Does piracetam boost excitotoxicity risk?

I cannot find any evidence that piracetam or other racetams exacerbate excitotoxicity at either the NMDA or AMPA receptor sites. In fact, there is evidence that racetams not only increase the influx of calcium and potassium though the various ion channels to enhance transmission, but also close the channel to protect from too high of concentrations as well.

http://www.ncbi.nlm.nih.gov/pubmed/9195198

The results suggest that piracetam and GVS-111 suppression of voltage-activated calcium and potassium currents of the neuronal membrane may regulate (both up and down) Ca2+ influx into neurons.

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http://ebm.rsmjournals.com/content/early/2012/10/05/ebm.2012.012128

We found that piracetam inhibited native CaV2.2 channels in superior cervical ganglion neurons in a dose-dependent manner

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http://www.sciencedirect.com/science/article/pii/S1059131197800222

This one found that piracetam protected from a known calcium and sodium channel convulsant.

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https://asm.confex.com/ipa/2003_Geneva/techprogram/paper_2223.htm

Our results allow to suggest that a desirable profile of action of nootropics should include a selective suppression of slow-inactivatng potassium currents without affecting (or with augmentation of) the fast-inactivating A-current.

So I cannot find any evidence of any racetam exacerbating excitotoxitiy at either the AMPA or NMDA sites. However, there are studies showing that they modulate both the influx and blockage of Ca2+ and K+ through their respective ion channels. They also increase membrane fluidity, which provides other neuroprotective benefits aside from their effects at the ion channels. All evidence points to them being perfectly safe and neuroprotective.