Dosing and uses of Pamelor, Aventyl (nortriptyline)
Adult dosage forms and strengths
capsule
- 10mg
- 25mg
- 50mg
- 75mg
oral solution
- 10mg/5mL
Depression
25mg PO q6-8hr
No more than 150 mg/day
Dosing considerations
- Total daily dose can be given HS
Chronic Urticaria, Nocturnal Pruritus, Angioedema (Off-label)
75mg/day PO
Smoking Cessation (Off-label)
25 mg PO qDay; start 1-2 weeks before quit date; may titrate to 75-100 mg/day 10-28 days prior to selected quit date
ADHD (Off-label)
25 mg PO q6-8hr
Postherpetic Neuralgia (Off-label)
10-25 mg PO qHS; may increase to 75 mg qHS or divided q12hr if tolerated
Dosing Modifications
Hepatic impairment: Administer lower dose and titrate at a slower rate
Pediatric dosage forms and strengths
capsule
- 10mg
- 25mg
- 50mg
- 75mg
oral solution
- 10mg/5mL
Depression (Off-label)
<6 years: Safety and efficacy not established
6-12 years: 1-3 mg/kg/day PO divided q6-8hr, OR 10-20 mg/day PO divided q6-8hr
>12 years: 30-50 mg PO qDay, divided or single dose
See Black Box Warning
Nocturnal Enuresis (Off-label)
6-7 years (20-25 kg): 10 mg PO qHs
8-11 years (26-35 kg): 10-20 mg PO qHs
>11 years (36-54 kg): 25-35 mg PO qHs
ADHD (Off-label)
0.5 mg/kg/day PO, titrated to maximum 2 mg/kg/day or 100 mg, whichever is less
Geriatric dosage forms and strengths
Depression
Initial: 30-50 mg PO qDay or in divided doses
May increase to 75-100 mg/day if tolerated
Pamelor, Aventyl (nortriptyline) adverse (side) effects
Frequency not defined
Fatigue
Lethargy
Sedation
Weakness
Dry mouth
Constipation
Blurred vision
Agitation
Anxiety
Headache
Insomnia
Nausea
Vomiting
Sweating
Orthostatic hypotension, ECG changes, tachycardia
Confusion, extrapyramidal symptoms, dizziness, paresthesia, tinnitus
Rash
Increased LFTs
Sexual dysfunction
Seizure
Agranulocytosis
Eosinophilia
Leukopenia
Thrombocytopenia
SIADH
Warnings
Black box warnings
In short-term studies, antidepressants increased the risk of suicidal thinking and behavior in children, adolescents, and young adults (<24 years) taking antidepressants for major depressive disorders or other psychiatric illnesses
This increase was not seen in patients aged over age 24 years; a slight decrease in suicidal thinking was seen in adults over age 65 years
In children and young adults, risks must be weighed against the benefits of taking antidepressants
Patients should be monitored closely for changes in behavior, clinical worsening, and suicidal tendencies; this should be done during the initial 1-2 months of therapy and dosage adjustments
The patient’s family should communicate any abrupt changes in behavior to the healthcare provider
Worsening behavior and suicidal tendencies that are not part of the presenting symptoms may require discontinuation of therapy
This drug is not approved for use in pediatric patients
Contraindications
Hypersensitivity
Any drugs or conditions that prolong QT intervaL
Acute recovery post-MI
Coadministration with serotonergic drugs
- Concomitant with or within 14 days of MAOIs (serotonin syndrome)
- Starting nortriptyline in a patient who is being treated with linezolid or IV methylene blue is contraindicated because of an increased risk of serotonin syndrome
- If linezolid or IV methylene blue must be administered, discontinue nortriptyline immediately and monitor for CNS toxicity; may resume nortriptyline 24 hours after last linezolid or methylene blue dose or after 2 weeks of monitoring, whichever comes first
Cautions
BPH
Urinary/GI retention
Hyperthyroidism
Seizure disorder
Brain tumor
Respiratory impairment
Bipolar mania
Clinical worsening and suicidal ideation may occur despite medication in adolescents and young adults (18-24 years)
Potentially life-threatening serotonin syndrome reported when coadministered with drugs that impair serotonin metabolism (in particular, MAOIs, including nonpsychiatric MAOIs, such as linezolid and IV methylene blue)
Risk of anticholinergic side effects
May cause bone marrow suppression (rare)
May cause orthostatic hypotension
Risk of mydriasis; may trigger angle closure attack in patients with angle closure glaucoma with anatomically narrow angles without a patent iridectomy
May cause sedation and impair physical or mental abilities
Withdraw gradually
Bone fractures have been associated with antidepressant treatment; consider possibility of bone fractures in patients if antidepressant treated patient presents with unexplained bone pain, swelling, bruising or point tenderness
Use with caution in patients who would not tolerate frequent hypotensive episodes, including patients with cardiovascular disease, hypovolemia or with concurrent medication that predisposes for hypotension/bradycardia
Use caution in patients with cardiovascular disease, diabetes mellitus (may alter glucose regulation), hepatic/renal impairment, and the elderly
Abrupt discontinuation or interruption of antidepressant therapy has been associated with a discontinuation syndrome, which may include vomiting, diarrhea, headaches, dizziness, chills, tremors, paresthesias, somnolence, fatigue, and sleep disturbances
May increase the risk of adverse effects associated with electroconvulsive therapy; discontinue therapy prior to electroconvulsive therapy if possible
Due to risk of drug interaction with anesthesia and of cardiac arrhythmia, discontinuation of therapy prior to elective surgery recommended
Pregnancy and lactation
Pregnancy category: d
Lactation: Excreted in breast milk; do not nurse (AAP states effect on nursing infants is unknown but may be of concern)
Pregnancy categories
A: Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.
B: May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk.
C: Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done.
D: Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk.
X: Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist.
NA: Information not available.
Pharmacology of Pamelor, Aventyl (nortriptyline)
Mechanism of action
Neurotransmitter (especially norepinephrine and serotonin) reuptake inhibitor; increases concentration of neurotransmitter in the CNs
Absorption
Onset of action: 1-3 weeks
Peak plasma time: 7-8.5 hr
Steady-state therapeutic plasma concentration: 50-150 ng/mL
Distribution
Protein bound: 93-95%
Vd: 21 L/kg
Metabolism
Hepatic CYP2D6
Elimination
Half-life: 28-31 hr
Excretion: Urine, feces
