"Heat" keeps me healthy | Prevent heat stroke in hot weather! These drugs may also induce heat stroke..

As the dog days of summer approach, the temperature is getting higher and higher. According to news reports, a hospital in Nanjing admitted seven patients with heat stroke in three days, and a man in Guangdong died of heat stroke. In hot weather, it is important to prevent heat stroke.

Heatstroke refers to a disease in which, in an environment of high temperature, high humidity and no wind, the patient's temperature regulation center becomes abnormal, sweat cannot be secreted normally, and water and electrolyte levels are seriously lower than normal.

According to the severity, heat stroke can be divided into heat cramps, heat exhaustion and heat stroke. Common causes include strenuous activities, high temperature environment, diseases or drugs. Among them, drugs can increase the risk of heat stroke in patients through various mechanisms, such as increased heat production, water and electrolyte imbalance, difficulty in sweating, peripheral vasoconstriction, and abnormal hypothalamic temperature regulation.

So, which drugs can increase the risk of heat stroke?

1. Anticholinergics

Cholinergic receptor blockers such as atropine and scopolamine block the acetylcholine receptors on the postsynaptic membrane of the nerve junction, preventing acetylcholine from binding to the receptors and exerting its effect. The function of acetylcholine is to promote the secretion of all glands controlled by the parasympathetic nerves, including sweat glands. Therefore, anticholinergic drugs can inhibit sweating and reduce the release of heat, directly leading to the occurrence of high fever symptoms and inducing heat stroke.

2. Sympathomimetic drugs

Sympathomimetic drugs, including cocaine and ephedrine, activate α and β receptors by promoting the release of neurotransmitters such as dopamine and norepinephrine in the body or preventing their reabsorption, which causes blood vessels to constrict, reduces blood flow to the skin, and reduces heat loss; at the same time, it also increases muscle excitability, strengthens muscle contraction, and leads to increased heat production.

3. Drugs that affect electrolyte balance

Diuretics such as furosemide, hydrochlorothiazide, spironolactone and other drugs that affect electrolyte balance will lead to insufficient effective circulating blood volume, reduce cardiac output, and reduce sweating. At the same time, it will also increase excretion, and the body is prone to electrolyte balance symptoms such as dehydration, which can also increase the incidence of heat stroke. Therefore, when taking such drugs, you should drink plenty of water to avoid heat stroke.

4. Antipsychotics

Antipsychotic drugs such as chlorpromazine and perphenazine can inhibit the afferent nerves of the hypothalamus, which inhibits the ability of the hypothalamic temperature regulation center to adjust body temperature with changes in ambient temperature, inhibiting both heat production and heat dissipation, causing body temperature to change with the external ambient temperature. Under high temperature conditions, high fever can be caused due to the inhibition of the compensatory effect of the hypothalamus.

Nonsteroidal anti-inflammatory analgesics such as aspirin and acetaminophen can inhibit cyclooxygenase in the hypothalamus, block the synthesis of prostaglandins, and restore the body temperature of a person with fever to normal, but such drugs cannot be used to treat heat stroke. This is because heat stroke is a non-regulated body temperature, which is essentially caused by the loss of control of the patient's temperature regulation center. The body temperature cannot be dissipated through sweating, and antipyretic analgesics cannot be used to lower the body temperature.

In general, physical cooling is the preferred way to treat heat stroke.

In the hot summer, to avoid heat stroke, you need to maintain adequate water and sodium intake and avoid activities in high temperatures. If you need to take the above-mentioned drugs, you should try to choose other alternative drugs; if you must use them, you should pay attention to the ambient temperature to avoid inducing heat stroke.

Author: Liu Yajuan, pharmacist at the First Hospital of Jilin University

Review expert: Wang Baoxin, deputy director and pharmacist of the Pharmacy Department of Peking University First Hospital

Wei Guoyi, Chief Pharmacist, Beijing Anzhen Hospital, Capital Medical University