Biomaterial Database

Dexamethasone: pharmacokinetics in neurological patients. 1984

M J Eadie, and T R Brophy, and G Ohlrich, and J H Tyrer

A high performance liquid chromatographic assay has been used to measure the time courses of plasma dexamethasone concentrations in patients with various neurological disorders being treated with this steroid. The pharmacokinetics of the drug in these circumstances differed from the kinetics in healthy volunteers. In particular whole body clearances were higher, causing a substantially impaired mean oral bioavailability of the drug with considerable interindividual variation in bioavailability. The clearance of dexamethasone was increased by concurrent phenytoin therapy, and dexamethasone and phenytoin are often given together in neurosurgical practice. The previously unrecognized bioavailability limitation of oral dexamethasone may explain individual instances of apparent steroid-resistant neurological disease, and suggests the desirability of monitoring plasma dexamethasone levels when using the steroid therapeutically. Some preliminary evidence has been obtained suggesting that it may be possible to avoid adrenal suppression from long-term high-dosage dexamethasone therapy, if plasma dexamethasone levels can be allowed to fall to zero between consecutive dexamethasone doses.

UI	MeSH Term	Description	Entries
D007275	Injections, Intravenous	Injections made into a vein for therapeutic or experimental purposes.	Intravenous Injections,Injection, Intravenous,Intravenous Injection
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D008297	Male		Males
D008657	Metabolic Clearance Rate	Volume of biological fluid completely cleared of drug metabolites as measured in unit time. Elimination occurs as a result of metabolic processes in the kidney, liver, saliva, sweat, intestine, heart, brain, or other site.	Total Body Clearance Rate,Clearance Rate, Metabolic,Clearance Rates, Metabolic,Metabolic Clearance Rates,Rate, Metabolic Clearance,Rates, Metabolic Clearance
D008875	Middle Aged	An adult aged 45 - 64 years.	Middle Age
D009157	Myasthenia Gravis	A disorder of neuromuscular transmission characterized by fatigable weakness of cranial and skeletal muscles with elevated titers of ACETYLCHOLINE RECEPTORS or muscle-specific receptor tyrosine kinase (MuSK) autoantibodies. Clinical manifestations may include ocular muscle weakness (fluctuating, asymmetric, external ophthalmoplegia; diplopia; ptosis; and weakness of eye closure) and extraocular fatigable weakness of facial, bulbar, respiratory, and proximal limb muscles. The disease may remain limited to the ocular muscles (ocular myasthenia). THYMOMA is commonly associated with this condition.	Anti-MuSK Myasthenia Gravis,MuSK MG,MuSK Myasthenia Gravis,Muscle-Specific Receptor Tyrosine Kinase Myasthenia Gravis,Muscle-Specific Tyrosine Kinase Antibody Positive Myasthenia Gravis,Myasthenia Gravis, Generalized,Myasthenia Gravis, Ocular,Anti MuSK Myasthenia Gravis,Generalized Myasthenia Gravis,Muscle Specific Receptor Tyrosine Kinase Myasthenia Gravis,Muscle Specific Tyrosine Kinase Antibody Positive Myasthenia Gravis,Myasthenia Gravis, Anti-MuSK,Myasthenia Gravis, MuSK,Ocular Myasthenia Gravis
D009422	Nervous System Diseases	Diseases of the central and peripheral nervous system. This includes disorders of the brain, spinal cord, cranial nerves, peripheral nerves, nerve roots, autonomic nervous system, neuromuscular junction, and muscle.	Neurologic Disorders,Nervous System Disorders,Neurological Disorders,Disease, Nervous System,Diseases, Nervous System,Disorder, Nervous System,Disorder, Neurologic,Disorder, Neurological,Disorders, Nervous System,Disorders, Neurologic,Disorders, Neurological,Nervous System Disease,Nervous System Disorder,Neurologic Disorder,Neurological Disorder
D011129	Polyradiculoneuropathy	Diseases characterized by injury or dysfunction involving multiple peripheral nerves and nerve roots. The process may primarily affect myelin or nerve axons. Two of the more common demyelinating forms are acute inflammatory polyradiculopathy (GUILLAIN-BARRE SYNDROME) and POLYRADICULONEUROPATHY, CHRONIC INFLAMMATORY DEMYELINATING. Polyradiculoneuritis refers to inflammation of multiple peripheral nerves and spinal nerve roots.	Autoimmune Demyelinating Disease, Peripheral,Demyelinating Autoimmune Disease, Peripheral,Demyelinating Disease, Peripheral Autoimmune,Peripheral Autoimmune Demyelinating Disease,Polyradiculoneuritis,Polyradiculoneuritides,Polyradiculoneuropathies
D001932	Brain Neoplasms	Neoplasms of the intracranial components of the central nervous system, including the cerebral hemispheres, basal ganglia, hypothalamus, thalamus, brain stem, and cerebellum. Brain neoplasms are subdivided into primary (originating from brain tissue) and secondary (i.e., metastatic) forms. Primary neoplasms are subdivided into benign and malignant forms. In general, brain tumors may also be classified by age of onset, histologic type, or presenting location in the brain.	Brain Cancer,Brain Metastases,Brain Tumors,Cancer of Brain,Malignant Primary Brain Tumors,Neoplasms, Intracranial,Benign Neoplasms, Brain,Brain Neoplasm, Primary,Brain Neoplasms, Benign,Brain Neoplasms, Malignant,Brain Neoplasms, Malignant, Primary,Brain Neoplasms, Primary Malignant,Brain Tumor, Primary,Brain Tumor, Recurrent,Cancer of the Brain,Intracranial Neoplasms,Malignant Neoplasms, Brain,Malignant Primary Brain Neoplasms,Neoplasms, Brain,Neoplasms, Brain, Benign,Neoplasms, Brain, Malignant,Neoplasms, Brain, Primary,Primary Brain Neoplasms,Primary Malignant Brain Neoplasms,Primary Malignant Brain Tumors,Benign Brain Neoplasm,Benign Brain Neoplasms,Benign Neoplasm, Brain,Brain Benign Neoplasm,Brain Benign Neoplasms,Brain Cancers,Brain Malignant Neoplasm,Brain Malignant Neoplasms,Brain Metastase,Brain Neoplasm,Brain Neoplasm, Benign,Brain Neoplasm, Malignant,Brain Neoplasms, Primary,Brain Tumor,Brain Tumors, Recurrent,Cancer, Brain,Intracranial Neoplasm,Malignant Brain Neoplasm,Malignant Brain Neoplasms,Malignant Neoplasm, Brain,Neoplasm, Brain,Neoplasm, Intracranial,Primary Brain Neoplasm,Primary Brain Tumor,Primary Brain Tumors,Recurrent Brain Tumor,Recurrent Brain Tumors,Tumor, Brain
D002538	Intracranial Arteriovenous Malformations	Congenital vascular anomalies in the brain characterized by direct communication between an artery and a vein without passing through the CAPILLARIES. The locations and size of the shunts determine the symptoms including HEADACHES; SEIZURES; STROKE; INTRACRANIAL HEMORRHAGES; mass effect; and vascular steal effect.	Arteriovenous Malformations, Cerebral,Intracranial Arteriovenous Malformations, Congenital,AVM (Arteriovenous Malformation) Intracranial,Cerebral Arteriovenous Malformations,Congenital Intracranial Arteriovenous Malformations,Intracranial Arteriovenous Malformation, Ruptured,Ruptured Intracranial Arteriovenous Malformation,Arteriovenous Malformation, Cerebral,Arteriovenous Malformation, Intracranial,Arteriovenous Malformations, Intracranial,Cerebral Arteriovenous Malformation,Intracranial Arteriovenous Malformation,Malformation, Cerebral Arteriovenous,Malformation, Intracranial Arteriovenous,Malformations, Cerebral Arteriovenous,Malformations, Intracranial Arteriovenous