Doxepin Hydrochloride

For most patients with illness of mild to moderate severity, a starting daily dose of 75 mg is recommended. Dosage may subsequently be increased or decreased at appropriate intervals and according to individual response. The usual optimum dose range is 75 mg/day to 150 mg/day.

In more severely ill patients higher doses may be required with subsequent gradual increase to 300 mg/day if necessary. Additional therapeutic effect is rarely to be obtained by exceeding a dose of 300 mg/day.

In patients with very mild symptomatology or emotional symptoms accompanying organic disease, lower doses may suffice. Some of these patients have been controlled on doses as low as 25–50 mg/day.

The total daily dosage of doxepin hydrochloride may be given on a divided or once-a-day dosage schedule. If the once-a-day schedule is employed, the maximum recommended dose is 150 mg/day. This dose may be given at bedtime. The 150 mg capsule strength is intended for maintenance therapy only and is not recommended for initiation of treatment.

Anti-anxiety effect is apparent before the antidepressant effect. Optimal antidepressant effect may not be evident for two to three weeks.

NOTE: Some of the adverse reactions noted below have not been specifically reported with doxepin hydrochloride use. However, due to the close pharmacological similarities among the tricyclics, the reactions should be considered when prescribing doxepin hydrochloride.

Anticholinergic Effects: Dry mouth, blurred vision, constipation and urinary retention have been reported. If they do not subside with continued therapy or become severe, it may be necessary to reduce the dosage.

Central Nervous System Effects: Drowsiness is the most commonly noticed side effect. This tends to disappear as therapy is continued. Other infrequently reported CNS side effects are confusion, disorientation, hallucinations, numbness, paresthesias, ataxia, extrapyramidal symptoms, seizures, tardive dyskinesia and tremor.

Cardiovascular: Cardiovascular effects including hypotension, hypertension and tachycardia have been reported occasionally.

Allergic: Skin rash, edema, photosensitization and pruritus have occasionally occurred.

Hematologic: Eosinophilia has been reported in a few patients. There have been occasional reports of bone marrow depression manifesting as agranulocytosis, leukopenia, thrombocytopenia and purpura.

Gastrointestinal: Nausea, vomiting, indigestion, taste disturbances, diarrhea, anorexia and aphthous stomatitis have been reported. (See Anticholinergic Effects.)

Endocrine: Raised or lowered libido, testicular swelling, gynecomastia in males, enlargement of breasts and galactorrhea in the female, raising or lowering of blood sugar levels and syndrome of inappropriate antidiuretic hormone secretion have been reported with tricyclic administration.

Other: Dizziness, tinnitus, weight gain, sweating, chills, fatigue, weakness, flushing, jaundice, alopecia, headache, exacerbation of asthma, angle closure glaucoma, mydriasis and hyperpyrexia (in association with chlorpromazine) have been occasionally observed as adverse effects.

Withdrawal Symptoms: The possibility of development of withdrawal symptoms upon abrupt cessation of treatment after prolonged doxepin hydrochloride administration should be borne in mind. These are not indicative of addiction and gradual withdrawal of medication should not cause these symptoms.

Doxepin hydrochloride is one of a class of psychotherapeutic agents known as dibenzoxepin tricyclic compounds. The molecular formula of the compound is C19H21NO•HCl having a molecular weight of 315.84. It is a white crystalline powder freely soluble in water, in alcohol, and methylene chloride.

Each 10 mg, 25 mg, 50 mg, 75 mg and 100 mg doxepin hydrochloride capsule for oral administration contains doxepin hydrochloride USP equivalent to 10 mg, 25 mg, 50 mg, 75 mg and 100 mg of doxepin, respectively and the following inactive ingredients: colloidal silicon dioxide, magnesium stearate, microcrystalline cellulose, pregelatinized starch and sodium lauryl sulfate. The empty gelatin capsule shells contain gelatin, sodium lauryl sulfate, and titanium dioxide. In addition, the 25 mg and 50 mg empty gelatin capsule shells contain iron oxide yellow, 75 mg, and 100 mg empty gelatin capsule shells contain iron oxide black, iron oxide yellow, and FD&C Blue 1.

The imprinting ink contains black iron oxide, potassium hydroxide, propylene glycol and shellac glaze.

Doxepin hydrochloride capsules complies with USP Dissolution test 3.

Doxepin hydrochloride is a dibenzoxepin derivative and is the first of a family of tricyclic psychotherapeutic agents. Specifically, it is an isomeric mixture of 1-Propanamine, 3-dibenz[b,e]oxepin-11 (6H)ylidene-N,N-dimethyl-hydrochloride.

Doxepin Hydrochloride

The mechanism of action of doxepin hydrochloride is not definitely known. It is not a central nervous system stimulant nor a monoamine oxidase inhibitor. The current hypothesis is that the clinical effects are due, at least in part, to influences on the adrenergic activity at the synapses so that deactivation of norepinephrine by reuptake into the nerve terminals is prevented. Animal studies suggest that doxepin hydrochloride does not appreciably antagonize the antihypertensive action of guanethidine. In animal studies anticholinergic, antiserotonin and antihistamine effects on smooth muscle have been demonstrated. At higher than usual clinical doses norepinephrine response was potentiated in animals. This effect was not demonstrated in humans.

At clinical dosages up to 150 mg per day, doxepin hydrochloride can be given to man concomitantly with guanethidine and related compounds without blocking the antihypertensive effect. At dosages above 150 mg per day blocking of the antihypertensive effect of these compounds has been reported.

Doxepin hydrochloride is virtually devoid of euphoria as a side effect. Characteristic of this type of compound, doxepin hydrochloride has not been demonstrated to produce the physical tolerance or psychological dependence associated with addictive compounds.

Doxepin Hydrochloride Capsules, USP are available in the following strengths and package sizes:

Doxepin Hydrochloride Capsules USP, 10 mg:
White opaque cap and white opaque body, size 4 hard gelatin capsule printed radially in black ink with “C700” on the cap.
Bottle pack of 90 capsules with Child Resistant Closure,   NDC 59746-700-90
Bottle pack of 100 capsules with Child Resistant Closure, NDC 59746-700-01
Bottle pack of 500 capsules,                                                NDC 59746-700-05

Doxepin Hydrochloride Capsules USP, 25 mg:
Yellow opaque cap and white opaque body, size 3 hard gelatin capsule printed radially in black ink with “C701” on the cap.
Bottle pack of 90 capsules with Child Resistant Closure,   NDC 59746-701-90
Bottle pack of 100 capsules with Child Resistant Closure, NDC 59746-701-01
Bottle pack of 500 capsules,                                                NDC 59746-701-05

Doxepin Hydrochloride Capsules USP, 50 mg:
Yellow opaque cap and yellow opaque body, size 3 hard gelatin capsule printed radially in black ink with “C702” on the cap.
Bottle pack of 90 capsules with Child Resistant Closure,   NDC 59746-702-90
Bottle pack of 100 capsules with Child Resistant Closure, NDC 59746-702-01
Bottle pack of 500 capsules,                                                NDC 59746-702-05

Doxepin Hydrochloride Capsules USP, 75 mg:
Green opaque cap and green opaque body, size 2 hard gelatin capsule printed radially in black ink with “C703” on the cap.
Bottle pack of 90 capsules with Child Resistant Closure,   NDC 59746-703-90
Bottle pack of 100 capsules with Child Resistant Closure, NDC 59746-703-01
Bottle pack of 500 capsules,                                                NDC 59746-703-05

Doxepin Hydrochloride Capsules USP, 100 mg:
Green opaque cap and white opaque body, size 1 hard gelatin capsule printed radially in black ink with “C704” on the cap.
Bottle pack of 90 capsules with Child Resistant Closure,   NDC 59746-704-90
Bottle pack of 100 capsules with Child Resistant Closure, NDC 59746-704-01
Bottle pack of 500 capsules,                                                NDC 59746-704-05

Store at 20° to 25°C (68° to 77°F). [See USP Controlled Room Temperature.]
Protect from light.

Dispense in a tight, light-resistant container as defined in the USP using a child-resistant closure.
PHARMACIST: Dispense a Medication Guide with each prescription.

Rx Only

Manufactured by:
Jubilant Cadista Pharmaceuticals Inc.
Salisbury, MD 21801, USA

Rev. # 09/2021

Clinical Worsening and Suicide Risk

Patients with major depressive disorder (MDD), both adult and pediatric, may experience worsening of their depression and/or the emergence of suicidal ideation and behavior (suicidality) or unusual changes in behavior, whether or not they are taking antidepressant medications, and this risk may persist until significant remission occurs. Suicide is a known risk of depression and certain other psychiatric disorders, and these disorders themselves are the strongest predictors of suicide. There has been a long-standing concern, however, that antidepressants may have a role in inducing worsening of depression and the emergence of suicidality in certain patients during the early phases of treatment. Pooled analyses of short-term placebo-controlled trials of antidepressant drugs (SSRIs and others) showed that these drugs increase the risk of suicidal thinking and behavior (suicidality) in children, adolescents, and young adults (ages 18 to 24) with major depressive disorder (MDD) and other psychiatric disorders. Short-term studies did not show an increase in the risk of suicidality with antidepressants compared to placebo in adults beyond age 24; there was a reduction with antidepressants compared to placebo in adults aged 65 and older.

The pooled analyses of placebo-controlled trials in children and adolescents with MDD, obsessive compulsive disorder (OCD), or other psychiatric disorders included a total of 24 short-term trials of nine antidepressant drugs in over 4,400 patients. The pooled analyses of placebo-controlled trials in adults with MDD or other psychiatric disorders included a total of 295 short-term trials (median duration of 2 months) of 11 antidepressant drugs in over 77,000 patients. There was considerable variation in risk of suicidality among drugs, but a tendency toward an increase in the younger patients for almost all drugs studied. There were differences in absolute risk of suicidality across the different indications, with the highest incidence in MDD. The risk differences (drug vs. placebo), however, were relatively stable within age strata and across indications. These risk differences (drug-placebo difference in the number of cases of suicidality per 1,000 patients treated) are provided in Table 1.

No suicides occurred in any of the pediatric trials. There were suicides in the adult trials, but the number was not sufficient to reach any conclusion about drug effect on suicide.

It is unknown whether the suicidality risk extends to longer-term use, i.e., beyond several months. However, there is substantial evidence from placebo-controlled maintenance trials in adults with depression that the use of antidepressants can delay the recurrence of depression.

All Patients being treated with antidepressants for any indication should be monitored appropriately and observed closely for clinical worsening, suicidality and unusual changes in behavior, especially during the initial few months of a course of drug therapy, or at times of dose changes, either increases or decrease.

The following symptoms, anxiety, agitation, panic attacks, insomnia, irritability, hostility, aggressiveness, impulsivity, akathisia (psychomotor restlessness), hypomania and mania, have been reported in adult and pediatric patients being treated with antidepressants for major depressive disorder as well as for other indications, both psychiatric and nonpsychiatric. Although a causal link between the emergence of such symptoms and either the worsening of depression and/or the emergence of suicidal impulses has not been established, there is concern that such symptoms may represent precursors to emerging suicidality.

Consideration should be given to changing the therapeutic regimen, including possibly discontinuing the medication, in patients whose depression is persistently worse, or who are experiencing emergent suicidality or symptoms that might be precursors to worsening depression or suicidality, especially if these symptoms are severe, abrupt in onset, or were not part of the patient’s presenting symptoms.

Families and caregivers of patients being treated with antidepressants for major depressive disorder or other indications, both psychiatric and nonpsychiatric, should be alerted about the need to monitor patients for the emergence of agitation, irritability, unusual changes in behavior, and the other symptoms described above, as well as the emergence of suicidality, and to report such symptoms immediately to healthcare providers. Such monitoring should include daily observation by families and caregivers. Prescriptions for doxepin hydrochloride should be written for the smallest number of capsules consistent with good patient management, in order to reduce the risk of overdose.

Screening Patients for Bipolar Disorder: A major depressive episode may be the initial presentation of bipolar disorder. It is generally believed (though not established in controlled trials) that treating such an episode with an antidepressant alone may increase the likelihood of precipitation of a mixed/manic episode in patients at risk for bipolar disorder. Whether any of the symptoms described above represent such a conversion is unknown. However, prior to initiating treatment with an antidepressant, patients with depressive symptoms should be adequately screened to determine if they are at risk for bipolar disorder; such screening should include a detailed psychiatric history, including a family history of suicide, bipolar disorder, and depression. It should be noted that doxepin hydrochloride is not approved for use in treating bipolar depression.

Angle-Closure Glaucoma: The pupillary dilation that occurs following use of many antidepressant drugs including doxepin hydrochloride capsules may trigger an angle closure attack in a patient with anatomically narrow angles who does not have a patent iridectomy.

Usage in Geriatric: The use of doxepin hydrochloride on a once a day dosage regimen in geriatric patients should be adjusted carefully based on the patient's condition (see PRECAUTIONS-Geriatric Use).

Usage in Pregnancy: Reproduction studies have been performed in rats, rabbits, monkeys and dogs and there was no evidence of harm to the animal fetus. The relevance to humans is not known. Since there is no experience in pregnant women who have received this drug, safety in pregnancy has not been established. There has been a report of apnea and drowsiness occurring in a nursing infant whose mother was taking doxepin hydrochloride.

Usage in Children: The use of doxepin hydrochloride in children under 12 years of age is not recommended because safe conditions for its use have not been established.