Strictly for the sake of fixing constricted, opiated pupils and not HR: Benzos either balance the pupils and make me look sober or dilate them somewhat, a nice dosage of antihistamines/anticholinergics (my preference being the sedative H1 antagonists i.e. hydroxyzine (best anxiolytic antihistamine, hands down), DPH, chlorphenamine (greatly sedative potentiator in Tussionex with AD and anxiolytic properties), orphenadrine and doxylamine succinate; haven't had the honor of trying the notoriously perfect antihistamine potentiator cyclizine; of which I'd give my left testicle to score some Diconal or at least try it JUST ONCE! lol, stimulants and amphetamines help regulate the pupils, but don't compliment opioids very well unless were talking about cocaine and heroin, maybe IV MPH or EPH could be included, d-amp isn't hateful with opi's because of how smooth it is, I've heard the right dose of methamphetamine can be a good cocktail; probably why some of my friends have convinced me I need to try a "Spaceball"= heroin + meth IV pretty much subsituting the classic cocaine + heroin/morphine speedball with crank. DXM is an obvious one. Call me strange, but I enjoy psychedelics (LSD! Psilocybin, 4-AcO-DMT) and empathogenics (ie MDA, MDMA, 6-APB) with opioids, particularly very potent opi's like IV heroin, oxymorphone, IV hydromorphone, fentanyl and such.
I can't recall if Ketamine or MXE dilates the pupils? but anyways I love dissociatives with my opioids.