Comparison of desmopressin (DDAVP) tablet and intranasal spray in the treatment of central diabetes insipidus
Desmoperssin is the drug of choice for treatment of central diabetes insipidus and most commonly it is used as intranasal spray. In this study, efficacy and side effects of oral desmopressin was compared with the intranasal spray. This study was before -after clinical trial on 14 outpatients (9 F, 5 M, age 14 -50 Y) with central diabetes insipidus who had been treated with intranasal spray of desmopressin previously. Weight, pulse rate and blood pressure (sitting -standing), biochemical profile, serum electrolytes, 24h urine volume, specific gravity of urine and LFT was measured before and after 1 month study. Starting dose for each patient was one oral tablet of DDAVP (0.1 mg) per 8 hours. Paired Samples T-Test was used for data analysis. No clinically significant changes were found as regard to weight, pulse rate, blood pressure, blood chemistry, electrolyte and urinalysis. Single reported adverse effect was headache (43%) in tablet group and dyspnea (7%) in spray group. Both dosage forms were able to control diurnal polyuria and nocturnal polyuria. The antidiuretic dose - equivalence ratio for intranasal to oral desmopressin was 1: 18. Spray was superior in terms of rapid onset of action and duration of antidiuretic action in 100% and 78% of cases (not significant), respectively. Tablets were more available and much more easily consumed as reported by patients, in 86% (P=0.0006). Treatment with tablets offers a good alternative to the intranasal route, especially in patients with chronic rhinitis or common cold and similar conditions.