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Показаны сообщения с ярлыком Т3. Показать все сообщения

четверг, 9 октября 2014 г.

Тиреоидная функция до и после лечения психотического эпизода

Background
Endocrine function in psychiatric patients may be affected by mental disorder itself as well as by antipsychotic medications.
The aim of this naturalistic observational study was to determine if treatment of acute psychotic episode with antipsychotic medication affects thyroid axis hormone concentrations and if such changes are associated with symptomatic improvement.
Methods
Eighty six adult acute psychotic patients, consecutively admitted to a mental hospital, were recruited for the study. All patients were physically healthy and without thyroid disease. During the hospitalization period all study patients received treatment with antipsychotic medication according to clinical need. Severity of the psychotic episode was evaluated using the Brief Psychiatric Rating Scale (BPRS) and venous blood samples were drawn for analysis of free triiodothyronine (FT3), free thyroxine (FT4), and thyroid stimulating hormone (TSH) concentrations on the day of admission and on the day of discharge from the hospital.
Results
Antipsychotic drug treatment was associated with decrease of mean FT3 (p < 0.001) and FT4 (p = 0.002) concentrations; and with increase of mean TSH (p = 0.016) concentrations. Changes in thyroid hormone concentrations were mostly predicted by baseline hormone concentrations. Individual changes were not limited to decrease in high hormone concentrations; in patients who had low FT3 or FT4 concentrations, treatment resulted in increase in concentrations. Such an increase was established in one-quarter of patients for FT3 concentrations and in one-third of patients for FT4 concentrations. Fall in FT4 concentrations negatively correlated with the improvement in the BPRS score (r = −0.235, p = 0.023).
Conclusions
The study indicates that antipsychotic treatment resulted in a decrease in mean FT3 concentrations and in an increase in mean TSH concentrations after recovery from acute psychosis. Symptomatic improvement was less evident in patients who experienced a decrease in FT4 concentrations.
 Thyroid axis function after in-patient treatment of acute psychosis with antipsychotics: a naturalistic study

четверг, 1 сентября 2011 г.

Психические расстройства при гипотиреозе и гипертиреозе

The symptoms and signs of hyperthyroidism resemble those of primary mental disorders. Overactivity of the adrenergic system caused by hyperthyroidism may explain the similarity between the clinical presentations of hyperthyroidism and mania or anxiety, as well as the precipitating role of hyperthyroidism in the development of mania or anxiety disorder. It may also explain the increased sense of well being often experienced in the early stages of hyperthyroidism.[20,21]

The relationship between hyperthyroidism and depression is less clear. Depression is usually linked to hypothyroidism, not to hyperthyroidism. However, prolonged hyperthyroidism might exhaust noradrenergic transmission and thus contribute to depression. Noradrenergic exhaustion might well occur in patients with hyperthyroidism who have bipolar disorder. In the initial phase of hyperthyroidism, thyroid hormone stimulation of the noradrenergic system may cause mania; later, when noradrenergic neurotransmission is exhausted, it may contribute to depression.[21]

Mental symptoms and disorders secondary to hyperthyroidism should be treated first by restoring euthyroidism. Most mental symptoms, including depression, usually resolve once euthyroidism has been regained. Treatment with beta-adrenergic antagonists alone may quickly relieve many symptoms, including mental symptoms, even if euthyroidism is not restored,[22] providing evidence that overactivity of the adrenergic system is largely responsible for mental symptoms in hyperthyroidism.

Thyroid deficits are frequently observed in bipolar patients, especially in women with the rapid cycling form of the disease.[24] Both subclinical hypothyroidism and subclinical hyperthyroidism increase the risk for Alzheimer's disease, especially in women.[25] However, most hypothyroid patients do not meet the criteria for a mental disorder.

A recent study evaluated brain glucose metabolism during T4 treatment of hypothyroidism. A reduction in depression and cognitive symptoms was associated with restoration of metabolic activity in brain areas that are integral to the regulation of mood and cognition.[26••]

In hypothyroidism, replacement therapy with T4 remains the treatment of choice and resolves most physical and psychological signs and symptoms in most patients. However, some patients do not feel entirely well despite doses of T4 that are usually adequate.[27] In T4-treated patients, it was found that reduced psychological well being is associated with occurrence of polymorphism in the D2 gene,[28••] as well as in the OATP1c1 gene.[29]

Thyroid hormone replacement with a combination of T4 and T3, in comparison with T4 monotherapy, improves mental functioning in some but not all hypothyroid patients,[30,31•] and most of the patients subjectively prefer combined treatment.[32] Two studies have evaluated whether D2 polymorphism is associated with changes in psychological well being after combined T4 and T3 treatment. One underpowered study[33] reported a trend toward improvement. In a second study[28••] involving a very large sample, D2 polymorphism was associated with improvement in psychological well being after T4 and T3 treatment.

Thyroid Disease and Mental Disorders: Cause and Effect or Only comorbidity?

четверг, 22 июля 2010 г.

Психические расстройства при гипотиреозе и гипертиреозе

The symptoms and signs of hyperthyroidism resemble those of primary mental disorders. Overactivity of the adrenergic system caused by hyperthyroidism may explain the similarity between the clinical presentations of hyperthyroidism and mania or anxiety, as well as the precipitating role of hyperthyroidism in the development of mania or anxiety disorder. It may also explain the increased sense of well being often experienced in the early stages of hyperthyroidism.[20,21]

The relationship between hyperthyroidism and depression is less clear. Depression is usually linked to hypothyroidism, not to hyperthyroidism. However, prolonged hyperthyroidism might exhaust noradrenergic transmission and thus contribute to depression. Noradrenergic exhaustion might well occur in patients with hyperthyroidism who have bipolar disorder. In the initial phase of hyperthyroidism, thyroid hormone stimulation of the noradrenergic system may cause mania; later, when noradrenergic neurotransmission is exhausted, it may contribute to depression.[21]

Mental symptoms and disorders secondary to hyperthyroidism should be treated first by restoring euthyroidism. Most mental symptoms, including depression, usually resolve once euthyroidism has been regained. Treatment with beta-adrenergic antagonists alone may quickly relieve many symptoms, including mental symptoms, even if euthyroidism is not restored,[22] providing evidence that overactivity of the adrenergic system is largely responsible for mental symptoms in hyperthyroidism.

Thyroid deficits are frequently observed in bipolar patients, especially in women with the rapid cycling form of the disease.[24] Both subclinical hypothyroidism and subclinical hyperthyroidism increase the risk for Alzheimer's disease, especially in women.[25] However, most hypothyroid patients do not meet the criteria for a mental disorder.

A recent study evaluated brain glucose metabolism during T4 treatment of hypothyroidism. A reduction in depression and cognitive symptoms was associated with restoration of metabolic activity in brain areas that are integral to the regulation of mood and cognition.[26••]

In hypothyroidism, replacement therapy with T4 remains the treatment of choice and resolves most physical and psychological signs and symptoms in most patients. However, some patients do not feel entirely well despite doses of T4 that are usually adequate.[27] In T4-treated patients, it was found that reduced psychological well being is associated with occurrence of polymorphism in the D2 gene,[28••] as well as in the OATP1c1 gene.[29]

Thyroid hormone replacement with a combination of T4 and T3, in comparison with T4 monotherapy, improves mental functioning in some but not all hypothyroid patients,[30,31•] and most of the patients subjectively prefer combined treatment.[32] Two studies have evaluated whether D2 polymorphism is associated with changes in psychological well being after combined T4 and T3 treatment. One underpowered study[33] reported a trend toward improvement. In a second study[28••] involving a very large sample, D2 polymorphism was associated with improvement in psychological well being after T4 and T3 treatment.

Thyroid Disease and Mental Disorders: Cause and Effect or Only comorbidity?

четверг, 8 июля 2010 г.

STAR*D


The Sequenced Treatment Alternatives to Relieve Depression (STAR*D) trial was a longitudinal, multi-center, 5-year study of common strategies for treating depression. To date, it is the United States’ largest National Institute of Mental Health funded study including over 4,000 patients. This four level trial compared traditional augmentation strategies with switching agents (Slide 2).30-34 Unlike most depression studies, in STAR*D the outcome measure was full remission.
In Level 1, the initial monotherapy phase, citalopram (mean dose of 41.8 mg) was effective at achieving remission for only ~30% of subjects. This finding has been accepted as an accurate reflection of clinical experience with any initial monotherapy. The remaining 70% were randomized to either receive bupropion or buspirone augmentation, or switched to one of three antidepressants as monotherapy—bupropion, venlafaxine, or sertraline. Augmentation resulted in a 30% response, while switching antidepressants resulted in ~20% of patients achieving remission. Level 3 included those non-remitters from Level 2 who were then randomized to either T3 or lithium augmentation, resulting in remission rates of 25% and 16% respectively. A Level 3 switch to nortriptyline (NTP) or mirtazapine (MTZ) was in general less successful than Level 3 augmentation, with 20% of NTP patients and 12% of MTZ patients remitting. Level 4 treatment options (monoamine oxidase inhibitors [MAOIs] or venlafaxine–mirtazapine-combination therapy) were provided to patients who had not responded satisfactorily to previous levels of the treatment protocol, and very few experienced full remission (14% and 7% respectively).12,35


An overall analysis of STAR*D results indicates that the chances of achieving and maintaining remission in patients with difficult-to-treat depression diminishes with every additional strategy needed. Those who fully remit early in the course of treatment have a better chance of remaining well than those who experience only symptomatic improvement. STAR*D does not tell us which treatment works better as a first or second adjunct, simply that the greatest chance of recovery appears to lie with the first two sequential treatments.

The Role of L-methylfolate in Depressive Disorders

четверг, 27 мая 2010 г.

Потенциирование трийодтиронином при недостаточном ответе на терапию ТЦА

"The exact mechanism of action of T3 augmentation remains largely unknown. In depressed patients, the circulating plasma levels of free T4 appear to be normal,
but levels of free T3 may be decreased. Approximately one third of depressed patients show blunting of the TSH response to thyrotropin releasing hormone.
Approximately 15% of depressed patients have elevated basal TSH levels, probably indicating subclinical hypothyroidism, and thyroid autoantibodies
are found in a similar percentage of patients.11
Thyroid abnormalities are found at a higher frequency among TCA nonresponders and this may link with the underlying mechanism of T3 augmentation.In most case reports, patients had normal thyroid function, as in our second case. There seems to be no
relationship between thyroid state and the efficacy of T3 augmentation. In the first case, the patient had sick euthyroid syndrome, which is sometimes seen in
depressed patients. In this condition, peripheral deiodination of T4 to T3 is reduced, although the TSH level is normal.
One proposed mechanism of T3 augmentation is that T3 may raise peripheral thyroid hormone concentrations in patients with covert or borderline hypothyroidism. Other authorities believe that there is no difference in the thyroid state of the
responders and nonresponders to T3 augmentation. 12 L-triiodothyronine may act in euthyroid patients through augmentation of the β-adrenergic system.13 Alternatively, T3 may also affect thyroid utilisation and local neuronal deiodination in the brain."

"The usual dose of T3 in augmentation therapy is 25 µg/d to 50 µg/d. A starting dose of 20 µg increasing to 40 µg was given to the patients in this study. Initial improvement in mood is usually apparent within several days. Goodwin et al reported that there was improvement in all aspects of the depressive syndrome within 1 to 3 days. For the two patients in this study,initial responses were noted after 3 and 7 days. An adequate trial of T3 augmentation should last for 7 to 14 days to reach its full effect. If T3 augmentation is effective, most studies recommend a maintenance
period of 2 months before gradually reducing the dose at the rate of 10 µg every 3 to 7 days."

Triiodothyronine augmentation for the treatment of depression in substance misusers unresponsive to tricyclic antidepressants.

вторник, 2 февраля 2010 г.

левотироксин натрия, взаимодейсвия













































Table 2: Drug– Thyroidal Axis Interactions
Drug
or Drug Class
Effect
Drugs that may reduce TSH secretion -the reduction is not
sustained; therefore, hypothyroidism does not occur
Dopamine / Dopamine
Agonists
Glucocorticoids
Octreotide
Use of these
agents may result in a transient reduction in TSH secretion when administered
at the following doses: Dopamine(≥ 1 mcg/kg/min); Glucocorticoids (hydrocortisone≥ 100 mg/day or equivalent); Octreotide (> 100 mcg/day).
Drugs that alter thyroid hormone secretion
Drugs that may decrease thyroid hormone secretion, which
may result in hypothyroidism

Aminoglutethimide
Amiodarone
Iodide
(including iodine- Containing Radiographic contrast agents)
Lithium
Methimazole
Propylthiouracil
(PTU)
Sulfonamides
Tolbutamide
Long-term lithium
therapy can result in goiter in up to 50% of patients, and either subclinical
or overt hypothyroidism, each in up to 20% of patients. The fetus, neonate,
elderly and euthyroid patients with underlying thyroid disease (e.g., Hashimoto's
thyroiditis or with Grave's disease previously treated with radioiodine
or surgery) are among those individuals who are particularly susceptible to
iodine-induced hypothyroidism. Oral cholecystographic agents and amiodarone
are slowly excreted, producing more prolonged hypothyroidism than parenterally
administered iodinated contrast agents. Long-term aminoglutethimide therapy
may minimally decrease T4 and T3 levels and increase
TSH, although all values remain within normal limits in most patients.
Drugs that may increase thyroid hormone secretion, which
may result in hyperthyroidism
Amiodarone
Iodide
(including iodine- containing Radiographic contrast agents)
Iodide and drugs
that contain pharmacologic amounts of iodide may cause hyperthyroidism in
euthyroid patients with Grave's disease previously treated with antithyroid
drugs or in euthyroid patients with thyroid autonomy (e.g., multinodular goiter
or hyperfunctioning thyroid adenoma). Hyperthyroidism may develop over several
weeks and may persist for several months after therapy discontinuation. Amiodarone
may induce hyperthyroidism by causing thyroiditis.
Drugs that may decrease T4 absorption, which may
result in hypothyroidism
Antacids
-
Aluminum &
Magnesium
Hydroxides
-
Simethicone
Bile Acid Sequestrants
- Cholestyramine
- Colestipol
Calcium
Carbonate
Cation Exchange Resins
- Kayexalate
Ferrous Sulfate
Sucralfate
Concurrent use
may reduce the efficacy of levothyroxine by binding and delaying or preventing
absorption, potentially resulting in hypothyroidism. Calcium carbonate may
form an insoluble chelate with levothyroxine, and ferrous sulfate likely forms
a ferric-thyroxine complex. Administer levothyroxine at least 4 hours apart
from these agents.
Drugs that may alter T4 and T3 serum
transport – but FT4 concentration remains normal; and, therefore,
the patient remains euthyroid
Drugs
that may decrease serum TBG concentration
Drugs
that may increase serum TBG concentration
Clofibrate
Estrogen-containing
oral contraceptives
Estrogens (oral)
Heroin / Methadone
5-Fluorouracil
Mitotane
Tamoxifen
Androgens /
Anabolic Steroids
Asparaginase
Glucocorticoids
Slow-Release Nicotinic
Acid
Drugs that may cause protein-binding site displacement
Furosemide (
> 80 mg IV)
Heparin
Hydantoins
Non Steroidal
Anti-Inflammatory
Drugs
- Fenamates
- Phenylbutazone
Salicylates
( > 2 g/day)
Administration
of these agents with levothyroxine results in an initial transient increase
in FT4. Continued administration results in a decrease in serum
T4 and normal FT4 and TSH concentrations and, therefore,
patients are clinically euthyroid. Salicylates inhibit binding of T4 and
T3 to TBG and transthyretin. An initial increase in serum FT4 is
followed by return of FT4 to normal levels with sustained therapeutic
serum salicylate concentrations, although total-T4 levels may decrease
by as much as 30%.
Drugs that may alter T4 and T3 metabolism
Drugs that may increase hepatic metabolism, which may result
in hypothyroidism
Carbamazepine
Hydantoins
Phenobarbital
Rifampin
Stimulation
of hepatic microsomal drug-metabolizing enzyme activity may cause increased
hepatic degradation of levothyroxine, resulting in increased levothyroxine
requirements. Phenytoin and carbamazepine reduce serum protein binding of
levothyroxine, and total- and free-T4 may be reduced by 20% to
40%, but most patients have normal serum TSH levels and are clinically euthyroid.
Drugs that may decrease T4 5'-deiodinase
activity
Amiodarone
Beta-adrenergic
antagonists
-
(e.g., Propranolol> 160 mg/day) Glucocorticoids
- (e.g.,
Dexamethasone
> 4 mg/day)
Propylthiouracil (PTU)
Administration
of these enzyme inhibitors decreases the peripheral conversion of T4 to
T3, leading to decreased T3 levels. However, serum T4 levels
are usually normal but may occasionally be slightly increased. In patients
treated with large doses of propranolol ( > 160 mg/day), T3 and
T4 levels change slightly, TSH levels remain normal, and patients
are clinically euthyroid. It should be noted that actions of particular beta-adrenergic
antagonists may be impaired when the hypothyroid patient is converted to the
euthyroid state. Short-term administration of large doses of glucocorticoids
may decrease serum T3 concentrations by 30% with minimal change
in serum T4 levels. However, long-term glucocorticoid therapy may
result in slightly decreased T3 and T4 levels due to
decreased TBG production (see above).
Miscellaneous
Anticoagulants
(oral)
- Coumarin Derivatives
- Indandione Derivatives
Thyroid hormones
appear to increase the catabolism of vitamin K-dependent clotting factors,
thereby increasing the anticoagulant activity of oral anticoagulants. Concomitant
use of these agents impairs the compensatory increases in clotting factor
synthesis. Prothrombin time should be carefully monitored in patients taking
levothyroxine and oral anticoagulants and the dose of anticoagulant therapy
adjusted accordingly.
Antidepressants
-
Tricyclics (e.g., Amitriptyline)
- Tetracyclics (e.g.,
Maprotiline)
- Selective Serotonin Reuptake Inhibitors
(SSRIs;
e.g., Sertraline)
Concurrent use
of tri/tetracyclic antidepressants and levothyroxine may increase the therapeutic
and toxic effects of both drugs, possibly due to increased receptor sensitivity
to catecholamines. Toxic effects may include increased risk of cardiac arrhythmias
and CNS stimulation; onset of action of tricyclics may be accelerated. Administration
of sertraline in patients stabilized on levothyroxine may result in increased
levothyroxine requirements.
Antidiabetic
Agents
- Biguanides
- Meglitinides
-
Sulfonylureas
- Thiazolidediones
-
Insulin
Addition of
levothyroxine to antidiabetic or insulin therapy may result in increased antidiabetic
agent or insulin requirements. Careful monitoring of diabetic control is recommended,
especially when thyroid therapy is started, changed, or discontinued.
Cardiac Glycosides Serum digitalis
glycoside levels may be reduced in hyperthyroidism or when the hypothyroid
patient is converted to the euthyroid state. Therapeutic effect of digitalis
glycosides may be reduced.
Cytokines
-
Interferon-α
- Interleukin-2
Thereapy wih
interferon-α has been associated with the development of antithyroid
microsomal antibodies in 20% of patients and some have transient hypothyroidism,
hyperthyroidism, or both. Patients who have antithyroid antibodies before
treatment are at higher risk for thyroid dysfunction during treatment. Interleukin-2
has been associated with transient painless thyroiditis in 20% of patients.
Interferon-β and -γ have not been reported to cause thyroid dysfunction.
Growth Hormones
-
Somatrem
- Somatropin
Excessive use
of thyroid hormones with growth hormones may accelerate epiphyseal closure.
However, untreated hypothyroidism may interfere with growth response to growth
hormone.
Ketamine Concurrent use
may produce marked hypertension and tachycardia; cautious administration to
patients receiving thyroid hormone therapy is recommended.
Methylxanthine
Bronchodilators
- (e.g., Theophylline)
Decreased theophylline
clearance may occur in hypothyroid patients; clearance returns to normal when
the euthyroid state is achieved.
Radiographic
Agents
Thyroid hormones
may reduce the uptake of 123I, 131I, and 99mTc
Sympathomimetics Concurrent use
may increase the effects of sympathomimetics or thyroid hormone. Thyroid hormones
may increase the risk of coronary insufficiency when sympathomimetic agents
are administered to patients with coronary artery disease.
Chloral Hydrate
Diazepam
Ethionamide
Lovastatin
Metoclopramide
6-Mercaptopurine
Nitroprusside
Para-aminosalicylate sodium
Perphenazine
Resorcinol
(excessive topical use)
Thiazide Diuretics
These agents
have been associated with thyroid hormone and / or TSH level alterations by
various mechanisms.

LEVOXYL® (levothyroxine sodium tablets, USP)

вторник, 11 августа 2009 г.

Резистентные к лечению депрессии



Antidepressants can be grouped into 6 major categories: tricyclic antidepressants (TCAs), SSRIs, serotonin norepinephrine reuptake inhibitors (SNRIs), monoamine oxidase inhibitors (MAOIs), serotonin neurotransmitter (5-HT2)-receptor antagonists (eg, nefazodone, trazodone), and novel agents (eg, mirtazapine, bupropion). If a patient fails to respond to one antidepressant class, it makes sense (at least conceptually) to switch to another, although most guidelines acknowledge that 2 failed trials of SSRIs may be justifiable before switching classes.
For example, in a study by Thase and colleagues,10 58 patients failed a trial of fluoxetine; however, there was a 76% response rate to citalopram among completers. Although this study was not blinded, it is interesting that citalopram (which is believed to be the most selective of the SSRIs) was effective when another SSRI was not.
Antidepressants that are associated with discontinuation symptoms (eg, paroxetine, venlafaxine, duloxetine) may produce discontinuation syndromes when stopped that can be erroneously attributed to adverse effects of the new drug, particularly if the new drug does not possess a significant degree of serotonin reuptake inhibition.
In a study by Zarate and colleagues,21 the onset of the antidepressant effect of ketamine occurred within 2 hours. Unfortunately, the drug must be given by intravenous infusion, but because the effect persisted for 7 days, ketamine treatment may be useful if given as a series.
Another NMDA-receptor antagonist now available in the United States is memantine (FDA-approved for Alzheimer disease). Memantine was shown to be effective in an open-label study in major depression. In a double-blind, randomized trial it showed comparable effects to escitalopram in patients with major depression and alcohol dependence.
Randomized controlled trials have supported the superior efficacy of a TCA/SSRI combination, as well as a mirtazapine/SSRI combination; open studies have done the same for TCA/MAOI and SSRI/bupropion combinations.
As with lithium, a recent review concluded that the trial data that support the efficacy of T3 augmentation are of better quality with TCAs than with SSRIs

Treatment-Resistant Depression