Global Journal of Science Frontier Research, G: Bio-Tech & Genetics, Volume 22 Issue 2

management devices give accurate international normalized ratio (INR) results comparable with average results obtained from laboratories (7). f) Alternative anticoagulants In some countries, other coumarins are used instead of warfarin, such as phenprocoumon. These drugs have a shorter (acenocoumarol) or longer (phenprocoumon) half-life, and are not wholly interchanged with warfarin. Several types of these drugs can offer the efficacy of warfarin without needing monitoring, such as dabigatran, apixaban, edoxaban, and rivaroxaban; they have been approved rather than classical warfarin. Complementing these drugs are available for dabigratan, apixabanan drivaroxaban which is suggested for edoxaban, but its use is considered off label because of limited evidence. A reversal agent for dabigratan, apixaban, edoxaban and rivaroxaban is in development (8). Figure 7: Chemical structure of coumarin molecule. Its molecular weight of 146.1427 g/mol, a boiling point equals 301.7 degrees Celsius, with a density of 935 kg/m 3 and a melting point of 71 degrees Celsius. g) Contraindications of warfarin during pregnancy Warfarin is contraindicated during pregnancy, as it passes through the placental barrier and can cause severe bleeding to the fetus; warfarin use in pregnancy is usually associated with spontaneous abortion, stillbirth, neonatal death, and preterm birth. Coumarins such as warfarin are also teratogens; they cause congenital disabilities; the incidence of congenital disability among fetuses has a possibility of 5%, although this possibility can reach 30% in some studies depending on when exposure occurs during pregnancy, two distinct abnormalities can appear. When warfarin, or any 4-hydroxycoumarin derivative, is given during the first trimester, particularly between the 6 th and 9 th week of pregnancy, a constellation of congenital disabilities is known as fetal warfarin syndrome, warfarin embryopathy can occur. Fetal warfarin syndrome is mainly characterized by skeletal abnormalities, which include nasal hypoplasia, a depressed or narrowed nasal bridge, scoliosis and calcifcation in the vertebral column, femur and heel bone which is shown in the X-rays. Limb abnormalities such as brachydactyly, usually short fingers and toes or underdeveloped extremities can also occur (9).Standard non-skeletal features of fetal warfarin syndrome include low birth weight and disabilities. h) Warfarin adverse effects 1. bleeding It is the most common side effect of warfarin. The risk of bleeding due to warfarin is low but definite; approximately the annual rate is 1% to 3%. And any benefits that need to outweigh the need to be considered. All types of bleeding are possible, but the most severe is spinal cord and brain bleeding, intracerebral hemorrhage, or hemorrhagic stroke (10). The risk of bleeding can be increased if the international normalized ratio is out of range due to accidental overdose or drug interactions (11). This risk is highly increased if the international normalized ratio exceeds 4.5 (12). Several risk scores appear with treatment using warfarin. A commonly used score is HAS-BLED includes known predictors of warfarin related bleeding, which are: H=uncontrolled high blood pressure A=abnormal kidney function S=previous stroke B=known bleeding condition L=previous label international normalized ration while taking warfarin E=elderly by defined age of 65 years or more D=drug associated with bleeding or alcohol misuse While their use is recommended in medical practice guidelines (13), they are good predictors of bleeding risk but are not efficient in detecting or even predict the risk of hemorrhagic stroke (14). Bleeding risk may become highly possible with people on hemodialysis (15). Another score used to assess bleeding risk with patients on anticoagulants, specifically with warfarin or Coumadin, is the ATRIA score, which uses a weighted additive score of clinical findings to detect bleeding danger (16). The risk of bleeding is increased when warfarin is taken with antiplatelet like clopidogrel, aspirin, or non-steroidal anti- inflammatory drug (NSAIDs). i) Warfarin necrosis It is rare, but it is a hazardous complication resulting from treatment with warfarin, which occurs shortly after commencing treatment with warfarin with patients who have a protein C deficiency. Protein C is a natural anticoagulant that, as most coagulation factors which are inhibited because of warfarin, requires vitamin K-dependent carboxylation for its activity. Because warfarin decreases protein C synthesis faster than the other coagulation factors, paradoxically, it can increase levels of coagulation when treatment is first begun, so most patients are given heparin to combat this problem Modulation of Warfarin Sodium into Warfarin Potassium for Patients with Hypertension 1 Year 2022 5 © 2022 Global Journals Global Journal of Science Frontier Research Volume XXII Issue ersion I VII ( G )