EN ISO 13485:2012 Performance Evaluations LIQUIPLASTIN ® Thromboplastin for PT determination Performance Evaluations EN ISO 13485:2012 INDEX S. No. Name of the Publication Pg Nos 1. British Journal of Clinical Pharmacology/65:5/2008 787 - 790 2. The European e- Journal of Clinical Nutrition and Metabolism (2008) 1-8 3. World Journal of Pharmaceutical Sciences 2016; 4(10) 50-56 4. International Journal of Nutrition, Pharmacology, Neurological Diseases | July-September 2016 | Vol 6 | Issue 3 101-110 5. Journal of Evolution of Medical and Dental Sciences/ Volume 2/ Issue 2/ January 14, 2013 72-78 6. International Journal of Research in Ayurveda & Pharmacy , 1(2), Nov-Dec 2010 586-589 7. Journal of Applied Pharmaceutical Science Vol. 7 (03), March, 2017 081-087 8. International Journal of Pharmacy and Pharmaceutical Sciences, Vol 7, Supple 1, 104-111 9. Journal of Chemical and Pharmaceutical Research, 2015, 7(5) 973-980 10. International Journal of Scientific Study | August 2016 | Vol 4 | Issue 5 216-221 11. International Journal of Current Research in Biosciences and Plant Biology, Vol 3 February 2016 106-113 12. International Journal of Pharma and Biosciences, 2014 July, (5)3 705-709 LIQUIPLASTIN ® Thromboplastin for PT determination British Journal of Clinical DOI:10.1111/j.1365-2125.2008.03113.x Pharmacology Correspondence Dr Nithya Gogtay, Department of Clinical A pilot study of the Pharmacology, New MS Building, 1st Floor, Seth GS Medical College and KEM Hospital, Parel, Mumbai 400012, India. association of Tel.: +91 22 2413 3767/2417 4420 Fax: +91 22 2411 2871 pharmacokinetic and E-mail: [email protected] ---------------------------------------------------------------------- *UPK was partly supported by the Short-term studentship programme 2006 pharmacodynamic of the Indian Council of Medical Research, New Delhi. parameters of warfarin with ---------------------------------------------------------------------- Keywords international normalized ratio, warfarin the dose in patients on ---------------------------------------------------------------------- Received 20 April 2007 long-term anticoagulation Accepted 3 January 2008 Uday P. Kulkarni,1* Balkrishna D. Swar,1 Dilip R. Karnad,2 Published OnlineEarly 21 February 2008 Sanish Davis,1 Anil M. Patwardhan,3 Nilima A. Kshirsagar1 & Nithya J. Gogtay1 Departments of 1Clinical Pharmacology, 2Medicine and 3Cardiovascular and Thoracic Surgery, Seth GS Medical College and KEM Hospital, Parel, Mumbai 400012, India WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT • Warfarin is a widely used anticoagulant with a low therapeutic index. AIMS • There is wide interindividual variation in the To assess the correlation between plasma total warfarin concentration, pharmacokinetics and pharmacodynamics plasma 7-hydroxywarfarin concentration and INR and the weekly doses of warfarin which is also reflected in the of warfarin in patients on long-term anticoagulation. warfarin dose requirement. METHODS • CYP2C9 and VKORC1 polymorphisms have Twenty-five patients on long-term anticoagulation with warfarin were been shown to affect warfarin dose studied. Plasma total warfarin and 7-hydroxywarfarin concentrations requirement. However a large amount of the and INR were determined. Equations were derived with the weekly variation in warfarin dose remains warfarin dose as the dependent variable and plasma total warfarin unaccounted for. concentration : plasma 7-hydroxywarfarin concentration, INR : plasma total warfarin concentration and INR : plasma 7-hydroxywarfarin concentration as independent variables. WHAT THIS STUDY ADDS RESULTS There was a good correlation between INR : plasma total warfarin • Our findings suggest that in patients who concentration and the weekly dose of warfarin (y = 46.73e-0.30x, are on long-term warfarin therapy, r2 = 0.65). There was a better correlation between INR : plasma INR : plasma 7-hydroxywarfarin 7-hydroxywarfarin concentration and the weekly dose of warfarin concentration correlates well with warfarin (y = 156.52x-0.63, r2 = 0.74) requirement and also accounts for a large CONCLUSIONS amount of variation in warfarin dose. Pharmacokinetic parameters along with INR seem to correlate with the weekly doses of warfarin in patients on long-term anticoagulation. These parameters may therefore be useful for predicting warfarin doses. © 2008 The Authors Br J Clin Pharmacol / 65:5 / 787–790 / 787 Journal compilation © 2008 Blackwell Publishing Ltd U. P.Kulkarni et al. Introduction centration : plasma 7-hydroxywarfarin concentration, INR : plasma total warfarin concentration and INR : plasma Warfarin is a widely used anticoagulant with a low thera- 7-hydroxywarfarin concentration as independent vari- peutic index. There is wide interindividual variation in the ables. The third INR value was used for deriving the pharmacokinetics and pharmacodynamics of warfarin. equations. Polymorphisms of CYP2C9 and VKORC1 have been shown to affect warfarin dose requirement. Previous studies have evaluated the utility of genotyping for CYP2C9 and Results VKORC1 in predicting warfarin dose in patients on long- term anticoagulation, but have found that these geno- The mean age of the patients (18 males and seven females) types account for only about 60% of variation in dose [1]. was 37.28 Ϯ 10.23 (SD) years (range 22–56 years).The indi- Hence genotyping for CYP2C9 and VKORC1 is not used cation for warfarin therapy was mitral valve replacement currently for optimizing warfarin therapy. Many factors (n = 8), deep vein thrombosis (n = 6), aortic valve replace- other than CYP2C9 and VKORC1 polymorphisms also affect ment (n = 3), aortic and mitral valve replacement (n = 3), warfarin requirement including polymorphisms in other atrial fibrillation (n = 2), venous sinus thrombosis (n = 2) genes, concomitant drug intake, ethnicity and vitamin K and arterial embolism (n = 1). The mean weekly dose content of the diet [2]. Therefore, models for prediction of of warfarin was 34.58 Ϯ 14.76 (SD) mg (range warfarin doses using parameters other than gene poly- 7–70 mg week-1). The mean INR at recruitment was morphisms are necessary. Hence the present study was 2.20 Ϯ 0.67 (SD) (range 1.3–3.7). The mean total warfarin undertaken to assess the correlation between plasma total concentration was 3.01 Ϯ 2.48 (SD) mgml-1. The mean warfarin concentration,plasma 7-hydroxywarfarin concen- 7-hydroxy warfarin concentration was 0.20 Ϯ 0.13 (SD) tration and INR and the weekly dose of warfarin in patients mgml-1. on long-term anticoagulation. There was an extremely poor correlation between the plasma total warfarin : plasma 7-hydroxywarfarin ratio and the weekly dose of warfarin (y = 26.67e0.01x, r2 = 0.02).There Methods was a better correlation between INR : plasma total war- farin concentration and the weekly dose of warfarin Twenty-five patients on long-term warfarin therapy were (y = 46.73e-0.30x, r2 = 0.65) (Figure 1). There was a good cor- studied as per a protocol approved by the Institutional relation between INR : plasma 7-hydroxywarfarin concen- Ethics Committee, after obtaining written informed tration and the weekly dose of warfarin (y = 156.52x-0.63, consent. At screening, two INR measurements 15 days r2 = 0.74) (Figure 2). apart were done. If these were within the therapeutic The concomitant drugs taken by patients during the range without any change in the dose, then the patient study were furosemide (6), diltiazem (3), digoxin (3), KCl (3), was eligible for recruitment to the study. As per the treat- aspirin (2),salbutamol (1),enalapril (1),pentoxyphylline (1), ment protocol followed in the hospital,the target range for vitamin B complex (1), amlodipine (1), phenytoin (1), ben- INR was between 2 and 3 for all indications except for zathine penicillin (1), folic acid (1), spironolactone (1) and patients with prosthetic mitral valves where the range was chlorpromazine (1). In the patient receiving phenytoin, the 2.5–3.5.Venous blood (7 ml) was collected from all patients 12 h after the last dose of warfarin.This sample was used to perform a third INR as well as estimate the concentration INR/W v/s weekly dose of warfarin (N = 25) of total warfarin and 7-hydroxywarfarin by high perfor- 80 mance liquid chromatography (HPLC) using a C-18 70 column.Briefly,isopropanol with phosphate buffer was the 60 –0.30x mobile phase, flow rate was 1 ml min-1, pressure range up 50 y = 46.73e r2 = 0.65 to 5000 psi, and wavelength (l) of the UV lamp was as 40 308 nm at 30°C. The standard concentrations for the drug 30 and metabolite were 0.05,0.1,0.5,1.0,2.5 and 5 mgml-1.The 20 assay was linear in the range of 0.05–5.0 mgml-1.The inter- 10 day coefficient of variation was between 8.75% and 0 12.85%. The intraday coefficient of variation was between (mg) warfarin of dose Weekly 01234567 4.23% and 7.14%. Carbamazepine was used as an internal INR/W standard. PT-INR (prothrombin time-International Normal- ized Ratio) was determined using the Liquiplastin reagent Figure 1 obtained from Tulip Diagnostics (P) Ltd, Goa, India. Equa- INR : plasma total warfarin concentration vs. weekly dose of warfarin tions were derived with the weekly warfarin dose as (n = 25). INR = International Normalized Ratio; W = Plasma warfarin con- the dependent variable and plasma total warfarin con- centration (mgml-1) 788 / 65:5 / Br J Clin Pharmacol Short report INR/M v/s weekly dose of warfarin (N = 25) dynamic index of warfarin and found that the warfarin 80 dose correlated well with the INR : plasma total warfarin -0.30x 2 70 ratio (y = 46.73e , r = 0.65). –0.63 60 y = 156.52x The dose of warfarin required to achieve adequate anti- r2 = 0.74 50 coagulation would be lower in patients with a higher 40 metabolic ratio as well as those with a higher INR : plasma 30 total warfarin concentration ratio. Thus both INR : plasma 20 total warfarin concentration ratio and the metabolic ratio 10 would have an inverse relationship with the dose. To sim- 0 plify things, we combined the pharmacodynamic index Weekly dose of warfarin (mg) warfarin of dose Weekly 0 102030405060708090100 and the metabolic ratio: INR/M Equation 1 Warfarin dose=× K11( INR : plasma total warfarin Figure 2 concentration) or INR : plasma total 7-hydroxywarfarin concentration vs.