Doxepin 25mg Capsules

Doxepin is a tricyclic antidepressant (TCA) that primarily inhibits the reuptake of norepinephrine (NE) and serotonin (5-HT) at the presynaptic neuronal membrane, thereby increasing the concentration of these neurotransmitters in the synaptic cleft. It also possesses potent antihistaminic (H1), anticholinergic (muscarinic), and alpha-1 adrenergic blocking properties, which contribute to its sedative and adverse effects.

Urgent Side Effects: Seek Medical Help Right Away

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 immediate medical attention:

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. Worsening of asthma symptoms has been reported in people taking this medication. If your asthma symptoms worsen while taking this medication, contact your doctor immediately.

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 symptoms. 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

Reporting Side Effects

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. This will help ensure your safety and prevent any potential interactions with other treatments.

Until you know how this medication affects you, avoid driving and engaging in activities that require you to be alert. You may not experience the full effects of the medication for several weeks.

Do not stop taking this medication abruptly without consulting your doctor, as this may increase your risk of side effects. If you need to discontinue the medication, your doctor will instruct you on how to gradually taper off the dosage to minimize potential risks.

While taking this medication, it is recommended that you avoid consuming alcohol. Additionally, consult your doctor before using marijuana, cannabis products, or prescription or over-the-counter medications that may cause drowsiness or impair 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 excessive sunburning while taking this medication.

If you have diabetes, it is crucial to closely monitor your blood sugar levels. Be aware of the signs of high or low blood sugar, which may include 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 or questions, discuss them with your doctor.

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

• Monoamine Oxidase Inhibitors (MAOIs) - risk of hyperpyretic crisis, severe convulsions, and death.
• Linezolid (reversible MAOI)
• Methylene Blue (reversible MAOI)

• CNS Depressants (e.g., alcohol, benzodiazepines, opioids, sedatives, hypnotics) - additive CNS depression.
• Anticholinergic Agents (e.g., atropine, scopolamine, antihistamines, antipsychotics) - additive anticholinergic effects (e.g., severe constipation, urinary retention, blurred vision, delirium).
• Sympathomimetics (e.g., epinephrine, norepinephrine, phenylephrine) - potentiation of cardiovascular effects.
• QT-prolonging drugs (e.g., antiarrhythmics, certain antipsychotics, fluoroquinolones) - increased risk of QT prolongation and arrhythmias.
• CYP2D6 Inhibitors (e.g., quinidine, fluoxetine, paroxetine, bupropion) - increased plasma concentrations of doxepin and desmethyldoxepin.
• Thyroid hormones - increased risk of cardiac arrhythmias.

• Cimetidine - inhibits doxepin metabolism, increasing plasma levels.
• Oral anticoagulants (e.g., warfarin) - potential for increased anticoagulant effect.
• Antihypertensives (e.g., guanethidine, clonidine) - doxepin may antagonize their hypotensive effects.
• Adrenergic neuron blockers (e.g., reserpine) - may reduce antidepressant effect.

• Tobacco smoking - may induce CYP1A2, potentially decreasing doxepin levels.

• Worsening depression
• Suicidal ideation or behavior
• Unusual changes in behavior (e.g., agitation, irritability, hostility, impulsivity, akathisia, hypomania, mania)
• Sedation or somnolence
• Dry mouth
• Blurred vision
• Urinary retention
• Constipation
• Dizziness or orthostatic hypotension
• Tachycardia or palpitations
• Confusion or delirium (especially in elderly)
• Seizures

Category C. Use during pregnancy only if the potential benefit justifies the potential risk to the fetus. Doxepin crosses the placenta. Neonatal withdrawal symptoms (e.g., respiratory distress, cyanosis, apnea, seizures, feeding difficulties, hypotonia, hypertonia, tremor, irritability, persistent 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 TCAs to be compatible with breastfeeding, but caution is advised. Monitor the infant for sedation, poor feeding, and weight gain.

Not approved for depression or anxiety in pediatric patients due to the Black Box Warning regarding increased risk of suicidality. Use for other conditions (e.g., pruritus) is off-label and should be done with extreme caution and close monitoring.

Elderly patients are more sensitive to the anticholinergic, sedative, and hypotensive effects of doxepin. Start with lower doses (e.g., 10-25 mg/day) and titrate slowly. Increased risk of falls, cognitive impairment, and cardiac arrhythmias. Avoid in patients with dementia-related psychosis.

• Doxepin is a potent H1 antagonist, making it highly sedating. This property is leveraged for its use in insomnia at very low doses (3-6 mg).
• Due to its anticholinergic properties, doxepin should be used with extreme caution or avoided in patients with narrow-angle glaucoma, urinary retention, or prostatic hypertrophy.
• The full antidepressant effect may take 2-4 weeks to manifest, but sedative effects are immediate.
• Orthostatic hypotension is a common side effect, especially at initiation and with dose increases. Advise patients to rise slowly.
• Plasma levels of doxepin and its active metabolite, desmethyldoxepin, can be measured, but therapeutic drug monitoring is not routinely required unless there is concern for toxicity, non-response, or drug interactions.
• Overdose can be life-threatening due to cardiac arrhythmias, severe hypotension, and CNS depression. Management is supportive.
• Consider ECG monitoring in elderly patients or those with pre-existing cardiac disease, especially at higher doses.

• For depression/anxiety: SSRIs (e.g., fluoxetine, sertraline, escitalopram), SNRIs (e.g., venlafaxine, duloxetine), other TCAs (e.g., amitriptyline, imipramine, nortriptyline), atypical antidepressants (e.g., bupropion, mirtazapine).
• For insomnia: Z-drugs (e.g., zolpidem, eszopiclone), benzodiazepines (e.g., temazepam), ramelteon, suvorexant, trazodone, mirtazapine.
• For pruritus: Antihistamines (e.g., hydroxyzine, diphenhydramine), topical corticosteroids, other antipruritics.

If your symptoms or health issues persist or worsen, it is essential to contact your doctor promptly. To ensure safe use, never share your medication with others, and do not take medication prescribed to someone else. This medication is accompanied by a Medication Guide, which provides crucial information for patients. It is important 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 healthcare provider. In the event of a suspected overdose, immediately call the poison control center or seek emergency medical attention. When seeking help, be prepared to provide details about the overdose, including the substance taken, the amount, and the time it occurred.