparathyroidism which was easily treated with change of antiepileptic drug and Vit D supplementation. The pentad of weakness, raised ALP, hypocalcaemia and increased PTH in a patient on CBZ can easily lead to diagnosis. Case Summary This 34 year old house wife a resident of nearby village of Kullu in state of Himachal Pradesh India presented in Medicine OPD with complaints of inability to walk for last 2 months and inability to do routine house work for last 8 months. Patient was brought in a wheel chair by her husband. The patient had been married for last10 years and had two kids of age 8 and 5 yrs which were born of a full term normal vaginal delivery at Regional Hospital Kullu. Her post partum period had been un-eventful. Patient had been a known case of partial seizures with cognitive loss for the last 4 years. Patient got evaluated for the complaints of seizures from Kullu and was diagnosed to have neurocystiscercosis which were calcified. Patient was started on carbamazapine 300 mg twice daily and was taking regularly. Her seizure episodes were under control and her last episode of seizure was 1 yr back. Patient started complaining of generalized weakness for last 8 months. She usually got fatigued after doing minimal house hold work and would need someone’s help. She always complained of low back ache and pain in legs. She could not climb stairs in one go and had to rest after 5 to 6 steps and then again walk. She could not get up from squatting position and had to be helped by someone. She had problem in rolling chapattis and picking up utensils from upper shelves. She also had problem in combing her hair or lifting objects above her head. For these complaints she had been showing at various places but no improvement was been seen. She also received multivitamin injections at various places and calcium tablets and injections but after minimal improvement she again complained same. She had been bed bound for last 1 month and only could go for toilet with someone’s help. During last one month she also started having twitches in right side of face and also complained that fingers of her hands would contract and adduct. This episode would remain for 1-2 minutes and then improve on its own. Considering it to be seizure her family doctor had increased dose of CBZ to 400 BD. During all this time her compliance for CBZ was good and she was seizure free. Otherwise she had no sensory complaints and her bladder and bowel habits were normal except for constipation. Her social relations were good and she had no complaints in relation to other organ systems. She was a vegetarian and her menstrual cycle was normal. Her body mass index was 20.3kg/m2which was normal for her age. On examination patient was conscious oriented to time place and person. She was not cheerful but maintained good eye to eye contact during whole conversation. Her pulse was 78/min, regular; her blood pressure in sitting position was 126/78 mm hg in right arm with no postural drop. Her respiratory rate was normal. She did not have pallor, jaundice lymphadenopathy, pedal edema or jugular venous pressure raised. Her skin and