Subsumed under this title is a diverse group of disorders of
the nervous system that result from drugs and other injurious or
poisonous substances. The neurologist must be concerned with the myriad
of chemical agents that have no therapeutic utility but may adversely
affect the nervous system; they abound in the environment as household
products, insecticides, industrial solvents and other poisons, as
well as those substances that may have therapeutic value but are
used for their psychotropic effects, or are conventional medications
with known toxic effects including those that are accidentally ingested.
Also included among neurotoxins are those generated by bacteria
and other infectious agents, as well as several found in nature,
such as marine toxins and agents made by living organisms.
It would hardly be possible within the confines of this chapter
to discuss the innumerable drugs and toxins that affect the nervous
system. The interested reader is referred to a number of comprehensive
monographs and references listed at the end of this chapter. In
addition, a current handbook of pharmacology and toxicology should
be part of the library of every physician.
The scope of this chapter is also limited because the therapeutic
and adverse effects of many drugs are considered elsewhere in this
volume in relation to particular symptoms and diseases. Thus, the toxic
effects of ethyl, methyl, amyl, and isopropyl alcohol, as well as
ethylene and diethylene glycol, are discussed in Chap. 42. The adverse effects of antibiotics on cochlear and vestibular
function and on neuromuscular transmission are discussed in Chaps. 15 and 53, respectively.
Many of the undesirable side effects of the common drugs used in
the treatment of extrapyramidal motor symptoms, pain, headache,
seizure and sleep disorders, psychiatric illnesses and so forth
are also considered in the chapters dealing with each of these disorders
and in the chapters that cover psychiatric diseases. Cyanide and
carbon monoxide poisoning are discussed in relation to anoxic encephalopathy
(Chap. 40). A number of therapeutic agents
that damage the peripheral nerves (e.g., cisplatin, disulfiram, vincristine,
dapsone) are mentioned in this chapter but are discussed further
in Chap. 46, and those that affect muscle
are discussed further in Chap. 51.
The presentation of this subject should be introduced by some
general remarks on the action of drugs on the nervous system. The
references at the end of the chapter are listed in relation to each of
The general principles guiding the action of drugs
on the nervous system
Opiates and synthetic analgesics
Plant poisons, venoms, bites, and stings
Antineoplastic and immunosuppressive agents
The rational use of any drug requires knowledge of the best route
of administration, the drug’s absorption characteristics,
its distribution in the nervous system and other organs and its
biotransformations and excretion (pharmacokinetics...