Amitriptyline 150mg Tablets
WARNING: Drugs like this one have raised the chance of suicidal thoughts or actions in children and young adults. The risk may be greater in people who have had these thoughts or actions in the past. All people who take this drug need to be watched closely. Call the doctor right away if signs like depression, nervousness, restlessness, grouchiness, panic attacks, or changes in mood or actions are new or worse. Call the doctor right away if any thoughts or actions of suicide occur.This drug is not approved for use in children. Talk with the doctor. @ COMMON USES: It is used to treat depression.It may be given to you for other reasons. Talk with the doctor.
Drug Class
Tricyclic Antidepressant (TCA)
Pharmacologic Class
Serotonin and Norepinephrine Reuptake Inhibitor (SNRI); Anticholinergic; Antihistamine; Alpha-1 Adrenergic Antagonist
Pregnancy Category
Category D
FDA Approved
Apr 1961
DEA Schedule
Not Controlled
Overview
What is this medicine?
Amitriptyline is a medication primarily used to treat depression, but it's also commonly used for nerve pain (neuropathic pain) and to prevent migraines. It works by affecting certain natural chemicals in the brain that help regulate mood and pain signals. It can also cause drowsiness, which can be helpful for sleep.
How to Use This Medicine
Taking Your Medication Correctly
To get the most benefit from your medication, take it exactly as directed by your doctor. Carefully read all the information provided with your prescription and follow the instructions closely. If you are taking this medication once a day, it is best to take it at bedtime. Continue taking your medication as prescribed by your doctor or healthcare provider, even if you start to feel well.
Storing and Disposing of Your Medication
To maintain the effectiveness and safety of your medication, store it at room temperature in a dry location, avoiding the bathroom. Keep all medications in a secure place, out of the reach of children and pets. When disposing of unused or expired medication, do not flush it down the toilet or pour it down the drain unless instructed to do so. Instead, consult with your pharmacist for guidance on the proper disposal method. You may also want to inquire about drug take-back programs available in your area.
What to Do If You Miss a Dose
If you miss a dose, take it as soon as you remember. However, if it is close to the time for your next scheduled dose, skip the missed dose and resume your regular dosing schedule. Do not take two doses at the same time or take extra doses to make up for the missed one.
To get the most benefit from your medication, take it exactly as directed by your doctor. Carefully read all the information provided with your prescription and follow the instructions closely. If you are taking this medication once a day, it is best to take it at bedtime. Continue taking your medication as prescribed by your doctor or healthcare provider, even if you start to feel well.
Storing and Disposing of Your Medication
To maintain the effectiveness and safety of your medication, store it at room temperature in a dry location, avoiding the bathroom. Keep all medications in a secure place, out of the reach of children and pets. When disposing of unused or expired medication, do not flush it down the toilet or pour it down the drain unless instructed to do so. Instead, consult with your pharmacist for guidance on the proper disposal method. You may also want to inquire about drug take-back programs available in your area.
What to Do If You Miss a Dose
If you miss a dose, take it as soon as you remember. However, if it is close to the time for your next scheduled dose, skip the missed dose and resume your regular dosing schedule. Do not take two doses at the same time or take extra doses to make up for the missed one.
Lifestyle & Tips
- Avoid alcohol and other CNS depressants (e.g., sedatives, opioids) as they can increase drowsiness and other side effects.
- Be cautious when driving or operating machinery until you know how this medication affects you, as it can cause drowsiness and blurred vision.
- To minimize dizziness or lightheadedness, especially when starting treatment, get up slowly from a sitting or lying position.
- Maintain good oral hygiene due to potential dry mouth (a common side effect).
- Avoid excessive sun exposure as it may increase sensitivity to sunlight.
- Report any unusual changes in mood or behavior, especially suicidal thoughts, to your doctor immediately.
Available Forms & Alternatives
Dosing & Administration
Adult Dosing
Standard Dose:
Depression: Initial 25-50 mg/day at bedtime, gradually increased to 100-150 mg/day. Neuropathic Pain: Initial 10-25 mg/day at bedtime, titrated up to 150 mg/day.
Dose Range:
10 - 300 mg
Condition-Specific Dosing:
Depression (outpatient):
Initial 75 mg/day in divided doses or 50-100 mg at bedtime; maintenance 50-150 mg/day.
Depression (hospitalized):
Initial 100 mg/day, gradually increased to 200-300 mg/day.
Neuropathic Pain:
Initial 10-25 mg at bedtime, titrate slowly up to 150 mg/day based on response and tolerability.
Migraine Prophylaxis:
Initial 10-25 mg at bedtime, titrate slowly up to 150 mg/day.
Pediatric Dosing
Neonatal:
Not established
Infant:
Not established
Child:
Not recommended for depression due to suicidality risk. Enuresis (off-label): 10-20 mg at bedtime for 6-10 years, 25-50 mg at bedtime for >10 years. Neuropathic pain (off-label): 0.1 mg/kg/day, titrate up to 1 mg/kg/day.
Adolescent:
Not recommended for depression due to suicidality risk. For other conditions (off-label), lower adult doses may be considered with caution.
Dose Adjustments
Renal Impairment:
Mild:
No specific adjustment typically required, but monitor for adverse effects.
Moderate:
Use with caution; consider lower initial doses and slower titration.
Severe:
Use with caution; consider lower initial doses and slower titration. Monitor closely for adverse effects.
Dialysis:
Not significantly dialyzable. Use with caution; consider lower doses and monitor for adverse effects.
Hepatic Impairment:
Mild:
Use with caution; consider lower initial doses and slower titration.
Moderate:
Significant dose reduction (e.g., 50%) may be necessary. Monitor plasma levels if available.
Severe:
Contraindicated or not recommended due to extensive hepatic metabolism and risk of accumulation. If used, extreme caution and significant dose reduction are required.
Pharmacology
Mechanism of Action
Amitriptyline is a tertiary amine tricyclic antidepressant (TCA). Its primary mechanism of action is the potent inhibition of the reuptake of norepinephrine and serotonin into presynaptic nerve terminals in the central nervous system, thereby increasing the concentrations of these neurotransmitters in the synaptic cleft. It also possesses significant anticholinergic (muscarinic), antihistaminic (H1), and alpha-1 adrenergic blocking properties, which contribute to its side effect profile.
Pharmacokinetics
Absorption:
Bioavailability:
30-60% (due to significant first-pass metabolism)
Tmax:
2-12 hours (parent drug); 4-16 hours (nortriptyline)
FoodEffect:
Food may slightly delay absorption but does not significantly affect bioavailability.
Distribution:
Vd:
5-10 L/kg
ProteinBinding:
>90% (to plasma proteins)
CnssPenetration:
Yes
Elimination:
HalfLife:
10-28 hours (amitriptyline); 18-44 hours (nortriptyline)
Clearance:
Not readily available as a single value, highly variable due to extensive metabolism.
ExcretionRoute:
Primarily renal (as metabolites)
Unchanged:
<5% (parent drug)
Pharmacodynamics
OnsetOfAction:
Sedative/anxiolytic effects: within hours to days. Analgesic effects: within days to 1-2 weeks. Antidepressant effects: 2-4 weeks (full effect may take 4-6 weeks).
PeakEffect:
Antidepressant: 4-6 weeks. Analgesic: 2-4 weeks.
DurationOfAction:
Due to long half-life, once-daily dosing is effective, effects persist for 24 hours.
Safety & Warnings
BLACK BOX WARNING
Antidepressants increased the risk compared to placebo of suicidal thinking and behavior (suicidality) in children, adolescents, and young adults in short-term studies of Major Depressive Disorder (MDD) and other psychiatric disorders. Anyone considering the use of amitriptyline or any other antidepressant in a child, adolescent, or young adult must balance this risk with the clinical need. Short-term studies did not show an increase in the risk of suicidality with antidepressants compared to placebo in adults beyond 24 years of age; there was a reduction in risk with antidepressants compared to placebo in adults aged 65 and older. Depression and certain other psychiatric disorders are themselves associated with increases in the risk of suicide. Patients of all ages who are started on antidepressant therapy should be monitored appropriately and observed closely for clinical worsening, suicidality, or unusual changes in behavior. Families and caregivers should be advised of the need for close observation and communication with the prescriber.
Side Effects
Serious 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 experience any of the following symptoms, contact your doctor or seek medical attention immediately:
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
Signs of liver problems, such as:
+ Dark urine
+ Tiredness
+ Decreased appetite
+ Upset stomach or stomach pain
+ Light-colored stools
+ Vomiting
+ Yellow skin or eyes
Weakness on one side of the body
Trouble speaking or thinking
Changes in balance
Drooping on one side of the face
Blurred eyesight
Chest pain or pressure
Fast heartbeat or abnormal heartbeat
Feeling confused, unable to focus, or changes in behavior
Trouble passing urine
Fever, chills, or sore throat
Unexplained bruising or bleeding
Feeling very tired or weak
Swelling
Shakiness
Seizures
Hallucinations (seeing or hearing things that are not there)
Burning, numbness, or tingling sensations that are not normal
Changes in sex interest
Difficulty getting or maintaining an erection
Swelling of the testicles
Enlarged breasts or nipple discharge
Severe constipation or stomach pain (may be signs of a severe bowel problem)
Inability to sweat during activities or in warm temperatures
Trouble sleeping
Bad dreams
Ringing in the ears
Changes in tongue color
Excessive sweating
Joint pain
Hair loss
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 side effects. If you experience any of the following side effects or any other side effects that bother you or do not go away, contact your doctor or seek medical attention:
Constipation
Diarrhea
Stomach pain
Upset stomach
Vomiting
Decreased appetite
Dizziness
Drowsiness
Tiredness
Weakness
Dry mouth
Headache
Anxiety
Feeling nervous and excitable
Changes in taste
Weight gain or loss
Mouth sores
Reporting Side Effects
This is not a complete list of all possible side effects. If you have questions 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.
Although rare, some people may experience severe and potentially life-threatening side effects while taking this medication. If you experience any of the following symptoms, contact your doctor or seek medical attention immediately:
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
Signs of liver problems, such as:
+ Dark urine
+ Tiredness
+ Decreased appetite
+ Upset stomach or stomach pain
+ Light-colored stools
+ Vomiting
+ Yellow skin or eyes
Weakness on one side of the body
Trouble speaking or thinking
Changes in balance
Drooping on one side of the face
Blurred eyesight
Chest pain or pressure
Fast heartbeat or abnormal heartbeat
Feeling confused, unable to focus, or changes in behavior
Trouble passing urine
Fever, chills, or sore throat
Unexplained bruising or bleeding
Feeling very tired or weak
Swelling
Shakiness
Seizures
Hallucinations (seeing or hearing things that are not there)
Burning, numbness, or tingling sensations that are not normal
Changes in sex interest
Difficulty getting or maintaining an erection
Swelling of the testicles
Enlarged breasts or nipple discharge
Severe constipation or stomach pain (may be signs of a severe bowel problem)
Inability to sweat during activities or in warm temperatures
Trouble sleeping
Bad dreams
Ringing in the ears
Changes in tongue color
Excessive sweating
Joint pain
Hair loss
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 side effects. If you experience any of the following side effects or any other side effects that bother you or do not go away, contact your doctor or seek medical attention:
Constipation
Diarrhea
Stomach pain
Upset stomach
Vomiting
Decreased appetite
Dizziness
Drowsiness
Tiredness
Weakness
Dry mouth
Headache
Anxiety
Feeling nervous and excitable
Changes in taste
Weight gain or loss
Mouth sores
Reporting Side Effects
This is not a complete list of all possible side effects. If you have questions 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.
Seek Immediate Medical Attention If You Experience:
- Worsening depression or suicidal thoughts
- New or worsening anxiety, agitation, panic attacks, insomnia, irritability, hostility, impulsivity
- Severe dizziness or fainting spells
- Fast, pounding, or irregular heartbeat
- Difficulty urinating or severe constipation
- Blurred vision or eye pain
- Muscle stiffness, fever, confusion (signs of neuroleptic malignant syndrome)
- Unexplained rash or hives
- Yellowing of skin or eyes (jaundice)
Before Using This Medicine
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.
If you have recently had a heart attack.
If you have taken certain medications for depression or Parkinson's disease within the last 14 days, including isocarboxazid, phenelzine, tranylcypromine, selegiline, or rasagiline, as this may lead to severely high blood pressure.
If you are currently taking linezolid or methylene blue, as these medications can interact with this drug.
* If you are taking cisapride, as it is not recommended to take this medication with cisapride.
This list is not exhaustive, and it is crucial to discuss all your medications, including prescription and over-the-counter drugs, natural products, and vitamins, with your doctor and pharmacist. They will help you determine if it is safe to take this medication with your existing medications and health conditions. Do not start, stop, or change the dose of any medication without first consulting 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.
If you have recently had a heart attack.
If you have taken certain medications for depression or Parkinson's disease within the last 14 days, including isocarboxazid, phenelzine, tranylcypromine, selegiline, or rasagiline, as this may lead to severely high blood pressure.
If you are currently taking linezolid or methylene blue, as these medications can interact with this drug.
* If you are taking cisapride, as it is not recommended to take this medication with cisapride.
This list is not exhaustive, and it is crucial to discuss all your medications, including prescription and over-the-counter drugs, natural products, and vitamins, with your doctor and pharmacist. They will help you determine if it is safe to take this medication with your existing medications and health conditions. Do not start, stop, or change the dose of any medication without first consulting your doctor.
Precautions & Cautions
Important Warnings and Precautions
Before taking this medication, inform all your healthcare providers, including doctors, nurses, pharmacists, and dentists, that you are using this drug. Your doctor may advise you to stop taking this medication before certain surgical procedures. If you need to stop taking this drug, your doctor will provide guidance on when to resume taking it after your surgery or procedure.
Caution with Daily Activities
Until you know how this medication affects you, avoid driving and other activities that require alertness. To minimize the risk of dizziness or fainting, get up slowly from a sitting or lying position. Be cautious when climbing stairs.
Stopping the Medication
Do not stop taking this medication abruptly without consulting your doctor, as this may increase the risk of withdrawal symptoms. If you need to discontinue this drug, your doctor will instruct you on how to gradually stop taking it.
Monitoring Blood Sugar Levels
If you have diabetes (high blood sugar), closely monitor your blood sugar levels while taking this medication. Inform your doctor if you experience symptoms of high or low blood sugar, such as:
Fruity-smelling breath
Dizziness
Rapid breathing
Rapid heartbeat
Confusion
Drowsiness
Weakness
Flushing
Headache
Increased thirst or hunger
Frequent urination
Shaking
Sweating
Interactions with Other Substances
Before using alcohol, marijuana, or other forms of cannabis, or prescription and over-the-counter medications that may cause drowsiness, consult your doctor.
Eye Problems
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. Immediately contact your doctor if you experience:
Eye pain
Changes in vision
Swelling or redness in or around the eye
Sun Sensitivity
This medication may increase your risk of sunburn. Take precautions when exposed to the sun, and inform your doctor if you experience excessive sunburn.
Heat and Fluid Loss
Be cautious in hot weather or during physical activity, and drink plenty of fluids to prevent dehydration.
Muscle Problems
There is a risk of developing a severe muscle condition called tardive dyskinesia, which may be irreversible. This risk is higher in individuals with diabetes, older adults, especially older females, and those taking higher doses or using the medication for an extended period. Contact your doctor immediately if you experience:
Uncontrolled body movements
Tongue sticking out
Puffing cheeks
Mouth puckering
* Chewing problems
Special Considerations
If you are 65 or older, use this medication with caution, as you may be more susceptible to side effects.
Pregnancy and Breastfeeding
Inform your doctor if you are pregnant, plan to become pregnant, or are breastfeeding. Your doctor will discuss the benefits and risks of using this medication during this time.
Before taking this medication, inform all your healthcare providers, including doctors, nurses, pharmacists, and dentists, that you are using this drug. Your doctor may advise you to stop taking this medication before certain surgical procedures. If you need to stop taking this drug, your doctor will provide guidance on when to resume taking it after your surgery or procedure.
Caution with Daily Activities
Until you know how this medication affects you, avoid driving and other activities that require alertness. To minimize the risk of dizziness or fainting, get up slowly from a sitting or lying position. Be cautious when climbing stairs.
Stopping the Medication
Do not stop taking this medication abruptly without consulting your doctor, as this may increase the risk of withdrawal symptoms. If you need to discontinue this drug, your doctor will instruct you on how to gradually stop taking it.
Monitoring Blood Sugar Levels
If you have diabetes (high blood sugar), closely monitor your blood sugar levels while taking this medication. Inform your doctor if you experience symptoms of high or low blood sugar, such as:
Fruity-smelling breath
Dizziness
Rapid breathing
Rapid heartbeat
Confusion
Drowsiness
Weakness
Flushing
Headache
Increased thirst or hunger
Frequent urination
Shaking
Sweating
Interactions with Other Substances
Before using alcohol, marijuana, or other forms of cannabis, or prescription and over-the-counter medications that may cause drowsiness, consult your doctor.
Eye Problems
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. Immediately contact your doctor if you experience:
Eye pain
Changes in vision
Swelling or redness in or around the eye
Sun Sensitivity
This medication may increase your risk of sunburn. Take precautions when exposed to the sun, and inform your doctor if you experience excessive sunburn.
Heat and Fluid Loss
Be cautious in hot weather or during physical activity, and drink plenty of fluids to prevent dehydration.
Muscle Problems
There is a risk of developing a severe muscle condition called tardive dyskinesia, which may be irreversible. This risk is higher in individuals with diabetes, older adults, especially older females, and those taking higher doses or using the medication for an extended period. Contact your doctor immediately if you experience:
Uncontrolled body movements
Tongue sticking out
Puffing cheeks
Mouth puckering
* Chewing problems
Special Considerations
If you are 65 or older, use this medication with caution, as you may be more susceptible to side effects.
Pregnancy and Breastfeeding
Inform your doctor if you are pregnant, plan to become pregnant, or are breastfeeding. Your doctor will discuss the benefits and risks of using this medication during this time.
Overdose Information
Overdose Symptoms:
- Severe drowsiness or coma
- Confusion, agitation, hallucinations
- Fast, irregular, or pounding heartbeat (tachycardia, arrhythmias)
- Low blood pressure (hypotension)
- Dilated pupils
- Dry mouth, blurred vision
- Urinary retention
- Seizures
- Respiratory depression
- Hypothermia
- Cardiac arrest
What to Do:
Seek immediate medical attention. Call 911 or your local emergency number. For poison control, call 1-800-222-1222.
Drug Interactions
Contraindicated Interactions
- Monoamine Oxidase Inhibitors (MAOIs) - risk of serotonin syndrome, hyperpyretic crises, convulsions, death (allow 14 days washout period)
- Cisapride, Astemizole, Terfenadine - increased risk of QT prolongation and arrhythmias
- Linezolid, Methylene Blue (IV) - risk of serotonin syndrome
Major Interactions
- 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, paralytic ileus, delirium)
- Adrenergic Neuron Blockers (e.g., guanethidine, clonidine) - may antagonize hypotensive effects
- QT-prolonging Drugs (e.g., antiarrhythmics, certain antipsychotics, fluoroquinolones) - increased risk of ventricular arrhythmias
- CYP2D6 Inhibitors (e.g., fluoxetine, paroxetine, quinidine, cimetidine) - increased amitriptyline plasma levels and toxicity
- Thyroid Hormones - increased risk of cardiac arrhythmias and toxicity
Moderate Interactions
- SSRIs (other than fluoxetine/paroxetine) - may increase amitriptyline levels, risk of serotonin syndrome
- Cimetidine - inhibits CYP metabolism, increasing amitriptyline levels
- Oral Contraceptives - may increase or decrease TCA levels
- Barbiturates, Carbamazepine, Phenytoin (CYP inducers) - may decrease amitriptyline plasma levels
- Sympathomimetics (e.g., epinephrine, norepinephrine) - enhanced pressor response
Minor Interactions
- Tobacco smoking - may decrease amitriptyline levels (CYP1A2 induction)
- Grapefruit juice - may inhibit CYP3A4, potentially increasing levels (minor effect)
Monitoring
Baseline Monitoring
Electrocardiogram (ECG)
Rationale: To assess for pre-existing cardiac conduction abnormalities or QT prolongation, especially in elderly patients or those with cardiac disease.
Timing: Prior to initiation
Liver Function Tests (LFTs)
Rationale: Amitriptyline is extensively metabolized by the liver; to assess baseline hepatic function.
Timing: Prior to initiation
Renal Function (BUN, Creatinine)
Rationale: To assess baseline renal function, as metabolites are renally excreted.
Timing: Prior to initiation
Electrolytes (Potassium, Magnesium)
Rationale: To identify baseline abnormalities that could predispose to arrhythmias.
Timing: Prior to initiation
Blood Pressure and Heart Rate
Rationale: To establish baseline and monitor for orthostatic hypotension or tachycardia.
Timing: Prior to initiation
Routine Monitoring
Clinical Response (e.g., mood, pain level)
Frequency: Weekly during titration, then monthly or as clinically indicated
Target: Improvement in target symptoms
Action Threshold: Lack of improvement or worsening symptoms may require dose adjustment or alternative therapy.
Adverse Effects (e.g., anticholinergic, CNS, cardiac)
Frequency: Regularly, especially during titration and dose changes
Target: Tolerable side effect profile
Action Threshold: Intolerable side effects may require dose reduction, symptomatic treatment, or discontinuation.
Blood Pressure and Heart Rate
Frequency: Weekly during titration, then periodically
Target: Within normal limits, minimal orthostatic changes
Action Threshold: Significant orthostatic hypotension or persistent tachycardia may require intervention.
ECG (if clinically indicated)
Frequency: Periodically in patients with pre-existing cardiac disease, elderly, or on high doses
Target: Normal rhythm, PR, QRS, QT intervals
Action Threshold: Significant changes (e.g., prolonged QT interval, new arrhythmias) require immediate evaluation.
Plasma Amitriptyline/Nortriptyline Levels (Therapeutic Drug Monitoring)
Frequency: Not routinely required, but useful in non-responders, suspected toxicity, or drug interactions
Target: Amitriptyline + Nortriptyline: 100-250 ng/mL (for depression)
Action Threshold: Levels outside therapeutic range may indicate need for dose adjustment.
Symptom Monitoring
- Worsening depression
- Emergence of suicidal thoughts or behavior (especially in young adults)
- Unusual changes in behavior or mood (e.g., agitation, irritability, anxiety, panic attacks, insomnia, impulsivity, mania/hypomania)
- Cardiac symptoms (e.g., palpitations, dizziness, syncope)
- Anticholinergic effects (e.g., dry mouth, blurred vision, constipation, urinary retention)
- CNS effects (e.g., sedation, confusion, disorientation, seizures)
- Gastrointestinal disturbances (e.g., nausea, vomiting)
- Weight changes
Special Patient Groups
Pregnancy
Category D. Amitriptyline crosses the placenta. Studies in humans have shown evidence of fetal risk, but potential benefits may warrant use of the drug in pregnant women despite potential risks (e.g., for severe depression where other treatments are ineffective). Neonatal withdrawal symptoms (e.g., respiratory distress, cyanosis, irritability, feeding difficulties) have been reported.
Trimester-Specific Risks:
First Trimester:
Potential for increased risk of congenital malformations, though data are conflicting and not consistently conclusive.
Second Trimester:
Less data on specific risks, but continued exposure.
Third Trimester:
Risk of neonatal withdrawal symptoms (e.g., respiratory distress, tremors, hypotonia, seizures) if used late in pregnancy.
Lactation
L3 (Moderate risk). Amitriptyline and its active metabolite, nortriptyline, are excreted into breast milk. While levels are generally low, potential for adverse effects in the infant (e.g., sedation, poor feeding, irritability) exists. Monitor infant for drowsiness, poor feeding, and weight gain. Nortriptyline may be preferred if a TCA is necessary due to lower levels in milk and less sedation.
Infant Risk:
Sedation, poor feeding, irritability, weight loss. Risk is generally low but present.
Pediatric Use
Not approved for depression in pediatric patients due to increased risk of suicidality (Black Box Warning). Use for other conditions (e.g., enuresis, neuropathic pain) is off-label and requires careful consideration of risks vs. benefits, with close monitoring for adverse effects and suicidality.
Geriatric Use
Elderly patients are more sensitive to the anticholinergic, sedative, and hypotensive effects of amitriptyline. Start with lower doses (e.g., 10-25 mg/day) and titrate slowly. Increased risk of falls, cognitive impairment, and cardiac conduction abnormalities. Avoid if possible in patients with dementia or significant cardiovascular disease.
Clinical Information
Clinical Pearls
- Amitriptyline is a potent TCA with significant anticholinergic and sedative properties, making it useful for depression with insomnia or anxiety, and for neuropathic pain.
- Due to its side effect profile, it is often not a first-line antidepressant but remains valuable for specific indications or when other agents fail.
- The 150mg dose is typically a maintenance dose for depression or a high dose for neuropathic pain; initial doses are much lower.
- Titrate dose slowly to minimize side effects, especially in elderly patients.
- Warn patients about the delayed onset of antidepressant effects (weeks) versus more immediate sedative/analgesic effects.
- Monitor for cardiac effects (ECG) and orthostatic hypotension, especially in vulnerable populations.
- Be vigilant for signs of serotonin syndrome when co-administered with other serotonergic agents.
- Overdose can be life-threatening due to cardiac toxicity and CNS depression.
Alternative Therapies
- For Depression: SSRIs, SNRIs, Bupropion, Mirtazapine, Electroconvulsive Therapy (ECT), Transcranial Magnetic Stimulation (TMS), Psychotherapy.
- For Neuropathic Pain: Gabapentin, Pregabalin, Duloxetine, Venlafaxine, Carbamazepine (for trigeminal neuralgia), topical agents (e.g., lidocaine, capsaicin).
- For Migraine Prophylaxis: Beta-blockers (e.g., Propranolol), Topiramate, CGRP inhibitors, Botox.
Cost & Coverage
Average Cost:
Varies widely, typically $10-$50 per 30 tablets (150mg)
Generic Available:
Yes
Insurance Coverage:
Tier 1 or Tier 2 (Generic)
General Drug Facts
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, a patient fact sheet that provides crucial information. Please 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 your local poison control center or seek emergency medical attention. When reporting the incident, be prepared to provide details about the medication taken, the quantity, and the time it occurred.