Sinequan 150mg Caps

Doxepin is a tricyclic antidepressant (TCA) that primarily inhibits the reuptake of norepinephrine and serotonin at presynaptic neuronal membranes, thereby increasing the concentration of these neurotransmitters in the synaptic cleft. It also possesses potent antihistaminic (H1 and H2), anticholinergic, and alpha-1 adrenergic blocking properties, which contribute to its sedative, anxiolytic, and adverse effects.

Urgent 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 interest
Enlarged breasts or nipple discharge
Swelling of the testicles

Important Warning for Asthma Patients

If you have asthma, use this medication with caution. Worsening of asthma has been reported in people taking this medication. If your asthma symptoms worsen while taking this medication, contact your doctor right away.

Other Possible Side Effects

Like all medications, this drug can cause side effects. Many people may not experience any side effects or may only have mild ones. However, if you notice any of the following side effects or if they bother you or do not go away, contact your doctor or seek medical help:

Feeling dizzy, sleepy, tired, or weak
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, such as foods or drugs. Be sure to describe the allergic reaction you experienced.
Certain health conditions, including:
+ Urinary retention or glaucoma
Current or recent use of specific medications, including:
+ Linezolid or methylene blue
+ Monoamine oxidase inhibitors (MAOIs) for depression or Parkinson's disease, such as isocarboxazid, phenelzine, tranylcypromine, selegiline, or rasagiline, within the last 14 days, as this may lead to severely 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 drugs and health conditions. Never start, stop, or change the dosage 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 alertness, 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 provide guidance on how to gradually stop taking it.

While taking this medication, avoid consuming alcohol. Additionally, consult your doctor before using marijuana, cannabis, or prescription or over-the-counter (OTC) drugs that may cause drowsiness or slow your reactions.

Some individuals may be at 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 spending time outdoors, and inform your doctor if you experience frequent sunburns while taking this medication.

If you have diabetes (high blood sugar), closely monitor your blood sugar levels. Be aware of signs of high or low blood sugar, such as fruity breath odor, dizziness, rapid breathing, rapid heartbeat, confusion, drowsiness, weakness, flushing, headache, unusual thirst or hunger, frequent urination, shaking, or sweating. Report any of these symptoms to 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, discuss them with your doctor.

If you are pregnant or plan to become pregnant, consult 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 crucial to discuss this with your doctor.

• Monoamine Oxidase Inhibitors (MAOIs) - risk of serotonin syndrome, hyperpyretic crises, convulsions, and death.
• Cisapride - risk of QT prolongation and arrhythmias.
• Patients with glaucoma or urinary retention (due to anticholinergic effects).

• CNS Depressants (e.g., alcohol, benzodiazepines, opioids, sedatives, hypnotics) - additive CNS depression.
• Anticholinergic agents (e.g., atropine, benztropine, diphenhydramine) - additive anticholinergic effects (severe constipation, urinary retention, paralytic ileus, delirium).
• Adrenergic neuron blocking agents (e.g., guanethidine, clonidine) - may block antihypertensive effects.
• CYP2D6 inhibitors (e.g., fluoxetine, paroxetine, quinidine) - increased doxepin levels and toxicity.
• Thyroid hormones - increased risk of cardiac arrhythmias.
• QT-prolonging drugs (e.g., antiarrhythmics, antipsychotics, macrolides, fluoroquinolones) - increased risk of QT prolongation and Torsades de Pointes.

• Cimetidine - increased doxepin levels.
• Oral anticoagulants (e.g., warfarin) - potential for increased anticoagulant effect.
• Sympathomimetics (e.g., epinephrine, norepinephrine) - enhanced pressor response.
• Antihypertensives - additive hypotensive effects.

• Not available

• Worsening depression
• Suicidal thoughts or behavior
• Unusual changes in behavior (agitation, irritability, panic attacks, insomnia, impulsivity, akathisia, hypomania, mania)
• Dry mouth
• Constipation
• Blurred vision
• Urinary retention
• Dizziness or lightheadedness (especially upon standing)
• Sedation or drowsiness
• Nausea
• Headache
• Tremor
• Palpitations or irregular heartbeat
• Confusion or disorientation (especially in elderly)

Doxepin is Pregnancy Category C. Studies in animals have shown adverse effects on the fetus, but there are no adequate and well-controlled studies in pregnant women. Use only if the potential benefit justifies the potential risk to the fetus. Neonates exposed to TCAs in the third trimester may experience withdrawal symptoms (e.g., respiratory distress, feeding difficulties, irritability, tremors).

Doxepin and its active metabolite nordoxepin 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 weight gain. L3 (Moderately Safe) or L4 (Possibly Hazardous) depending on source and dose. Low doses (e.g., for insomnia) may pose less risk.

Not approved for depression or anxiety in pediatric patients. Black Box Warning regarding increased risk of suicidality in children, adolescents, and young adults. Use for insomnia (Silenor) is not approved for pediatric patients. Topical doxepin cream is approved for pruritus in children ≥12 years. Oral use in children for other indications is off-label and requires careful consideration of risks vs. benefits.

Elderly patients are more sensitive to the anticholinergic, sedative, and hypotensive effects of doxepin. Start with lower doses (e.g., 10-25 mg/day for depression/anxiety, 3 mg for insomnia) and titrate slowly. Increased risk of falls, cognitive impairment, and cardiac adverse events (e.g., orthostatic hypotension, arrhythmias). Monitor closely for adverse effects.

• Doxepin's strong antihistaminic properties make it highly sedating, which is leveraged for its use in insomnia (Silenor, low dose) and pruritus.
• The 150mg capsule is a high dose, typically reserved for severe depression or anxiety, and should be initiated with careful titration from lower doses.
• Due to its long half-life, once-daily dosing (especially at bedtime) is often preferred for depression/anxiety to minimize daytime sedation.
• Be aware of the significant anticholinergic side effects (dry mouth, constipation, urinary retention, blurred vision) and counsel patients on management strategies.
• Orthostatic hypotension is a common and potentially serious side effect, especially in the elderly; advise patients to rise slowly.
• Cardiac monitoring (ECG) is important, especially in patients with pre-existing cardiac disease or those receiving high doses, due to potential for QT prolongation and conduction abnormalities.
• Avoid abrupt discontinuation, especially after prolonged use, to prevent withdrawal symptoms (e.g., nausea, headache, malaise, sleep disturbance, irritability).

• For Depression: SSRIs (e.g., fluoxetine, sertraline), SNRIs (e.g., venlafaxine, duloxetine), Atypical Antidepressants (e.g., bupropion, mirtazapine), other TCAs (e.g., amitriptyline, imipramine, nortriptyline).
• For Anxiety: SSRIs, SNRIs, benzodiazepines (short-term), buspirone.
• For Insomnia: Z-drugs (e.g., zolpidem, eszopiclone), ramelteon, suvorexant, other sedating antidepressants (e.g., mirtazapine, trazodone), antihistamines (e.g., diphenhydramine).
• For Pruritus: Antihistamines (e.g., hydroxyzine, cetirizine), topical corticosteroids, other topical antipruritics.

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 vital to read this guide carefully and review it again whenever your prescription is refilled. If you have any questions or concerns about this medication, consult your doctor, pharmacist, or other healthcare provider.

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, the amount taken, and the time it was taken.