Sinequan (doxepin)

Antidepressant Medication

When is It Prescribed?

Sinequan (doxepin) is used to treat the following conditions:

Sinequan, a trycyclic antidepressant (TCA), works by bringing the levels of the neurotransmitter norepinephrine to normal levels.

This medication may also be prescribed for purposes other than what’s listed above.

When Will It Start to Work?

You should start feeling the effects of Sinequan (doxepin) within two to four weeks. The time it takes to experience the full effects of Sinequan depends on dosage and varies from person to person.

Do not stop taking this medication unless your prescribing doctor or therapist tells you it is alright to do so. Stopping this medication suddenly can cause severe nausea, headache, and malaise.

Are There Any Drug Interactions?

Remember, always follow your physician's or therapist'srecommendations on how to take your medication.

Who Should Not Take Sinequan (doxepin)?

Do not take Sinequan (doxepin) if you have taken a monoamine oxidase inhibitor such as Marplan (isocarboxazid), Nardil (phenelzine), or Parnate (tranylcypromine) within the last 14 days.

If you are taking any other prescription medications, herbal remedies, vitamins, and/or over-the-counter medications, be sure to tell your physician.

Pregnancy and Breastfeeding Issues

It is not known whether Sinequan (doxepin) will harm an unborn baby. Do not take this medication without first talking to your prescribing doctor or therapist if you are pregnant or planning a pregnancy.

Sinequan (doxepin) passes into breast milk and may affect a nursing baby. Do not take this medication without first talking to your doctor or therapist if you are breast-feeding a baby.

Other Important Information and Precautions

Before taking Sinequan (doxepin), tell your prescribing doctor or therapist if you have:

  • Liver or kidney disease

  • Asthma

  • Thyroid disease

  • Diabetes

  • Stomach or intestinal problems

  • High blood pressure or heart disease

  • Had a heart attack in the last 6 weeks

  • An enlarged prostate or difficulty urinating

  • Glaucoma

You may not be able to take Sinequan (doxepin), or you may require a lower dose or special monitoring during therapy if you have any of these conditions.

Sinequan (doxepin) may cause dizziness. Use caution when driving, operating machinery, or performing other hazardous activities.

Dizziness is also likely to occur when you rise from a sitting or lying position. Rise slowly to prevent a possible fall.

Use alcohol cautiously. Alcohol may increase drowsiness and dizziness while you are taking this medication.

If you are over 60 years of age, you may be more likely to experience side effects such as drowsiness, dizziness, unsteadiness, feeling uncoordinated, low blood pressure, and as a result may require a lower dose of this medication.

In addition to the information listed above, there may be other important issues or precautions related to this medication. For further information, you can ask your prescribing doctor or therapist.

Side-Effect Information

Only some people will experience side-effects and no one experiences them in exactly the same way. If you should experience any side-effect, contact your doctor or therapist right away.

The following list may not contain all of the side-effects associated with this medication:

Most Common Side-Effects drowsiness, dizziness, insomnia, blurred vision, rash, dry mouth
Infrequent Side-Effects photosensitivity, agitation, diarrhea, high blood pressure, hair loss, increased or decreased libido, nausea, sweating, swelling, weight gain or loss, worsening of paranoid psychosis in schizophrenic patients
Rare Side-Effects/Risks seizures, delirium, delusions, hallucinations, Tourette syndrome, liver/kidney toxicity, heart rhythm disturbances, abnormally low white blood cell and platelet count, tremors, nightmares, high blood pressure, hypotension

Side-effects and risks other than those listed above may also occur. Talk to your prescribing doctor or therapist about any potential or existing side-effects that you’re concerned about.

Every effort has been made to ensure that the information provided by is accurate and up-to-date, but no guarantee is made to that effect.’s medication information is a reference resource designed as a supplement to, and not a substitute for, the expertise, skill, knowledge, and judgment of healthcare practitioners in patient care. does not assume any responsibility for any aspect of healthcare administered with the aid of information provides.