Depression is one of the most common psychiatric disorders. It is characterized by feelings of intense sadness,helplessness, worthlessness, and impaired functioning.Those experiencing a major depressive episode exhibit physical and psychological symptoms, such as appetite disturbances, sleep disturbances, and loss of interest in job, family, and other activities usually enjoyed. A major depressive episode is a depressed or dysphoric (extreme or exaggerated sadness, anxiety, or unhappiness) mood that interferes with daily functioning and includes five or more of the symptoms listed in Display
Symptoms of Depression
1 Depressed mood
2 Diminished interest in activities of life
3 Significant weight loss or gain (without dieting)
4 Insomnia (inability to sleep) or hypersomnia (excessive sleeping)
5 Psychomotor agitation or retardation
6Fatigue or loss of energy
7 Feelings of worthlessness
8 Excessive or inappropriate guilt
9 Diminished ability to think or concentrate, or indecisiveness
10 Recurrent thoughts of death or suicide (or suicide attempt)
To be classified as a major depression, these symptoms should occur daily or nearly every day for a period
of 2 weeks or more. The symptoms of major depression should not be the result of normal bereavement, such as the loss of a loved one, or disease, such as hypothy-roidism.Depression is treated with the use of antidepressant drugs. Psychotherapy is used in conjunction with the antidepressant drugs in treating major depressive episodes.
The four types of antidepressants are:
• Tricyclic antidepressants (TCAs)
• Monoamine oxidase inhibitors (MAOIs)
• Selective serotonin reuptake inhibitors (SSRIs)
• A group of miscellaneous, unrelated drugs
ACTIONS
For several years it was thought that the antidepressants blocked the reuptake of the endogenous neurohormones norepinephrine and serotonin, which resulted in stimulation of the central nervous system (CNS).Although the exact mechanism of action is unknown,this theory is now being questioned. New research indicates that the effects of the antidepressants are related to the slower adaptive changes in norepinephrine and serotonin receptor systems. Treatment with the antidepressants is thought to produce complex changes in the sensitivities of both presynaptic and postsynaptic receptor sites. The antidepressants increase the sensitivity of postsynaptic alpha -adrenergic and serotonin receptors and decrease the sensitivity of the presynaptic receptor sites. This enhances the recovery from the depressive episode by normalizing neurotransmission activity.
The TCAs, such as amitriptyline (Elavil) and doxepin (Sinequan), inhibit reuptake of norepinephrine or
serotonin at the presynaptic neuron. Drugs classified as MAOIs inhibit the activity of monoamine oxidase, a
complex enzyme system that is responsible for breaking down amines. This results in an increase in endogenous epinephrine, norepinephrine, and serotonin in the nervous system. An increase in these neurohormones results in stimulation of the CNS. The action of the SSRIs is linked to their inhibition of CNS neuronal uptake of serotonin (a CNS neurotransmitter). The increase in serotonin levels is thought to act as a stimulant to reverse depression.
The mechanism of action of most of the miscellaneous antidepressants is not clearly understood. Examples of this group of drugs include fluoxetine (Prozac) and bupropion (Wellbutrin).
USES
Antidepressant drugs are used to manage depressive episodes such as major depression or depression
accompanied by anxiety. These drugs may be used in conjunction with psychotherapy in severe depression.
The SSRIs also are used to treat obsessive-compulsive disorders.Treatment is usually continued for 9 months after recovery from the first major depressive episode. If the patient, at a later date, experiences another major depressive episode, treatment is continued for 5 years,and with a third episode, treatment is continued indefinitely.
ADVERSE REACTIONS
TCAs
Sedation and dry mouth are the most common adversereactions seen with the use of TCAs. Tolerance to these effects develops with continued use. Orthostatic hypotension can occur with the administration of the
TCAs. Orthostatic hypotension is a drop in blood pressure of 20 to 30 points when a person changes position, such as going from a lying position to a standing position. Mental confusion, lethargy, disorientation,
rash, nausea, vomiting, constipation, urinary retention,visual disturbances, photosensitivity, and nasal congestion also may be seen. Sexual dysfunction may occur with administration of clomipramine.
MAOIs
Orthostatic hypotension is a common adverse reaction seen with the administration of the MAOIs. Other common adverse reactions include dizziness, vertigo, nausea, constipation, dry mouth, diarrhea, headache, and overactivity.One serious adverse reaction associated with the use of the MAOIs is hypertensive crisis (extremely high blood pressure), which may occur when foods containing tyramine (an amino acid present in some foods) are eaten (see Home Care Checklist: Avoiding Drug–Food Interactions With MAOIs).
One of the earliest symptoms of hypertensive crisis is headache (usually occipital), followed by a stiff or sore
neck, nausea, vomiting, sweating, fever, chest pain,dilated pupils, and bradycardia or tachycardia. If a hypertensive crisis occurs, immediate medical intervention is necessary to reduce the blood pressure. Strokes (cerebrovascular accidents) and death have been reported.
SSRIs
Some of the more common adverse reactions associated with the administration of the SSRIs include headache,nervousness, dizziness, insomnia, nausea, vomiting,weight loss, sweating, rash, pharyngitis, and painful menstruation.
Miscellaneous Antidepressants
Adverse reactions with administration of bupropion include agitation, dry mouth, insomnia, headache, nausea, constipation, anorexia, weight loss, and seizures.Fluoxetine administration may result in headache, activation of mania or hypomania, insomnia, anxiety, nervousness, nausea, vomiting, and sexual dysfunction.
Trazodone administration may cause the following
adverse reactions: drowsiness, skin disorders, anger, hostility, anemia, priapism, nausea, and vomiting. Additional adverse reactions and adverse reactions associated with
the use of other miscellaneous antidepressant drugs are
CONTRAINDICATIONS, PRECAUTIONS,
AND INTERACTIONS
TCAs
The TCAs are contraindicated in patients with known
hypersensitivity to the drugs. Doxepin is contraindicated
in patients with glaucoma or in those with a tendency for
urinary retention. The TCAs are not given within 14 days
of the MAOIs, in patients with a recent myocardial infarction, or during pregnancy or lactation. These drugs are Pregnancy Category C drugs (except imipramine, which is Pregnancy Category B), and the safety of their use during pregnancy has not been established. TCAs are contraindicated in patients scheduled to have a myelogram (x-ray of the spinal cord and associated nerves) during the next 48 hours or within 24 hours of having a myelogram.
As with all antidepressants, the TCAs are used cautiously in patients with hepatic or renal impairment.
The tricyclics are used cautiously in patients with heart
disease, angina, paroxysmal tachycardia, increased intraocular pressure, prostatic hypertrophy, or a history
of seizures.
If the tricyclics are administered with the MAOIs, the patient is at risk for hypertensive episodes, severe convulsions, and hyperpyretic episodes. Use of the MAOIs must be discontinued at least 2 weeks before treatment with the tricyclics begins. The tricyclics may prevent the therapeutic effect of many antihypertensives. When the tricyclics are administered with dicumarol, the risk for bleeding
increases.
Arrhythmias and hypertension have been reported when the TCAs are administered with the adrenergic
drugs. There is a risk of severe hypertension when the TCAs are administered with clonidine.
MAOIs
The MAOI antidepressant drugs are contraindicated in patients with known hypersensitivity to the drugs, liver
and kidney disease, cerebrovascular disease, hypertension, or congestive heart failure and in the elderly.
These drugs are given cautiously to patients with impaired liver function, history of seizures, parkinsonian symptoms, diabetes, or hyperthyroidism.
Foods containing tyramine must not be eaten by patients taking MAOIs because a hypertensive crisis
can occur (see Home Care Checklist: Avoiding Drug–Food Interactions With MAOIs). Use of the
MAOIs should be discontinued several weeks before surgery because they can cause unpredictable reactions
in patients undergoing surgery. Serious adverse reactions (hypertension or hypotension, coma, and death)
have been reported when the MAOIs are administered with the opiates. Concurrent use of the MAOIs with the thiazide diuretics may result in exaggerated hypotensive effect. Administration of the MAOIs with the adrenergic drugs increases the sympathomimetic effects, possibly resulting in hypertensive crisis.
SSRIs
The SSRIs are contraindicated in patients with a hypersensitivity to the drugs and during pregnancy. The SSRIs are Pregnancy Category C drugs (except for fluoxetine, which is Pregnancy Category B). SSRIs are
used cautiously in patients with diabetes mellitus or impaired liver or kidney function and during lactation.
Use of the MAOIs must be discontinued 2 weeks before the administration of the SSRIs. When the SSRIs
are administered with the tricyclic antidepressants,there is an increased risk of toxic effects and an
increased therapeutic effect. When sertraline is administered with a MAOI, a potentially fatal reaction can
occur. Symptoms of a serious reaction include hyperthermia, rigidity, autonomic instability with fluctuating
vital signs and agitation, delirium, and coma. Sertraline blood levels are increased when administered with
cimetidine.There is a decreased effectiveness of fluoxetine in patients who smoke cigarettes during administration of the drug. Fluoxetine is not administered with lithium because this combination can increase lithium levels.The SSRIs are not administered with herbal preparations containing St. John’s wort because there is an increased risk for severe reactions.
Miscellaneous Antidepressants
The miscellaneous antidepressant drugs are contraindicated in patients with known hypersensitivity to the
drugs. Among the miscellaneous antidepressants,bupropion and maprotiline are Pregnancy Category B
drugs. Other miscellaneous antidepressants discussed in this chapter are Pregnancy Category C drugs. Safe use of the antidepressants during pregnancy has not been established. They should be used during pregnancy only when the potential benefits outweigh the potential hazards to the developing fetus. These drugs are used cautiously in patients with liver or kidney impairment and during lactation. The miscellaneous antidepressants are given with caution to patients taking alcohol or otherCNS depressants.The effects of buspirone are decreased when the drug is administered with fluoxetine. Increased serum levels of buspirone occur if the drug is taken with erythromycin or itraconazole. Should any of these combinations be required, the dosage of buspirone is decreased to 2.5 mg BID, and the patient is monitored closely. Venlafaxine blood levels increase with a risk of toxicity when administered with MAOIs or cimetidine. There is an increased risk of toxicity when trazodone is administered with the phenothiazines and decreased effectiveness of trazodone when it is administered with carbamazepine.Increased serum digoxin levels have occurred when digoxin is administered with trazodone. There is a risk for increased phenytoin levels when phenytoin is administered with trazodone.
Symptoms of Depression
1 Depressed mood
2 Diminished interest in activities of life
3 Significant weight loss or gain (without dieting)
4 Insomnia (inability to sleep) or hypersomnia (excessive sleeping)
5 Psychomotor agitation or retardation
6Fatigue or loss of energy
7 Feelings of worthlessness
8 Excessive or inappropriate guilt
9 Diminished ability to think or concentrate, or indecisiveness
10 Recurrent thoughts of death or suicide (or suicide attempt)
To be classified as a major depression, these symptoms should occur daily or nearly every day for a period
of 2 weeks or more. The symptoms of major depression should not be the result of normal bereavement, such as the loss of a loved one, or disease, such as hypothy-roidism.Depression is treated with the use of antidepressant drugs. Psychotherapy is used in conjunction with the antidepressant drugs in treating major depressive episodes.
The four types of antidepressants are:
• Tricyclic antidepressants (TCAs)
• Monoamine oxidase inhibitors (MAOIs)
• Selective serotonin reuptake inhibitors (SSRIs)
• A group of miscellaneous, unrelated drugs
ACTIONS
For several years it was thought that the antidepressants blocked the reuptake of the endogenous neurohormones norepinephrine and serotonin, which resulted in stimulation of the central nervous system (CNS).Although the exact mechanism of action is unknown,this theory is now being questioned. New research indicates that the effects of the antidepressants are related to the slower adaptive changes in norepinephrine and serotonin receptor systems. Treatment with the antidepressants is thought to produce complex changes in the sensitivities of both presynaptic and postsynaptic receptor sites. The antidepressants increase the sensitivity of postsynaptic alpha -adrenergic and serotonin receptors and decrease the sensitivity of the presynaptic receptor sites. This enhances the recovery from the depressive episode by normalizing neurotransmission activity.
The TCAs, such as amitriptyline (Elavil) and doxepin (Sinequan), inhibit reuptake of norepinephrine or
serotonin at the presynaptic neuron. Drugs classified as MAOIs inhibit the activity of monoamine oxidase, a
complex enzyme system that is responsible for breaking down amines. This results in an increase in endogenous epinephrine, norepinephrine, and serotonin in the nervous system. An increase in these neurohormones results in stimulation of the CNS. The action of the SSRIs is linked to their inhibition of CNS neuronal uptake of serotonin (a CNS neurotransmitter). The increase in serotonin levels is thought to act as a stimulant to reverse depression.
The mechanism of action of most of the miscellaneous antidepressants is not clearly understood. Examples of this group of drugs include fluoxetine (Prozac) and bupropion (Wellbutrin).
USES
Antidepressant drugs are used to manage depressive episodes such as major depression or depression
accompanied by anxiety. These drugs may be used in conjunction with psychotherapy in severe depression.
The SSRIs also are used to treat obsessive-compulsive disorders.Treatment is usually continued for 9 months after recovery from the first major depressive episode. If the patient, at a later date, experiences another major depressive episode, treatment is continued for 5 years,and with a third episode, treatment is continued indefinitely.
ADVERSE REACTIONS
TCAs
Sedation and dry mouth are the most common adversereactions seen with the use of TCAs. Tolerance to these effects develops with continued use. Orthostatic hypotension can occur with the administration of the
TCAs. Orthostatic hypotension is a drop in blood pressure of 20 to 30 points when a person changes position, such as going from a lying position to a standing position. Mental confusion, lethargy, disorientation,
rash, nausea, vomiting, constipation, urinary retention,visual disturbances, photosensitivity, and nasal congestion also may be seen. Sexual dysfunction may occur with administration of clomipramine.
MAOIs
Orthostatic hypotension is a common adverse reaction seen with the administration of the MAOIs. Other common adverse reactions include dizziness, vertigo, nausea, constipation, dry mouth, diarrhea, headache, and overactivity.One serious adverse reaction associated with the use of the MAOIs is hypertensive crisis (extremely high blood pressure), which may occur when foods containing tyramine (an amino acid present in some foods) are eaten (see Home Care Checklist: Avoiding Drug–Food Interactions With MAOIs).
One of the earliest symptoms of hypertensive crisis is headache (usually occipital), followed by a stiff or sore
neck, nausea, vomiting, sweating, fever, chest pain,dilated pupils, and bradycardia or tachycardia. If a hypertensive crisis occurs, immediate medical intervention is necessary to reduce the blood pressure. Strokes (cerebrovascular accidents) and death have been reported.
SSRIs
Some of the more common adverse reactions associated with the administration of the SSRIs include headache,nervousness, dizziness, insomnia, nausea, vomiting,weight loss, sweating, rash, pharyngitis, and painful menstruation.
Miscellaneous Antidepressants
Adverse reactions with administration of bupropion include agitation, dry mouth, insomnia, headache, nausea, constipation, anorexia, weight loss, and seizures.Fluoxetine administration may result in headache, activation of mania or hypomania, insomnia, anxiety, nervousness, nausea, vomiting, and sexual dysfunction.
Trazodone administration may cause the following
adverse reactions: drowsiness, skin disorders, anger, hostility, anemia, priapism, nausea, and vomiting. Additional adverse reactions and adverse reactions associated with
the use of other miscellaneous antidepressant drugs areCONTRAINDICATIONS, PRECAUTIONS,
AND INTERACTIONS
TCAs
The TCAs are contraindicated in patients with known
hypersensitivity to the drugs. Doxepin is contraindicated
in patients with glaucoma or in those with a tendency for
urinary retention. The TCAs are not given within 14 days
of the MAOIs, in patients with a recent myocardial infarction, or during pregnancy or lactation. These drugs are Pregnancy Category C drugs (except imipramine, which is Pregnancy Category B), and the safety of their use during pregnancy has not been established. TCAs are contraindicated in patients scheduled to have a myelogram (x-ray of the spinal cord and associated nerves) during the next 48 hours or within 24 hours of having a myelogram.
As with all antidepressants, the TCAs are used cautiously in patients with hepatic or renal impairment.
The tricyclics are used cautiously in patients with heart
disease, angina, paroxysmal tachycardia, increased intraocular pressure, prostatic hypertrophy, or a history
of seizures.
If the tricyclics are administered with the MAOIs, the patient is at risk for hypertensive episodes, severe convulsions, and hyperpyretic episodes. Use of the MAOIs must be discontinued at least 2 weeks before treatment with the tricyclics begins. The tricyclics may prevent the therapeutic effect of many antihypertensives. When the tricyclics are administered with dicumarol, the risk for bleeding
increases.
Arrhythmias and hypertension have been reported when the TCAs are administered with the adrenergic
drugs. There is a risk of severe hypertension when the TCAs are administered with clonidine.
MAOIs
The MAOI antidepressant drugs are contraindicated in patients with known hypersensitivity to the drugs, liver
and kidney disease, cerebrovascular disease, hypertension, or congestive heart failure and in the elderly.
These drugs are given cautiously to patients with impaired liver function, history of seizures, parkinsonian symptoms, diabetes, or hyperthyroidism.
Foods containing tyramine must not be eaten by patients taking MAOIs because a hypertensive crisis
can occur (see Home Care Checklist: Avoiding Drug–Food Interactions With MAOIs). Use of the
MAOIs should be discontinued several weeks before surgery because they can cause unpredictable reactions
in patients undergoing surgery. Serious adverse reactions (hypertension or hypotension, coma, and death)
have been reported when the MAOIs are administered with the opiates. Concurrent use of the MAOIs with the thiazide diuretics may result in exaggerated hypotensive effect. Administration of the MAOIs with the adrenergic drugs increases the sympathomimetic effects, possibly resulting in hypertensive crisis.
SSRIs
The SSRIs are contraindicated in patients with a hypersensitivity to the drugs and during pregnancy. The SSRIs are Pregnancy Category C drugs (except for fluoxetine, which is Pregnancy Category B). SSRIs are
used cautiously in patients with diabetes mellitus or impaired liver or kidney function and during lactation.
Use of the MAOIs must be discontinued 2 weeks before the administration of the SSRIs. When the SSRIs
are administered with the tricyclic antidepressants,there is an increased risk of toxic effects and an
increased therapeutic effect. When sertraline is administered with a MAOI, a potentially fatal reaction can
occur. Symptoms of a serious reaction include hyperthermia, rigidity, autonomic instability with fluctuating
vital signs and agitation, delirium, and coma. Sertraline blood levels are increased when administered with
cimetidine.There is a decreased effectiveness of fluoxetine in patients who smoke cigarettes during administration of the drug. Fluoxetine is not administered with lithium because this combination can increase lithium levels.The SSRIs are not administered with herbal preparations containing St. John’s wort because there is an increased risk for severe reactions.
Miscellaneous Antidepressants
The miscellaneous antidepressant drugs are contraindicated in patients with known hypersensitivity to the
drugs. Among the miscellaneous antidepressants,bupropion and maprotiline are Pregnancy Category B
drugs. Other miscellaneous antidepressants discussed in this chapter are Pregnancy Category C drugs. Safe use of the antidepressants during pregnancy has not been established. They should be used during pregnancy only when the potential benefits outweigh the potential hazards to the developing fetus. These drugs are used cautiously in patients with liver or kidney impairment and during lactation. The miscellaneous antidepressants are given with caution to patients taking alcohol or otherCNS depressants.The effects of buspirone are decreased when the drug is administered with fluoxetine. Increased serum levels of buspirone occur if the drug is taken with erythromycin or itraconazole. Should any of these combinations be required, the dosage of buspirone is decreased to 2.5 mg BID, and the patient is monitored closely. Venlafaxine blood levels increase with a risk of toxicity when administered with MAOIs or cimetidine. There is an increased risk of toxicity when trazodone is administered with the phenothiazines and decreased effectiveness of trazodone when it is administered with carbamazepine.Increased serum digoxin levels have occurred when digoxin is administered with trazodone. There is a risk for increased phenytoin levels when phenytoin is administered with trazodone.
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