Antidepressant Medications
Major
depression, the kind of depression that will most likely benefit from
treatment with medications, is more than just “the blues.” It is a
condition that lasts 2 weeks or more, and interferes with a person’s
ability to carry on daily tasks and enjoy activities that previously
brought pleasure. Depression is associated with abnormal functioning of
the brain. An interaction between genetic tendency and life history
appears to determine a person’s chance of becoming depressed. Episodes
of depression may be triggered by stress, difficult life events, side
effects of medications, or medication/substance withdrawal, or even
viral infections that can affect the brain.
Depressed people will
seem sad, or “down,” or may be unable to enjoy their normal activities.
They may have no appetite and lose weight (although some people eat
more and gain weight when depressed). They may sleep too much or too
little, have difficulty going to sleep, sleep restlessly, or awaken
very early in the morning. They may speak of feeling guilty, worthless,
or hopeless; they may lack energy or be jumpy and agitated. They may
think about killing themselves and may even make a suicide attempt.
Some depressed people have delusions (false, fixed ideas) about
poverty, sickness, or sinfulness that are related to their depression.
Often feelings of depression are worse at a particular time of day, for
instance, every morning or every evening.
Not everyone who is
depressed has all these symptoms, but everyone who is depressed has at
least some of them, co-existing, on most days. Depression can range in
intensity from mild to severe. Depression can co-occur with other
medical disorders such as cancer, heart disease, stroke, Parkinson’s
disease, Alzheimer’s disease, and diabetes. In such cases, the
depression is often overlooked and is not treated. If the depression is
recognized and treated, a person’s quality of life can be greatly
improved.
Antidepressants are used most often for serious
depressions, but they can also be helpful for some milder depressions.
Antidepressants are not “uppers” or stimulants, but rather take away or
reduce the symptoms of depression and help depressed people feel the
way they did before they became depressed.
The doctor chooses an
antidepressant based on the individual’s symptoms. Some people notice
improvement in the first couple of weeks; but usually the medication
must be taken regularly for at least 6 weeks and, in some cases, as
many as 8 weeks before the full therapeutic effect occurs. If there is
little or no change in symptoms after 6 or 8 weeks, the doctor may
prescribe a different medication or add a second medication such as
lithium, to augment the action of the original antidepressant. Because
there is no way of knowing beforehand which medication will be
effective, the doctor may have to prescribe first one and then another.
To give a medication time to be effective and to prevent a relapse of
the depression once the patient is responding to an antidepressant, the
medication should be continued for 6 to 12 months, or in some cases
longer, carefully following the doctor’s instructions. When a patient
and the doctor feel that medication can be discontinued, withdrawal
should be discussed as to how best to taper off the medication
gradually. Never discontinue medication without talking to the doctor about it.
For those who have had several bouts of depression, long-term treatment
with medication is the most effective means of preventing more episodes.
Dosage
of antidepressants varies, depending on the type of drug and the
person’s body chemistry, age, and, sometimes, body weight.
Traditionally, antidepressant dosages are started low and raised
gradually over time until the desired effect is reached without the
appearance of troublesome side effects. Newer antidepressants may be
started at or near therapeutic doses.
Early Antidepressants. From the 1960s through the 1980s, tricyclic antidepressants
(named for their chemical structure) were the first line of treatment
for major depression. Most of these medications affected two chemical
neurotransmitters, norepinephrine and serotonin. Though the tricyclics
are as effective in treating depression as the newer antidepressants,
their side effects are usually more unpleasant; thus, today tricyclics
such as imipramine, amitriptyline, nortriptyline, and desipramine are
used as a second- or third-line treatment. Other antidepressants
introduced during this period were monoamine oxidase inhibitors (MAOIs).
MAOIs are effective for some people with major depression who do not
respond to other antidepressants. They are also effective for the
treatment of panic disorder and bipolar depression. MAOIs approved for
the treatment of depression are phenelzine (Nardil), tranylcypromine
(Parnate), and isocarboxazid (Marplan). Because substances in certain
foods, beverages, and medications can cause dangerous interactions when
combined with MAOIs, people on these agents must adhere to dietary
restrictions. This has deterred many clinicians and patients from using
these effective medications, which are in fact quite safe when used as
directed.
The past decade has seen the introduction of many new
antidepressants that work as well as the older ones but have fewer side
effects. Some of these medications primarily affect one
neurotransmitter, serotonin, and are called >selective serotonin reuptake inhibitors (SSRIs). These include fluoxetine (Prozac), sertraline (Zoloft), fluvoxamine (Luvox), paroxetine (Paxil), and citalopram (Celexa).
The
late 1990s ushered in new medications that, like the tricyclics, affect
both norepinephrine and serotonin but have fewer side effects. These
new medications include venlafaxine (Effexor) and nefazadone (Serzone).
Cases
of life-threatening hepatic failure have been reported in patients
treated with nefazodone (Serzone). Patients should call the doctor if
the following symptoms of liver dysfunction occur—yellowing of the skin
or white of eyes, unusually dark urine, loss of appetite that lasts for
several days, nausea, or abdominal pain.
Other newer medications chemically unrelated to the other antidepressants are the sedating mirtazepine (Remeron) and the more activating bupropion (Wellbutrin).
Wellbutrin has not been associated with weight gain or sexual
dysfunction but is not used for people with, or at risk for, a seizure
disorder.
Each antidepressant differs in its side effects and in
its effectiveness in treating an individual person, but the majority of
people with depression can be treated effectively by one of these
antidepressants.
Side Effects of Antidepressant Medications
Antidepressants
may cause mild, and often temporary, side effects (sometimes referred
to as adverse effects) in some people. Typically, these are not
serious. However, any reactions or side effects that are unusual,
annoying, or that interfere with functioning should be reported to the
doctor immediately. The most common side effects of tricyclic
antidepressants, and ways to deal with them, are as follows:
- Dry mouth—it is helpful to drink sips of water; chew sugarless gum; brush teeth daily.
- Constipation—bran cereals, prunes, fruit, and vegetables should be in the diet.
- Bladder problems—emptying
the bladder completely may be difficult, and the urine stream may not
be as strong as usual. Older men with enlarged prostate conditions may
be at particular risk for this problem. The doctor should be notified
if there is any pain.
- Sexual problems—sexual functioning may be impaired; if this is worrisome, it should be discussed with the doctor.
- Blurred vision—this
is usually temporary and will not necessitate new glasses. Glaucoma
patients should report any change in vision to the doctor.
- Dizziness—rising from the bed or chair slowly is helpful.
- Drowsiness as a daytime problem—this
usually passes soon. A person who feels drowsy or sedated should not
drive or operate heavy equipment. The more sedating antidepressants are
generally taken at bedtime to help sleep and to minimize daytime
drowsiness.
- Increased heart rate—pulse rate is often elevated. Older patients should have an electrocardiogram (EKG) before beginning tricyclic treatment.
The newer antidepressants, including SSRIs, have different types of side effects, as follows:
- Sexual problems—fairly common, but reversible, in both men and women. The doctor should be consulted if the problem is persistent or worrisome.
- Headache—this will usually go away after a short time.
- Nausea—may occur after a dose, but it will disappear quickly.
- Nervousness and insomnia (trouble falling asleep or waking often during the night)—these may occur during the first few weeks; dosage reductions or time will usually resolve them.
- Agitation (feeling jittery)—if this happens for the first time after the drug is taken and is more than temporary, the doctor should be notified.
- Any
of these side effects may be amplified when an SSRI is combined with
other medications that affect serotonin. In the most extreme cases,
such a combination of medications (e.g., an SSRI and an MAOI) may
result in a potentially serious or even fatal “serotonin syndrome,”
characterized by fever, confusion, muscle rigidity, and cardiac, liver,
or kidney problems.
The small number of people for whom MAOIs
are the best treatment need to avoid taking decongestants and consuming
certain foods that contain high levels of tyramine, such as many
cheeses, wines, and pickles. The interaction of tyramine with MAOIs can
bring on a sharp increase in blood pressure that can lead to a stroke.
The doctor should furnish a complete list of prohibited foods that the
individual should carry at all times. Other forms of antidepressants
require no food restrictions. MAOIs also should not be combined with
other antidepressants, especially SSRIs, due to the risk of serotonin
syndrome.
Medications of any kind—prescribed, over-the-counter, or herbal supplements—should never be mixed without consulting the doctor; nor should medications ever be borrowed from another person.
Other health professionals who may prescribe a drug—such as a dentist
or other medical specialist—should be told that the person is taking a
specific antidepressant and the dosage. Some drugs, although safe when
taken alone, can cause severe and dangerous side effects if taken with
other drugs. Alcohol (wine, beer, and hard liquor) or street drugs, may
reduce the effectiveness of antidepressants and their use should be
minimized or, preferably, avoided by anyone taking antidepressants.
Some people who have not had a problem with alcohol use may be
permitted by their doctor to use a modest amount of alcohol while
taking one of the newer antidepressants. The potency of alcohol may be
increased by medications since both are metabolized by the liver; one
drink may feel like two.
Additional Resources:
- For related articles on psychiatric medications on the Web, click on: “Sphere: Related Content” located at the
bottom of this blog post.
- For related books or blog posts with related
content in Dr. Jeff’s and Dr. Tanya’s Blog, go to “Psychiatric
Medications: General” or type in the keyword “psychiatric medications”
into “Google Search” located in the sidebar.
- For more books with related
content, click any hyperlinked keyword in the blog or type in the keyword,
“psychiatric medications” into “Amazon Search” on the Amazon banner located in the
side bar.
Source: National Institute of Mental Health
Dr. Jeffrey Speller
Dr. Tanya Korkosz
Psychopharmacology Associates of New England
www.psychopharmassociates.com
