Contemporary playwrights seem forever bent on proving Tolstoy’s line that “all families are unhappy in their own way.” The latest example is Nicky Silvers, who has mined such territory to fruitful comic effect in plays like Raised in Captivity, The Food Chain and others. Unfortunately, The Lyons, his latest effort, feels all too redolent of the sort of untapped anger and shame that would have been better explored in therapy.

The characters in this dark comedy directed by Mark Brokaw are all troubled or repellant. Ben (Dick Latessa), the patriarch of the Lyons family, is dying of cancer, but that doesn’t stop him from spewing obscene tirades at everyone around him. His long-suffering wife Rita (Linda Lavin) mainly sits by his bed flipping the pages of a magazine in-between providing acidly sarcastic comments. Daughter Lisa (Kate Jennings) is a divorced alcoholic, and gay son Curtis (Michael Esper) clearly has psychological issues.

The play’s first act, set in Ben’s hospital room, is cohesive enough, with the family members basically insulting each other with impunity. The playwright hasn’t lost his ability to craft sharp one-liners, which are delivered by old pros Latessa and Lavin with comic perfection. But the humor is forced, with a heavy reliance on would-be shocking profanity to garner cheap laughs.

The play goes completely off the rails in the second act, especially in a lengthy scene depicting an encounter between Curtis and a hunky real estate broker (Gregory Wooddell) that takes a shocking and violent turn. Curtis then winds up in the hospital, being attended to by the same nurse (Brenda Pressley, making the most of her small role) that handled his late father.

To many theater insiders’ surprise, Lavin took this role rather than transfer to Broadway in the acclaimed productions of Other Desert Cities or Follies. It’s easy to see why the actress was attracted to her role here—it’s a deliciously colorful one, and she basically runs away with the evening. But compared to those works, The Lyons is a trivial, shallow enterprise that only exploits her considerable talents.   

Vineyard Theatre, 108 E. 15th St. 212-353-0303. www.vineyardtheatre.org.