What Are the Different Types of Antidepressant Drugs?

Antidepressive drugs refer to a group of psychotropic drugs that are mainly used to treat mental illness with prominent symptoms of emotional depression. The difference with stimulants is that they can only eliminate the depressive symptoms of depressed patients, but not improve the mood of normal people. Antidepressants came out in the 1950s. Prior to this, there was no suitable medical treatment for depressive diseases, and electric shock was often used for treatment. Since the 1950s, antidepressants have become the treatment of choice for patients with depression, largely replacing shock treatment, and greatly reducing the number of patients requiring shock treatment.

Antidepressants are a large class of many psychotropic drugs that are mainly used to treat depression and various depressive states. There are two common first-generation antidepressants, namely monoamine oxidase inhibitors (MAOI) and tricyclic antidepressants (TCA).

Due to the rapid development of new drugs, new drugs have emerged endlessly, such as venlafaxine, nafazodone, etc., but currently selective serotonin (5-HT) reuptake inhibitors are still the mainstay, and the clinical application of these drugs is also the most widespread. The antidepressant effects of certain antipsychotic drugs such as sulpiride, anxiolytic alprazolam, roller, buspirone, and central stimulant methylphenidate are still controversial, so they are omitted.

Chinese name: Antidepressants
Foreign name: antidepressive drugs

Treatment: Emotional depression is a mental illness with prominent symptoms
Classification: MAOI and tricyclic antidepressants

Antidepressants Common Drugs

Monoamine oxidase

Isopropylhydrazine was the first antidepressant to come out in the 1950s. Promethazine is an anti-tuberculosis drug. Because of its central excitatory effects such as hyperactivity, hyperactivity, insomnia, and euphoria, it was tried in 1957 and was successfully used. Animal experiments have confirmed that it can reverse the apathy and less movement caused by reserpine, and at the same time, the brain monoamine content increases. It is speculated that the central excitatory and antidepressant effects are due to the inhibition of monoamine oxidase in the brain, which reduces the degradation of monoamine, which increases the monoamine content in the interstitial space. This suggested that the relationship between animal behaviors and brain single receptor transmitters has important theoretical and practical significance, laying a foundation for the study of psychopharmacology and the etiology of mental diseases.

Also falling into this category are isocarbohydrazine, phenethylhydrazine, tranylcypromine and the like. These drugs were widely used for a time, and were soon eliminated due to serious adverse reactions such as hypertension crisis and acute yellow liver atrophy that occurred due to the interaction with certain foods and drugs.

In the late 1980s, a new generation of half-day oxidase inhibitors appeared, that is, a reversible monoamine oxidase subtype (MAO-A) depression agent. It is characterized by: 1 high selectivity to MAO-A, and another isoenzyme MAO-B is less selective, so it can still degrade the cool amines in food, thereby reducing the risk of hypertension crisis. 2 has a reversible MAO-A inhibitory effect, which restores enzyme activity in only 8-10 hours, while the old hemidayamine oxidase inhibitors inhibit for up to 2 weeks, thus reducing the risk of interaction with food. The main product is moclobemide, dose 150-450mg / d, divided into doses. The efficacy is said to be comparable to tricyclic antidepressants.

Although it is safer than the old hemi-day amine oxidase inhibitors, it is still necessary to pay attention to orthostatic hypotension and potential food-drug interactions, and it is generally not the first choice.

Antidepressants tricyclics

Is another type of antidepressant immediately after monoamine oxidase inhibitors, represented by imipramine.

Its chemical structure is similar to chlorpromazine. It was thought to be a new antipsychotic drug, but the results of clinical trials were unexpected. The drug was ineffective against schizophrenia but improved depression. Later, a large number of double-blind placebo-controlled studies have confirmed that it has replaced monoamine oxidase inhibitors and has become the drug of choice for the treatment of depression. It has monopolized the antidepressant market for 30 years.

There are more than 10 kinds of tricyclic antidepressants. In addition to imipramine in China, there are amitriptyline, doxepin and clomipramine. Although Maprotiline has a tetracyclic structure, its pharmacological effect is consistent with that of tricyclic antidepressants. The indications for tricyclic antidepressants are various types of depression, with an effective rate of about 70% -80%, an onset time of 1-2 weeks, a dosage range of 50-250mg / d, a slow increase and a divided dose. Due to the strong sedative effect, the dose should be larger at night. The therapeutic range of plasma concentrations of imipramine and amitriptyline is 50-250ng / ml.

Tricyclic antidepressants have been used for the longest period of time, and their pharmacological effects have been studied the most and most fully. In short, their main pharmacological effects are: 1 block the reuptake of monoamine transmitters (mainly adrenaline and 5-HT) , So that the synaptic space alone increased content and produce antidepressant effects. 2Blocking a variety of transmitter receptors, which has nothing to do with treatment, but is the main cause of many adverse reactions, such as blocking acetylcholine M receptors, dry mouth, blurred vision, sinus tachycardia, constipation, urine may occur Retention, exacerbation of glaucoma, memory dysfunction; blocking the adrenaline a1 receptor may enhance the hypotensive effect of prazosin, orthostatic hypotension, dizziness, reflex tachycardia; block the histamine H1 receptor, It may appear to strengthen the role of central inhibitors, sedation, drowsiness, increase weight, and lower blood pressure; block dopamine D2 receptors may appear extrapyramidal symptoms and endocrine changes.

Antidepressant drugs with severe side effects should be reduced, discontinued or replaced with other drugs. In general, the combination of two or more antidepressants is not recommended. Due to the high recurrence rate of this disease, treatment should be maintained for 4-6 months after the symptoms are relieved, in order to consolidate the curative effect and prevent recurrence.

Most pharmacies can't buy the above medicines.They can only be bought at regular hospitals, and Mafulong will not cause depression.

New antidepressants

Selective 5-HT reuptake inhibitors (SSRIs) are new antidepressants. This class of drugs has been developed since the 1970s, and dozens of them have been developed. Fluoxetine, paroxetine, sertraline, fluvoxamine, citalopram, etc. are commonly used in clinical practice. This class of drugs has a small sedative effect, does not damage psychomotor function, and has little effect on cardiovascular and autonomic nervous system functions. This class of drugs also has dual effects of antidepressant and antianxiety, and is mostly used for depression caused by 5-HT decrease in the brain.

Antidepressant Medication Guide

Antidepressants reflect the elimination of pathological depression and improve mood. Psychotropic drugs used to treat depressive disorders. It is different from a psychostimulant and can only eliminate pathological depression and does not improve the mood of normal people. There are three types that have been used clinically.

(1) Tricyclic antidepressants (TCA): commonly used drugs are imipramine, amitriptyline, doxepine, chloroprimipramine, etc. The therapeutic dose is 50-200 mg / d. Mainly applicable to depressive symptoms that occur in internal depression and other diseases. Can also be used for treatment of symptoms and panic attacks. Severe heart, liver, kidney and glaucoma patients are prohibited, elderly patients, pregnant women, patients with enlarged prostate and epilepsy should be used with caution.

The mechanism of TCA's antidepressant effect has not yet blocked the amine pump by TCA and reduced the recovery of biogenic amines by the presynaptic membrane, especially the reduction of noradrenaline (NE) and serotonin (5-HT), making post-synaptic exposure The concentration of effective neurotransmitters in the body part increases, which plays an antidepressant effect.

TCA has the earliest sedative effects, followed by improvements in diet and behavior, and generally improves mood after 2 to 4 weeks. In application, the dose-increment method is adopted. After the therapeutic effect is obtained, the treatment dose is continued for 4 to 6 weeks, and then reduced to half the amount for 6 months.

TCA side effects, peripheral anticholinergic side effects are common, such as dry mouth, constipation, blurred vision, dysuria, and orthostatic hypotension, which can lead to urinary retention and intestinal paralysis in elderly patients. The effect on blood pressure and the toxicity to the heart is large, which can cause myocardial damage. The rhythm and ECG changes should be closely observed. There are also side effects such as inducing mania, fine tremor in the hands, and anti-cholinergic delirium.

(B) Monoamine oxidase inhibitor (MAOI) is the earliest antidepressant. It mainly reduces the destruction of monoamine transmitters in the central nervous system through depression, and increases the concentration in the synaptic space , Play a role in improving emotions. Due to the many side effects of MAOI, the antidepressant effect is less than that of TCA, and has been gradually replaced by TCA in the past 20 years.

Commonly used drugs are phenelzine (hydrazine), starting from 15 mg twice a day, gradually increasing the amount, the maximum daily amount is 75 mg; the daily dose of superphenylcypromine is 10 to 30 mg. During treatment, pay attention to observe its anticholinergic side effects and damage to the liver. Those with cardiovascular, liver and kidney diseases should not use it. It is not advisable to eat foods containing higher amines (such as cheese, chicken liver, beer, etc.) during the medication period, otherwise high blood pressure crisis is likely to occur. The interaction of MAOI with many drugs or foods should alert medical staff and alert patients.

It is generally not combined with TCA. If you need to switch to TCA, you should stop using MAOI for 2 weeks before you start taking TCA.

(3) The representative drug of tetracyclic antidepressants (tetracyclica) is maprotiline, which has a similar effect to TCA, but has the advantages of quick effect, few side effects, and a wide spectrum of antidepressant effects. Because it is less toxic to the heart, the drug is better tolerated by patients, and it is more suitable for elderly or depression patients with cardiovascular disease.

Medication method is the same as TCA, the maximum daily dose is 200mg.

Antidepressant side effects

Drowsiness, dry mouth, blurred vision, constipation, accelerated heartbeat, difficulty urinating and orthostatic hypotension. Such side effects generally do not affect the treatment and can gradually adapt during the treatment process; severe cardiovascular side effects, urinary retention and bowel Paralysis is rare. Overdose can cause acute poisoning and even death.

Recent research has also proven to increase the risk of cerebral hemorrhage. ^[1]