Фармакотерапия когнитивных нарушений при травмах головного мозга

Recommended treatments for mild TBI-related cognitive deficits

Deficit	First-line medication	Side effects	Contraindications	Other treatments
Memory	Donepezil (5 to 10 mg/d)	Diarrhea, nausea, vomiting, muscle cramps, fatigue, anorexia	Hypersensitivity to donepezil or piperidine derivatives	Rivastigmine, galantamine, physostigmine, CDP-choline
Speed of processing	Methylphenidate (0.3 mg/kg twice daily)	Headache, insomnia, decreased appetite, nausea, vomiting, anxiety, irritability	Hypersensitivity to methylphenidate, glaucoma, history of Tourette syndrome or tics, use of MAOI within 14 days	Dextroamphetamine
Executive function	Amantadine (200 to 400 mg/d)	CNS depression, orthostatic hypotension, peripheral edema, agitation, nausea, anorexia	Hypersensitivity to amantadine	Bromocriptine, pramipexole, carbidopa/levodopa
CDP-choline: cytidinediphosphocholine; MAOI: monoamine oxidase inhibitor
Source:Reference 8

Executive function responds to non-stimulant catecholaminergics. In a review, Writer and Schillerstrom5 found that TBI patients who received catecholaminergic augmentation showed improved function in 6 of 7 studies. In 2 randomized controlled trials (RCTs) and 4 nonrandomized, placebo-controlled trials, patients with mild to severe TBI showed improved executive function, attention, global cognitive function, memory, language, and/ or arousal with use of bromocriptine, pramipexole, carbidopa/levodopa, or amantadine.5 The greatest improvements were found in executive function. In 1 RCT, 10 patients with mild to severe TBI showed no functional improvement after 2 weeks of treatment.

Amantadine, 200 to 400 mg/d, has been shown to safely improve arousal and cognitive function in patients with moderate to severe TBI when started 3 days to 5 months after injury.9 Amantadine, 400 mg/d, also improves executive function measures without significant benefit in attention or memory in patients with mild to severe TBI 6 months post-injury.10

Memory responds to cholinesterase inhibitors. Memory deficits secondary to TBI affect immediate and delayed memory. The cholinesterase inhibitor donepezil is approved for treating Alzheimer’s disease (AD) in the United States and Canada, and research suggests memory deficits after TBI may be similar to those seen in AD.11 This includes deficits in long-term memory storage, which likely is associated with the cholinergic system.11 Post-mortem studies have found similarities in traumatically injured brains and those of AD patients.11

Three small prospective studies of done-pezil have shown improved memory and attention in TBI patients when cognition is the primary outcome, with 1 small negative open-label trial.7 In a study of 53 patients, Whelan et al12 found that donepezil improved patients’ intelligence quotient and clinician-based assessment of cognition over 2 years. Taverni et al13 found memory improvement in 2 TBI patients within 3 weeks of starting donepezil. These results suggest that donepezil may be used in acute and late phases of memory deficits following mild, moderate, or severe TBI.6 All studies titrated donepezil from 5 to 10 mg/d over several weeks. Dosing guidelines for donepezil in AD suggest 5 mg/d for 4 to 6 weeks, which may be increased to 10 mg/d if needed.8

Rivastigmine (3 to 6 mg/d) has been shown to be effective in mild TBI when started 1 year after injury and safe for 12 to 38 weeks of treatment.14,15 One retrospective cohort study of 111 patients with chronic TBI found no difference among donepezil, rivastigmine, or galantamine, with mean doses of 7.2 mg/d, 10 mg/d, and 2.3 mg/d, respectively.16 Sixty-one percent of patients showed improvement and the remainder had modest or no response. This study suggests that positive response on cognition may be similar among cholinesterase inhibitors. In case reports, physostigmine has offered some benefit17,18; however, cardiovascular and autonomic side effects restrict its use.11 Tacrine is associated with problematic gastrointestinal and hepatic side effects.

Processing speed responds to stimulant catecholaminergics. Although the incidence of psychiatric illness is not correlated with TBI severity, evidence suggests that speed of processing mediates the relationship between injury severity and functional decline.19 Therefore, aggressively treating these deficits may help improve function.

Methylphenidate improves attention and processing speed after TBI. A review of 7 randomized trials and 2 nonrandomized trials indicated that patients with mild to severe, chronic TBI experienced significantly improved cognitive function after methylphenidate treatment.5 Willmott and Ponsford20 found significant enhancement in information processing speed within 2 weeks of methylphenidate treatment in 40 patients with moderate or severe TBI. Methylphenidate increased the rate of recovery and led to improvement in acute21 and post-acute phases.22 In addition, methylphenidate may improve processing speed even in the absence of significant changes in attention.23

The standard methylphenidate dose used in most studies, 0.3 mg/kg twice daily, is safe and effective. Dosing usually is started at 5 mg/d and titrated to symptomatic relief. Because methylphenidate does not lower the seizure threshold, it is safe for patients at high risk for seizure.24 Methylphenidate also significantly improves attention and speed of processing in pediatric head trauma.25,26

Dextroamphetamine also is used to treat speed of processing dysfunction after TBI, but is less studied than methylphenidate. Dextroamphetamine, 5 to 30 mg/d, was found to effectively treat attention problems that interfered with rehabilitation in patients with severe TBI.

Traumatic brain injury: Pharmacotherapy options for cognitive deficits

Когнитивное снижение при шизофрении

The cholinergic system

In the 1970s, it was found that Alzheimer disease was caused primarily by the degeneration of acetylcholine (ACH) or cholinergic neurons that emanate from the nucleus basalis of Meynert. This landmark finding was on the one hand startling, since it had been thought that more widespread neurochemical deficits would be found. On the other hand, it was consistent with decades of work that showed that anticholinergic medications disrupted cognitive functions and, in particular, memory in nonpatient populations. Regarding schizophrenia, a small but compelling literature indicates that anticholinergics counter the therapeutic action of neuroleptics.14 Findings from recent clinical trials indicate that both muscarinic and nicotinic agonists hold promise in the treatment of cognitive symptoms of schizophrenia.
While awaiting new cholinergic agonists, we can begin to address the cholinergic deficit in schizophrenia. First is to “do no harm” by avoiding the use of highly anticholinergic regimens that can exacerbate cognitive deficits. For example, if the use of anticholinergics to treat extrapyramidal syndrome (EPS) appears to be exacerbating cognitive symptoms, consider amantadine, which treats EPS but is not an anticholinergic. In a double-blind, cross-over study, Silver and Geraisy17 showed that biperiden (an anticholinergic), but not amantadine, interferes with memory and, in particular, visual memory.

It is extremely important to help those with schizophrenia to stop smoking; bear in mind, however, that they may smoke because nicotine improves their cognitive symptoms. While the smoking itself should cease, nicotine replacement therapy may need to be continued indefinitely to prevent a worsening of cognition.

D1 dopamine–mediated processes

A link has been shown between prefrontal dysfunction and the cognitive deficits observed in schizophrenia.18,19 Goldman–Rakic20 has suggested that disruption of D1 dopamine receptor activity can contribute to the cognitive symptoms of schizophrenia, while stimulation of the D1 dopamine receptor improves cognition.21

Modafinil has been found to improve short–term verbal memory span, visual memory, and spatial planning in patients with chronic schizophrenia. It is reasonable to hypothesize that it does this, at least in part, by stimulating D1 dopamine receptors.22

Hypofunction of the NMDAglutamate system

In the 1980s, phencyclidine (PCP), “angel dust,” was a widely used recreational drug of abuse. Some people were brought to psychiatric emergency departments with schizophrenia–like symptoms, including positive, negative, and cognitive symptoms. The hypothesis that schizophrenia may be a result of hypofunction of the NMDA glutamate system emerged when it was found that PCP blocked calcium efflux through channels controlled by NMDA glutamate receptors.

In the NMDA glutamate system, glutamate binding to a subset of receptors leads to the opening of the calcium channel, but only if a second site is simultaneously occupied by either glycine or D–serine, both of which are released into the synapse by astrocytes. Glycine’s action is terminated when it binds to a glycine transporter protein and is brought back to the astrocytes where it is oxidized. High doses of dietary glycine added to antipsychotic regimens can lead to clinical improvement, but in clinical practice, glycine–induced nausea limits its utility.23

Recently, another promising strategy has emerged. Glycine levels in the synapses can be raised by glycine transport inhibitors that prevent glycine from entering the surroundingastrocytes. Consequently, more glycine remains in the synapse.

Several glycine transport inhibitors are presently in or are entering clinical trials. One promising candidate is N–methylglycine, or sarcosine.24 Preliminary studies indicate that added to antipsychotics, 1 to 2 g of sarcosine per day can lead to significant improvement in positive, negative, and cognitive symptoms.

Cognitive Symptoms in Schizophrenia Recognizing and Treating Cognitive Deficits in Schizophrenia

Амантадин для коррекции набора веса при терапии оланзапином

OBJECTIVE: This study sought to determine if amantadine affects weight gain in psychiatric patients taking olanzapine. METHOD: Twenty-one adults who had gained at least 5 lb with olanzapine were randomly assigned to receive amantadine (N=12) or placebo (N=9) in addition to olanzapine. The length of time taking olanzapine ranged from 1 to 44 months. Body mass index, psychiatric status, and fasting blood levels were assessed at baseline and 12 weeks. RESULTS: Significantly fewer subjects taking amantadine gained weight, with a mean change in body mass index of –0.07 kg/m2 for the amantadine group and 1.24 kg/m2 for the placebo group. This effect remained significant when the authors controlled for baseline body mass index and length of olanzapine treatment. No changes in fasting glucose, insulin, leptin, prolactin, and lipid levels were seen. Positive and Negative Syndrome Scale scores remained stable. CONCLUSIONS: Amantadine induced weight stabilization in subjects taking olanzapine and was well tolerated.
Double-Blind, Placebo-Controlled Investigation of Amantadine for Weight Loss in Subjects Who Gained Weight With Olanzapine

Treatment of Sexual Side Effects: Antidotes

Treatment of Sexual Side Effects: Antidotes

A variety of antidotes have been reported to treat SSRI-induced sexual dysfunction effectively; however, virtually all the data on these agents are derived from open case reports and case series. Insofar as sexual function improvement may be responsive to placebo effects, it is impossible to estimate the true efficacy of these antidotes.[27]

Most of these antidotes either have serotonin-blocking properties (especially 5HT-2 antagonistic effects) or augment catecholamine activity, especially that of dopamine. The antiserotonergic antidotes are cyproheptadine, buspirone, nefazodone, and mianserin. Medications enhancing dopaminergic tone include amantadine, bupropion, and stimulants, with yohimbine showing noradrenergic effects. Among the reported antidotes, the only 2 without antiserotonergic effects or catecholaminergic activity are gingko biloba and urecholine.

Cyproheptadine is an antihistamine with antiserotonergic properties that has been reported for over a decade to reverse antidepressant-induced sexual dysfunction. Only case reports and case series attest to its efficacy.[13,42-44] Effective doses range from 2mg to 16mg. In the most recent and largest case series, 12 of 25 patients described improvement in sexual function when treated with cyproheptadine (mean dose, 8.6mg).[13] Anorgasmia is the sexual side effect most often reported to be alleviated by cyproheptadine. Cyproheptadine is effective when taken either on an as-needed basis (typically, 1 to 2 hours before intercourse) or on a regular basis.

However, cyproheptadine's utility is often limited by its potential side effects. Excessive sedation and the reversal of the therapeutic effect of the antidepressant are major problems that limit its usefulness. Effectively treated depression and bulimic symptoms have been reported to reemerge soon after cyproheptadine was started.[42,45-48] This reversal of therapeutic effects is itself reversible upon discontinuation.

Buspirone is a serotonin-IA partial agonist typically prescribed to treat persistent anxiety. One case series reported that buspirone reversed both decreased sexual interest and orgasmic dysfunction caused by SSRIs.[49] Most patients using buspirone to treat sexual dysfunction take it daily. The dosage is the same as that used for anxiety (15mg to 60mg daily). The mechanism of action of buspirone in treating sexual dysfunction may be reduction of serotonergic tone via stimulation of presynaptic autoreceptors or the alpha-2 antagonist effects of one of buspirone's major metabolites, 1-pyrimidinylpiperazine.

Nefazodone and mianserin are antidepressants with strong postsynaptic blocking properties. In one case report, nefazodone 150mg taken 1 hour prior to sexual activity completely reversed sertraline-induced anorgasmia.[50] Mianserin, an antidepressant with 5HT-2 and alpha-2 adrenergic antagonist properties, is available in many countries but not in the US. It has been reported to reverse serotonin reuptake inhibitor-induced sexual dysfunction in 9 of 15 patients.[51] Mirtazapine is similar in its biological activity to mianserin and might also be effective in reversing sexual side effects. No case reports or case series have yet been published attesting to this, although clinicians have described such an effect. The putative capacity of mianserin and mirtazapine to reverse sexual side effects can be attributed either to their serotonergic activity or presynaptic alpha-2 activity.

Amantadine, a dopamine agonist, is used both as an antiviral agent and as a treatment for Parkinson's disease. It has been shown in a number of small case series to reverse anorgasmia.[13,52-54] Reported effective doses have ranged between 100mg to 400mg taken either on a daily or as-needed basis. In the most recent case series, 8 (42%) out of 19 patients with SSRI-induced sexual dysfunction improved with amantadine 200mg daily.[13] Given dopamine's consistent effect as a neurotransmitter involved in sexual arousal, a number of other dopamine agonists have been explored as treatments for sexual side effects.[2,55,56]

Bupropion is another commonly touted antidote for SSRI-induced sexual dysfunction.[57,58] It is assumed that the mechanism of action by which bupropion reverses sexual side effects is its weak dopamine agonism. The evidence for bupropion's efficacy is scant, except for unpublished, anecdotal reports, one case report,[57] and a case series[58] in which 31 (66%) of 47 patients showed improvement when bupropion was added to the regimen along with the serotonergic antidepressant. Most patients (18/31) with a successful outcome responded to as-needed use of bupropion 75mg to 150mg. Libido, arousal, and orgasmic difficulties were all effectively reversed. Fifteen percent of treated patients stopped taking bupropion because of its stimulation side effects. It is unclear whether bupropion doses need to be somewhat lower than usual when added to fluoxetine or paroxetine, to compensate for pharmacokinetic interactions resulting in increased bupropion levels.[59]

Stimulants, such as methylphenidate, D-amphetamine, and pemoline, are reported to reverse a variety of sexual side effects caused by SSRIs or MAOIs.[60-62] Low doses of 10mg-25mg of methylphenidate or D-amphetamine have been effective. One should add stimulants to an MAOI with extreme caution because of the risk of a hypertensive episode. However, use of an MAOI/stimulant combination has been shown to be safe in a case series.[63] SSRI/stimulant combinations show no similar risks.

Yohimbine is available with or without a prescription (and with unclear purity) in health food stores. It is an alkaloid from the bark of Corynanthe yohimbi (family, Rubiaceae) and has been used for decades to reverse erectile dysfunction.[64-66] Its efficacy in treating sexual dysfunction may be associated with its ability to block presynaptic alpha-2 adrenergic sites, leading to enhanced adrenergic tone.[65] A variety of sexual side effects have been reported to be alleviated by yohimbine in doses ranging from 2.7mg to 16.2mg daily, prescribed either on a regular 5.4mg 3 times daily basis or on an as-needed basis with single doses up to 16.2mg.[13,67-69] In the largest case series, 17 (81%) of 21 patients showed improvement of sexual side effects when treated with yohimbine (mean dose, 16.2mg).[12]

Typical side effects associated with yohimbine include anxiety, nausea, flushing, urinary urgency, and sweating. Yohimbine has been the subject of the only double-blind, placebo-controlled study to evaluate treatment of sexual dysfunction occurring as a drug side effect.[27] Unfortunately, the placebo effect was marked, showing a minimal drug-placebo difference with yohimbine given at a dose of 5.4mg 3 times daily. Yohimbine is also available in lower potency without a prescription. The purity, potency, and safety of these preparations, however, are unknown.

Bethanechol is a cholinergic agonist that has occasionally been useful in reversing sexual dysfunction associated with TCAs and MAOIs.[70-73] Typical doses are 10mg to 20mg as needed or 30mg to 100mg daily in a divided dose. Potential side effects with bethanechol include diarrhea, cramps, and diaphoresis. No reports have evaluated or suggested the efficacy of bethanechol for treating SSRI-induced sexual side effects.

Gingko biloba is an herbal extract reported to reverse a variety of sexual dysfunctions associated with antidepressants. Information about gingko's ability in this regard is derived from the experience of 1 clinician presenting a large case series.[74] The response rate was greater than 80%, with doses ranging from 60mg twice daily to 120mg twice daily (mean daily dose, 207mg). Reported side effects include gastrointestinal upset, lightheadedness, and stimulation effects. Because gingko may inhibit platelet-activating factor, caution should be used in considering its use by any patient with a bleeding diathesis. The mechanism by which gingko might alleviate sexual dysfunction is unknown.

http://www.medscape.com/viewarticle/430614_5

Основные препараты и дозировки для лечения сексуальной дисфункции вызванной антипсихотиками

Основные препараты и дозировки для лечения сексуальной дисфункции вызванной антипсихотиками