The use of benzodiazepines has a profound effect on almost every aspect of brain and body function, either directly or indirectly.Benzodiazepines cause a decrease in norepinephrine (noradrenaline), serotonin, acetylcholine, and dopamine. These neurotransmitters are needed for normal memory, mood, muscle tone and coordination, emotional responses, endocrine gland secretions, heart rate, and blood pressure control. With chronic benzodiazepine use, tolerance develops rapidly to most of its effects, so that, when benzodiazepines are withdrawn, various neurotransmitter systems go into overdrive due to the lack of inhibitory GABA-ergic activity. Withdrawal symptoms then emerge as a result, and persist until the nervous system physically reverses the adaptions (physical dependence) that have occurred in the CNS.Withdrawal symptoms typically consist of a mirror image of the drugs effects: Sedative effects and suppression of REM and SWS stages of sleep can be replaced by insomnia, nightmares, and hypnogogic hallucinations; its antianxiety effects are replaced with anxiety and panic; muscle-relaxant effects are replaced with muscular spasms or cramps; and anticonvulsant effects are replaced with seizures, especially in cold turkey or overly-rapid withdrawal.Benzodiazepine withdrawal represents in part excitotoxicity to brain neurons. Rebound activity of the hypothalamic-pituitary-adrenocortical axis also plays an important role in the severity of benzodiazepine withdrawal. Tolerance and the resultant withdrawal syndrome may be due to alterations in gene expression, which results in long-term changes in the function of the GABAergic neuronal system.During withdrawal from full or partial agonists, changes occur in benzodiazepine receptor with upregulation of some receptor subtypes and downregulation of other receptor subtypes.
Some physicians favor administering the maximum safe dose (calculated based on a number of factors), while others favor administering smaller doses, which may still be effective in ablating all thyroid tissue. I-131 is used for ablation of the thyroid tissue. Minimally invasive thyroidectomy has been used in recent years in cases where the nodules are small. Finding disease recurrence
Some studies have shown that thyroglobulin (Tg) testing combined with neck ultrasound is more productive in finding disease recurrence than full- or whole-body scans (WBS) using radioactive iodine. However, current protocol (in the USA) suggests a small number of clean annual WBS are required before relying on Tg testing plus neck ultrasound. When needed, whole body scans consist of withdrawal from thyroxine medication and/or injection of recombinant human Thyroid stimulating hormone (TSH). In both cases, a low iodine diet regimen must also be followed to optimize the takeup of the radioactive iodine dose. Low dose radioiodine of a few millicuries is administered. Full body nuclear medicine scan follows using a gamma camera. Scan doses of radioactive iodine may be I131 or I123. Recombinant human TSH, commercial name Thyrogen, is produced in cell culture from genetically engineered hamster cells.