Poisoning by, adverse effect of and underdosing of antiepileptic, sedative- hypnotic and antiparkinsonism drugs (T42)

Browse all the diagnosis codes used for poisoning by, adverse effect of and underdosing of antiepileptic, sedative- hypnotic and antiparkinsonism drugs (t42). For easy navigation, the diagnosis codes are sorted in alphabetical order and grouped by sections. Each section is clearly marked with its description, and the corresponding three-digit code range. This format makes it simple to browse diagnosis codes in this chapter or section and find what you're looking for. We've also added green checkmark icons to label billable codes, and red warning icons for non-billable ones. This makes it easy to identify which codes can be billed.

Clinical Information

AIDS Arteritis, Central Nervous System - Inflammation of ARTERIES in the CENTRAL NERVOUS SYSTEM that occurs in patients with ACQUIRED IMMUNODEFICIENCY SYNDROME or AIDS-RELATED OPPORTUNISTIC INFECTIONS.

Alprazolam - A triazolobenzodiazepine compound with antianxiety and sedative-hypnotic actions, that is efficacious in the treatment of PANIC DISORDERS, with or without AGORAPHOBIA, and in generalized ANXIETY DISORDERS. (From AMA Drug Evaluations Annual, 1994, p238)

Amantadine - An antiviral that is used in the prophylactic or symptomatic treatment of influenza A. It is also used as an antiparkinsonian agent, to treat extrapyramidal reactions, and for postherpetic neuralgia. The mechanisms of its effects in movement disorders are not well understood but probably reflect an increase in synthesis and release of dopamine, with perhaps some inhibition of dopamine uptake.

Baclofen - A GAMMA-AMINOBUTYRIC ACID derivative that is a specific agonist of GABA-B RECEPTORS. It is used in the treatment of MUSCLE SPASTICITY, especially that due to SPINAL CORD INJURIES. Its therapeutic effects result from actions at spinal and supraspinal sites, generally the reduction of excitatory transmission.

Barbital - A long-acting barbiturate that depresses most metabolic processes at high doses. It is used as a hypnotic and sedative and may induce dependence. Barbital is also used in veterinary practice for central nervous system depression.

Barbiturates - A class of chemicals derived from barbituric acid or thiobarbituric acid. Many of these are GABA MODULATORS used as HYPNOTICS AND SEDATIVES, as ANESTHETICS, or as ANTICONVULSANTS.

Benserazide - An inhibitor of DOPA DECARBOXYLASE that does not enter the central nervous system. It is often given with LEVODOPA in the treatment of parkinsonism to prevent the conversion of levodopa to dopamine in the periphery, thereby increasing the amount that reaches the central nervous system and reducing the required dose. It has no antiparkinson actions when given alone.

Benzodiazepines - A group of two-ring heterocyclic compounds consisting of a benzene ring fused to a diazepine ring.

Brain Diseases - Pathologic conditions affecting the BRAIN, which is composed of the intracranial components of the CENTRAL NERVOUS SYSTEM. This includes (but is not limited to) the CEREBRAL CORTEX; intracranial white matter; BASAL GANGLIA; THALAMUS; HYPOTHALAMUS; BRAIN STEM; and CEREBELLUM.

Brain Diseases, Metabolic - Acquired or inborn metabolic diseases that produce brain dysfunction or damage. These include primary (i.e., disorders intrinsic to the brain) and secondary (i.e., extracranial) metabolic conditions that adversely affect cerebral function.

Brain Diseases, Metabolic, Inborn - Brain disorders resulting from inborn metabolic errors, primarily from enzymatic defects which lead to substrate accumulation, product reduction, or increase in toxic metabolites through alternate pathways. The majority of these conditions are familial, however spontaneous mutation may also occur in utero.

Bromazepam - One of the BENZODIAZEPINES that is used in the treatment of ANXIETY DISORDERS.

Bromine - A halogen with the atomic symbol Br, atomic number 35, and atomic weight 79.904. It is a volatile reddish-brown liquid that gives off suffocating vapors, is corrosive to the skin, and may cause severe gastroenteritis if ingested.

Bromine Compounds - Inorganic compounds that contain bromine as an integral part of the molecule.

Bromine Radioisotopes - Unstable isotopes of bromine that decay or disintegrate emitting radiation. Br atoms with atomic weights 74-78, 80, and 82-90 are radioactive bromine isotopes.

Bromisovalum - A sedative and mild hypnotic with potentially toxic effects.

Bromocriptine - A semisynthetic ergotamine alkaloid that is a dopamine D2 agonist. It suppresses prolactin secretion.

Cabergoline - An ergoline derivative and dopamine D2-agonist that inhibits PROLACTIN secretion. It is used in the management of HYPERPROLACTINEMIA, and to suppress lactation following childbirth for medical reasons. Cabergoline is also used in the management of PARKINSON DISEASE.

Carbamazepine - A dibenzazepine that acts as a sodium channel blocker. It is used as an anticonvulsant for the treatment of grand mal and psychomotor or focal SEIZURES. It may also be used in the management of BIPOLAR DISORDER, and has analgesic properties.

Carisoprodol - A centrally acting skeletal muscle relaxant whose mechanism of action is not completely understood but may be related to its sedative actions. It is used as an adjunct in the symptomatic treatment of musculoskeletal conditions associated with painful muscle spasm. (From Martindale, The Extra Pharmacopoeia, 30th ed, p1202)

Central Nervous System - The main information-processing organs of the nervous system, consisting of the brain, spinal cord, and meninges.

Central Nervous System Agents - A class of drugs producing both physiological and psychological effects through a variety of mechanisms. They can be divided into specific agents, e.g., affecting an identifiable molecular mechanism unique to target cells bearing receptors for that agent, and nonspecific agents, those producing effects on different target cells and acting by diverse molecular mechanisms. Those with nonspecific mechanisms are generally further classed according to whether they produce behavioral depression or stimulation. Those with specific mechanisms are classed by locus of action or specific therapeutic use. (From Gilman AG, et al., Goodman and Gilman's The Pharmacological Basis of Therapeutics, 8th ed, p252)

Central Nervous System Bacterial Infections - Bacterial infections of the brain, spinal cord, and meninges, including infections involving the perimeningeal spaces.

Central Nervous System Cysts - Congenital or acquired cysts of the brain, spinal cord, or meninges which may remain stable in size or undergo progressive enlargement.

Central Nervous System Depressants - A very loosely defined group of drugs that tend to reduce the activity of the central nervous system. The major groups included here are ethyl alcohol, anesthetics, hypnotics and sedatives, narcotics, and tranquilizing agents (antipsychotics and antianxiety agents).

Central Nervous System Diseases - Diseases of any component of the brain (including the cerebral hemispheres, diencephalon, brain stem, and cerebellum) or the spinal cord.

Central Nervous System Fungal Infections - MYCOSES of the brain, spinal cord, and meninges which may result in ENCEPHALITIS; MENINGITIS, FUNGAL; MYELITIS; BRAIN ABSCESS; and EPIDURAL ABSCESS. Certain types of fungi may produce disease in immunologically normal hosts, while others are classified as opportunistic pathogens, causing illness primarily in immunocompromised individuals (e.g., ACQUIRED IMMUNODEFICIENCY SYNDROME).

Central Nervous System Helminthiasis - Infections of the BRAIN; SPINAL CORD; or MENINGES caused by HELMINTHS (parasitic worms).

Central Nervous System Infections - Pathogenic infections of the brain, spinal cord, and meninges. DNA VIRUS INFECTIONS; RNA VIRUS INFECTIONS; BACTERIAL INFECTIONS; MYCOPLASMA INFECTIONS; SPIROCHAETALES INFECTIONS; fungal infections; PROTOZOAN INFECTIONS; HELMINTHIASIS; and PRION DISEASES may involve the central nervous system as a primary or secondary process.

Central Nervous System Neoplasms - Benign and malignant neoplastic processes that arise from or secondarily involve the brain, spinal cord, or meninges.

Central Nervous System Parasitic Infections - Infections of the brain, spinal cord, and meninges caused by parasites.

Central Nervous System Protozoal Infections - Infections of the brain, spinal cord, or meninges by single celled organisms of the former subkingdom known as protozoa. The central nervous system may be the primary or secondary site of protozoal infection. These diseases may occur as OPPORTUNISTIC INFECTIONS or arise in immunocompetent hosts.

Central Nervous System Sensitization - An increased response to stimulation that is mediated by amplification of signaling in the CENTRAL NERVOUS SYSTEM (CNS).

Central Nervous System Stimulants - A loosely defined group of drugs that tend to increase behavioral alertness, agitation, or excitation. They work by a variety of mechanisms, but usually not by direct excitation of neurons. The many drugs that have such actions as side effects to their main therapeutic use are not included here.

Central Nervous System Vascular Malformations - Congenital, inherited, or acquired abnormalities involving ARTERIES; VEINS; or venous sinuses in the BRAIN; SPINAL CORD; and MENINGES.

Central Nervous System Venous Angioma - A vascular anomaly characterized by a radial or wedge-shaped arrangement of dilated VEINS draining into a larger vein in the brain, spinal cord, or the meninges. Veins in a venous angioma are surrounded by normal nervous tissue, unlike a CENTRAL NERVOUS SYSTEM CAVERNOUS HEMANGIOMA that lacks intervening nervous tissue. Drainage of venous angioma is fully integrated with the body's venous system, therefore, in most cases there is no clinical signs and rare bleeding.

Central Nervous System Viral Diseases - Viral infections of the brain, spinal cord, meninges, or perimeningeal spaces.

Cerebral Phaeohyphomycosis - CNS infections caused by neurotropic dematiaceous fungi that contain melanin in their cell walls. The infections often result in BRAIN ABSCESS; ENCEPHALITIS; and MENINGITIS in patients who are often immunocompetent. The common causative fungi include members Cladophialophora bantiana, Exophiala dermatitidis, Rhinocladiella mackenziei, and Ochroconis gallopavum. R. mackenziei infection is seen almost exclusively in patients from the MIDDLE EAST.

Chlordiazepoxide - An anxiolytic benzodiazepine derivative with anticonvulsant, sedative, and amnesic properties. It has also been used in the symptomatic treatment of alcohol withdrawal.

Chlormethiazole - A sedative and anticonvulsant often used in the treatment of alcohol withdrawal. Chlormethiazole has also been proposed as a neuroprotective agent. The mechanism of its therapeutic activity is not entirely clear, but it does potentiate GAMMA-AMINOBUTYRIC ACID receptors response and it may also affect glycine receptors.

Chlormezanone - A non-benzodiazepine that is used in the management of anxiety. It has been suggested for use in the treatment of muscle spasm.

Chlorphenesin - A centrally acting muscle relaxant. Its mode of action is unknown. (From Martindale, The Extra Pharmacopoeia, 30th ed, p1203)

Chlorzoxazone - A centrally acting central muscle relaxant with sedative properties. It is claimed to inhibit muscle spasm by exerting an effect primarily at the level of the spinal cord and subcortical areas of the brain. (From Martindale, The Extra Pharmacopoea, 30th ed, p1202)

Clobazam - A benzodiazepine derivative that is a long-acting GABA-A RECEPTOR agonist. It is used as an antiepileptic in the treatment of SEIZURES, including seizures associated with LENNOX-GASTAUT SYNDROME. It is also used as an anxiolytic, for the short-term treatment of acute ANXIETY.

Clonazepam - An anticonvulsant used for several types of seizures, including myotonic or atonic seizures, photosensitive epilepsy, and absence seizures, although tolerance may develop. It is seldom effective in generalized tonic-clonic or partial seizures. The mechanism of action appears to involve the enhancement of GAMMA-AMINOBUTYRIC ACID receptor responses.

Clozapine - A tricylic dibenzodiazepine, classified as an atypical antipsychotic agent. It binds several types of central nervous system receptors, and displays a unique pharmacological profile. Clozapine is a serotonin antagonist, with strong binding to 5-HT 2A/2C receptor subtype. It also displays strong affinity to several dopaminergic receptors, but shows only weak antagonism at the dopamine D2 receptor, a receptor commonly thought to modulate neuroleptic activity. Agranulocytosis is a major adverse effect associated with administration of this agent.

Dantrolene - Skeletal muscle relaxant that acts by interfering with excitation-contraction coupling in the muscle fiber. It is used in spasticity and other neuromuscular abnormalities. Although the mechanism of action is probably not central, dantrolene is usually grouped with the central muscle relaxants.

Diazepam - A benzodiazepine with anticonvulsant, anxiolytic, sedative, muscle relaxant, and amnesic properties and a long duration of action. Its actions are mediated by enhancement of GAMMA-AMINOBUTYRIC ACID activity.

Diazepam Binding Inhibitor - An 86-amino acid polypeptide, found in central and peripheral tissues, that displaces diazepam from the benzodiazepine recognition site on the gamma-aminobutyric acid receptor (RECEPTORS, GABA). It also binds medium- and long-chain acyl-CoA esters and serves as an acyl-CoA transporter. This peptide regulates lipid metabolism.

Dipsacales - An order of dicotyledonous flowering plants which includes six families. It is best known for its ornamental plants such as LONICERA (honeysuckle), VIBURNUM (arrowwood and guelder rose), and SCABIOSA (scabious, or pincushion flower).

Estazolam - A benzodiazepine with anticonvulsant, hypnotic, and muscle relaxant properties. It has been shown in some cases to be more potent than DIAZEPAM or NITRAZEPAM.

Ethchlorvynol - A sedative and hypnotic that has been used in the short-term management of INSOMNIA. Its use has been superseded by other drugs.

Ethosuximide - An anticonvulsant especially useful in the treatment of absence seizures unaccompanied by other types of seizures.

Flunitrazepam - A benzodiazepine with pharmacologic actions similar to those of DIAZEPAM that can cause ANTEROGRADE AMNESIA. Some reports indicate that it is used as a date rape drug and suggest that it may precipitate violent behavior. The United States Government has banned the importation of this drug.

Flurazepam - A benzodiazepine derivative used mainly as a hypnotic.

Glutethimide - A hypnotic and sedative. Its use has been largely superseded by other drugs.

Hemangioma, Cavernous, Central Nervous System - A vascular anomaly composed of a collection of large, thin walled tortuous VEINS that can occur in any part of the central nervous system but lack intervening nervous tissue. Familial occurrence is common and has been associated with a number of genes mapped to 7q, 7p and 3q. Clinical features include SEIZURES; HEADACHE; STROKE; and progressive neurological deficit.

Hereditary Central Nervous System Demyelinating Diseases - Inherited conditions characterized by a loss of MYELIN in the central nervous system.

Hexobarbital - A barbiturate that is effective as a hypnotic and sedative.

Levodopa - The naturally occurring form of DIHYDROXYPHENYLALANINE and the immediate precursor of DOPAMINE. Unlike dopamine itself, it can be taken orally and crosses the blood-brain barrier. It is rapidly taken up by dopaminergic neurons and converted to DOPAMINE. It is used for the treatment of PARKINSONIAN DISORDERS and is usually given with agents that inhibit its conversion to dopamine outside of the central nervous system.

Lisuride - An ergot derivative that acts as an agonist at dopamine D2 receptors (DOPAMINE AGONISTS). It may also act as an antagonist at dopamine D1 receptors, and as an agonist at some serotonin receptors (SEROTONIN RECEPTOR AGONISTS).

Lorazepam - A benzodiazepine used as an anti-anxiety agent with few side effects. It also has hypnotic, anticonvulsant, and considerable sedative properties and has been proposed as a preanesthetic agent.

Lupus Vasculitis, Central Nervous System - Central nervous system vasculitis that is associated with SYSTEMIC LUPUS ERYTHEMATOSUS. Clinical manifestations may include DEMENTIA; SEIZURES; CRANIAL NERVE DISEASES; HEMIPARESIS; BLINDNESS; DYSPHASIA; and other neurological disorders.

Lyme Neuroborreliosis - Nervous system infections caused by tick-borne spirochetes of the BORRELIA BURGDORFERI GROUP. The disease may affect elements of the central or peripheral nervous system in isolation or in combination. Common clinical manifestations include a lymphocytic meningitis, cranial neuropathy (most often a facial neuropathy), POLYRADICULOPATHY, and a mild loss of memory and other cognitive functions. Less often more extensive inflammation involving the central nervous system (encephalomyelitis) may occur. In the peripheral nervous system, B. burgdorferi infection is associated with mononeuritis multiplex and polyradiculoneuritis. (From J Neurol Sci 1998 Jan 8;153(2):182-91)

Medazepam - A benzodiazepine derivative used in the treatment of anxiety. It has sedative, muscle relaxant, and anticonvulsant properties. One of its metabolites is DIAZEPAM and one of its excretion products is OXAZEPAM.

Mephenesin - A centrally acting muscle relaxant with a short duration of action.

Mephenytoin - An anticonvulsant effective in tonic-clonic epilepsy (EPILEPSY, TONIC-CLONIC). It may cause blood dyscrasias.

Mephobarbital - A barbiturate that is metabolized to PHENOBARBITAL. It has been used for similar purposes, especially in EPILEPSY, but there is no evidence mephobarbital offers any advantage over PHENOBARBITAL.

Metergoline - A dopamine agonist and serotonin antagonist. It has been used similarly to BROMOCRIPTINE as a dopamine agonist and also for MIGRAINE DISORDERS therapy.

Methocarbamol - A centrally acting muscle relaxant whose mode of action has not been established. It is used as an adjunct in the symptomatic treatment of musculoskeletal conditions associated with painful muscle spasm. (From Martindale, The Extra Pharmacopoeia, 30th ed, p1206)

Midazolam - A short-acting hypnotic-sedative drug with anxiolytic and amnestic properties. It is used in dentistry, cardiac surgery, endoscopic procedures, as preanesthetic medication, and as an adjunct to local anesthesia. The short duration and cardiorespiratory stability makes it useful in poor-risk, elderly, and cardiac patients. It is water-soluble at pH less than 4 and lipid-soluble at physiological pH.

Neurocysticercosis - Infection of the brain, spinal cord, or perimeningeal structures with the larval forms of the genus TAENIA (primarily T. solium in humans). Lesions formed by the organism are referred to as cysticerci. The infection may be subacute or chronic, and the severity of symptoms depends on the severity of the host immune response and the location and number of lesions. SEIZURES represent the most common clinical manifestation although focal neurologic deficits may occur. (From Joynt, Clinical Neurology, 1998, Ch27, pp46-50)

Neuroschistosomiasis - SCHISTOSOMIASIS of the brain, spinal cord, or meninges caused by infections with trematodes of the genus SCHISTOSOMA (primarily SCHISTOSOMA JAPONICUM; SCHISTOSOMA MANSONI; and SCHISTOSOMA HAEMATOBIUM in humans). S. japonicum infections of the nervous system may cause an acute meningoencephalitis or a chronic encephalopathy. S. mansoni and S. haematobium nervous system infections are associated with acute transverse myelitis involving the lower portions of the spinal cord. (From Joynt, Clinical Neurology, 1998, Ch27, pp61-2)

Neurosyphilis - Infections of the central nervous system caused by TREPONEMA PALLIDUM which present with a variety of clinical syndromes. The initial phase of infection usually causes a mild or asymptomatic meningeal reaction. The meningovascular form may present acutely as BRAIN INFARCTION. The infection may also remain subclinical for several years. Late syndromes include general paresis; TABES DORSALIS; meningeal syphilis; syphilitic OPTIC ATROPHY; and spinal syphilis. General paresis is characterized by progressive DEMENTIA; DYSARTHRIA; TREMOR; MYOCLONUS; SEIZURES; and Argyll-Robertson pupils. (Adams et al., Principles of Neurology, 6th ed, pp722-8)

Nitrazepam - A benzodiazepine derivative used as an anticonvulsant and hypnotic.

Nordazepam - An intermediate in the metabolism of DIAZEPAM to OXAZEPAM. It may have actions similar to those of diazepam.

Oxazepam - A benzodiazepine used in the treatment of anxiety, alcohol withdrawal, and insomnia.

Oxcarbazepine - A carbamazepine derivative that acts as a voltage-gated sodium channel blocker. It is used for the treatment of PARTIAL SEIZURES with or without secondary generalization. It is also an inducer of CYTOCHROME P-450 CYP3A4.

Paraldehyde - A hypnotic and sedative with anticonvulsant effects. However, because of the hazards associated with its administration, its tendency to react with plastic, and the risks associated with its deterioration, it has largely been superseded by other agents. It is still occasionally used to control status epilepticus resistant to conventional treatment. (From Martindale, The Extra Pharmacopoeia, 30th ed, p608-9)

Pentobarbital - A short-acting barbiturate that is effective as a sedative and hypnotic (but not as an anti-anxiety) agent and is usually given orally. It is prescribed more frequently for sleep induction than for sedation but, like similar agents, may lose its effectiveness by the second week of continued administration. (From AMA Drug Evaluations Annual, 1994, p236)

Pergolide - A long-acting dopamine agonist which has been used to treat PARKINSON DISEASE and HYPERPROLACTINEMIA but withdrawn from some markets due to potential for HEART VALVE DISEASES.

Phenobarbital - A barbituric acid derivative that acts as a nonselective central nervous system depressant. It potentiates GAMMA-AMINOBUTYRIC ACID action on GABA-A RECEPTORS, and modulates chloride currents through receptor channels. It also inhibits glutamate induced depolarizations.

Phenytoin - An anticonvulsant that is used to treat a wide variety of seizures. It is also an anti-arrhythmic and a muscle relaxant. The mechanism of therapeutic action is not clear, although several cellular actions have been described including effects on ion channels, active transport, and general membrane stabilization. The mechanism of its muscle relaxant effect appears to involve a reduction in the sensitivity of muscle spindles to stretch. Phenytoin has been proposed for several other therapeutic uses, but its use has been limited by its many adverse effects and interactions with other drugs.

Piribedil - A dopamine D2 agonist. It is used in the treatment of parkinson disease, particularly for alleviation of tremor. It has also been used for circulatory disorders and in other applications as a D2 agonist.

Prazepam - A benzodiazepine that is used in the treatment of ANXIETY DISORDERS.

Primidone - A barbiturate derivative that acts as a GABA modulator and anti-epileptic agent. It is partly metabolized to PHENOBARBITAL in the body and owes some of its actions to this metabolite.

Receptors, GABA-A - Cell surface proteins which bind GAMMA-AMINOBUTYRIC ACID and contain an integral membrane chloride channel. Each receptor is assembled as a pentamer from a pool of at least 19 different possible subunits. The receptors belong to a superfamily that share a common CYSTEINE loop.

Receptors, GABA-B - A subset of GABA RECEPTORS that signal through their interaction with HETEROTRIMERIC G-PROTEINS.

Secobarbital - A barbiturate that is used as a sedative. Secobarbital is reported to have no anti-anxiety activity.

Selegiline - A selective, irreversible inhibitor of Type B monoamine oxidase that is used for the treatment of newly diagnosed patients with PARKINSON DISEASE, and for the treatment of depressive disorders. The compound without isomeric designation is Deprenyl.

Temazepam - A benzodiazepine that acts as a GAMMA-AMINOBUTYRIC ACID modulator and anti-anxiety agent.

Toxoplasmosis, Cerebral - Infections of the BRAIN caused by the protozoan TOXOPLASMA gondii that primarily arise in individuals with IMMUNOLOGIC DEFICIENCY SYNDROMES (see also AIDS-RELATED OPPORTUNISTIC INFECTIONS). The infection may involve the brain diffusely or form discrete abscesses. Clinical manifestations include SEIZURES, altered mentation, headache, focal neurologic deficits, and INTRACRANIAL HYPERTENSION. (From Joynt, Clinical Neurology, 1998, Ch27, pp41-3)

Triazolam - A short-acting benzodiazepine used in the treatment of insomnia. Some countries temporarily withdrew triazolam from the market because of concerns about adverse reactions, mostly psychological, associated with higher dose ranges. Its use at lower doses with appropriate care and labeling has been reaffirmed by the FDA and most other countries.

Trimethadione - An anticonvulsant effective in absence seizures, but generally reserved for refractory cases because of its toxicity. (From AMA Drug Evaluations Annual, 1994, p378)

Tuberculosis, Central Nervous System - Tuberculosis of the brain, spinal cord, or meninges (TUBERCULOSIS, MENINGEAL), most often caused by MYCOBACTERIUM TUBERCULOSIS and rarely by MYCOBACTERIUM BOVIS. The infection may be limited to the nervous system or coexist in other organs (e.g., TUBERCULOSIS, PULMONARY). The organism tends to seed the meninges causing a diffuse meningitis and leads to the formation of TUBERCULOMA, which may occur within the brain, spinal cord, or perimeningeal spaces. Tuberculous involvement of the vertebral column (TUBERCULOSIS, SPINAL) may result in nerve root or spinal cord compression. (From Adams et al., Principles of Neurology, 6th ed, pp717-20)

Valerian - A plant genus of the family VALERIANACEAE, order Dipsacales, subclass Asteridae, class Magnoliopsida. It is best known for the sedative use and valepotriate content of the roots. It is sometimes called Garden Heliotrope but is unrelated to true Heliotrope (HELIOTROPIUM).

Valerianaceae - The Valerian plant family of the order Dipsacales, subclass Asteridae, class Magnoliopsida that is characterized by 3-5-lobed tubular flowers, often spurred at the base and clustered in tight heads.

Valerianella - A plant genus of the family VALERIANACEAE. It is sometimes called goosefoot cornsalad but should not be confused with true goosefoot (CHENOPODIUM).

Valproic Acid - A fatty acid with anticonvulsant and anti-manic properties that is used in the treatment of EPILEPSY and BIPOLAR DISORDER. The mechanisms of its therapeutic actions are not well understood. It may act by increasing GAMMA-AMINOBUTYRIC ACID levels in the brain or by altering the properties of VOLTAGE-GATED SODIUM CHANNELS.

Vasculitis, Central Nervous System - Inflammation of blood vessels within the central nervous system. Primary vasculitis is usually caused by autoimmune or idiopathic factors, while secondary vasculitis is caused by existing disease process. Clinical manifestations are highly variable but include HEADACHE; SEIZURES; behavioral alterations; INTRACRANIAL HEMORRHAGES; TRANSIENT ISCHEMIC ATTACK; and BRAIN INFARCTION. (From Adams et al., Principles of Neurology, 6th ed, pp856-61)

Vertigo - An illusion of movement, either of the external world revolving around the individual or of the individual revolving in space. Vertigo may be associated with disorders of the inner ear (EAR, INNER); VESTIBULAR NERVE; BRAINSTEM; or CEREBRAL CORTEX. Lesions in the TEMPORAL LOBE and PARIETAL LOBE may be associated with FOCAL SEIZURES that may feature vertigo as an ictal manifestation. (From Adams et al., Principles of Neurology, 6th ed, pp300-1)

Vigabatrin - An analogue of GAMMA-AMINOBUTYRIC ACID. It is an irreversible inhibitor of 4-AMINOBUTYRATE TRANSAMINASE, the enzyme responsible for the catabolism of GAMMA-AMINOBUTYRIC ACID and is used as an anticonvulsant. (From Martindale The Extra Pharmacopoeia, 31st ed)

Zolpidem - An imidazopyridine derivative and short-acting GABA-A receptor agonist that is used for the treatment of INSOMNIA.

Zoxazolamine - A uricosuric and muscle relaxant. Zoxazolamine acts centrally as a muscle relaxant, but the mechanism of its action is not understood.

Instructional Notations

Type 2 Excludes

A type 2 excludes note represents "Not included here". An excludes2 note indicates that the condition excluded is not part of the condition represented by the code, but a patient may have both conditions at the same time. When an Excludes2 note appears under a code, it is acceptable to use both the code and the excluded code together, when appropriate.

• drug dependence and related mental and behavioral disorders due to psychoactive substance use F10 F19

7th Character Note

Certain ICD-10-CM categories have applicable 7th characters. The applicable 7th character is required for all codes within the category, or as the notes in the Tabular List instruct. The 7th character must always be the 7th character in the data field. If a code that requires a 7th character is not 6 characters, a placeholder X must be used to fill in the empty characters.

• The appropriate 7th character is to be added to each code from category T42

7th Character

Indicates that a seventh character is to be assigned to codes in a subcategory.

• A - initial encounter
• D - subsequent encounter
• S - sequela