ABSTRACT
Editor’s Note .................................................................................................................................. 98 4.1 Introduction ..........................................................................................................................99 4.2 Chemical Neurotransmission .......................................................................................... 100 4.3 Sites Where Drugs Act ...................................................................................................... 103 4.4 Acetylcholine ...................................................................................................................... 103
4.4.1 Synthesis, Storage, Release, and Inactivation of Acetylcholine ....................... 105 4.4.2 Acetylcholine Receptors........................................................................................ 107
4.4.2.1 Nicotinic Receptors ................................................................................. 108 4.4.2.2 Muscarinic Receptors ............................................................................. 108
4.4.3 Clinically Useful Drugs That Alter Cholinergic Neurotransmission ............ 109 4.4.3.1 Facilitators of Cholinergic Neurotransmission .................................. 109 4.4.3.2 Inhibitors of Cholinergic Neurotransmission .................................... 110
4.4.4 Cholinergic Drugs in the TBI Patient .................................................................. 111 4.5 Norepinephrine .................................................................................................................. 112
4.5.1 Synthesis, Storage, Release, and Inactivation of Norepinephrine .................. 113 4.5.2 Norepinephrine Receptors ................................................................................... 116 4.5.3 Clinically Useful Drugs That Alter Noradrenergic Neurotransmission ....... 117
4.5.3.1 Facilitators of Noradrenergic Neurotransmission ............................. 117 4.5.3.2 Inhibitors of Noradrenergic Neurotransmission ............................... 120
4.5.4 Noradrenergic Drugs in the TBI Patient ............................................................. 121 4.6 Dopamine............................................................................................................................ 121
4.6.1 Synthesis, Storage, Release, and Inactivation of Dopamine ............................ 121 4.6.2 Dopamine Receptors ............................................................................................. 123 4.6.3 Clinically Useful Drugs That Alter Dopamine Neurotransmission .............. 124
4.6.3.1 Facilitators of Dopaminergic Neurotransmission .............................. 124 4.6.3.2 Inhibitors of Dopaminergic Neurotransmission ................................ 125
4.6.4 Dopaminergic Drugs in the TBI Patient ............................................................. 126 4.7 5-Hydroxytryptamine (Serotonin) .................................................................................. 126
4.7.1 Synthesis, Storage, Release, and Inactivation of Serotonin .............................. 127 4.7.2 Serotonin Receptors ............................................................................................... 129 4.7.3 Clinically Useful Drugs That Alter Serotonergic Neurotransmission .......... 130
4.7.3.1 Facilitators of Serotonergic Neurotransmission ................................. 130 4.7.3.2 Inhibitors of Serotonergic Neurotransmission ................................... 131
4.7.4 Serotonergic Drugs in the TBI Patient ................................................................ 131
Pharmacologic treatment of traumatic brain injury (TBI) is complex and still in its infancy as a fi eld of clinical investigation. Patients with TBI have a wide variety of central nervous system (CNS) problems, as well as numerous peripheral disorders (e.g., hypertension, reduced bowel function) that can be addressed pharmacologically. One of the major diffi culties in identifying useful medications for TBI patients is the diversity of brain injury encountered in this population. The non-CNS medical problems in TBI patients often require the use of drugs to control hypertension or to increase bowel function, and drugs that affect the autonomic nervous system are commonly used for such disorders. Although this chapter focuses on the medications that are used to alter neurologic or behavioral functions (i.e., those that act on the CNS), neurotransmission in the autonomic nervous system and the drugs that modify it are also described.
