If streptokinase (SK) or anistreplase (APSAC) is used, heparin should be given only in those patients who are at high risk for systemic emboli (. large anterior MI, atrial fibrillation, previous embolus, or known LV thrombus) (See standard dosage). Heparin should not be given <= 4 hours after fibrinolytic therapy and should be given when the aPTT is < 70 (goal aPTT 50—70 seconds). After 48 hours, consideration may be given to subcutaneous heparin administration (initial dose about 17,500 Units every 12 hours to maintain aPTT —2 times control), LMWH, or oral anticoagulants. If the patient has no risk factors and SK or APSAC is the thrombolytic that was used, therapeutic heparin is not recommended.
Norgestimate, also known as 17α-ethynyl-18-methyl-19-nortestosterone 3-oxime 17β-acetate or as 17α-ethynyl-18-methylestr-4-en-17β-ol-3-one 3-oxime 17β-acetate , is a synthetic estrane steroid and a derivative of testosterone .   It is more specifically a derivative of norethisterone (17α-ethynyl-19-nortestosterone) and is a member of the gonane (18-methylestrane) subgroup of the 19-nortestosterone family of progestins.  Norgestimate is the C3 oxime and C17β acetate ester of levonorgestrel and is also known as levonorgestrel acetate oxime .  A related compound is norethisterone acetate oxime (norethisterone-3-oxime 17β-acetate).