Sinequan (doxepin) is a tricyclic antidepressant most commonly used to treat depression or anxiety. Less commonly it may be used to treat nerve pain, insomnia, itchiness, and other disorders. This product should not be used in patients under 12 years of age.

Sinequan is particularly good at treating symptoms of depression and anxiety, which are often present in the same person. The medication alleviates symptoms of:

• Depression
• Anxiety
• Fatigue
• Apprehension
• Worry
• Guilt
• Difficulty sleeping
• Tension

This product is a serotonin-norepinephrine reuptake inhibitor (SNRI), thought to work by inhibiting the reuptake of serotonin and norepinephrine, among other effects, though the exact mechanism by which this medication works is unclear.

Sinequan for Depression & Anxiety

This medication sees the most use in treating depression or anxiety, and it is also for these two treatments that dosage is largest. Sinequan is usually administered by tablet, or oral solution for those who have difficulty with tablets. Food is not necessary. The oral concentrate can be mixed with a non-carbonated beverage if desired.

Treatment of depression or anxiety is very similar:

• Start with 75 mg per day.
• Dosage can be gradually increased up to 300 mg per day.
• Doses up to 150 mg per day can be taken in a single dose before bed.
• Doses greater than 150 mg should be divided into two daily doses.
• The majority of patients find 75 to 150 mg per day to be optimal.

Some patients may notice changes within days of starting Sinequan treatment, particularly anti-anxiety effects. It will take two to three weeks for full anti-depression effects to be felt; if results are not powerful enough after two or three weeks, dosage should be increased. However, 300 mg per day is rarely exceeded.

Treatment may continue for as long as it provides benefit, typically at least nine months.

Sinequan is also used to treat depression and/or anxiety associated with withdrawal from alcohol, heroin, or other drugs, provided the drugs are no longer being consumed.

Other Uses

Sinequan is also used to treat nerve pain, insomnia, itchiness, and other disorders. Dosage here is typically much smaller than in depression or anxiety, though there are exceptions. In the majority of cases 25 to 50 mg per day is sufficient. Treatment in these cases, when dosage is low, can span days to years.

The active ingredient in Sinequan, doxepin, is also available in a topical ointment for application to the skin to treat moderate itchiness, typically sold under the names Prudoxin or Zonalon. Treatment with topical solutions rarely extend past 8 days at a time.

Potential Complications

Sinequan, like any medication, can cause side effects. These are usually mild and not cause for concern unless they become severe enough to be disruptive. In the majority of cases any side effects experienced will fade as the body adjusts to treatment. Common side effects include:

• Dry mouth
• Blurred vision
• Ringing in ears
• Swollen breasts (in both genders)
• Increased sweating
• Drowsiness
• Nausea
• Constipation
• Weight gain

More serious side effects are rare, but do warrant immediate medical attention:

• Rapid heartbeat
• Severe dizziness
• Hallucinations
• Confusion
• Difficult or painful urination
• Reduced urination
• Uncontrolled muscle movements
• Muscle weakness

Sinequan should not be used if an MAO inhibitor has been taken in the past 14 days. It should not be taken if allergic to similar medications, including amitriptyline, amoxapine, clomipramine, desipramine, imipramine, nortriptyline, protriptyline, or trimipramine.

This product can interact with other medications. Check with a doctor or pharmacist before mixing treatments.