One of the problems of the insane war on drugs is that street drugs are produced to shoddy standards.
This results in:

1. Known drugs being cut with toxic compounds and produced unhygienically.
2. Incorrect dosages with either low or absent doses of the actual agent which can cause users to overestimate their usage and overdose when they get true doses (common with heroin and other opiates). They can also easily overdose on other secondary agents or adjuvants used to bulk up or enhance the effect of the primary agent.
3. Substitution of known drugs with novel compounds which have more dangerous effects or almost as bad their effects are unknown - which presents a major headache for physicians when these people turn up at hospitals.
4. Drugs being taken in unhygienic or inappropriate ways. Such as for example certain oral preparations being taken IV which can result in thrombo-embolic events including PE, stroke and ultimately death.

It sounds like Krokodil combines several of these issues to create a nightmare substitute which is significantly more harmful than heroin itself.

I made a lot of these points in my old post about drugs. I hope that the tide is now turning in relation to drug policy with the slow legalisation of marijhuana.

It is absolute hypocrisy that alcohol and tobacco which are amongst the most harmful and addictive of drugs are legal and get special dispensation.

Let's hope common sense eventually prevails. People will always take drugs. The money wasted on the false war and criminalising people is better spent treating addiction.