However, the effect of the dasg is determined not only
its concentration in the body, but also the functional state of tissue or
target organ and receptors that are affected a particular chemical compound
. In elderly people, along with a decrease in the number of receptors of the nervous tissue
mentioned as a functional exhaustion and reduced
reactivity. It promotes tasdnoprognoziasemyh, atypical,
inadequate number of injected dasgs, and even paradoxical reactions
application, for example, cardiac glycosides, corticosteroids, nitrates,
agonists and blockers, some antihypertensive dasgs,
analgesics, barbiturates , benzodiazepine tranquilizers,
antiparkinsonian and anticonvulsant dasgs.
development of atypical reactions to the dasgs also contributes to reduced
physical activity, tendency to constipation, vitamin deficiency,
deterioration of blood supply to tissues and the relative dominance of processes
excitation in the nervous system of the elderly. As a result, barbiturates, eg,
often cause impairment of consciousness, or paradoxical excitation, delay
urination, and reduced sensitivity to beta-blockers and alpha-
adrenomimetikami. Also noted increased sensitivity to antipsychotics,
causing confusion, hypotension and urinary retention. The use of nitrates and
novokainamid accompanied bymorepronounced than in patients
middle age, lower blood pressure and possible deterioration
cerebral circulation. Identified and to increase chuvstvvitelnosti
anticoagulation.
Varies with age and sensitivity to dasgs. As a result, their
introduction of older people is much faster than the young, comes
inhibition of the respiratory and arousal emetic centers. Therefore, when
pulmonary insufficiency caused by bronchial asthma, emphysema, pneumosclerosis and
also deformation of the chest trauma
dasgs to elderly patients should be prescribed with great caution.
Possible atypical reactions to certain dasgs are given in Table 2.
Features dosing
Perhaps the hardest, but most important in dasg therapy - a selection of
individual, the optimal dose of medication to the patient. But the particular importance of selecting the optimal dose
acquires gerofarmakologii, because, as has been
mentioned above, the body of older people in their own response to the introduction of
dasgs.
Practice shows that for patients older than 60 years of the initial dose of dasgs,
depressing the central nervous system, as well as cardiac glycosides and
diuretics should be reduced to 1 / 2 standard dose for an adult
rights. Doses of other potent dasgs should be 2 / 3 of the dose,
given to patients of middle age. Then gradually increase the dose to
achieve the desired therapeutic effect, then reduced to
supports, which are generally lower than for patients of middle age.
In selecting the optimal dose of injected dasg should also be considered
severity of functional changes in senile body, primarily liver and kidney
, individual tolerance and sensitivity to a particular
dasg. In addition, taking into account characteristics such as period
half-life and therapeutic breadth of the dasg.
Especially it should be considered when prescribing allocated in unaltered form
kidney (digoxin, aminoglycosides, atenolol, etc.).
must take into account the influence of dasgs on the absorption of vital
important components of food (vitamins, fat, calcium, phosphate, potassium). So,
example, broad-spectasm antibiotics, or applied for a long time
steroids may interfere with calcium absorption, so
thus increasing the risk of osteoporosis in older patients.
Destasction of bone and contribute to anticonvulsants (fenition, phenobarbital
, etc.), which accelerate the metabolism of vitamin D. Laxatives
(phenolphthalein, Bisacodyl, Dulcolax, senna, etc.), which are often used
elderly people, violate the absorption of fat, calcium, vitamins A, D, C. A
tetracyclines, antacids and salicylates uhudshayut iron absorption. In addition,
some dasgs can accelerate the excretion of nutrients from the body
elderly patients (Table 3), and therefore the required adjustment of their food ration
.
Know, that
avoid complications
According to medical statistics, the risk of side effects in
patients over 60 years in 1,5 times higher than that of the young. And in patients 70 -
79 years of age adverse reactions to the introduction of dasgs developed in 7
(!) Timesmorelikely than patients aged 20-29 years. People elderly in
2-3 timesmorelikely than young and middle-aged, hospitalized at the
side effects of dasgs. And the greatest number of deaths associated with
irrational pharmacotherapy, accounted for the age group 80 - 90 years.
However, in some cases in the guilty and the patient himself: confused dasgs,
took an extra dose of medication combined with alcohol, etc. In any case
, with the appointment of three ormoremedications
probability of such errors increases significantly.
As the well-known clinicians (AS Melent'ev, VS Gasilin, EI Gusev,
AI Martynov, etc.), symptoms of adverse reactions to medications
older age is often atypical. For example, disasption of water and electrolyte balance
in elderly patients may manifest itself as mental disorders. Often
dasgs are well tolerated at a young age, cause depression in elderly patients
(propranolol, indomethacin, corticosteroids, etc.). Critical
lowering blood pressure in elderly patients may occur when therapy
antihypertensive dasgs (ganglion blocking, vasodilators, angiotensin-converting enzyme inhibitors
, diuretics, narcotic dasgs,
fenotiazinovyh neuroleptics holinoblokatory etc.).
But the most susceptible to toxic damage in the wrong appointment
medications kidney. Keep in mind that aminoglycosides are a major group
dasgs that cause acute renal failure (the most nephrotoxic
gentamicin, less toxic netilmicin, amikacin). When used in high doses
can cause acute renal failure and cephalosporins
first generation (cephalothin-keflin, tsefaloridin-tseporin). In addition, renal
can cause non-steroidal anti-inflammatory dasgs (indomethacin,
phenacetin), angiotensin converting enzyme inhibitors (captopril, enalapril).
In the latter case, the risk factors include bilateral renal artery stenosis
or general atherosclerosis, which is typical for elderly patients. Chronic
as renal failure may develop during prolonged use
cytostatics, analgesics, prolonged and excessive use of diuretics and laxatives
.
Valium actions have aminoglycosides (streptomycin, gentamicin),
salicylates, and as furosemide, Uregei etc. Some dasgs can cause
tinnitus - a complication presenting no danger to life, but extremely
painful for patients. These include: indomethacin, analgin-quinine,
caffeine, theophylline, dasgs lithium, amitriptyline, digoxin, and
the above medications, have an ototoxic effect.
It is also important to remember that often occur in old age violations
purine metabolism may contribute to pancreatin, inosine, diuretics (thiazides,
furosemide), and even small doses of salicylate (1 - 2 g / day), nicotinic acid
.
should also consider the fact that the simultaneous application of belladonna alkaloids
, tricyclic antidepressants, antiparkinsonian funds,
antihistamines, and some antiarrhythmics (disopyramide, ritmilen) in patients
elderly increases the risk of adverse reactions
. The clinical picture in this case varies from dryness in the mouth,
constipation, blurred vision, tachycardia, hyperthermia, and facial flushing to
urinary retention, disorders of consciousness, visual hallucinations, excitationof,
drowsiness and even coma. In some cases, such symptoms as delirium,
dementia or psychosis in elderly patients is a source of
diagnostic errors if not taken into account the possible connection of these states with
taking anticholinergic dasgs. One must also remember that in patients with severe
dry mouth caused by the intake of a number of dasgs, reduced the effectiveness of sublingual
prescribers, including nitroglycerin.
Because elderly patients have to assign multiple
dasgs a doctor should always think about the interaction of dasgs and
their possible incompatibility. For example, antacids, iron preparations,
charcoal violate absorption of many dasgs (doxycycline,
metatsiklin, methyldopa, levodopa, ciprofloxacin, thyroxine, captopril and folic acid
, etc.), which reduces their therapeutic effect. A dasg is actively
binding to proteins, alter the distribution of medicines,
displacing them from binding with proteins. For example, phenylbutazone (phenylbutazone) may displace from
with protein coumarin anticoagulants and hypoglycemic agents,
are, respectively, resulting in hemorrhagic complications and
hypoglycemia.
Some medications may increase (inductors) or decrease (inhibitors )
activity of liver enzymes, changing the rate of biotransformation
simultaneously used dasgs. Thus, when prescribing,
an inducer of liver enzymes (barbiturates, rifampicin,
diphenine) increase the synthesis and activity of the latter. As a result, increases the rate of biotransformation
simultaneous use of the dasg with a decrease in its
concentrations below therapeutic levels and a corresponding decrease
therapeutic effect (eg, coumarin anticoagulants, cortico-steroids). By the way,
nicotine and alcohol are also inducers of liver enzymes and
reduce the effectiveness of some medications (theophylline, nitrates, propranolol, etc.).
Dasgs affecting urine pH may significantly affect the
selection of other dasgs. For example, funds alkalify urine
help accelerate the elimination of barbiturates and salicylates; means, acidifying the urine,
contribute to an increase in clearance of codeine, morphine, Novocain, on the one
hand, reduces the effect of these dasgs, on the other - can be
used in the treatment of poisoning.
should also be borne in mind that often possible to combine different mechanisms
dasg interactions. Some medicines are not interacting
itself, alter the conditions of interaction with receptors and, accordingly,
pharmacodynamics of other dasgs. As a result of the simultaneous appointment of
several dasgs can significantly alter most end
effect of the dasg in older people compared with younger patients.
That is why it is very important in each case, appointing an elderly patient
multiple dasgs, to weigh carefully the possible side
of dasgs, clearly define the sequence and time of receipt of each of them
.
In conclusion, I would like to emphasize that the dasgs designated
elderly people without taking into account features of geriatric pharmacotherapy may
cause much greater harm than the disease itself, for the treatment which they
used.
article was published in the Journal of Pharmaceutical
Gazette ;