Rob Reiner’s junkie son Nick failed to appear in LA court Tuesday to face charges that he slit the throats of his famed director dad and mom — with his lawyer saying he has yet to be “medically cleared.’’ Nick’s lawyer Alan Jackson told reporters outside the courthouse that his client’s first appearance in court could be as early as Wednesday, although that will be decided on a “day-to-day” basis. “Every inmate has to be medically cleared before they can be transported to court,” the high-profile lawyer said. “He has not been medically cleared, it’s just a procedural issue.” The ne’er-do-well nepo baby is accused of killing Rob, 78, and his 68-year-old wife, Michele, inside their Brentwood home sometime between Saturday night and Sunday afternoon.