Sinequan 25mg Capsules

Doxepin is a tricyclic antidepressant (TCA) that primarily inhibits the reuptake of norepinephrine and serotonin at the presynaptic neuronal membrane, thereby increasing their concentrations in the synaptic cleft. It also possesses potent antagonism at histamine H1 receptors, moderate antagonism at serotonin (5-HT2) and alpha-1 adrenergic receptors, and weak anticholinergic (muscarinic) activity. Its sedative effects are largely attributed to H1 antagonism, while antidepressant effects are linked to monoamine reuptake inhibition.

Serious Side Effects: Seek Medical Attention Immediately

Although rare, some people may experience severe and potentially life-threatening side effects while taking this medication. If you notice any of the following symptoms, contact your doctor or seek medical help right away:

Signs of an allergic reaction, such as:
+ Rash
+ Hives
+ Itching
+ Red, swollen, blistered, or peeling skin with or without fever
+ Wheezing
+ Tightness in the chest or throat
+ Trouble breathing, swallowing, or talking
+ Unusual hoarseness
+ Swelling of the mouth, face, lips, tongue, or throat
Signs of high or low blood pressure, including:
+ Severe headache or dizziness
+ Passing out
+ Changes in eyesight
Fast heartbeat
Difficulty urinating
Feeling extremely nervous or excitable
Fever, chills, or sore throat
Unexplained bruising or bleeding
Feeling very tired or weak
Yellowing of the skin or eyes (jaundice)
Ringing in the ears (tinnitus)
Changes in sex drive
Enlarged breasts or nipple discharge
Swelling of the testicles

Important Warning for Asthma Patients

If you have asthma, use this medication with caution. Some people with asthma have experienced worsening symptoms while taking this drug. If your asthma symptoms worsen, contact your doctor right away.

Other Possible Side Effects

Like all medications, this drug can cause side effects. While many people may not experience any side effects or only minor ones, it's essential to discuss any concerns with your doctor. Contact your doctor or seek medical help if you experience any of the following side effects or if they persist or bother you:

Dizziness, drowsiness, tiredness, or weakness
Constipation, diarrhea, stomach pain, upset stomach, vomiting, or decreased appetite
Dry mouth
Changes in taste
Mouth irritation or mouth sores
Weight gain
Excessive sweating
Flushing
Hair loss
* Headache

This is not an exhaustive list of possible side effects. If you have questions or concerns about side effects, contact your doctor. You can also report side effects to the FDA at 1-800-332-1088 or online at https://www.fda.gov/medwatch.

Before Taking This Medication: Important Information to Share with Your Doctor

It is essential to inform your doctor about the following:

Any allergies you have, including allergies to this medication, its components, or other substances. Be sure to describe the allergic reaction you experienced.
Certain health conditions, such as:
+ Difficulty urinating
+ Glaucoma
Current or recent use of specific medications, including:
+ Linezolid or methylene blue
+ Certain antidepressants or Parkinson's disease medications taken within the last 14 days, including isocarboxazid, phenelzine, tranylcypromine, selegiline, or rasagiline (as this may lead to very high blood pressure)
Use of other medications that can cause drowsiness, as there are many drugs with this potential effect. If you are unsure, consult your doctor or pharmacist.
* If you are breastfeeding, as you should not breastfeed while taking this medication.

This list is not exhaustive, and it is crucial to discuss all your medications (prescription, over-the-counter, natural products, and vitamins) and health problems with your doctor and pharmacist. They will help determine if it is safe to take this medication with your other medications and health conditions. Never start, stop, or change the dose of any medication without first consulting your doctor.

It is essential to inform all your healthcare providers, including doctors, nurses, pharmacists, and dentists, that you are taking this medication. Before engaging in activities that require your full attention, such as driving, wait until you understand how this drug affects you.

Please note that it may take several weeks to experience the full effects of this medication. Do not abruptly stop taking this drug without consulting your doctor, as this may increase your risk of side effects. If you need to discontinue this medication, your doctor will guide you on how to gradually stop taking it to minimize potential risks.

While taking this medication, it is recommended that you avoid consuming alcohol. Additionally, before using marijuana, other forms of cannabis, or prescription or over-the-counter (OTC) drugs that may cause drowsiness, consult with your doctor.

Some individuals may have a higher risk of developing eye problems while taking this medication. Your doctor may recommend an eye exam to assess your risk. If you experience eye pain, changes in vision, or swelling and redness in or around the eye, contact your doctor immediately.

This medication may increase your sensitivity to the sun, making you more prone to sunburn. Take necessary precautions when exposed to sunlight, and inform your doctor if you experience frequent sunburns while taking this medication.

If you have diabetes (high blood sugar), it is crucial to closely monitor your blood sugar levels. Be aware of signs of high or low blood sugar, such as fruity-smelling breath, dizziness, rapid breathing, rapid heartbeat, confusion, sleepiness, weakness, flushing, headache, unusual thirst or hunger, frequent urination, shaking, or sweating. If you experience any of these symptoms, notify your doctor.

If you are 65 years or older, use this medication with caution, as you may be more susceptible to side effects.

Some medications, including this one, may affect fertility and the ability to conceive. If you have concerns or questions, discuss them with your doctor.

If you are pregnant or planning to become pregnant, consult with your doctor to weigh the benefits and risks of taking this medication during pregnancy. Taking this drug in the third trimester may lead to health problems in the newborn, so it is essential to discuss this with your doctor.

• Monoamine Oxidase Inhibitors (MAOIs) - concurrent use or within 14 days of MAOI discontinuation (risk of serotonin syndrome, hyperpyrexic crisis, severe convulsions, and death)
• Cisapride (risk of QT prolongation and arrhythmias)

• CNS Depressants (e.g., alcohol, benzodiazepines, opioids, sedatives, hypnotics, antihistamines) - additive CNS depression
• Anticholinergic Agents (e.g., atropine, scopolamine, benztropine, some antipsychotics) - additive anticholinergic effects (dry mouth, blurred vision, urinary retention, constipation, confusion)
• Sympathomimetic Agents (e.g., epinephrine, norepinephrine, phenylephrine) - potentiated cardiovascular effects (hypertension, arrhythmias)
• CYP2D6 Inhibitors (e.g., fluoxetine, paroxetine, quinidine, cimetidine) - increased doxepin plasma concentrations and toxicity risk
• QT-prolonging Drugs (e.g., antiarrhythmics, certain antipsychotics, macrolide antibiotics) - increased risk of QT prolongation and Torsades de Pointes
• Thyroid Hormones - increased risk of cardiac arrhythmias and other adverse effects

• Cimetidine - inhibits doxepin metabolism, leading to increased plasma levels
• Barbiturates - may decrease doxepin plasma levels due to enzyme induction
• Oral Contraceptives - may alter doxepin metabolism
• Warfarin - potential for altered anticoagulant effect (monitor INR)

• Not available

• Worsening depression
• Emergence of suicidal thoughts or behavior
• Unusual changes in behavior (e.g., agitation, irritability, hostility, impulsivity, akathisia, hypomania, mania)
• Sedation/drowsiness
• Dizziness/lightheadedness (especially upon standing)
• Dry mouth
• Blurred vision
• Constipation
• Urinary retention
• Confusion or cognitive impairment (especially in elderly)
• Cardiac symptoms (e.g., palpitations, chest pain, syncope)

Category C. Doxepin should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus. Neonatal withdrawal symptoms (e.g., respiratory distress, cyanosis, apnea, seizures, feeding difficulties, hypotonia, hypertonia, tremor, irritability, prolonged crying) have been reported in neonates exposed to TCAs during the third trimester.

Doxepin and its active metabolite are excreted into breast milk. The American Academy of Pediatrics considers doxepin to be a drug for which the effect on the nursing infant is unknown but may be of concern. Monitor infants for sedation, poor feeding, and poor weight gain. Use with caution, or consider alternative agents, especially in preterm or neonates.

Doxepin is not FDA-approved for depression or anxiety in pediatric patients. A Black Box Warning exists regarding increased risk of suicidal thoughts and behavior in children, adolescents, and young adults (up to 24 years of age) treated with antidepressants. Use with extreme caution and close monitoring if prescribed off-label.

Elderly patients are more sensitive to the anticholinergic, sedative, and hypotensive effects of doxepin. They are also at increased risk for falls, cognitive impairment, and cardiac conduction abnormalities. Start with lower doses (e.g., 10-25 mg/day) and titrate slowly. Avoid if possible in patients with dementia or significant cardiovascular disease.

• Doxepin has significant anticholinergic and sedative properties, which can be beneficial for insomnia or anxiety with agitation, but problematic for other patients.
• Orthostatic hypotension is a common side effect, especially in the elderly; advise patients to rise slowly from sitting or lying positions.
• Cardiac conduction abnormalities (e.g., QT prolongation, arrhythmias) can occur, particularly at higher doses or in patients with pre-existing cardiac disease. ECG monitoring may be warranted.
• Abrupt discontinuation can lead to withdrawal symptoms (e.g., nausea, vomiting, dizziness, headache, irritability, sleep disturbance); taper dose gradually.
• Therapeutic drug monitoring (TDM) for doxepin and desmethyldoxepin levels can be useful in cases of non-response, suspected toxicity, or drug interactions.
• Due to its potent H1 antagonism, low-dose doxepin (3-6 mg) is specifically approved for insomnia (Silenor brand) and should not be confused with the higher doses used for depression/anxiety.

• Other Tricyclic Antidepressants (TCAs): Amitriptyline, Imipramine, Nortriptyline
• Selective Serotonin Reuptake Inhibitors (SSRIs): Fluoxetine, Sertraline, Paroxetine, Citalopram, Escitalopram
• Serotonin-Norepinephrine Reuptake Inhibitors (SNRIs): Venlafaxine, Duloxetine
• Atypical Antidepressants: Bupropion, Mirtazapine, Trazodone
• Benzodiazepines (for anxiety, short-term use): Alprazolam, Lorazepam, Diazepam
• Non-benzodiazepine hypnotics (for insomnia): Zolpidem, Eszopiclone, Zaleplon

If your symptoms or health issues persist or worsen, it is essential to contact your doctor promptly. To ensure safe and effective treatment, never share your medication with others or take someone else's medication.

This medication is accompanied by a Medication Guide, a patient fact sheet that provides crucial information. It is essential to read this guide carefully and review it again each time your prescription is refilled. If you have any questions or concerns about this medication, consult your doctor, pharmacist, or other healthcare provider for guidance.

In the event of a suspected overdose, immediately call your local poison control center or seek emergency medical attention. When reporting the incident, be prepared to provide detailed information, including the name of the medication taken, the quantity, and the time it occurred.