This invention relates to compounds that are agonists of the muscarinic M1 receptor and/or M4 receptor and which are useful in the treatment of muscarinic M1/M4 receptor mediated diseases. Also provided are pharmaceutical compositions containing the compounds and the therapeutic uses of the compounds. Compounds include those according to formula (1a) or a salt thereof, wherein p, q, r, s, Q, R3 and R4 are as defined herein.