Amitriptyline

Antidepressants increase the risk of suicidal thinking and behavior in children, adolescents, and young adults (18 to 24 years of age) with major depressive disorder (MDD) and other psychiatric disorders; consider risk prior to prescribing. Short-term studies did not show an increased risk in patients >24 years of age and showed a decreased risk in patients ≥65 years. Closely monitor patients for clinical worsening, suicidality, or unusual changes in behavior, particularly during the initial 1-2 months of therapy or during periods of dosage adjustments (increases or decreases); the patient’s family or caregiver should be instructed to closely observe the patient and communicate condition with healthcare provider. A medication guide concerning the use of antidepressants should be dispensed with each prescription. Amitriptyline is not FDA-approved for use in children.

May cause anticholinergic effects (constipation, xerostomia, blurred vision, urinary retention); use with caution in patients with decreased gastrointestinal motility, increased intraocular pressure (IOP), narrow-angle glaucoma, paralytic ileus, urinary retention, BPH, xerostomia, or visual problems. The degree of anticholinergic blockade produced by this agent is high relative to other antidepressants.

May cause CNS depression, which may impair physical or mental abilities; patients must be cautioned about performing tasks that require mental alertness (eg, operating machinery or driving).

Bone fractures have been associated with antidepressant treatment. Consider the possibility of a fragility fracture if an antidepressant-treated patient presents with unexplained bone pain, point tenderness, swelling, or bruising (Rabenda 2013; Rizzoli 2012).

TCAs may rarely cause bone marrow suppression; monitor for any signs of infection and obtain CBC if symptoms (eg, fever, sore throat) evident.

May cause mild pupillary dilation which in susceptible individuals can lead to an episode of narrow-angle glaucoma. Consider evaluating patients who have not had an iridectomy for narrow-angle glaucoma risk factors.

May cause orthostatic hypotension (risk is very high relative to other antidepressants); use with caution in patients at risk of this effect or in those who would not tolerate transient hypotensive episodes (cerebrovascular disease, cardiovascular disease, hypovolemia, or concurrent medication use which may predispose to hypotension/bradycardia). Therapy is relatively contraindicated in patients with symptomatic hypotension. Disease-related concerns:

Use with caution in patients with a history of cardiovascular disease (including previous MI, stroke, tachycardia, or conduction abnormalities); the risk of conduction abnormalities with this agent is high relative to other antidepressants. Heart block may be precipitated in patients with preexisting conduction system disease and use is relatively contraindicated in patients with conduction abnormalities. In a scientific statement from the American Heart Association, amitriptyline has been determined to be an agent that may exacerbate underlying myocardial dysfunction (magnitude: moderate) (AHA [Page 2016]).

Use with caution in patients with diabetes mellitus; may alter glucose regulation.

Use with caution in patients with hepatic impairment.

May precipitate a shift to mania or hypomania in patients with bipolar disorder. Patients presenting with depressive symptoms should be screened for bipolar disorder, including details regarding family history of suicide, bipolar disorder, and depression. Amitriptyline is not FDA approved for the treatment of bipolar depression.

Use with caution in patients with renal impairment.

Use with caution in patients at risk of seizures, including those with a history of seizures, head trauma, brain damage, alcoholism, or concurrent therapy with medications which may lower seizure threshold. Concurrent drug therapy issues:

Potentially significant interactions may exist, requiring dose or frequency adjustment, additional monitoring, and/or selection of alternative therapy. Consult drug interactions database for more detailed information. Other warnings/precautions:

Abrupt discontinuation or interruption of antidepressant therapy has been associated with a discontinuation syndrome. Symptoms arising may vary with antidepressant however commonly include nausea, vomiting, diarrhea, headaches, light-headedness, dizziness, diminished appetite, sweating, chills, tremors, paresthesias, fatigue, somnolence, and sleep disturbances (eg, vivid dreams, insomnia). Less common symptoms include electric shock-like sensations, cardiac arrhythmias (more common with tricyclic antidepressants), myalgias, parkinsonism, arthralgias, and balance difficulties. Psychological symptoms may also emerge such as agitation, anxiety, akathisia, panic attacks, irritability, aggressiveness, worsening of mood, dysphoria, mood lability, hyperactivity, mania/hypomania, depersonalization, decreased concentration, slowed thinking, confusion, and memory or concentration difficulties. Greater risks for developing a discontinuation syndrome have been associated with antidepressants with shorter half-lives, longer durations of treatment, and abrupt discontinuation. For antidepressants of short or intermediate half-lives, symptoms may emerge within 2-5 days after treatment discontinuation and last 7-14 days (APA, 2010; Fava, 2006; Haddad, 2001; Shelton, 2001; Warner, 2006).

May increase the risks associated with electroconvulsive therapy; consider discontinuing, when possible, prior to ECT treatment.

Recommended by the manufacturer to discontinue prior to elective surgery; risks exist for drug interactions with anesthesia and for cardiac arrhythmias. However, definitive drug interactions have not been widely reported in the literature and continuation of tricyclic antidepressants is generally recommended as long as precautions are taken to reduce the significance of any adverse events that may occur. Norepinephrine should be considered the vasopressor of choice for TCA-related hypotension (Pass, 2004). Therapy should not be abruptly discontinued in patients receiving high doses for prolonged periods.