Commonly used antidepressants
Chronic pain not only causes physical pain to patients, but also produces psychological reactions, especially depression, which greatly affects the recovery of chronic pain patients. Generally speaking, acute pain leads to anxiety, while chronic pain, with the prolongation of time, patients repeatedly go to many hospitals and receive a variety of treatment methods are not satisfied, it may make them lose confidence in whether the disease can be cured, on the basis of anxiety secondary to depression, and even depression becomes the main mental disorder. As depression and pain interact with each other, a vicious cycle can be formed, i.e., pain → depression → lower pain threshold → increased pain → severe depression [1]. Once a patient is depressed, he or she may be resistant to medical staff and treatment plans, which in turn affects the treatment of the painful disease itself; in addition, because of the unstable psychological state of the patient, the incidence of doctor-patient conflict and patient suicide is greatly increased, which will make the treatment more difficult. Sun Bing, Department of Pain Medicine, Qingdao Eighth People’s Hospital
The incidence of depressive mood in chronic pain patients is mostly in the range of 17.8% to 92.4% [2-5], and the results of a multicenter cross-sectional epidemiological survey of 246 chronic pain patients showed that the incidence of depressive mood was 38.62%.
In chronic pain patients with combined depressed mood, it is difficult to treat pain only without recognizing and treating depressed mood to relieve pain fundamentally and rapidly and effectively; the analgesic efficacy is significantly improved after paying attention to and actively treating depressed mood. Therefore, the treatment of depressed mood is an important part of chronic pain treatment.
I. Depressed mood treatment goals
(i) To improve the apparent efficiency and clinical cure rate, and to minimize the disability and suicide rate.
(ii) To improve the quality of survival, restore social function, and achieve a true cure.
(C), to prevent relapse.
II. Commonly used antidepressants.
Treatment of depression in patients with chronic pain: ① Somatic treatment: abandon the cause of pain as soon as possible and completely cure the original disease; for those whose cause cannot be identified temporarily, effective analgesic measures should be used, such as the application of drugs, nerve blocks and other methods to relieve the patient of pain first. ②Psychotherapy: such as through analytical therapy, cognitive therapy, supportive therapy and other methods, so that the patient can truly appreciate that doctors and nurses care about and consider his or her suffering and are doing their best to actively treat him or her, thus helping the patient to establish confidence in overcoming the disease. ③ Antidepressant medication: Antidepressant medication refers to the drugs mainly used to treat depressive mental disorders, which do not affect the mood of normal people.
Clinically used antidepressants.
(a), tricyclic antidepressants (TCAs).
1, commonly used drugs: Doxepin (Doxepin), amitriptyline, promethazine, chlorpromazine.
2, mechanism of action: ① M1 receptor blocking effect, ② α receptor blocking effect, ③ H1 receptor blocking effect, ④ inhibit the re-uptake of 5-HT, ⑤ inhibit the re-uptake of NE.
3.Common adverse reactions and treatment.
(1) Peripheral anticholinergic effects cause adverse reactions Main manifestations: dry mouth, blurred vision, urinary retention, bowel movements.
The main manifestations are: dry mouth, blurred vision, urinary retention, constipation, etc. Treatment: ①Dose can be reduced, changed or discontinued. ②Symptomatic treatment. (3) Neostigmine can be tried to counteract.
(2) Central anticholinergic effects cause adverse reactions often occur in drug overdose or special
Individuals, delirium, agitation, myoclonus, chorea or confusion, coma and seizures; some cases may appear delusions, delusions, hallucinations, may be accompanied by flushing, tachycardia, dilated pupils, sweating, hyperthermia, reduced bowel sounds and other symptoms of the vegetative nervous system.
Treatment: ① Discontinue the drug for close observation. ②A state of agitation, delirium or convulsions can be given diazepam 5-10mg, intramuscularly. (3) Vague consciousness or shallow coma state can be given poisonous lentil base 1mg, intravenous slow push or intramuscular injection, 1~2mg per hour. (4) General symptomatic or supportive therapy.
(3) Cardiovascular adverse reactions
1) Postural hypotension and sinus tachycardia are common, mostly due to blockade of α1-adrenergic receptors, and generally do not require special treatment, keep the patient lying down and observe closely.
2) Quinidine-like adverse reactions may occur in patients with occult heart disease; the effect on the cardiac conduction system may be Ⅰ to Ⅲ degree atrioventricular block, bundle branch block or intraventricular block, which may be accompanied by prolonged myocardial repolarization process, secondary atrial premature beats, atrial flutter or ventricular rhythm disturbance.
Treatment: Immediate discontinuation of the drug, cardiac monitoring, and symptomatic management.
Prevention: Strictly exclude contraindications before drug administration.
(4) Metabolic reactions are rare.
Treatment: Immediate discontinuation, symptomatic anti-allergic treatment, and hormone treatment in severe cases.
(5) Other adverse reactions include weight gain, change in libido and other metabolic and endocrine disorders. Teratogenic effects have not been determined, and use is prohibited in the first trimester of pregnancy.
(ii) Monoamine oxidase inhibitors (MAOIs).
1. Commonly used drugs: phenelzine (phenelzine), moclobemide (moclobemide).
2, mechanism of action: inhibit the activity of MAO and other enzymes, reduce the breakdown of central monoamine transmitters, in order to increase the concentration of monoamine transmitters in the synaptic gap.
3, common adverse reactions and treatment mainly for hypertensive crisis and hepatotoxic effects caused by the combination with TCAs. The treatment is based on prevention.
(C) selective 5-hydroxytryptamine reuptake inhibitors (SSRIs): SSRIs are currently the most commonly used antidepressants.
1.Commonly used drugs: fluoxetine (Pepto-Bismol), paroxetine (Sellett), fluvoxamine (fluvoxamine, LanShi), sertraline (sertraline, Zoloft), citalopram (citalopram, Cipro).
2, mechanism of action: selectively inhibit the reuptake of presynaptic membrane 5-hydroxytryptamine, increase the concentration of pentazocine in the synaptic gap, play the antidepressant effect.
3, common advantages of SSRI drugs.
The characteristics of SSRIs can be summarized as STEPS:
S (Safety): small side effects, good safety;
T(Tolerability): good tolerability and high safety;
E(Efficacy): Efficacy is around 70%;
P(Payment): single dose is more expensive, but not more expensive than tricyclic and heterocyclic drugs according to the course of treatment;
S(Simplicity): easy to use.
(D), 5-hydroxytryptamine reuptake enhancers.
1.Commonly used drugs: Datilan (tianeptine)
2, mechanism of action: increase the spontaneous activity of hippocampal pyramidal cells, and accelerate the recovery of its function after inhibition; increase the reuptake of 5-hydroxytryptamine by neurons in the cerebral cortex and hippocampus.
3.Adverse effects are rare and generally not serious. May appear anorexia, dry mouth, nausea, vomiting, abdominal distension, abdominal pain, constipation; insomnia, dizziness, headache, etc.
(E), 5-hydroxytryptamine (5-HT) and norepinephrine (NE) reabsorption dual inhibitors (SNRIs).
1, commonly used drugs: venlafaxine hydrochloride extended-release capsules, trade name Enox, is the world’s first 5-HT and NE dual reuptake inhibitors (SNRIs), the first FDA-approved antidepressant for the treatment of generalized anxiety (GAD).
2. Mechanism of action: dose-dependent monoamine pharmacological profile
(1) Low dose (<75mg/day) with 5-HT reuptake blockade only.
(2) Medium to high dose ( ³150mg/day) with 5-HT and NE reuptake block.
(3) Very high doses have 3 monoamine reuptake blocks: dopamine (DA) as well as 5-HT and NE.
3, adverse reactions Common adverse reactions are: gastrointestinal discomfort (nausea, dry mouth, anorexia, constipation and vomiting), central nervous system abnormalities (dizziness, drowsiness, strange dreams, insomnia and nervousness), visual abnormalities, yawning, sweating and sexual function abnormalities (impotence, abnormal ejaculation, decreased libido). Occasionally, adverse reactions are: weakness, gas, tremor, agitation, diarrhea, and rhinitis.
Adverse reactions mostly occur in the initial phase of treatment, and these symptoms gradually decrease as the treatment progresses.
Table 10-1 Dose range of commonly used antidepressants
Drug name
Commonly used dose (mg)
Usage
Doxepin
Amitriptyline
Fluoxetine (Prozac)
Sertraline (Zoloft)
Paroxetine (Seroquel)
Dactylan
Venlafaxine
25-300
25～300
20～80
50～200
20～80
12.5
75～225
qn
qn
qd
qd
qd
tid
qd
Third, the principles of drug selection.
(a) Use the most familiar drugs, try to avoid the combination of more than two drugs, and fully understand the drug interactions.
(2) Start with small doses and slowly increase the dosage.
(C) the principle of individualization, according to age, sex, weight, disease status and past drug history.
(D) Stronger sedative drugs (such as doxorubicin, amitriptyline, etc.) are suitable for people with anxiety or sleep disorders, and should generally be administered in the evening.
(e) MAOIs should not be used as the first choice, and MAOIs should be used only after two weeks of discontinuation in cases where TCAs are ineffective.
IV. Treatment of combined anxiety
Clinically, sleep disturbances, appetite changes, cardiovascular system/digestive system symptoms, attention disorders, irritability, and decreased energy are symptoms shared by depressed and anxious moods, which are often difficult to distinguish clearly and treat thoroughly [7], a phenomenon known as the co-morbidity of depression and anxiety.
For depressed patients with comorbid anxiety, benzodiazepines (BZDs) can be used along with antidepressants for anxiety. the advantages of BZDs are that they can rapidly relieve anxiety symptoms and are inexpensive and well tolerated by patients; the disadvantages are that long-term use can lead to medically induced drug dependence and affect psychomotor function.
V. Conclusion
The incidence of depressive mood is high in patients with chronic pain, and only by fully recognizing and actively treating depressive mood can we treat chronic pain more effectively and prevent the occurrence of adverse behaviors such as suicide.