Doxepin

What is doxepin?

Doxepin is an FDA-approved medication for the treatment of insomnia. It is in a class of medications called tricyclic antidepressants and requires a prescription from a doctor. At higher doses, it is also prescribed to treat anxiety and depression.

What is insomnia?

Insomnia is a common sleep disorder that affects your ability to get the sleep your body needs.  Insomnia can have an adverse effect on mood, cognition and general and cardiovascular health.

How does doxepin work?

Doxepin works by blocking the effects of histamine. Histamine is a chemical which occurs naturally in your body, and helps manage your sleep-wake cycle. When histamine is blocked, drowsiness can ensue.

What does doxepin look like?

Doxepin is made in both tablet and capsule formulations. The color and imprint will depend on the manufacturer and the dosage.

Who makes doxepin?

Doxepin is a generic medication made by several different manufacturers such as Mylan Pharmaceuticals, Watson Pharmaceuticals, Rugby and others.

Examples of name-brand doxepin capsules include Sinequan, Prudoxin, and Zonalon, manufactured by Pfizer, Mylan Pharmaceuticals and Prestium Pharma, respectively.

Doxepin vs. gabapentin

Gabapentin is an anticonvulsant medication typically used to treat seizures and pain. While doxepin works by blocking the uptake of histamine, gabapentin works by increasing the concentration of GABA, a chemical that can regulate pain perception in your brain.

Although gabapentin has also been shown to have sleep-enhancing effects, it more commonly treats sleep disruption specifically associated with pain. Gabapentin is not prescribed for insomnia as often as doxepin.

Active Ingredients

The active ingredient in doxepin is doxepin hydrochloride at a concentration of 10mg, 25mg, 75mg, 100mg, or 150mg, depending on the dosage.

Inactive Ingredients

The inactive ingredients in doxepin capsules include hard gelatin capsules, magnesium stearate, sodium lauryl sulfate, and starch.

Doxepin dosage

To treat insomnia, the dosage of doxepin will vary between tablets and capsules. 

• Tablets: 3 to 6 mg once daily
• Capsules: 10 mg once daily

How to take doxepin

Always take doxepin as prescribed by your doctor. Doxepin is usually prescribed as a daily medication, to be taken 30 minutes before bedtime. Avoid taking the medication within three hours of eating food.

How long does doxepin take to work?

Doxepin is fast-acting and may begin working within 30 minutes of ingestion. 

Doxepin Side Effects

Doxepin may cause adverse reactions on the following body systems:

• Central nervous system such as confusion and disorientation
• Cardiovascular such as high or low blood pressure and tachycardia
• Gastrointestinal such as nausea, vomiting, and indigestion 
• Endocrine such as altered libido
• Anticholinergic such as dry mouth, blurred vision, and constipation
• Hematologic such as eosinophilia

Other side effects include:

• Allergic reaction such as a skin rash and edema
• Dizziness
• Tinnitus
• Weight gain
• Sweating
• Chills
• Fatigue
• Weakness

This is not a complete list of all possible side effects. For a comprehensive list, you can access FDA drug information here.

If you experience any severe side effects or thoughts of suicide, please report to your doctor immediately.