A little Botox goes a long way in “Sex and the City,” but a little decent writing would have gone even further. A dumpy big-screen makeover of that much-adored small-screen delight, the movie was written and directed by Michael Patrick King, one of the guiding lights and bright wits of the original series, based on Candace Bushnell’s newspaper columns and subsequent book. Once again, Sarah Jessica Parker has stepped into the dizzyingly high heels of Carrie Bradshaw, that postmodern Lorelei Lee  a hardly working New York writer with a passion for men and Manolos  but this time she’s taken a terrible tumble.

Fans of the show were accustomed to Carrie’s falls, metaphoric and literal (as in her spectacularly horrible trip during her catwalk promenade); they were crucial to the show’s appeal, softening its hard, brittle edges. Then in her mid-30s, Carrie was one of New York’s most fearless of the zipless It Girls, able to leap tall men in a single bound without batting a single mascaraed eyelash, but as the show’s nifty opening credit sequence reminded you, episode after episode, she wasn’t above getting muck on her tutu. Her vulnerability  and that of her girlfriends  was the badly kept secret of the show, the glue holding together the froufrou, the lunches, those absolutely fabulous and ghastly clothes and all that muscly man bait.

The froufrou and the lunches are back, as are, kind of, Carrie’s three girlfriends, Miranda (Cynthia Nixon), Charlotte (Kristin Davis) and Samantha (Kim Cattrall), all tricked out with their customary accessories (men, children, handbags). Also back and in and out of Carrie’s bed is Mr. Big (Chris Noth), the longtime lover and habitual heartbreaker with whom she had (hallelujah) reunited during the show’s bitter and sweet finale four years ago. Written by Mr. King, that episode opened with Carrie wandering Paris in a funk and then stumbling into bliss by literally falling to the ground with Big. At once melancholic and defiantly hopeful, it was the kind of rueful happy ending that didn’t make you choke on your own tears.

Image From left, Kristin Davis, Kim Cattrall and Cynthia Nixon. Credit... Craig Blankenhorn/New Line Cinema

“Sex and the City” delivered the television goods for six seasons, no small thing in the pop culture annals. That should have been enough or at least plenty for all concerned, but Ms. Parker apparently felt compelled to go big screen, making good on a project that had started to come together in 2004, only to fall apart over money issues and Ms. Cattrall’s reluctance to climb aboard. I wish Ms. Parker had let that bee in her bonnet go silent, because the movie that she and Mr. King have come up with is the pits, a vulgar, shrill, deeply shallow  and, at 2 hours and 22 turgid minutes, overlong  addendum to a show that had, over the years, evolved and expanded in surprising ways.