Along with the aging of our society’s population, more and more elderly patients are suffering from more kinds of diseases, and the types of drugs used in treatment also increase accordingly, so the occurrence of adverse drug reactions cannot help but draw the attention of medical workers and patients. Some statistics show that the incidence of adverse drug reactions in the elderly is 2~3 times higher than that of young people. Therefore, understanding the physiological characteristics of the elderly, mastering the common adverse drug reactions and preventive measures for the elderly is the prerequisite to ensure the safe use of drugs and rational use of drugs for elderly patients. This article briefly introduces the clinical manifestations, common causes and prevention of adverse drug reactions in the elderly. Liu Hongliang, Department of Geriatrics, The First Affiliated Hospital of Henan College of Traditional Chinese Medicine
1 Common types of adverse drug reactions in the elderly Common and serious adverse reactions and related drugs are as follows.
1.1 Abnormal liver and kidney function
Most drugs are metabolized by the liver and excreted by the kidneys. As the elderly are in a state of decline in many aspects such as physiology and psychology, especially the declining liver and kidney function, resulting in the body’s metabolism and excretion of drugs and other functions, the half-life of drugs is prolonged, accumulating in the body, increasing the burden on the liver and kidneys, thus causing liver and kidney cell damage and abnormal liver and kidney function, such as: anti-tuberculosis drugs (isoniazid), acetaminophen, antifungal drugs (fluconazole), chemotherapy drugs and immunosuppressants (aminopterin), oral hypoglycemic drugs (troglitazone), aminoglycoside antibiotics (gentamicin), etc.
1.2 Cardiac arrhythmia
Some drugs applied on the selection of improper dose or with other serious underlying diseases can appear arrhythmias, such as: digitalis, morphine, ephedrine, atropine, benzoin, quinidine, etc.
1.3 Postural hypotension
Postural hypotension may occur when taking vasodilators, antihypertensive drugs, diuretics, etc., such as: sodium nitroprusside, captopril, guanethidine, prazosin, hydrochlorothiazide, chlorpromazine, etc.
1.4 Urinary retention
Urinary retention is likely to occur with anti-Parkinsonian drugs, bicyclic antidepressants, M-blockers, etc. It is more likely to be induced in elderly patients with prostatic hypertrophy.
1.5 Ototoxicity
Some drugs have ototoxicity, such as: aminoglycoside antibiotics, chloramphenicol, furosemide, etc.
1.6 Anaphylaxis
Once it occurs, the danger is serious and the mortality rate is extremely high, such as: penicillin, streptomycin, cefotaxime sodium, etc.
1.7 Severe drug rash and anaphylactic purpura
It can cause circumscribed chronic congestion, bruising, rash and anaphylactic purpura, such as: penicillin, streptomycin, chloramphenicol, isoniazid, sulfonamides, etc.
1.8 Leukocytopenia and thrombocytopenia
May inhibit bone marrow hematopoietic function, such as: chloramphenicol, interferon, anticancer drugs, etc. .
1.9 Psychoneurological symptoms
May cause neurasthenia, ataxia, insomnia and forgetfulness, hallucinations, depression or mania, such as: atropine, scopolamine, Librium, glucocorticoids, amantadine, reserpine, chloramphenicol, isoniazid, etc.
2 Reasons for the occurrence of adverse drug reactions in the elderly
Mainly due to the physiological characteristics of the elderly themselves determine the incidence of adverse drug reactions.
(1) Tissue and organ cell aging and reduction, the ability to respond to drugs is poor.
(2) Low plasma protein content increases the concentration of free drugs, which can easily cause drug accumulation poisoning.
(3) Decrease in body water and increase in the proportion of fat, which affects the distribution of drugs in the body.
(4) Decrease in hepatic blood flow and decrease in metabolism and detoxification ability of drugs, which can easily cause drug accumulation poisoning in the body with continuous drug use.
(5) Decreased glomerular filtration rate, decreased renal tubular excretion and reabsorption capacity, resulting in slow excretion of drugs.
(6) Prostate hypertrophy and bladder muscle weakness, also affect drug excretion.
(7) Weakened myocardial contractility, reduced cardiac output, reduced cardiac reserve function, and weakened reactive regulation, which can easily lead to arrhythmias, etc.
(8) Cerebral vascular sclerosis narrowing, brain cells gradually decrease, making the central nervous system function is reduced, the sensitivity of nerve endings is reduced, and the possibility of adverse reactions of the nervous system increases.
(9) Atherosclerosis, vasomotor center regulation ability is reduced, the body’s own regulation ability is poor when the condition changes, once the adverse reaction occurs, the mortality rate is high.
(10) The elderly are forgetful, inattentive, prone to abuse, misuse or overdose of drugs.
3 Preventive measures for adverse drug reactions in the elderly
3.1 Reasonable choice of drugs
On the basis of clear diagnosis, according to the physiological characteristics of the elderly, choose the drug with certain efficacy and minimum effective dose. the dose for the elderly over 60 years old is 3/4 of the adult dose, and the central nervous system suppressant should be 1/2 or 3/4 of the adult dose as the starting dose. For prudence, it is best to start with small doses for the elderly, and if blood concentration monitoring can be performed, the dose can be more accurately adjusted according to individual differences. For the comprehensive treatment of multiple chronic diseases, the number of medications should be small and precise, generally no more than 5. Although the elderly can have a variety of illnesses, medication should be used according to the priority of the illness. Generally, drugs for acute diseases should be given first, and then drugs for other diseases should be taken into consideration after the disease is basically controlled.
3.2 Develop individualized drug administration plan
According to the physiological characteristics of the elderly, the functional status of each organ, the type of diseases they suffer from and the severity of the diseases they suffer from, individualized medication plan is formulated.
3.3 Strictly control the preventive medication
Grasp the indications for preventive medication and avoid abusing drugs at will.
3.4 Improve medication adherence
To prevent this, elderly people should take medication with the assistance and supervision of family members, relatives and friends. Taking medication as prescribed by the doctor is an important guarantee to improve the efficacy and avoid accidents. Health care workers should do a good job of medication follow-up and adjust the dose and type of medication in time.
3.5 Correct medication misconceptions
Some elderly people rely on their own experience of “becoming a doctor after a long time” and use drugs casually or increase the dosage of drugs without diagnosis, which is especially dangerous for the elderly who are in poor health or suffering from multiple chronic diseases. Some elderly people also listen to advertisements and believe in famous, expensive, new drugs or health products, which are inappropriate.
3.6 Control of hobbies and diet
The elderly should control their hobbies such as smoking, alcohol, sugar and tea during the medication period, which may affect the efficacy of the drugs, and should pay attention to dietary taboos according to the instructions of various drugs to avoid reactions with them. The elderly should be guided to adjust the dietary structure, and a reasonable diet is conducive to the efficacy of drugs.
3.7 Psychological intervention
When a person’s mental state is good, his or her own immune function will be enhanced, so psychological intervention will also affect the efficacy of drugs.