Hemodynamic Homeostasis · §16 · reduce SVR/volume pressor drive: rejected alone (RP4), not rejected paired with H1

Lever H3: unload the effector — paired-only, because alone it is the side-effect class

Lever H3 unloads the effector by reducing SVR/volume pressor drive, but alone it is the operating-point push the loop rejects back (RP4), which is the structural side-effect class. Paired with an H1 reference reset it is not rejected. H3 is therefore a paired-only lever, the analgesic L1 analogue with an integrator caveat [V].

Lever H3 is the analgesic L1 analogue — reduce the inward (pressor) drive at the effector. The genuine cross-package finding lives here: in the nociceptor gate L1 works alone because there is no integral controller, but the arterial-pressure loop HAS one, so the same lever applied alone is rejected back (RP4) and constitutes the side-effect class. H3 is therefore admissible only when paired with an H1 reference reset.

Unloading the effector is the operating-point push

Lever H3 reduces the effector drive — systemic vascular resistance and volume pressor tone. In isolation this is precisely the operating-point antagonist that RP4 shows the integral controller opposes back to the reset reference: its durable effect collapses to 0 mmHg and the reflex it summons (tachycardia, renin escape, fluid retention) is the structural side-effect class. So H3 alone is the very direction the comfort principle warns against.

The integrator caveat: the cross-package contrast

This axis carries the clearest cross-package finding. In the non-opioid analgesic whitepaper the L1 lever — reduce the inward depolarising current at the nociceptor — works as a standalone lever, because the nociceptor gate has no integral controller to reject a sustained shift. The arterial-pressure loop is different: the kidney is an integral controller, so the same “reduce the inward drive” lever applied at the operating point is rejected back. The lever frame is identical across the two packages; the presence of the integrator is the entire difference. That is why H3 is admissible only paired with an H1 reference reset — once the reference is lowered, the effector unload is no longer an operating-point error and is not rejected.

Grade and boundary

The pairing rule is graded [V]: it is read directly off the proven RP4 rejection plus the integrator contrast, with no new substrate mathematics. The per-axis vasodilator/diuretic pharmacology is cited biology [O]. Nothing here names a molecule or an exposure schedule, and the side-effect discussion is a structural reading of counter-regulation, not a tolerability result; §20 states the boundary.