Levonorgestrel 0.75 mg is taken as 2 doses 12 hrs apa or 1.5 mg of levonorgestrel can be taken as a single dose only. Levonorgestrel (LNG): Prostinar tablet contains 0.75 mg LNG. One tablet should be taken within 72 hrs of unprotected intercourse and another 12hrs later. Alternately, two tablets can be taken as a single dose. The failure rate 1.1%. The tablets can be offered upto 120 hrs but its efficacy decreases with the longer coital-drug interval. LNG prevents ovulation and causes desynchronization of endomerium through its receptors (luteal phase deficiency). The period may come earlier or delayed. Side effects are those of progesterone. The hormone is not teratogenic in case of preganancy does occur but risk of ectopic pregnancy remains. Advantages: It has no oestrogen and its associated side effects. It can be offered to hypeensive, cardiac and diabetic woman It can be offered to a lactating woman It can be given as late as 120 hr after the unprotected intercourse Single-dose therapy is an advantage Contraindicated in liver disease, contains lactate, so allergy to galactose. The drug is also contraindicated in a woman with the history of thrombophlebitis and migraine. Ref: Shaw&;s textbook of Gynaecology 17th edition Pgno: 270