Medications and Drugs
Pharmacy Author: Omudhome Ogbru, PharmD
Medical and Pharmacy Editor: Jay W. Marks, MD
GENERIC NAME: doxepin
BRAND NAME: Sinequan, Adapin
DRUG CLASS AND MECHANISM: Doxepin belongs to a class of drugs called
tricyclic antidepressants (TCAs) that are used primarily to treat depression and
anxiety. Other examples of TCAs include
amitriptyline (Elavil), nortriptyline
(Pamelor), desipramine (Norpramin), and several others. Depression is an
all-pervasive sense of sadness and gloom. In some patients with depression, an
imbalance in levels of neurotransmitters in the brain may be the cause of the
depression. Neurotransmitters are chemicals that nerves use to communicate with
each other. Neurotransmitters affected by doxepin include serotonin,
norepinephrine, acetylcholine, and histamine. Doxepin may elevate mood by
raising the levels of serotonin and norepinephrine. It also blocks the activity
of acetylcholine and histamine. The FDA approved doxepin in March 1974.
PRESCRIPTION: Yes
GENERIC AVAILABLE: Yes
PREPARATIONS: Capsules: 10, 25, 50, 75, 100, 150 mg; Liquid: 10 mg/ml
STORAGE: Doxepin should be stored below 30 C (86 F) in a tight, light
resistant container.
PRESCRIBED FOR: Doxepin is used for treating depression and
anxiety.
It also is used for treating depression due to
alcoholism or brain damage and
depression associated with bipolar disorder.
DOSING: The usual dose of doxepin is 75 to 300 mg daily administered
at bedtime or in three divided doses. Doses greater than 300 mg daily are not
more effective. Optimal improvement in depressive symptoms is seen after 2-3
weeks; anti-anxiety effects occur much sooner.
DRUG INTERACTIONS: Tricyclic antidepressants should not be used with
monoamine oxidase inhibiting drugs, for example, tranylcypromine (Parnate),
because high fever, convulsions, and even death may occur from such
combinations.
Cimetidine (Tagamet) increases the breakdown of doxepin by the liver and can
increase doxepin blood levels, possibly causing side effects from doxepin.
PREGNANCY: There are no adequate studies of doxepin use in
pregnant
women.
NURSING MOTHERS: It is not known if doxepin is secreted in
breast
milk. There is one report of apnea (cessation of breathing) and drowsiness
occurring in a nursing infant whose mother was taking doxepin.
SIDE EFFECTS: The most common side effect of doxepin is drowsiness.
Drowsiness improves as therapy continues. Other side effects associated with
doxepin include blurred vision, urinary retention (difficulty urinating),
dry
mouth, constipation, weight gain or loss, and low blood pressure when rising
from a sitting position (orthostatic hypotension). Rash, hives, rapid heart
rate, seizures, and hepatitis are rare side effects. Doxepin also can cause
elevated pressure in the eyes of some patients with glaucoma. If
antidepressants, including doxepin, are discontinued abruptly, symptoms such as
dizziness, headache, nausea, and changes in mood may occur. Such symptoms of
withdrawal may occur even when a few doses of antidepressant are missed.
Therefore, it is recommended that the dose of antidepressant be reduced
gradually when therapy is discontinued.
Antidepressants increased the risk of
suicidal thinking and behavior in
short-term studies in children and adolescents with depression and other
psychiatric disorders. Anyone considering the use of any antidepressant in a
child or adolescent must balance this risk with the clinical need. Patients who
are started on therapy should be closely observed for clinical worsening,
suicidal thinking or behavior, and unusual changes in behavior.
Reference: FDA Prescribing Information
Last Editorial Review: 2/19/2009
Report Problems to the Food and Drug Administration
You are encouraged to report negative side effects of prescription drugs to the FDA. Visit the FDA MedWatch website or call 1-800-FDA-1088.
- Drug Interactions - Learn about potential drug interactions you may be exposed to. Drug interactions can occur with prescription drugs, OTC medication, vitamins, herbs, and supplements.
- Anxiety - Read about anxiety (generalized anxiety disorder, GAD) causes, physical symptoms and signs, medications and treatment. Learn about symptoms (worry, fear) and other types of anxiety disorders.
- amitriptyline. Elavil, Endep - Learn about amitriptyline ((Elavil, Endep) an antidepressant drug used to treat depression. Drug interactions and side effects are also included in the information.
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