Hmm.
Shake'n'bake is a revolting, really crude as fuck way of doing it, and for the cook, dangerous as hell. Its ghetto stuff, as likely as not to go up in a cook's face.
Its a variation on the Birch type reductions, using lithium and ammonia, and I did read a thread here recently where somebody was saying that their opioid (oxy, IIRC) was having no effect whilst they were on lithium carbonate for bipolar. I wonder, if there were traces (or more, given the crude, ghetto nature of shake and bake, and the really low quality, low skill product/manufacture of the stuff)
So perhaps they didn't wash out the Li salts, or not all of them (hell, wouldn't put it past shake and bake 'cooks' to leave it in to add weight, even. Sketchy shit, that, and/or unreduced pseudoephedrine/ephedrine present could cause such nasty effects. In opioid WD, there is a LOT of hyperactivation of the sympathetic nervous system, and catecholamine (noradrenaline, adrenaline etc.) release, and pseudo/ephedrine are, if not reduced, noradrenergic releasers, that IMO could cause just that sort of unpleasantness.
Stick to real meth mate, don't use shake and bake, its bad stuff, badly made, and dirty. If you are going to use meth, make it ice, or at least clean powder. If making it yourself, abandon the shake and bake, its a damn dangerous procedure. It is possible to use a stream of anhydrous GASEOUS ammonia, rather than cryogenic liquefied NH3, if this is run through a drying tube, before bubbling into anhydrous diethyl ether, under a flow of argon to keep unwanted reactions from occurring. The formation of the solvated electron blue does take place when this is done at room temperature, just needs the quantity of lithium or sodium pre-calculating for the relevant quantity of PSE/ephedrine, and before adding the feedstock and proton donor, gassing an ethereal suspension of Li or Na cut up really finely, with a constant stream of NH3. It takes several hours for the solvated electron 'soup' to form, and get dark and concentrated, and of course the exhaust ammonia needs venting through first a suck-back trap, then a tank full of bog or kitchen roll, moistened with something like concentrated phosphoric acid, or with HCl to trap any escaping NH3 as a nonvolatile, insoluble salt before it can exit to the environment and set up a stink. Works though, and despite the need for a lot of NH3 gas, this is easily prepared from ammonium sulfate or phosphate fertilizer and NaOH, dripping H2O onto it slowly via a sep. funnel or pressure-equalizing addition funnel more ideally, then the gas passed through a drying tube containing calcium oxide (quicklime), to dry the NH3 gas, before it is bubbled as a constant stream into the suspension of alkali metal in dry diethyl ether.
Just be sure to use argon for the inert gas coverage, rather than nitrogen, if using Li metal rather than sodium to prepare the solvated electrons, because while nitrogen is usually unreactive towards most things, it isn't inert to lithium, which forms an extremely strongly basic nitride, which may have explosive properties. Sodium, potassium though, do not form such a nitride with atmospheric pressure and room-temperature Na or K, just lithium. So argon, whilst a little more expensive, is by far the better to use.
A helium atmosphere could also be used instead, but helium is inferior too for this purpose IMO, because of its very low density, helium floats in air, and would float up out of the reaction flask, whereas argon is pretty heavy, dense stuff and helps form a protective pad over the surface of a reaction conducted under inert gas atmospheres, and it is a lot more willing to stay there , blanketing the reaction rather than trying to float out and bugger off.
And btw, the ethereal reaction described here for harm reduction purposes is NOT conducted under pressure. The dry ether is loaded into the flask, the flask headspace purged with argon by bubbling dry argon through the ether, before adding th pe Li, cut up into fine little tiny pieces to maximize the surface area of the alkali metal in contact with the incoming ammonia stream. The NH3 is generated in a second flask, with an ammonium salt, and NaOH, using the pressure-equalizing addition funnel to drip water into the NaOH/ammonium salt mixture to provide the stream of gas to be passed through a drying tube of quicklime and into the reaction to create the solvated electrons needed for the reduction.